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janet/src/core/ev.c
Calvin Rose 9d5cc5c11f Proper locking on select.
2021-12-09 18:59:59 -06:00

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/*
* Copyright (c) 2021 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef JANET_AMALG
#include "features.h"
#include <janet.h>
#include "util.h"
#include "gc.h"
#include "state.h"
#include "fiber.h"
#endif
#ifdef JANET_EV
#include <math.h>
#ifdef JANET_WINDOWS
#include <winsock2.h>
#include <windows.h>
#else
#include <pthread.h>
#include <limits.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/wait.h>
#ifdef JANET_EV_EPOLL
#include <sys/epoll.h>
#include <sys/timerfd.h>
#endif
#ifdef JANET_EV_KQUEUE
#include <sys/event.h>
#endif
#endif
typedef struct {
JanetVM *thread;
JanetFiber *fiber;
uint32_t sched_id;
enum {
JANET_CP_MODE_READ,
JANET_CP_MODE_WRITE,
JANET_CP_MODE_CHOICE_READ,
JANET_CP_MODE_CHOICE_WRITE,
JANET_CP_MODE_CLOSE
} mode;
} JanetChannelPending;
typedef struct {
JanetQueue items;
JanetQueue read_pending;
JanetQueue write_pending;
int32_t limit;
int closed;
int is_threaded;
JanetOSMutex lock;
} JanetChannel;
typedef struct {
JanetFiber *fiber;
Janet value;
JanetSignal sig;
uint32_t expected_sched_id; /* If the fiber has been rescheduled this loop, don't run first scheduling. */
} JanetTask;
/* Wrap return value by pairing it with the callback used to handle it
* in the main thread */
typedef struct {
JanetEVGenericMessage msg;
JanetThreadedCallback cb;
} JanetSelfPipeEvent;
/* Structure used to initialize threads in the thread pool
* (same head structure as self pipe event)*/
typedef struct {
JanetEVGenericMessage msg;
JanetThreadedCallback cb;
JanetThreadedSubroutine subr;
JanetHandle write_pipe;
} JanetEVThreadInit;
#define JANET_MAX_Q_CAPACITY 0x7FFFFFF
static void janet_q_init(JanetQueue *q) {
q->data = NULL;
q->head = 0;
q->tail = 0;
q->capacity = 0;
}
static void janet_q_deinit(JanetQueue *q) {
janet_free(q->data);
}
static int32_t janet_q_count(JanetQueue *q) {
return (q->head > q->tail)
? (q->tail + q->capacity - q->head)
: (q->tail - q->head);
}
static int janet_q_push(JanetQueue *q, void *item, size_t itemsize) {
int32_t count = janet_q_count(q);
/* Resize if needed */
if (count + 1 >= q->capacity) {
if (count + 1 >= JANET_MAX_Q_CAPACITY) return 1;
int32_t newcap = (count + 2) * 2;
if (newcap > JANET_MAX_Q_CAPACITY) newcap = JANET_MAX_Q_CAPACITY;
q->data = janet_realloc(q->data, itemsize * newcap);
if (NULL == q->data) {
JANET_OUT_OF_MEMORY;
}
if (q->head > q->tail) {
/* Two segments, fix 2nd seg. */
int32_t newhead = q->head + (newcap - q->capacity);
size_t seg1 = (size_t)(q->capacity - q->head);
if (seg1 > 0) {
memmove((char *) q->data + (newhead * itemsize),
(char *) q->data + (q->head * itemsize),
seg1 * itemsize);
}
q->head = newhead;
}
q->capacity = newcap;
}
memcpy((char *) q->data + itemsize * q->tail, item, itemsize);
q->tail = q->tail + 1 < q->capacity ? q->tail + 1 : 0;
return 0;
}
static int janet_q_pop(JanetQueue *q, void *out, size_t itemsize) {
if (q->head == q->tail) return 1;
memcpy(out, (char *) q->data + itemsize * q->head, itemsize);
q->head = q->head + 1 < q->capacity ? q->head + 1 : 0;
return 0;
}
/* Forward declaration */
static void janet_unlisten(JanetListenerState *state, int is_gc);
/* Get current timestamp (millisecond precision) */
static JanetTimestamp ts_now(void);
/* Get current timestamp + an interval (millisecond precision) */
static JanetTimestamp ts_delta(JanetTimestamp ts, double delta) {
ts += (int64_t)round(delta * 1000);
return ts;
}
/* Look at the next timeout value without
* removing it. */
static int peek_timeout(JanetTimeout *out) {
if (janet_vm.tq_count == 0) return 0;
*out = janet_vm.tq[0];
return 1;
}
/* Remove the next timeout from the priority queue */
static void pop_timeout(size_t index) {
if (janet_vm.tq_count <= index) return;
janet_vm.tq[index] = janet_vm.tq[--janet_vm.tq_count];
for (;;) {
size_t left = (index << 1) + 1;
size_t right = left + 1;
size_t smallest = index;
if (left < janet_vm.tq_count &&
(janet_vm.tq[left].when < janet_vm.tq[smallest].when))
smallest = left;
if (right < janet_vm.tq_count &&
(janet_vm.tq[right].when < janet_vm.tq[smallest].when))
smallest = right;
if (smallest == index) return;
JanetTimeout temp = janet_vm.tq[index];
janet_vm.tq[index] = janet_vm.tq[smallest];
janet_vm.tq[smallest] = temp;
index = smallest;
}
}
/* Add a timeout to the timeout min heap */
static void add_timeout(JanetTimeout to) {
size_t oldcount = janet_vm.tq_count;
size_t newcount = oldcount + 1;
if (newcount > janet_vm.tq_capacity) {
size_t newcap = 2 * newcount;
JanetTimeout *tq = janet_realloc(janet_vm.tq, newcap * sizeof(JanetTimeout));
if (NULL == tq) {
JANET_OUT_OF_MEMORY;
}
janet_vm.tq = tq;
janet_vm.tq_capacity = newcap;
}
/* Append */
janet_vm.tq_count = (int32_t) newcount;
janet_vm.tq[oldcount] = to;
/* Heapify */
size_t index = oldcount;
while (index > 0) {
size_t parent = (index - 1) >> 1;
if (janet_vm.tq[parent].when <= janet_vm.tq[index].when) break;
/* Swap */
JanetTimeout tmp = janet_vm.tq[index];
janet_vm.tq[index] = janet_vm.tq[parent];
janet_vm.tq[parent] = tmp;
/* Next */
index = parent;
}
}
/* Create a new event listener */
static JanetListenerState *janet_listen_impl(JanetStream *stream, JanetListener behavior, int mask, size_t size, void *user) {
if (stream->flags & JANET_STREAM_CLOSED) {
janet_panic("cannot listen on closed stream");
}
if (stream->_mask & mask) {
janet_panic("cannot listen for duplicate event on stream");
}
if (janet_vm.root_fiber->waiting != NULL) {
janet_panic("current fiber is already waiting for event");
}
if (size < sizeof(JanetListenerState))
size = sizeof(JanetListenerState);
JanetListenerState *state = janet_malloc(size);
if (NULL == state) {
JANET_OUT_OF_MEMORY;
}
state->machine = behavior;
state->fiber = janet_vm.root_fiber;
janet_vm.root_fiber->waiting = state;
state->stream = stream;
state->_mask = mask;
stream->_mask |= mask;
state->_next = stream->state;
stream->state = state;
/* Keep track of a listener for GC purposes */
int resize = janet_vm.listener_cap == janet_vm.listener_count;
if (resize) {
size_t newcap = janet_vm.listener_count ? janet_vm.listener_cap * 2 : 16;
janet_vm.listeners = janet_realloc(janet_vm.listeners, newcap * sizeof(JanetListenerState *));
if (NULL == janet_vm.listeners) {
JANET_OUT_OF_MEMORY;
}
janet_vm.listener_cap = newcap;
}
size_t index = janet_vm.listener_count++;
janet_vm.listeners[index] = state;
state->_index = index;
/* Emit INIT event for convenience */
state->event = user;
state->machine(state, JANET_ASYNC_EVENT_INIT);
return state;
}
/* Indicate we are no longer listening for an event. This
* frees the memory of the state machine as well. */
static void janet_unlisten_impl(JanetListenerState *state, int is_gc) {
state->machine(state, JANET_ASYNC_EVENT_DEINIT);
/* Remove state machine from poll list */
JanetListenerState **iter = &(state->stream->state);
while (*iter && *iter != state)
iter = &((*iter)->_next);
janet_assert(*iter, "failed to remove listener");
*iter = state->_next;
/* Remove mask */
state->stream->_mask &= ~(state->_mask);
/* Ensure fiber does not reference this state */
if (!is_gc) {
JanetFiber *fiber = state->fiber;
if (NULL != fiber && fiber->waiting == state) {
fiber->waiting = NULL;
}
}
/* Untrack a listener for gc purposes */
size_t index = state->_index;
janet_vm.listeners[index] = janet_vm.listeners[--janet_vm.listener_count];
janet_vm.listeners[index]->_index = index;
janet_free(state);
}
static const JanetMethod ev_default_stream_methods[] = {
{"close", janet_cfun_stream_close},
{"read", janet_cfun_stream_read},
{"chunk", janet_cfun_stream_chunk},
{"write", janet_cfun_stream_write},
{NULL, NULL}
};
/* Create a stream*/
JanetStream *janet_stream(JanetHandle handle, uint32_t flags, const JanetMethod *methods) {
JanetStream *stream = janet_abstract(&janet_stream_type, sizeof(JanetStream));
stream->handle = handle;
stream->flags = flags;
stream->state = NULL;
stream->_mask = 0;
if (methods == NULL) methods = ev_default_stream_methods;
stream->methods = methods;
return stream;
}
/* Close a stream */
static void janet_stream_close_impl(JanetStream *stream, int is_gc) {
if (stream->flags & JANET_STREAM_CLOSED) return;
JanetListenerState *state = stream->state;
while (NULL != state) {
if (!is_gc) {
state->machine(state, JANET_ASYNC_EVENT_CLOSE);
}
JanetListenerState *next_state = state->_next;
janet_unlisten(state, is_gc);
state = next_state;
}
stream->state = NULL;
stream->flags |= JANET_STREAM_CLOSED;
#ifdef JANET_WINDOWS
#ifdef JANET_NET
if (stream->flags & JANET_STREAM_SOCKET) {
closesocket((SOCKET) stream->handle);
} else
#endif
{
CloseHandle(stream->handle);
}
stream->handle = INVALID_HANDLE_VALUE;
#else
close(stream->handle);
stream->handle = -1;
#endif
}
void janet_stream_close(JanetStream *stream) {
janet_stream_close_impl(stream, 0);
}
/* Called to clean up a stream */
static int janet_stream_gc(void *p, size_t s) {
(void) s;
JanetStream *stream = (JanetStream *)p;
janet_stream_close_impl(stream, 1);
return 0;
}
/* Mark a stream for GC */
static int janet_stream_mark(void *p, size_t s) {
(void) s;
JanetStream *stream = (JanetStream *) p;
JanetListenerState *state = stream->state;
while (NULL != state) {
if (NULL != state->fiber) {
janet_mark(janet_wrap_fiber(state->fiber));
}
(state->machine)(state, JANET_ASYNC_EVENT_MARK);
state = state->_next;
}
return 0;
}
static int janet_stream_getter(void *p, Janet key, Janet *out) {
JanetStream *stream = (JanetStream *)p;
if (!janet_checktype(key, JANET_KEYWORD)) return 0;
const JanetMethod *stream_methods = stream->methods;
return janet_getmethod(janet_unwrap_keyword(key), stream_methods, out);
}
static void janet_stream_marshal(void *p, JanetMarshalContext *ctx) {
JanetStream *s = p;
if (!(ctx->flags & JANET_MARSHAL_UNSAFE)) {
janet_panic("can only marshal stream with unsafe flag");
}
janet_marshal_abstract(ctx, p);
janet_marshal_int(ctx, (int32_t) s->flags);
janet_marshal_int64(ctx, (intptr_t) s->methods);
#ifdef JANET_WINDOWS
/* TODO - ref counting to avoid situation where a handle is closed or GCed
* while in transit, and it's value gets reused. DuplicateHandle does not work
* for network sockets, and in general for winsock it is better to nipt duplicate
* unless there is a need to. */
HANDLE duph = INVALID_HANDLE_VALUE;
if (s->flags & JANET_STREAM_SOCKET) {
duph = s->handle;
} else {
DuplicateHandle(
GetCurrentProcess(),
s->handle,
GetCurrentProcess(),
&duph,
0,
FALSE,
DUPLICATE_SAME_ACCESS);
}
janet_marshal_int64(ctx, (int64_t)(duph));
#else
/* Marshal after dup becuse it is easier than maintaining our own ref counting. */
int duph = dup(s->handle);
if (duph < 0) janet_panicf("failed to duplicate stream handle: %V", janet_ev_lasterr());
janet_marshal_int(ctx, (int32_t)(duph));
#endif
}
static void *janet_stream_unmarshal(JanetMarshalContext *ctx) {
if (!(ctx->flags & JANET_MARSHAL_UNSAFE)) {
janet_panic("can only unmarshal stream with unsafe flag");
}
JanetStream *p = janet_unmarshal_abstract(ctx, sizeof(JanetStream));
/* Can't share listening state and such across threads */
p->_mask = 0;
p->state = NULL;
p->flags = (uint32_t) janet_unmarshal_int(ctx);
p->methods = (void *) janet_unmarshal_int64(ctx);
#ifdef JANET_WINDOWS
p->handle = (JanetHandle) janet_unmarshal_int64(ctx);
#else
p->handle = (JanetHandle) janet_unmarshal_int(ctx);
#endif
return p;
}
static Janet janet_stream_next(void *p, Janet key) {
JanetStream *stream = (JanetStream *)p;
return janet_nextmethod(stream->methods, key);
}
const JanetAbstractType janet_stream_type = {
"core/stream",
janet_stream_gc,
janet_stream_mark,
janet_stream_getter,
NULL,
janet_stream_marshal,
janet_stream_unmarshal,
NULL,
NULL,
NULL,
janet_stream_next,
JANET_ATEND_NEXT
};
/* Register a fiber to resume with value */
void janet_schedule_signal(JanetFiber *fiber, Janet value, JanetSignal sig) {
if (fiber->gc.flags & JANET_FIBER_EV_FLAG_CANCELED) return;
JanetTask t = { fiber, value, sig, ++fiber->sched_id };
if (sig == JANET_SIGNAL_ERROR) fiber->gc.flags |= JANET_FIBER_EV_FLAG_CANCELED;
janet_q_push(&janet_vm.spawn, &t, sizeof(t));
}
void janet_cancel(JanetFiber *fiber, Janet value) {
janet_schedule_signal(fiber, value, JANET_SIGNAL_ERROR);
}
void janet_schedule(JanetFiber *fiber, Janet value) {
janet_schedule_signal(fiber, value, JANET_SIGNAL_OK);
}
void janet_fiber_did_resume(JanetFiber *fiber) {
/* Cancel any pending fibers */
if (fiber->waiting) {
fiber->waiting->machine(fiber->waiting, JANET_ASYNC_EVENT_CANCEL);
janet_unlisten(fiber->waiting, 0);
}
}
/* Mark all pending tasks */
void janet_ev_mark(void) {
/* Pending tasks */
JanetTask *tasks = janet_vm.spawn.data;
if (janet_vm.spawn.head <= janet_vm.spawn.tail) {
for (int32_t i = janet_vm.spawn.head; i < janet_vm.spawn.tail; i++) {
janet_mark(janet_wrap_fiber(tasks[i].fiber));
janet_mark(tasks[i].value);
}
} else {
for (int32_t i = janet_vm.spawn.head; i < janet_vm.spawn.capacity; i++) {
janet_mark(janet_wrap_fiber(tasks[i].fiber));
janet_mark(tasks[i].value);
}
for (int32_t i = 0; i < janet_vm.spawn.tail; i++) {
janet_mark(janet_wrap_fiber(tasks[i].fiber));
janet_mark(tasks[i].value);
}
}
/* Pending timeouts */
for (size_t i = 0; i < janet_vm.tq_count; i++) {
janet_mark(janet_wrap_fiber(janet_vm.tq[i].fiber));
if (janet_vm.tq[i].curr_fiber != NULL) {
janet_mark(janet_wrap_fiber(janet_vm.tq[i].curr_fiber));
}
}
/* Pending listeners */
for (size_t i = 0; i < janet_vm.listener_count; i++) {
JanetListenerState *state = janet_vm.listeners[i];
if (NULL != state->fiber) {
janet_mark(janet_wrap_fiber(state->fiber));
}
janet_stream_mark(state->stream, sizeof(JanetStream));
(state->machine)(state, JANET_ASYNC_EVENT_MARK);
}
}
static int janet_channel_push(JanetChannel *channel, Janet x, int mode);
static int janet_channel_pop(JanetChannel *channel, Janet *item, int is_choice);
static Janet make_supervisor_event(const char *name, JanetFiber *fiber, int threaded) {
Janet tup[2];
tup[0] = janet_ckeywordv(name);
tup[1] = threaded ? fiber->last_value : janet_wrap_fiber(fiber) ;
return janet_wrap_tuple(janet_tuple_n(tup, 2));
}
/* Common init code */
void janet_ev_init_common(void) {
janet_q_init(&janet_vm.spawn);
janet_vm.listener_count = 0;
janet_vm.listener_cap = 0;
janet_vm.listeners = NULL;
janet_vm.tq = NULL;
janet_vm.tq_count = 0;
janet_vm.tq_capacity = 0;
janet_table_init_raw(&janet_vm.threaded_abstracts, 0);
janet_rng_seed(&janet_vm.ev_rng, 0);
}
/* Common deinit code */
void janet_ev_deinit_common(void) {
janet_q_deinit(&janet_vm.spawn);
janet_free(janet_vm.tq);
janet_free(janet_vm.listeners);
janet_vm.listeners = NULL;
janet_table_deinit(&janet_vm.threaded_abstracts);
}
/* Short hand to yield to event loop */
void janet_await(void) {
janet_signalv(JANET_SIGNAL_EVENT, janet_wrap_nil());
}
/* Set timeout for the current root fiber */
void janet_addtimeout(double sec) {
JanetFiber *fiber = janet_vm.root_fiber;
JanetTimeout to;
to.when = ts_delta(ts_now(), sec);
to.fiber = fiber;
to.curr_fiber = NULL;
to.sched_id = fiber->sched_id;
to.is_error = 1;
add_timeout(to);
}
void janet_ev_inc_refcount(void) {
janet_vm.extra_listeners++;
}
void janet_ev_dec_refcount(void) {
janet_vm.extra_listeners--;
}
/* Channels */
#define JANET_MAX_CHANNEL_CAPACITY 0xFFFFFF
static inline int janet_chan_is_threaded(JanetChannel *chan) {
return chan->is_threaded;
}
static int janet_chan_pack(JanetChannel *chan, Janet *x) {
if (!janet_chan_is_threaded(chan)) return 0;
switch (janet_type(*x)) {
default: {
JanetBuffer *buf = janet_malloc(sizeof(JanetBuffer));
if (NULL == buf) {
JANET_OUT_OF_MEMORY;
}
janet_buffer_init(buf, 10);
janet_marshal(buf, *x, NULL, JANET_MARSHAL_UNSAFE);
*x = janet_wrap_buffer(buf);
return 0;
}
case JANET_NIL:
case JANET_NUMBER:
case JANET_POINTER:
case JANET_BOOLEAN:
case JANET_CFUNCTION:
return 0;
}
}
static int janet_chan_unpack(JanetChannel *chan, Janet *x, int is_cleanup) {
if (!janet_chan_is_threaded(chan)) return 0;
switch (janet_type(*x)) {
default:
return 1;
case JANET_BUFFER: {
JanetBuffer *buf = janet_unwrap_buffer(*x);
int flags = is_cleanup ? (JANET_MARSHAL_UNSAFE | JANET_MARSHAL_DECREF) : JANET_MARSHAL_UNSAFE;
*x = janet_unmarshal(buf->data, buf->count, flags, NULL, NULL);
janet_buffer_deinit(buf);
janet_free(buf);
return 0;
}
case JANET_NIL:
case JANET_NUMBER:
case JANET_POINTER:
case JANET_BOOLEAN:
case JANET_CFUNCTION:
return 0;
}
}
static void janet_chan_init(JanetChannel *chan, int32_t limit, int threaded) {
chan->limit = limit;
chan->closed = 0;
chan->is_threaded = threaded;
janet_q_init(&chan->items);
janet_q_init(&chan->read_pending);
janet_q_init(&chan->write_pending);
janet_os_mutex_init(&chan->lock);
}
static void janet_chan_deinit(JanetChannel *chan) {
janet_q_deinit(&chan->read_pending);
janet_q_deinit(&chan->write_pending);
if (janet_chan_is_threaded(chan)) {
Janet item;
while (!janet_q_pop(&chan->items, &item, sizeof(item))) {
janet_chan_unpack(chan, &item, 1);
}
}
janet_q_deinit(&chan->items);
janet_os_mutex_deinit(&chan->lock);
}
static void janet_chan_lock(JanetChannel *chan) {
if (!janet_chan_is_threaded(chan)) return;
janet_os_mutex_lock(&chan->lock);
}
static void janet_chan_unlock(JanetChannel *chan) {
if (!janet_chan_is_threaded(chan)) return;
janet_os_mutex_unlock(&chan->lock);
}
/*
* Janet Channel abstract type
*/
static Janet janet_wrap_channel(JanetChannel *channel) {
return janet_wrap_abstract(channel);
}
static int janet_chanat_gc(void *p, size_t s) {
(void) s;
JanetChannel *channel = p;
janet_chan_deinit(channel);
return 0;
}
static void janet_chanat_mark_fq(JanetQueue *fq) {
JanetChannelPending *pending = fq->data;
if (fq->head <= fq->tail) {
for (int32_t i = fq->head; i < fq->tail; i++)
janet_mark(janet_wrap_fiber(pending[i].fiber));
} else {
for (int32_t i = fq->head; i < fq->capacity; i++)
janet_mark(janet_wrap_fiber(pending[i].fiber));
for (int32_t i = 0; i < fq->tail; i++)
janet_mark(janet_wrap_fiber(pending[i].fiber));
}
}
static int janet_chanat_mark(void *p, size_t s) {
(void) s;
JanetChannel *chan = p;
janet_chanat_mark_fq(&chan->read_pending);
janet_chanat_mark_fq(&chan->write_pending);
JanetQueue *items = &chan->items;
Janet *data = chan->items.data;
if (items->head <= items->tail) {
for (int32_t i = items->head; i < items->tail; i++)
janet_mark(data[i]);
} else {
for (int32_t i = items->head; i < items->capacity; i++)
janet_mark(data[i]);
for (int32_t i = 0; i < items->tail; i++)
janet_mark(data[i]);
}
return 0;
}
static Janet make_write_result(JanetChannel *channel) {
Janet *tup = janet_tuple_begin(2);
tup[0] = janet_ckeywordv("give");
tup[1] = janet_wrap_channel(channel);
return janet_wrap_tuple(janet_tuple_end(tup));
}
static Janet make_read_result(JanetChannel *channel, Janet x) {
Janet *tup = janet_tuple_begin(3);
tup[0] = janet_ckeywordv("take");
tup[1] = janet_wrap_channel(channel);
tup[2] = x;
return janet_wrap_tuple(janet_tuple_end(tup));
}
static Janet make_close_result(JanetChannel *channel) {
Janet *tup = janet_tuple_begin(2);
tup[0] = janet_ckeywordv("close");
tup[1] = janet_wrap_channel(channel);
return janet_wrap_tuple(janet_tuple_end(tup));
}
/* Callback to use for scheduling a fiber from another thread. */
static void janet_thread_chan_cb(JanetEVGenericMessage msg) {
uint32_t sched_id = (uint32_t) msg.argi;
JanetFiber *fiber = msg.fiber;
int mode = msg.tag;
JanetChannel *channel = (JanetChannel *) msg.argp;
Janet x = msg.argj;
if (fiber->sched_id == sched_id) {
if (mode == JANET_CP_MODE_CHOICE_READ) {
janet_assert(!janet_chan_unpack(channel, &x, 0), "packing error");
janet_schedule(fiber, make_read_result(channel, x));
} else if (mode == JANET_CP_MODE_CHOICE_WRITE) {
janet_schedule(fiber, make_write_result(channel));
} else if (mode == JANET_CP_MODE_READ) {
janet_assert(!janet_chan_unpack(channel, &x, 0), "packing error");
janet_schedule(fiber, x);
} else if (mode == JANET_CP_MODE_WRITE) {
janet_schedule(fiber, janet_wrap_channel(channel));
} else { /* (mode == JANET_CP_MODE_CLOSE) */
janet_schedule(fiber, janet_wrap_nil());
}
} else if (mode != JANET_CP_MODE_CLOSE) {
/* Fiber has already been cancelled or resumed. */
/* Resend event to another waiting thread, depending on mode */
int is_read = (mode == JANET_CP_MODE_CHOICE_READ) || (mode == JANET_CP_MODE_READ);
if (is_read) {
JanetChannelPending reader;
janet_chan_lock(channel);
if (!janet_q_pop(&channel->read_pending, &reader, sizeof(reader))) {
JanetVM *vm = reader.thread;
JanetEVGenericMessage msg;
msg.tag = reader.mode;
msg.fiber = reader.fiber;
msg.argi = (int32_t) reader.sched_id;
msg.argp = channel;
msg.argj = x;
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
}
janet_chan_unlock(channel);
} else {
JanetChannelPending writer;
janet_chan_lock(channel);
if (!janet_q_pop(&channel->write_pending, &writer, sizeof(writer))) {
JanetVM *vm = writer.thread;
JanetEVGenericMessage msg;
msg.tag = writer.mode;
msg.fiber = writer.fiber;
msg.argi = (int32_t) writer.sched_id;
msg.argp = channel;
msg.argj = janet_wrap_nil();
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
}
janet_chan_unlock(channel);
}
}
}
/* Push a value to a channel, and return 1 if channel should block, zero otherwise.
* If the push would block, will add to the write_pending queue in the channel.
* Handles both threaded and unthreaded channels. */
static int janet_channel_push(JanetChannel *channel, Janet x, int mode) {
JanetChannelPending reader;
int is_empty;
if (janet_chan_pack(channel, &x)) {
janet_panicf("failed to pack value for channel: %v", x);
}
janet_chan_lock(channel);
if (channel->closed) {
janet_chan_unlock(channel);
janet_panic("cannot write to closed channel");
}
int is_threaded = janet_chan_is_threaded(channel);
if (is_threaded) {
/* don't dereference fiber from another thread */
is_empty = janet_q_pop(&channel->read_pending, &reader, sizeof(reader));
} else {
do {
is_empty = janet_q_pop(&channel->read_pending, &reader, sizeof(reader));
} while (!is_empty && (reader.sched_id != reader.fiber->sched_id));
}
if (is_empty) {
/* No pending reader */
if (janet_q_push(&channel->items, &x, sizeof(Janet))) {
janet_chan_unlock(channel);
janet_panicf("channel overflow: %v", x);
} else if (janet_q_count(&channel->items) > channel->limit) {
/* No root fiber, we are in completion on a root fiber. Don't block. */
if (mode == 2) {
janet_chan_unlock(channel);
return 0;
}
/* Pushed successfully, but should block. */
JanetChannelPending pending;
pending.thread = &janet_vm;
pending.fiber = janet_vm.root_fiber,
pending.sched_id = janet_vm.root_fiber->sched_id,
pending.mode = mode ? JANET_CP_MODE_CHOICE_WRITE : JANET_CP_MODE_WRITE;
janet_q_push(&channel->write_pending, &pending, sizeof(pending));
janet_chan_unlock(channel);
if (is_threaded) {
janet_gcroot(janet_wrap_fiber(pending.fiber));
}
return 1;
}
} else {
/* Pending reader */
if (is_threaded) {
JanetVM *vm = reader.thread;
JanetEVGenericMessage msg;
msg.tag = reader.mode;
msg.fiber = reader.fiber;
msg.argi = (int32_t) reader.sched_id;
msg.argp = channel;
msg.argj = x;
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
} else {
if (reader.mode == JANET_CP_MODE_CHOICE_READ) {
janet_schedule(reader.fiber, make_read_result(channel, x));
} else {
janet_schedule(reader.fiber, x);
}
}
}
janet_chan_unlock(channel);
return 0;
}
/* Pop from a channel - returns 1 if item was obtained, 0 otherwise. The item
* is returned by reference. If the pop would block, will add to the read_pending
* queue in the channel. */
static int janet_channel_pop(JanetChannel *channel, Janet *item, int is_choice) {
JanetChannelPending writer;
janet_chan_lock(channel);
if (channel->closed) {
janet_chan_unlock(channel);
*item = janet_wrap_nil();
return 1;
}
int is_threaded = janet_chan_is_threaded(channel);
if (janet_q_pop(&channel->items, item, sizeof(Janet))) {
/* Queue empty */
JanetChannelPending pending;
pending.thread = &janet_vm;
pending.fiber = janet_vm.root_fiber,
pending.sched_id = janet_vm.root_fiber->sched_id;
pending.mode = is_choice ? JANET_CP_MODE_CHOICE_READ : JANET_CP_MODE_READ;
janet_q_push(&channel->read_pending, &pending, sizeof(pending));
janet_chan_unlock(channel);
if (is_threaded) {
janet_gcroot(janet_wrap_fiber(pending.fiber));
}
return 0;
}
janet_assert(!janet_chan_unpack(channel, item, 0), "bad channel packing");
if (!janet_q_pop(&channel->write_pending, &writer, sizeof(writer))) {
/* Pending writer */
if (is_threaded) {
JanetVM *vm = writer.thread;
JanetEVGenericMessage msg;
msg.tag = writer.mode;
msg.fiber = writer.fiber;
msg.argi = (int32_t) writer.sched_id;
msg.argp = channel;
msg.argj = janet_wrap_nil();
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
} else {
if (writer.mode == JANET_CP_MODE_CHOICE_WRITE) {
janet_schedule(writer.fiber, make_write_result(channel));
} else {
janet_schedule(writer.fiber, janet_wrap_abstract(channel));
}
}
}
janet_chan_unlock(channel);
return 1;
}
JanetChannel *janet_channel_unwrap(void *abstract) {
return abstract;
}
JanetChannel *janet_getchannel(const Janet *argv, int32_t n) {
return janet_channel_unwrap(janet_getabstract(argv, n, &janet_channel_type));
}
JanetChannel *janet_optchannel(const Janet *argv, int32_t argc, int32_t n, JanetChannel *dflt) {
if (argc > n && !janet_checktype(argv[n], JANET_NIL)) {
return janet_getchannel(argv, n);
} else {
return dflt;
}
}
/* Channel Methods */
JANET_CORE_FN(cfun_channel_push,
"(ev/give channel value)",
"Write a value to a channel, suspending the current fiber if the channel is full. "
"Returns the channel if the write succeeded, nil otherwise.") {
janet_fixarity(argc, 2);
JanetChannel *channel = janet_getchannel(argv, 0);
if (janet_channel_push(channel, argv[1], 0)) {
janet_await();
}
return argv[0];
}
JANET_CORE_FN(cfun_channel_pop,
"(ev/take channel)",
"Read from a channel, suspending the current fiber if no value is available.") {
janet_fixarity(argc, 1);
JanetChannel *channel = janet_getchannel(argv, 0);
Janet item;
if (janet_channel_pop(channel, &item, 0)) {
janet_schedule(janet_vm.root_fiber, item);
}
janet_await();
}
JANET_CORE_FN(cfun_channel_choice,
"(ev/select & clauses)",
"Block until the first of several channel operations occur. Returns a tuple of the form [:give chan], [:take chan x], or [:close chan], where "
"a :give tuple is the result of a write and :take tuple is the result of a read. Each clause must be either a channel (for "
"a channel take operation) or a tuple [channel x] for a channel give operation. Operations are tried in order, such that the first "
"clauses will take precedence over later clauses. Both and give and take operations can return a [:close chan] tuple, which indicates that "
"the specified channel was closed while waiting, or that the channel was already closed.") {
janet_arity(argc, 1, -1);
int32_t len;
const Janet *data;
/* Check channels for immediate reads and writes */
for (int32_t i = 0; i < argc; i++) {
if (janet_indexed_view(argv[i], &data, &len) && len == 2) {
/* Write */
JanetChannel *chan = janet_getchannel(data, 0);
janet_chan_lock(chan);
if (chan->closed) {
janet_chan_unlock(chan);
return make_close_result(chan);
}
if (janet_q_count(&chan->items) < chan->limit) {
janet_chan_unlock(chan);
janet_channel_push(chan, data[1], 1);
return make_write_result(chan);
}
janet_chan_unlock(chan);
} else {
/* Read */
JanetChannel *chan = janet_getchannel(argv, i);
janet_chan_lock(chan);
if (chan->closed) {
janet_chan_unlock(chan);
return make_close_result(chan);
}
if (chan->items.head != chan->items.tail) {
Janet item;
janet_chan_unlock(chan);
janet_channel_pop(chan, &item, 1);
return make_read_result(chan, item);
}
janet_chan_unlock(chan);
}
}
/* Wait for all readers or writers */
for (int32_t i = 0; i < argc; i++) {
if (janet_indexed_view(argv[i], &data, &len) && len == 2) {
/* Write */
JanetChannel *chan = janet_getchannel(data, 0);
janet_channel_push(chan, data[1], 1);
} else {
/* Read */
Janet item;
JanetChannel *chan = janet_getchannel(argv, i);
janet_channel_pop(chan, &item, 1);
}
}
janet_await();
}
JANET_CORE_FN(cfun_channel_full,
"(ev/full channel)",
"Check if a channel is full or not.") {
janet_fixarity(argc, 1);
JanetChannel *channel = janet_getchannel(argv, 0);
janet_chan_lock(channel);
Janet ret = janet_wrap_boolean(janet_q_count(&channel->items) >= channel->limit);
janet_chan_unlock(channel);
return ret;
}
JANET_CORE_FN(cfun_channel_capacity,
"(ev/capacity channel)",
"Get the number of items a channel will store before blocking writers.") {
janet_fixarity(argc, 1);
JanetChannel *channel = janet_getchannel(argv, 0);
janet_chan_lock(channel);
Janet ret = janet_wrap_integer(channel->limit);
janet_chan_unlock(channel);
return ret;
}
JANET_CORE_FN(cfun_channel_count,
"(ev/count channel)",
"Get the number of items currently waiting in a channel.") {
janet_fixarity(argc, 1);
JanetChannel *channel = janet_getchannel(argv, 0);
janet_chan_lock(channel);
Janet ret = janet_wrap_integer(janet_q_count(&channel->items));
janet_chan_unlock(channel);
return ret;
}
/* Fisher yates shuffle of arguments to get fairness */
static void fisher_yates_args(int32_t argc, Janet *argv) {
for (int32_t i = argc; i > 1; i--) {
int32_t swap_index = janet_rng_u32(&janet_vm.ev_rng) % i;
Janet temp = argv[swap_index];
argv[swap_index] = argv[i - 1];
argv[i - 1] = temp;
}
}
JANET_CORE_FN(cfun_channel_rchoice,
"(ev/rselect & clauses)",
"Similar to ev/select, but will try clauses in a random order for fairness.") {
fisher_yates_args(argc, argv);
return cfun_channel_choice(argc, argv);
}
JANET_CORE_FN(cfun_channel_new,
"(ev/chan &opt capacity)",
"Create a new channel. capacity is the number of values to queue before "
"blocking writers, defaults to 0 if not provided. Returns a new channel.") {
janet_arity(argc, 0, 1);
int32_t limit = janet_optnat(argv, argc, 0, 0);
JanetChannel *channel = janet_abstract(&janet_channel_type, sizeof(JanetChannel));
janet_chan_init(channel, limit, 0);
return janet_wrap_abstract(channel);
}
JANET_CORE_FN(cfun_channel_new_threaded,
"(ev/thread-chan &opt limit)",
"Create a threaded channel. A threaded channel is a channel that can be shared between threads and "
"used to communicate between any number of operating system threads.") {
janet_arity(argc, 0, 1);
int32_t limit = janet_optnat(argv, argc, 0, 0);
JanetChannel *tchan = janet_abstract_threaded(&janet_channel_type, sizeof(JanetChannel));
janet_chan_init(tchan, limit, 1);
return janet_wrap_abstract(tchan);
}
JANET_CORE_FN(cfun_channel_close,
"(ev/chan-close chan)",
"Close a channel. A closed channel will cause all pending reads and writes to return nil. "
"Returns the channel.") {
janet_fixarity(argc, 1);
JanetChannel *channel = janet_getchannel(argv, 0);
janet_chan_lock(channel);
if (!channel->closed) {
channel->closed = 1;
JanetChannelPending writer;
while (!janet_q_pop(&channel->write_pending, &writer, sizeof(writer))) {
if (writer.thread != &janet_vm) {
JanetVM *vm = writer.thread;
JanetEVGenericMessage msg;
msg.fiber = writer.fiber;
msg.argp = channel;
msg.tag = JANET_CP_MODE_CLOSE;
msg.argi = (int32_t) writer.sched_id;
msg.argj = janet_wrap_nil();
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
} else {
if (writer.mode == JANET_CP_MODE_CHOICE_WRITE) {
janet_schedule(writer.fiber, janet_wrap_nil());
} else {
janet_schedule(writer.fiber, make_close_result(channel));
}
}
}
JanetChannelPending reader;
while (!janet_q_pop(&channel->read_pending, &reader, sizeof(reader))) {
if (reader.thread != &janet_vm) {
JanetVM *vm = reader.thread;
JanetEVGenericMessage msg;
msg.fiber = reader.fiber;
msg.argp = channel;
msg.tag = JANET_CP_MODE_CLOSE;
msg.argi = (int32_t) reader.sched_id;
msg.argj = janet_wrap_nil();
janet_ev_post_event(vm, janet_thread_chan_cb, msg);
} else {
if (reader.mode == JANET_CP_MODE_CHOICE_READ) {
janet_schedule(reader.fiber, janet_wrap_nil());
} else {
janet_schedule(reader.fiber, make_close_result(channel));
}
}
}
}
janet_chan_unlock(channel);
return argv[0];
}
static const JanetMethod ev_chanat_methods[] = {
{"select", cfun_channel_choice},
{"rselect", cfun_channel_rchoice},
{"count", cfun_channel_count},
{"take", cfun_channel_pop},
{"give", cfun_channel_push},
{"capacity", cfun_channel_capacity},
{"full", cfun_channel_full},
{"close", cfun_channel_close},
{NULL, NULL}
};
static int janet_chanat_get(void *p, Janet key, Janet *out) {
(void) p;
if (!janet_checktype(key, JANET_KEYWORD)) return 0;
return janet_getmethod(janet_unwrap_keyword(key), ev_chanat_methods, out);
}
static Janet janet_chanat_next(void *p, Janet key) {
(void) p;
return janet_nextmethod(ev_chanat_methods, key);
}
const JanetAbstractType janet_channel_type = {
"core/channel",
janet_chanat_gc,
janet_chanat_mark,
janet_chanat_get,
NULL, /* put */
NULL, /* marshal */
NULL, /* unmarshal */
NULL, /* tostring */
NULL, /* compare */
NULL, /* hash */
janet_chanat_next,
JANET_ATEND_NEXT
};
/* Main event loop */
void janet_loop1_impl(int has_timeout, JanetTimestamp timeout);
int janet_loop_done(void) {
return !(janet_vm.listener_count ||
(janet_vm.spawn.head != janet_vm.spawn.tail) ||
janet_vm.tq_count ||
janet_vm.extra_listeners);
}
JanetFiber *janet_loop1(void) {
/* Schedule expired timers */
JanetTimeout to;
JanetTimestamp now = ts_now();
while (peek_timeout(&to) && to.when <= now) {
pop_timeout(0);
if (to.curr_fiber != NULL) {
/* This is a deadline (for a fiber, not a function call) */
JanetFiberStatus s = janet_fiber_status(to.curr_fiber);
int isFinished = (s == JANET_STATUS_DEAD ||
s == JANET_STATUS_ERROR ||
s == JANET_STATUS_USER0 ||
s == JANET_STATUS_USER1 ||
s == JANET_STATUS_USER2 ||
s == JANET_STATUS_USER3 ||
s == JANET_STATUS_USER4);
if (!isFinished) {
janet_cancel(to.fiber, janet_cstringv("deadline expired"));
}
} else {
/* This is a timeout (for a function call, not a whole fiber) */
if (to.fiber->sched_id == to.sched_id) {
if (to.is_error) {
janet_cancel(to.fiber, janet_cstringv("timeout"));
} else {
janet_schedule(to.fiber, janet_wrap_nil());
}
}
}
}
/* Run scheduled fibers */
while (janet_vm.spawn.head != janet_vm.spawn.tail) {
JanetTask task = {NULL, janet_wrap_nil(), JANET_SIGNAL_OK, 0};
janet_q_pop(&janet_vm.spawn, &task, sizeof(task));
if (task.fiber->gc.flags & JANET_FIBER_EV_FLAG_SUSPENDED) janet_ev_dec_refcount();
task.fiber->gc.flags &= ~(JANET_FIBER_EV_FLAG_CANCELED | JANET_FIBER_EV_FLAG_SUSPENDED);
if (task.expected_sched_id != task.fiber->sched_id) continue;
Janet res;
JanetSignal sig = janet_continue_signal(task.fiber, task.value, &res, task.sig);
void *sv = task.fiber->supervisor_channel;
int is_suspended = sig == JANET_SIGNAL_EVENT || sig == JANET_SIGNAL_YIELD || sig == JANET_SIGNAL_INTERRUPT;
if (is_suspended) {
task.fiber->gc.flags |= JANET_FIBER_EV_FLAG_SUSPENDED;
janet_ev_inc_refcount();
}
if (NULL == sv) {
if (!is_suspended) {
janet_stacktrace_ext(task.fiber, res, "");
}
} else if (sig == JANET_SIGNAL_OK || (task.fiber->flags & (1 << sig))) {
JanetChannel *chan = janet_channel_unwrap(sv);
janet_channel_push(chan, make_supervisor_event(janet_signal_names[sig],
task.fiber, chan->is_threaded), 2);
} else if (!is_suspended) {
janet_stacktrace_ext(task.fiber, res, "");
}
if (sig == JANET_SIGNAL_INTERRUPT) {
/* On interrupts, return the interrupted fiber immediately */
return task.fiber;
}
}
/* Poll for events */
if (janet_vm.listener_count || janet_vm.tq_count || janet_vm.extra_listeners) {
JanetTimeout to;
memset(&to, 0, sizeof(to));
int has_timeout;
/* Drop timeouts that are no longer needed */
while ((has_timeout = peek_timeout(&to)) && (to.curr_fiber == NULL) && to.fiber->sched_id != to.sched_id) {
pop_timeout(0);
}
/* Run polling implementation only if pending timeouts or pending events */
if (janet_vm.tq_count || janet_vm.listener_count || janet_vm.extra_listeners) {
janet_loop1_impl(has_timeout, to.when);
}
}
/* No fiber was interrupted */
return NULL;
}
/* Same as janet_interpreter_interrupt, but will also
* break out of the event loop if waiting for an event
* (say, waiting for ev/sleep to finish). Does this by pushing
* an empty event to the event loop. */
void janet_loop1_interrupt(JanetVM *vm) {
janet_interpreter_interrupt(vm);
JanetEVGenericMessage msg = {0};
JanetCallback cb = NULL;
janet_ev_post_event(vm, cb, msg);
}
void janet_loop(void) {
while (!janet_loop_done()) {
JanetFiber *interrupted_fiber = janet_loop1();
if (NULL != interrupted_fiber) {
janet_schedule(interrupted_fiber, janet_wrap_nil());
}
}
}
/*
* Self-pipe handling code.
*/
#ifdef JANET_WINDOWS
/* On windows, use PostQueuedCompletionStatus instead for
* custom events */
#else
static void janet_ev_setup_selfpipe(void) {
if (janet_make_pipe(janet_vm.selfpipe, 0)) {
JANET_EXIT("failed to initialize self pipe in event loop");
}
}
/* Handle events from the self pipe inside the event loop */
static void janet_ev_handle_selfpipe(void) {
JanetSelfPipeEvent response;
while (read(janet_vm.selfpipe[0], &response, sizeof(response)) > 0) {
if (NULL != response.cb) {
response.cb(response.msg);
}
}
}
static void janet_ev_cleanup_selfpipe(void) {
close(janet_vm.selfpipe[0]);
close(janet_vm.selfpipe[1]);
}
#endif
#ifdef JANET_WINDOWS
static JanetTimestamp ts_now(void) {
return (JanetTimestamp) GetTickCount64();
}
void janet_ev_init(void) {
janet_ev_init_common();
janet_vm.iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
if (NULL == janet_vm.iocp) janet_panic("could not create io completion port");
}
void janet_ev_deinit(void) {
janet_ev_deinit_common();
CloseHandle(janet_vm.iocp);
}
JanetListenerState *janet_listen(JanetStream *stream, JanetListener behavior, int mask, size_t size, void *user) {
/* Add the handle to the io completion port if not already added */
JanetListenerState *state = janet_listen_impl(stream, behavior, mask, size, user);
if (!(stream->flags & JANET_STREAM_IOCP)) {
if (NULL == CreateIoCompletionPort(stream->handle, janet_vm.iocp, (ULONG_PTR) stream, 0)) {
janet_panicf("failed to listen for events: %V", janet_ev_lasterr());
}
stream->flags |= JANET_STREAM_IOCP;
}
return state;
}
static void janet_unlisten(JanetListenerState *state, int is_gc) {
janet_unlisten_impl(state, is_gc);
}
void janet_loop1_impl(int has_timeout, JanetTimestamp to) {
ULONG_PTR completionKey = 0;
DWORD num_bytes_transfered = 0;
LPOVERLAPPED overlapped = NULL;
/* Calculate how long to wait before timeout */
uint64_t waittime;
if (has_timeout) {
JanetTimestamp now = ts_now();
if (now > to) {
waittime = 0;
} else {
waittime = (uint64_t)(to - now);
}
} else {
waittime = INFINITE;
}
BOOL result = GetQueuedCompletionStatus(janet_vm.iocp, &num_bytes_transfered, &completionKey, &overlapped, (DWORD) waittime);
if (result || overlapped) {
if (0 == completionKey) {
/* Custom event */
JanetSelfPipeEvent *response = (JanetSelfPipeEvent *)(overlapped);
if (NULL != response->cb) {
response->cb(response->msg);
}
janet_free(response);
} else {
/* Normal event */
JanetStream *stream = (JanetStream *) completionKey;
JanetListenerState *state = stream->state;
while (state != NULL) {
if (state->tag == overlapped) {
state->event = overlapped;
state->bytes = num_bytes_transfered;
JanetAsyncStatus status = state->machine(state, JANET_ASYNC_EVENT_COMPLETE);
if (status == JANET_ASYNC_STATUS_DONE) {
janet_unlisten(state, 0);
}
break;
} else {
state = state->_next;
}
}
}
}
}
#elif defined(JANET_EV_EPOLL)
static JanetTimestamp ts_now(void) {
struct timespec now;
janet_assert(-1 != clock_gettime(CLOCK_MONOTONIC, &now), "failed to get time");
uint64_t res = 1000 * now.tv_sec;
res += now.tv_nsec / 1000000;
return res;
}
static int make_epoll_events(int mask) {
int events = 0;
if (mask & JANET_ASYNC_LISTEN_READ)
events |= EPOLLIN;
if (mask & JANET_ASYNC_LISTEN_WRITE)
events |= EPOLLOUT;
return events;
}
static void janet_epoll_sync_callback(JanetEVGenericMessage msg) {
JanetListenerState *state = msg.argp;
JanetAsyncStatus status1 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status2 = JANET_ASYNC_STATUS_NOT_DONE;
if (state->stream->_mask & JANET_ASYNC_LISTEN_WRITE)
status1 = state->machine(state, JANET_ASYNC_EVENT_WRITE);
if (state->stream->_mask & JANET_ASYNC_LISTEN_WRITE)
status2 = state->machine(state, JANET_ASYNC_EVENT_READ);
if (status1 == JANET_ASYNC_STATUS_DONE ||
status2 == JANET_ASYNC_STATUS_DONE) {
janet_unlisten(state, 0);
} else {
/* Repost event */
janet_ev_post_event(NULL, janet_epoll_sync_callback, msg);
}
}
/* Wait for the next event */
JanetListenerState *janet_listen(JanetStream *stream, JanetListener behavior, int mask, size_t size, void *user) {
int is_first = !(stream->state);
int op = is_first ? EPOLL_CTL_ADD : EPOLL_CTL_MOD;
JanetListenerState *state = janet_listen_impl(stream, behavior, mask, size, user);
struct epoll_event ev;
ev.events = make_epoll_events(state->stream->_mask);
ev.data.ptr = stream;
int status;
do {
status = epoll_ctl(janet_vm.epoll, op, stream->handle, &ev);
} while (status == -1 && errno == EINTR);
if (status == -1) {
if (errno == EPERM) {
/* Couldn't add to event loop, so assume that it completes
* synchronously. In that case, fire the completion
* event manually, since this should be a read or write
* event to a file. So we just post a custom event to do the read/write
* asap. */
/* Use flag to indicate state is not registered in epoll */
state->_mask |= (1 << JANET_ASYNC_EVENT_COMPLETE);
JanetEVGenericMessage msg = {0};
msg.argp = state;
janet_ev_post_event(NULL, janet_epoll_sync_callback, msg);
} else {
/* Unexpected error */
janet_unlisten_impl(state, 0);
janet_panicv(janet_ev_lasterr());
}
}
return state;
}
/* Tell system we are done listening for a certain event */
static void janet_unlisten(JanetListenerState *state, int is_gc) {
JanetStream *stream = state->stream;
if (!(stream->flags & JANET_STREAM_CLOSED)) {
/* Use flag to indicate state is not registered in epoll */
if (!(state->_mask & (1 << JANET_ASYNC_EVENT_COMPLETE))) {
int is_last = (state->_next == NULL && stream->state == state);
int op = is_last ? EPOLL_CTL_DEL : EPOLL_CTL_MOD;
struct epoll_event ev;
ev.events = make_epoll_events(stream->_mask & ~state->_mask);
ev.data.ptr = stream;
int status;
do {
status = epoll_ctl(janet_vm.epoll, op, stream->handle, &ev);
} while (status == -1 && errno == EINTR);
if (status == -1) {
janet_panicv(janet_ev_lasterr());
}
}
}
/* Destroy state machine and free memory */
janet_unlisten_impl(state, is_gc);
}
#define JANET_EPOLL_MAX_EVENTS 64
void janet_loop1_impl(int has_timeout, JanetTimestamp timeout) {
struct itimerspec its;
if (janet_vm.timer_enabled || has_timeout) {
memset(&its, 0, sizeof(its));
if (has_timeout) {
its.it_value.tv_sec = timeout / 1000;
its.it_value.tv_nsec = (timeout % 1000) * 1000000;
}
timerfd_settime(janet_vm.timerfd, TFD_TIMER_ABSTIME, &its, NULL);
}
janet_vm.timer_enabled = has_timeout;
/* Poll for events */
struct epoll_event events[JANET_EPOLL_MAX_EVENTS];
int ready;
do {
ready = epoll_wait(janet_vm.epoll, events, JANET_EPOLL_MAX_EVENTS, -1);
} while (ready == -1 && errno == EINTR);
if (ready == -1) {
JANET_EXIT("failed to poll events");
}
/* Step state machines */
for (int i = 0; i < ready; i++) {
void *p = events[i].data.ptr;
if (&janet_vm.timerfd == p) {
/* Timer expired, ignore */;
} else if (janet_vm.selfpipe == p) {
/* Self-pipe handling */
janet_ev_handle_selfpipe();
} else {
JanetStream *stream = p;
int mask = events[i].events;
JanetListenerState *state = stream->state;
while (NULL != state) {
state->event = events + i;
JanetListenerState *next_state = state->_next;
JanetAsyncStatus status1 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status2 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status3 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status4 = JANET_ASYNC_STATUS_NOT_DONE;
if (mask & EPOLLOUT)
status1 = state->machine(state, JANET_ASYNC_EVENT_WRITE);
if (mask & EPOLLIN)
status2 = state->machine(state, JANET_ASYNC_EVENT_READ);
if (mask & EPOLLERR)
status3 = state->machine(state, JANET_ASYNC_EVENT_ERR);
if ((mask & EPOLLHUP) && !(mask & (EPOLLOUT | EPOLLIN)))
status4 = state->machine(state, JANET_ASYNC_EVENT_HUP);
if (status1 == JANET_ASYNC_STATUS_DONE ||
status2 == JANET_ASYNC_STATUS_DONE ||
status3 == JANET_ASYNC_STATUS_DONE ||
status4 == JANET_ASYNC_STATUS_DONE)
janet_unlisten(state, 0);
state = next_state;
}
}
}
}
void janet_ev_init(void) {
janet_ev_init_common();
janet_ev_setup_selfpipe();
janet_vm.epoll = epoll_create1(EPOLL_CLOEXEC);
janet_vm.timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
janet_vm.timer_enabled = 0;
if (janet_vm.epoll == -1 || janet_vm.timerfd == -1) goto error;
struct epoll_event ev;
ev.events = EPOLLIN | EPOLLET;
ev.data.ptr = &janet_vm.timerfd;
if (-1 == epoll_ctl(janet_vm.epoll, EPOLL_CTL_ADD, janet_vm.timerfd, &ev)) goto error;
ev.events = EPOLLIN | EPOLLET;
ev.data.ptr = janet_vm.selfpipe;
if (-1 == epoll_ctl(janet_vm.epoll, EPOLL_CTL_ADD, janet_vm.selfpipe[0], &ev)) goto error;
return;
error:
JANET_EXIT("failed to initialize event loop");
}
void janet_ev_deinit(void) {
janet_ev_deinit_common();
close(janet_vm.epoll);
close(janet_vm.timerfd);
janet_ev_cleanup_selfpipe();
janet_vm.epoll = 0;
}
/*
* End epoll implementation
*/
#elif defined(JANET_EV_KQUEUE)
/* Definition from:
* https://github.com/wahern/cqueues/blob/master/src/lib/kpoll.c
* NetBSD uses intptr_t while others use void * for .udata */
#define EV_SETx(ev, a, b, c, d, e, f) EV_SET((ev), (a), (b), (c), (d), (e), ((__typeof__((ev)->udata))(f)))
#define JANET_KQUEUE_TF (EV_ADD | EV_ENABLE | EV_CLEAR | EV_ONESHOT)
#define JANET_KQUEUE_MIN_INTERVAL 0
/* NOTE:
* NetBSD and OpenBSD expect things are always intervals, and FreeBSD doesn't
* like an ABSTIME in the past so just use intervals always. Introduces a
* calculation to determine the minimum timeout per timeout requested of
* kqueue. Also note that NetBSD doesn't accept timeout intervals less than 1
* millisecond, so correct all intervals on that platform to be at least 1
* millisecond.*/
JanetTimestamp to_interval(const JanetTimestamp ts) {
return ts >= JANET_KQUEUE_MIN_INTERVAL ? ts : JANET_KQUEUE_MIN_INTERVAL;
}
#define JANET_KQUEUE_INTERVAL(timestamp) (to_interval((timestamp - ts_now())))
/* TODO: make this available be we using kqueue or epoll, instead of
* redefinining it for kqueue and epoll separately? */
static JanetTimestamp ts_now(void) {
struct timespec now;
janet_assert(-1 != clock_gettime(CLOCK_MONOTONIC, &now), "failed to get time");
uint64_t res = 1000 * now.tv_sec;
res += now.tv_nsec / 1000000;
return res;
}
/* NOTE: Assumes Janet's timestamp precision is in milliseconds. */
static void timestamp2timespec(struct timespec *t, JanetTimestamp ts) {
t->tv_sec = ts == 0 ? 0 : ts / 1000;
t->tv_nsec = ts == 0 ? 0 : (ts % 1000) * 1000000;
}
void add_kqueue_events(const struct kevent *events, int length) {
/* NOTE: Status should be equal to the amount of events added, which isn't
* always known since deletions or modifications occur. Can't use the
* eventlist argument for it to report to us what failed otherwise we may
* poll in events to handle! This code assumes atomicity, that kqueue can
* either succeed or fail, but never partially (which is seemingly how it
* works in practice). When encountering an "inbetween" state we currently
* just panic!
*
* The FreeBSD man page kqueue(2) shows a check through the change list to
* check if kqueue had an error with any of the events being pushed to
* change. Maybe we should do this, even tho the man page also doesn't
* note that kqueue actually does this. We do not do this at this time. */
int status;
status = kevent(janet_vm.kq, events, length, NULL, 0, NULL);
if (status == -1 && errno != EINTR)
janet_panicv(janet_ev_lasterr());
}
JanetListenerState *janet_listen(JanetStream *stream, JanetListener behavior, int mask, size_t size, void *user) {
JanetListenerState *state = janet_listen_impl(stream, behavior, mask, size, user);
struct kevent kev[2];
int length = 0;
if (state->stream->_mask & JANET_ASYNC_LISTEN_READ) {
EV_SETx(&kev[length], stream->handle, EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, stream);
length++;
}
if (state->stream->_mask & JANET_ASYNC_LISTEN_WRITE) {
EV_SETx(&kev[length], stream->handle, EVFILT_WRITE, EV_ADD | EV_ENABLE, 0, 0, stream);
length++;
}
if (length > 0) {
add_kqueue_events(kev, length);
}
return state;
}
static void janet_unlisten(JanetListenerState *state, int is_gc) {
JanetStream *stream = state->stream;
if (!(stream->flags & JANET_STREAM_CLOSED)) {
/* Use flag to indicate state is not registered in kqueue */
if (!(state->_mask & (1 << JANET_ASYNC_EVENT_COMPLETE))) {
int is_last = (state->_next == NULL && stream->state == state);
int op = is_last ? EV_DELETE : EV_DISABLE | EV_ADD;
struct kevent kev[2];
EV_SETx(&kev[1], stream->handle, EVFILT_WRITE, op, 0, 0, stream);
int length = 0;
if (stream->_mask & JANET_ASYNC_EVENT_WRITE) {
EV_SETx(&kev[length], stream->handle, EVFILT_WRITE, op, 0, 0, stream);
length++;
}
if (stream->_mask & JANET_ASYNC_EVENT_READ) {
EV_SETx(&kev[length], stream->handle, EVFILT_READ, op, 0, 0, stream);
length++;
}
add_kqueue_events(kev, length);
}
}
janet_unlisten_impl(state, is_gc);
}
#define JANET_KQUEUE_MAX_EVENTS 64
void janet_loop1_impl(int has_timeout, JanetTimestamp timeout) {
/* Poll for events */
/* NOTE:
* We calculate the timeout interval per iteration. When the interval
* drops to 0 or negative, we effect a timeout of 0. Effecting a timeout
* of infinity will not work and could make other fibers with timeouts
* miss their timeouts if we did so.
* JANET_KQUEUE_INTERVAL insures we have a timeout of no less than 0. */
int status;
struct timespec ts;
struct kevent events[JANET_KQUEUE_MAX_EVENTS];
do {
if (janet_vm.timer_enabled || has_timeout) {
timestamp2timespec(&ts, JANET_KQUEUE_INTERVAL(timeout));
status = kevent(janet_vm.kq, NULL, 0, events,
JANET_KQUEUE_MAX_EVENTS, &ts);
} else {
status = kevent(janet_vm.kq, NULL, 0, events,
JANET_KQUEUE_MAX_EVENTS, NULL);
}
} while (status == -1 && errno == EINTR);
if (status == -1)
JANET_EXIT("failed to poll events");
/* Make sure timer is set accordingly. */
janet_vm.timer_enabled = has_timeout;
/* Step state machines */
for (int i = 0; i < status; i++) {
void *p = (void *) events[i].udata;
if (janet_vm.selfpipe == p) {
/* Self-pipe handling */
janet_ev_handle_selfpipe();
} else {
JanetStream *stream = p;
JanetListenerState *state = stream->state;
while (NULL != state) {
JanetListenerState *next_state = state->_next;
state->event = events + i;
JanetAsyncStatus statuses[4];
for (int i = 0; i < 4; i++)
statuses[i] = JANET_ASYNC_STATUS_NOT_DONE;
if (!(events[i].flags & EV_ERROR)) {
if (events[i].filter == EVFILT_WRITE)
statuses[0] = state->machine(state, JANET_ASYNC_EVENT_WRITE);
if (events[i].filter == EVFILT_READ)
statuses[1] = state->machine(state, JANET_ASYNC_EVENT_READ);
if ((events[i].flags & EV_EOF) && !(events[i].data > 0))
statuses[3] = state->machine(state, JANET_ASYNC_EVENT_HUP);
} else {
statuses[2] = state->machine(state, JANET_ASYNC_EVENT_ERR);
}
if (statuses[0] == JANET_ASYNC_STATUS_DONE ||
statuses[1] == JANET_ASYNC_STATUS_DONE ||
statuses[2] == JANET_ASYNC_STATUS_DONE ||
statuses[3] == JANET_ASYNC_STATUS_DONE)
janet_unlisten(state, 0);
state = next_state;
}
}
}
}
void janet_ev_init(void) {
janet_ev_init_common();
janet_ev_setup_selfpipe();
janet_vm.kq = kqueue();
janet_vm.timer_enabled = 0;
if (janet_vm.kq == -1) goto error;
struct kevent event;
EV_SETx(&event, janet_vm.selfpipe[0], EVFILT_READ, EV_ADD | EV_ENABLE, 0, 0, janet_vm.selfpipe);
add_kqueue_events(&event, 1);
return;
error:
JANET_EXIT("failed to initialize event loop");
}
void janet_ev_deinit(void) {
janet_ev_deinit_common();
close(janet_vm.kq);
janet_ev_cleanup_selfpipe();
janet_vm.kq = 0;
}
#else
#include <poll.h>
static JanetTimestamp ts_now(void) {
struct timespec now;
janet_assert(-1 != clock_gettime(CLOCK_REALTIME, &now), "failed to get time");
uint64_t res = 1000 * now.tv_sec;
res += now.tv_nsec / 1000000;
return res;
}
static int make_poll_events(int mask) {
int events = 0;
if (mask & JANET_ASYNC_LISTEN_READ)
events |= POLLIN;
if (mask & JANET_ASYNC_LISTEN_WRITE)
events |= POLLOUT;
return events;
}
/* Wait for the next event */
JanetListenerState *janet_listen(JanetStream *stream, JanetListener behavior, int mask, size_t size, void *user) {
size_t oldsize = janet_vm.listener_cap;
JanetListenerState *state = janet_listen_impl(stream, behavior, mask, size, user);
size_t newsize = janet_vm.listener_cap;
if (newsize > oldsize) {
janet_vm.fds = janet_realloc(janet_vm.fds, (newsize + 1) * sizeof(struct pollfd));
if (NULL == janet_vm.fds) {
JANET_OUT_OF_MEMORY;
}
}
struct pollfd ev;
ev.fd = stream->handle;
ev.events = make_poll_events(state->stream->_mask);
ev.revents = 0;
janet_vm.fds[state->_index + 1] = ev;
return state;
}
static void janet_unlisten(JanetListenerState *state, int is_gc) {
janet_vm.fds[state->_index + 1] = janet_vm.fds[janet_vm.listener_count];
janet_unlisten_impl(state, is_gc);
}
void janet_loop1_impl(int has_timeout, JanetTimestamp timeout) {
/* Poll for events */
int ready;
do {
int to = -1;
if (has_timeout) {
JanetTimestamp now = ts_now();
to = now > timeout ? 0 : (int)(timeout - now);
}
ready = poll(janet_vm.fds, janet_vm.listener_count + 1, to);
} while (ready == -1 && errno == EINTR);
if (ready == -1) {
JANET_EXIT("failed to poll events");
}
/* Check selfpipe */
if (janet_vm.fds[0].revents & POLLIN) {
janet_vm.fds[0].revents = 0;
janet_ev_handle_selfpipe();
}
/* Step state machines */
for (size_t i = 0; i < janet_vm.listener_count; i++) {
struct pollfd *pfd = janet_vm.fds + i + 1;
/* Skip fds where nothing interesting happened */
JanetListenerState *state = janet_vm.listeners[i];
/* Normal event */
int mask = pfd->revents;
JanetAsyncStatus status1 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status2 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status3 = JANET_ASYNC_STATUS_NOT_DONE;
JanetAsyncStatus status4 = JANET_ASYNC_STATUS_NOT_DONE;
state->event = pfd;
if (mask & POLLOUT)
status1 = state->machine(state, JANET_ASYNC_EVENT_WRITE);
if (mask & POLLIN)
status2 = state->machine(state, JANET_ASYNC_EVENT_READ);
if (mask & POLLERR)
status3 = state->machine(state, JANET_ASYNC_EVENT_ERR);
if ((mask & POLLHUP) && !(mask & (POLLIN | POLLOUT)))
status4 = state->machine(state, JANET_ASYNC_EVENT_HUP);
if (status1 == JANET_ASYNC_STATUS_DONE ||
status2 == JANET_ASYNC_STATUS_DONE ||
status3 == JANET_ASYNC_STATUS_DONE ||
status4 == JANET_ASYNC_STATUS_DONE)
janet_unlisten(state, 0);
}
}
void janet_ev_init(void) {
janet_ev_init_common();
janet_vm.fds = NULL;
janet_ev_setup_selfpipe();
janet_vm.fds = janet_malloc(sizeof(struct pollfd));
if (NULL == janet_vm.fds) {
JANET_OUT_OF_MEMORY;
}
janet_vm.fds[0].fd = janet_vm.selfpipe[0];
janet_vm.fds[0].events = POLLIN;
janet_vm.fds[0].revents = 0;
return;
}
void janet_ev_deinit(void) {
janet_ev_deinit_common();
janet_ev_cleanup_selfpipe();
janet_free(janet_vm.fds);
janet_vm.fds = NULL;
}
#endif
/*
* End poll implementation
*/
/*
* Generic Callback system. Post a function pointer + data to the event loop (from another
* thread or even a signal handler). Allows posting events from another thread or signal handler.
*/
void janet_ev_post_event(JanetVM *vm, JanetCallback cb, JanetEVGenericMessage msg) {
vm = vm ? vm : &janet_vm;
#ifdef JANET_WINDOWS
JanetHandle iocp = vm->iocp;
JanetSelfPipeEvent *event = janet_malloc(sizeof(JanetSelfPipeEvent));
if (NULL == event) {
JANET_OUT_OF_MEMORY;
}
event->msg = msg;
event->cb = cb;
janet_assert(PostQueuedCompletionStatus(iocp,
sizeof(JanetSelfPipeEvent),
0,
(LPOVERLAPPED) event),
"failed to post completion event");
#else
JanetSelfPipeEvent event;
memset(&event, 0, sizeof(event));
event.msg = msg;
event.cb = cb;
int fd = vm->selfpipe[1];
/* handle a bit of back pressure before giving up. */
int tries = 4;
while (tries > 0) {
int status;
do {
status = write(fd, &event, sizeof(event));
} while (status == -1 && errno == EINTR);
if (status > 0) break;
sleep(0);
tries--;
}
janet_assert(tries > 0, "failed to write event to self-pipe");
#endif
}
/*
* Threaded calls
*/
#ifdef JANET_WINDOWS
static DWORD WINAPI janet_thread_body(LPVOID ptr) {
JanetEVThreadInit *init = (JanetEVThreadInit *)ptr;
JanetEVGenericMessage msg = init->msg;
JanetThreadedSubroutine subr = init->subr;
JanetThreadedCallback cb = init->cb;
JanetHandle iocp = init->write_pipe;
/* Reuse memory from thread init for returning data */
init->msg = subr(msg);
init->cb = cb;
janet_assert(PostQueuedCompletionStatus(iocp,
sizeof(JanetSelfPipeEvent),
0,
(LPOVERLAPPED) init),
"failed to post completion event");
return 0;
}
#else
static void *janet_thread_body(void *ptr) {
JanetEVThreadInit *init = (JanetEVThreadInit *)ptr;
JanetEVGenericMessage msg = init->msg;
JanetThreadedSubroutine subr = init->subr;
JanetThreadedCallback cb = init->cb;
int fd = init->write_pipe;
janet_free(init);
JanetSelfPipeEvent response;
memset(&response, 0, sizeof(response));
response.msg = subr(msg);
response.cb = cb;
/* handle a bit of back pressure before giving up. */
int tries = 4;
while (tries > 0) {
int status;
do {
status = write(fd, &response, sizeof(response));
} while (status == -1 && errno == EINTR);
if (status > 0) break;
sleep(1);
tries--;
}
return NULL;
}
#endif
void janet_ev_threaded_call(JanetThreadedSubroutine fp, JanetEVGenericMessage arguments, JanetThreadedCallback cb) {
JanetEVThreadInit *init = janet_malloc(sizeof(JanetEVThreadInit));
if (NULL == init) {
JANET_OUT_OF_MEMORY;
}
init->msg = arguments;
init->subr = fp;
init->cb = cb;
#ifdef JANET_WINDOWS
init->write_pipe = janet_vm.iocp;
HANDLE thread_handle = CreateThread(NULL, 0, janet_thread_body, init, 0, NULL);
if (NULL == thread_handle) {
janet_free(init);
janet_panic("failed to create thread");
}
CloseHandle(thread_handle); /* detach from thread */
#else
init->write_pipe = janet_vm.selfpipe[1];
pthread_t waiter_thread;
int err = pthread_create(&waiter_thread, NULL, janet_thread_body, init);
if (err) {
janet_free(init);
janet_panicf("%s", strerror(err));
}
pthread_detach(waiter_thread);
#endif
/* Increment ev refcount so we don't quit while waiting for a subprocess */
janet_ev_inc_refcount();
}
/* Default callback for janet_ev_threaded_await. */
void janet_ev_default_threaded_callback(JanetEVGenericMessage return_value) {
janet_ev_dec_refcount();
if (return_value.fiber == NULL) {
return;
}
switch (return_value.tag) {
default:
case JANET_EV_TCTAG_NIL:
janet_schedule(return_value.fiber, janet_wrap_nil());
break;
case JANET_EV_TCTAG_INTEGER:
janet_schedule(return_value.fiber, janet_wrap_integer(return_value.argi));
break;
case JANET_EV_TCTAG_STRING:
case JANET_EV_TCTAG_STRINGF:
janet_schedule(return_value.fiber, janet_cstringv((const char *) return_value.argp));
if (return_value.tag == JANET_EV_TCTAG_STRINGF) janet_free(return_value.argp);
break;
case JANET_EV_TCTAG_KEYWORD:
janet_schedule(return_value.fiber, janet_ckeywordv((const char *) return_value.argp));
break;
case JANET_EV_TCTAG_ERR_STRING:
case JANET_EV_TCTAG_ERR_STRINGF:
janet_cancel(return_value.fiber, janet_cstringv((const char *) return_value.argp));
if (return_value.tag == JANET_EV_TCTAG_STRINGF) janet_free(return_value.argp);
break;
case JANET_EV_TCTAG_ERR_KEYWORD:
janet_cancel(return_value.fiber, janet_ckeywordv((const char *) return_value.argp));
break;
case JANET_EV_TCTAG_BOOLEAN:
janet_schedule(return_value.fiber, janet_wrap_boolean(return_value.argi));
break;
}
janet_gcunroot(janet_wrap_fiber(return_value.fiber));
}
/* Convenience method for common case */
JANET_NO_RETURN
void janet_ev_threaded_await(JanetThreadedSubroutine fp, int tag, int argi, void *argp) {
JanetEVGenericMessage arguments;
memset(&arguments, 0, sizeof(arguments));
arguments.tag = tag;
arguments.argi = argi;
arguments.argp = argp;
arguments.fiber = janet_root_fiber();
janet_gcroot(janet_wrap_fiber(arguments.fiber));
janet_ev_threaded_call(fp, arguments, janet_ev_default_threaded_callback);
janet_await();
}
/*
* C API helpers for reading and writing from streams.
* There is some networking code in here as well as generic
* reading and writing primitives.
*/
void janet_stream_flags(JanetStream *stream, uint32_t flags) {
if (stream->flags & JANET_STREAM_CLOSED) {
janet_panic("stream is closed");
}
if ((stream->flags & flags) != flags) {
const char *rmsg = "", *wmsg = "", *amsg = "", *dmsg = "", *smsg = "stream";
if (flags & JANET_STREAM_READABLE) rmsg = "readable ";
if (flags & JANET_STREAM_WRITABLE) wmsg = "writable ";
if (flags & JANET_STREAM_ACCEPTABLE) amsg = "server ";
if (flags & JANET_STREAM_UDPSERVER) dmsg = "datagram ";
if (flags & JANET_STREAM_SOCKET) smsg = "socket";
janet_panicf("bad stream, expected %s%s%s%s%s", rmsg, wmsg, amsg, dmsg, smsg);
}
}
/* When there is an IO error, we need to be able to convert it to a Janet
* string to raise a Janet error. */
#ifdef JANET_WINDOWS
#define JANET_EV_CHUNKSIZE 4096
Janet janet_ev_lasterr(void) {
int code = GetLastError();
char msgbuf[256];
msgbuf[0] = '\0';
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
code,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
msgbuf,
sizeof(msgbuf),
NULL);
if (!*msgbuf) sprintf(msgbuf, "%d", code);
char *c = msgbuf;
while (*c) {
if (*c == '\n' || *c == '\r') {
*c = '\0';
break;
}
c++;
}
return janet_cstringv(msgbuf);
}
#else
Janet janet_ev_lasterr(void) {
return janet_cstringv(strerror(errno));
}
#endif
/* State machine for read/recv/recvfrom */
typedef enum {
JANET_ASYNC_READMODE_READ,
JANET_ASYNC_READMODE_RECV,
JANET_ASYNC_READMODE_RECVFROM
} JanetReadMode;
typedef struct {
JanetListenerState head;
int32_t bytes_left;
int32_t bytes_read;
JanetBuffer *buf;
int is_chunk;
JanetReadMode mode;
#ifdef JANET_WINDOWS
OVERLAPPED overlapped;
#ifdef JANET_NET
WSABUF wbuf;
DWORD flags;
struct sockaddr from;
int fromlen;
#endif
uint8_t chunk_buf[JANET_EV_CHUNKSIZE];
#else
int flags;
#endif
} StateRead;
JanetAsyncStatus ev_machine_read(JanetListenerState *s, JanetAsyncEvent event) {
StateRead *state = (StateRead *) s;
switch (event) {
default:
break;
case JANET_ASYNC_EVENT_MARK:
janet_mark(janet_wrap_buffer(state->buf));
break;
case JANET_ASYNC_EVENT_CLOSE:
janet_schedule(s->fiber, janet_wrap_nil());
return JANET_ASYNC_STATUS_DONE;
#ifdef JANET_WINDOWS
case JANET_ASYNC_EVENT_COMPLETE: {
/* Called when read finished */
state->bytes_read += s->bytes;
if (state->bytes_read == 0 && (state->mode != JANET_ASYNC_READMODE_RECVFROM)) {
janet_schedule(s->fiber, janet_wrap_nil());
return JANET_ASYNC_STATUS_DONE;
}
janet_buffer_push_bytes(state->buf, state->chunk_buf, s->bytes);
state->bytes_left -= s->bytes;
if (state->bytes_left == 0 || !state->is_chunk || s->bytes == 0) {
Janet resume_val;
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_READMODE_RECVFROM) {
void *abst = janet_abstract(&janet_address_type, state->fromlen);
memcpy(abst, &state->from, state->fromlen);
resume_val = janet_wrap_abstract(abst);
} else
#endif
{
resume_val = janet_wrap_buffer(state->buf);
}
janet_schedule(s->fiber, resume_val);
return JANET_ASYNC_STATUS_DONE;
}
}
/* fallthrough */
case JANET_ASYNC_EVENT_USER: {
int32_t chunk_size = state->bytes_left > JANET_EV_CHUNKSIZE ? JANET_EV_CHUNKSIZE : state->bytes_left;
s->tag = &state->overlapped;
memset(&(state->overlapped), 0, sizeof(OVERLAPPED));
int status;
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_READMODE_RECVFROM) {
state->wbuf.len = (ULONG) chunk_size;
state->wbuf.buf = state->chunk_buf;
status = WSARecvFrom((SOCKET) s->stream->handle, &state->wbuf, 1,
NULL, &state->flags, &state->from, &state->fromlen, &state->overlapped, NULL);
if (status && (WSA_IO_PENDING != WSAGetLastError())) {
janet_cancel(s->fiber, janet_ev_lasterr());
return JANET_ASYNC_STATUS_DONE;
}
} else
#endif
{
status = ReadFile(s->stream->handle, state->chunk_buf, chunk_size, NULL, &state->overlapped);
if (!status && (ERROR_IO_PENDING != WSAGetLastError())) {
if (WSAGetLastError() == ERROR_BROKEN_PIPE) {
if (state->bytes_read) {
janet_schedule(s->fiber, janet_wrap_buffer(state->buf));
} else {
janet_schedule(s->fiber, janet_wrap_nil());
}
} else {
janet_cancel(s->fiber, janet_ev_lasterr());
}
return JANET_ASYNC_STATUS_DONE;
}
}
}
break;
#else
case JANET_ASYNC_EVENT_ERR: {
if (state->bytes_read) {
janet_schedule(s->fiber, janet_wrap_buffer(state->buf));
} else {
janet_schedule(s->fiber, janet_wrap_nil());
}
return JANET_ASYNC_STATUS_DONE;
}
case JANET_ASYNC_EVENT_HUP:
case JANET_ASYNC_EVENT_READ: {
JanetBuffer *buffer = state->buf;
int32_t bytes_left = state->bytes_left;
int32_t read_limit = state->is_chunk ? (bytes_left > 4096 ? 4096 : bytes_left) : bytes_left;
janet_buffer_extra(buffer, read_limit);
ssize_t nread;
#ifdef JANET_NET
char saddr[256];
socklen_t socklen = sizeof(saddr);
#endif
do {
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_READMODE_RECVFROM) {
nread = recvfrom(s->stream->handle, buffer->data + buffer->count, read_limit, state->flags,
(struct sockaddr *)&saddr, &socklen);
} else if (state->mode == JANET_ASYNC_READMODE_RECV) {
nread = recv(s->stream->handle, buffer->data + buffer->count, read_limit, state->flags);
} else
#endif
{
nread = read(s->stream->handle, buffer->data + buffer->count, read_limit);
}
} while (nread == -1 && errno == EINTR);
/* Check for errors - special case errors that can just be waited on to fix */
if (nread == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
return JANET_ASYNC_STATUS_NOT_DONE;
}
/* In stream protocols, a pipe error is end of stream */
if (errno == EPIPE && (state->mode != JANET_ASYNC_READMODE_RECVFROM)) {
nread = 0;
} else {
janet_cancel(s->fiber, janet_ev_lasterr());
return JANET_ASYNC_STATUS_DONE;
}
}
/* Only allow 0-length packets in recv-from. In stream protocols, a zero length packet is EOS. */
state->bytes_read += nread;
if (state->bytes_read == 0 && (state->mode != JANET_ASYNC_READMODE_RECVFROM)) {
janet_schedule(s->fiber, janet_wrap_nil());
return JANET_ASYNC_STATUS_DONE;
}
/* Increment buffer counts */
buffer->count += nread;
bytes_left -= nread;
state->bytes_left = bytes_left;
/* Resume if done */
if (!state->is_chunk || bytes_left == 0 || nread == 0) {
Janet resume_val;
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_READMODE_RECVFROM) {
void *abst = janet_abstract(&janet_address_type, socklen);
memcpy(abst, &saddr, socklen);
resume_val = janet_wrap_abstract(abst);
} else
#endif
{
resume_val = janet_wrap_buffer(buffer);
}
janet_schedule(s->fiber, resume_val);
return JANET_ASYNC_STATUS_DONE;
}
}
break;
#endif
}
return JANET_ASYNC_STATUS_NOT_DONE;
}
static void janet_ev_read_generic(JanetStream *stream, JanetBuffer *buf, int32_t nbytes, int is_chunked, JanetReadMode mode, int flags) {
StateRead *state = (StateRead *) janet_listen(stream, ev_machine_read,
JANET_ASYNC_LISTEN_READ, sizeof(StateRead), NULL);
state->is_chunk = is_chunked;
state->buf = buf;
state->bytes_left = nbytes;
state->bytes_read = 0;
state->mode = mode;
#ifdef JANET_WINDOWS
ev_machine_read((JanetListenerState *) state, JANET_ASYNC_EVENT_USER);
state->flags = (DWORD) flags;
#else
state->flags = flags;
#endif
}
void janet_ev_read(JanetStream *stream, JanetBuffer *buf, int32_t nbytes) {
janet_ev_read_generic(stream, buf, nbytes, 0, JANET_ASYNC_READMODE_READ, 0);
}
void janet_ev_readchunk(JanetStream *stream, JanetBuffer *buf, int32_t nbytes) {
janet_ev_read_generic(stream, buf, nbytes, 1, JANET_ASYNC_READMODE_READ, 0);
}
#ifdef JANET_NET
void janet_ev_recv(JanetStream *stream, JanetBuffer *buf, int32_t nbytes, int flags) {
janet_ev_read_generic(stream, buf, nbytes, 0, JANET_ASYNC_READMODE_RECV, flags);
}
void janet_ev_recvchunk(JanetStream *stream, JanetBuffer *buf, int32_t nbytes, int flags) {
janet_ev_read_generic(stream, buf, nbytes, 1, JANET_ASYNC_READMODE_RECV, flags);
}
void janet_ev_recvfrom(JanetStream *stream, JanetBuffer *buf, int32_t nbytes, int flags) {
janet_ev_read_generic(stream, buf, nbytes, 0, JANET_ASYNC_READMODE_RECVFROM, flags);
}
#endif
/*
* State machine for write/send/send-to
*/
typedef enum {
JANET_ASYNC_WRITEMODE_WRITE,
JANET_ASYNC_WRITEMODE_SEND,
JANET_ASYNC_WRITEMODE_SENDTO
} JanetWriteMode;
typedef struct {
JanetListenerState head;
union {
JanetBuffer *buf;
const uint8_t *str;
} src;
int is_buffer;
JanetWriteMode mode;
void *dest_abst;
#ifdef JANET_WINDOWS
OVERLAPPED overlapped;
#ifdef JANET_NET
WSABUF wbuf;
DWORD flags;
#endif
#else
int flags;
int32_t start;
#endif
} StateWrite;
JanetAsyncStatus ev_machine_write(JanetListenerState *s, JanetAsyncEvent event) {
StateWrite *state = (StateWrite *) s;
switch (event) {
default:
break;
case JANET_ASYNC_EVENT_MARK:
janet_mark(state->is_buffer
? janet_wrap_buffer(state->src.buf)
: janet_wrap_string(state->src.str));
if (state->mode == JANET_ASYNC_WRITEMODE_SENDTO) {
janet_mark(janet_wrap_abstract(state->dest_abst));
}
break;
case JANET_ASYNC_EVENT_CLOSE:
janet_cancel(s->fiber, janet_cstringv("stream closed"));
return JANET_ASYNC_STATUS_DONE;
#ifdef JANET_WINDOWS
case JANET_ASYNC_EVENT_COMPLETE: {
/* Called when write finished */
if (s->bytes == 0 && (state->mode != JANET_ASYNC_WRITEMODE_SENDTO)) {
janet_cancel(s->fiber, janet_cstringv("disconnect"));
return JANET_ASYNC_STATUS_DONE;
}
janet_schedule(s->fiber, janet_wrap_nil());
return JANET_ASYNC_STATUS_DONE;
}
break;
case JANET_ASYNC_EVENT_USER: {
/* Begin write */
int32_t len;
const uint8_t *bytes;
if (state->is_buffer) {
/* If buffer, convert to string. */
/* TODO - be more efficient about this */
JanetBuffer *buffer = state->src.buf;
JanetString str = janet_string(buffer->data, buffer->count);
bytes = str;
len = buffer->count;
state->is_buffer = 0;
state->src.str = str;
} else {
bytes = state->src.str;
len = janet_string_length(bytes);
}
s->tag = &state->overlapped;
memset(&(state->overlapped), 0, sizeof(WSAOVERLAPPED));
int status;
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_WRITEMODE_SENDTO) {
SOCKET sock = (SOCKET) s->stream->handle;
state->wbuf.buf = (char *) bytes;
state->wbuf.len = len;
const struct sockaddr *to = state->dest_abst;
int tolen = (int) janet_abstract_size((void *) to);
status = WSASendTo(sock, &state->wbuf, 1, NULL, state->flags, to, tolen, &state->overlapped, NULL);
if (status && (WSA_IO_PENDING != WSAGetLastError())) {
janet_cancel(s->fiber, janet_ev_lasterr());
return JANET_ASYNC_STATUS_DONE;
}
} else
#endif
{
/*
* File handles in IOCP need to specify this if they are writing to the
* ends of files, like how this is used here.
* If the underlying resource doesn't support seeking
* byte offsets, they will be ignored
* but this otherwise writes to the end of the file in question
* Right now, os/open streams aren't seekable, so this works.
* for more details see the lpOverlapped parameter in
* https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-writefile
*/
state->overlapped.Offset = (DWORD) 0xFFFFFFFF;
state->overlapped.OffsetHigh = (DWORD) 0xFFFFFFFF;
status = WriteFile(s->stream->handle, bytes, len, NULL, &state->overlapped);
if (!status && (ERROR_IO_PENDING != WSAGetLastError())) {
janet_cancel(s->fiber, janet_ev_lasterr());
return JANET_ASYNC_STATUS_DONE;
}
}
}
break;
#else
case JANET_ASYNC_EVENT_ERR:
janet_cancel(s->fiber, janet_cstringv("stream err"));
return JANET_ASYNC_STATUS_DONE;
case JANET_ASYNC_EVENT_HUP:
janet_cancel(s->fiber, janet_cstringv("stream hup"));
return JANET_ASYNC_STATUS_DONE;
case JANET_ASYNC_EVENT_WRITE: {
int32_t start, len;
const uint8_t *bytes;
start = state->start;
if (state->is_buffer) {
JanetBuffer *buffer = state->src.buf;
bytes = buffer->data;
len = buffer->count;
} else {
bytes = state->src.str;
len = janet_string_length(bytes);
}
ssize_t nwrote = 0;
if (start < len) {
int32_t nbytes = len - start;
void *dest_abst = state->dest_abst;
do {
#ifdef JANET_NET
if (state->mode == JANET_ASYNC_WRITEMODE_SENDTO) {
nwrote = sendto(s->stream->handle, bytes + start, nbytes, state->flags,
(struct sockaddr *) dest_abst, janet_abstract_size(dest_abst));
} else if (state->mode == JANET_ASYNC_WRITEMODE_SEND) {
nwrote = send(s->stream->handle, bytes + start, nbytes, state->flags);
} else
#endif
{
nwrote = write(s->stream->handle, bytes + start, nbytes);
}
} while (nwrote == -1 && errno == EINTR);
/* Handle write errors */
if (nwrote == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) break;
janet_cancel(s->fiber, janet_ev_lasterr());
return JANET_ASYNC_STATUS_DONE;
}
/* Unless using datagrams, empty message is a disconnect */
if (nwrote == 0 && !dest_abst) {
janet_cancel(s->fiber, janet_cstringv("disconnect"));
return JANET_ASYNC_STATUS_DONE;
}
if (nwrote > 0) {
start += nwrote;
} else {
start = len;
}
}
state->start = start;
if (start >= len) {
janet_schedule(s->fiber, janet_wrap_nil());
return JANET_ASYNC_STATUS_DONE;
}
break;
}
break;
#endif
}
return JANET_ASYNC_STATUS_NOT_DONE;
}
static void janet_ev_write_generic(JanetStream *stream, void *buf, void *dest_abst, JanetWriteMode mode, int is_buffer, int flags) {
StateWrite *state = (StateWrite *) janet_listen(stream, ev_machine_write,
JANET_ASYNC_LISTEN_WRITE, sizeof(StateWrite), NULL);
state->is_buffer = is_buffer;
state->src.buf = buf;
state->dest_abst = dest_abst;
state->mode = mode;
#ifdef JANET_WINDOWS
state->flags = (DWORD) flags;
ev_machine_write((JanetListenerState *) state, JANET_ASYNC_EVENT_USER);
#else
state->start = 0;
state->flags = flags;
#endif
}
void janet_ev_write_buffer(JanetStream *stream, JanetBuffer *buf) {
janet_ev_write_generic(stream, buf, NULL, JANET_ASYNC_WRITEMODE_WRITE, 1, 0);
}
void janet_ev_write_string(JanetStream *stream, JanetString str) {
janet_ev_write_generic(stream, (void *) str, NULL, JANET_ASYNC_WRITEMODE_WRITE, 0, 0);
}
#ifdef JANET_NET
void janet_ev_send_buffer(JanetStream *stream, JanetBuffer *buf, int flags) {
janet_ev_write_generic(stream, buf, NULL, JANET_ASYNC_WRITEMODE_SEND, 1, flags);
}
void janet_ev_send_string(JanetStream *stream, JanetString str, int flags) {
janet_ev_write_generic(stream, (void *) str, NULL, JANET_ASYNC_WRITEMODE_SEND, 0, flags);
}
void janet_ev_sendto_buffer(JanetStream *stream, JanetBuffer *buf, void *dest, int flags) {
janet_ev_write_generic(stream, buf, dest, JANET_ASYNC_WRITEMODE_SENDTO, 1, flags);
}
void janet_ev_sendto_string(JanetStream *stream, JanetString str, void *dest, int flags) {
janet_ev_write_generic(stream, (void *) str, dest, JANET_ASYNC_WRITEMODE_SENDTO, 0, flags);
}
#endif
/* For a pipe ID */
#ifdef JANET_WINDOWS
static volatile long PipeSerialNumber;
#endif
/*
* mode = 0: both sides non-blocking.
* mode = 1: only read side non-blocking: write side sent to subprocess
* mode = 2: only write side non-blocking: read side sent to subprocess
*/
int janet_make_pipe(JanetHandle handles[2], int mode) {
#ifdef JANET_WINDOWS
/*
* On windows, the built in CreatePipe function doesn't support overlapped IO
* so we lift from the windows source code and modify for our own version.
*/
JanetHandle shandle, chandle;
UCHAR PipeNameBuffer[MAX_PATH];
SECURITY_ATTRIBUTES saAttr;
memset(&saAttr, 0, sizeof(saAttr));
saAttr.nLength = sizeof(saAttr);
saAttr.bInheritHandle = TRUE;
sprintf(PipeNameBuffer,
"\\\\.\\Pipe\\JanetPipeFile.%08x.%08x",
GetCurrentProcessId(),
InterlockedIncrement(&PipeSerialNumber));
/* server handle goes to subprocess */
shandle = CreateNamedPipeA(
PipeNameBuffer,
(mode == 2 ? PIPE_ACCESS_INBOUND : PIPE_ACCESS_OUTBOUND) | FILE_FLAG_OVERLAPPED,
PIPE_TYPE_BYTE | PIPE_WAIT,
255, /* Max number of pipes for duplication. */
4096, /* Out buffer size */
4096, /* In buffer size */
120 * 1000, /* Timeout in ms */
&saAttr);
if (shandle == INVALID_HANDLE_VALUE) {
return -1;
}
/* we keep client handle */
chandle = CreateFileA(
PipeNameBuffer,
(mode == 2 ? GENERIC_WRITE : GENERIC_READ),
0,
&saAttr,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
NULL);
if (chandle == INVALID_HANDLE_VALUE) {
CloseHandle(shandle);
return -1;
}
if (mode == 2) {
handles[0] = shandle;
handles[1] = chandle;
} else {
handles[0] = chandle;
handles[1] = shandle;
}
return 0;
#else
if (pipe(handles)) return -1;
if (mode != 2 && fcntl(handles[0], F_SETFD, FD_CLOEXEC)) goto error;
if (mode != 1 && fcntl(handles[1], F_SETFD, FD_CLOEXEC)) goto error;
if (mode != 2 && fcntl(handles[0], F_SETFL, O_NONBLOCK)) goto error;
if (mode != 1 && fcntl(handles[1], F_SETFL, O_NONBLOCK)) goto error;
return 0;
error:
close(handles[0]);
close(handles[1]);
return -1;
#endif
}
/* C functions */
JANET_CORE_FN(cfun_ev_go,
"(ev/go fiber &opt value supervisor)",
"Put a fiber on the event loop to be resumed later. Optionally pass "
"a value to resume with, otherwise resumes with nil. Returns the fiber. "
"An optional `core/channel` can be provided as a supervisor. When various "
"events occur in the newly scheduled fiber, an event will be pushed to the supervisor. "
"If not provided, the new fiber will inherit the current supervisor.") {
janet_arity(argc, 1, 3);
Janet value = argc >= 2 ? argv[1] : janet_wrap_nil();
void *supervisor = janet_optabstract(argv, argc, 2, &janet_channel_type, janet_vm.root_fiber->supervisor_channel);
JanetFiber *fiber;
if (janet_checktype(argv[0], JANET_FUNCTION)) {
/* Create a fiber for the user */
JanetFunction *func = janet_unwrap_function(argv[0]);
if (func->def->min_arity > 1) {
janet_panicf("task function must accept 0 or 1 arguments");
}
fiber = janet_fiber(func, 64, func->def->min_arity, &value);
fiber->flags |=
JANET_FIBER_MASK_ERROR |
JANET_FIBER_MASK_USER0 |
JANET_FIBER_MASK_USER1 |
JANET_FIBER_MASK_USER2 |
JANET_FIBER_MASK_USER3 |
JANET_FIBER_MASK_USER4;
if (!janet_vm.fiber->env) {
janet_vm.fiber->env = janet_table(0);
}
fiber->env = janet_table(0);
fiber->env->proto = janet_vm.fiber->env;
} else {
fiber = janet_getfiber(argv, 0);
}
fiber->supervisor_channel = supervisor;
janet_schedule(fiber, value);
return janet_wrap_fiber(fiber);
}
/* For ev/thread - Run an interpreter in the new thread. */
static JanetEVGenericMessage janet_go_thread_subr(JanetEVGenericMessage args) {
JanetBuffer *buffer = (JanetBuffer *) args.argp;
const uint8_t *nextbytes = buffer->data;
const uint8_t *endbytes = nextbytes + buffer->count;
uint32_t flags = args.tag;
args.tag = 0;
janet_init();
JanetTryState tstate;
JanetSignal signal = janet_try(&tstate);
if (!signal) {
/* Set abstract registry */
if (!(flags & 0x2)) {
Janet aregv = janet_unmarshal(nextbytes, endbytes - nextbytes,
JANET_MARSHAL_UNSAFE, NULL, &nextbytes);
if (!janet_checktype(aregv, JANET_TABLE)) janet_panic("expected table for abstract registry");
janet_vm.abstract_registry = janet_unwrap_table(aregv);
janet_gcroot(janet_wrap_table(janet_vm.abstract_registry));
}
/* Get supervsior */
if (flags & 0x8) {
Janet sup =
janet_unmarshal(nextbytes, endbytes - nextbytes,
JANET_MARSHAL_UNSAFE, NULL, &nextbytes);
/* Hack - use a global variable to avoid longjmp clobber */
janet_vm.user = janet_unwrap_pointer(sup);
}
/* Set cfunction registry */
if (!(flags & 0x4)) {
uint32_t count1;
memcpy(&count1, nextbytes, sizeof(count1));
size_t count = (size_t) count1;
if (count > (endbytes - nextbytes) * sizeof(JanetCFunRegistry)) {
janet_panic("thread message invalid");
}
janet_vm.registry_count = count;
janet_vm.registry_cap = count;
janet_vm.registry = janet_malloc(count * sizeof(JanetCFunRegistry));
if (janet_vm.registry == NULL) {
JANET_OUT_OF_MEMORY;
}
janet_vm.registry_dirty = 1;
nextbytes += sizeof(uint32_t);
memcpy(janet_vm.registry, nextbytes, count * sizeof(JanetCFunRegistry));
nextbytes += count * sizeof(JanetCFunRegistry);
}
Janet fiberv = janet_unmarshal(nextbytes, endbytes - nextbytes,
JANET_MARSHAL_UNSAFE, NULL, &nextbytes);
Janet value = janet_unmarshal(nextbytes, endbytes - nextbytes,
JANET_MARSHAL_UNSAFE, NULL, &nextbytes);
JanetFiber *fiber;
if (!janet_checktype(fiberv, JANET_FIBER)) {
if (!janet_checktype(fiberv, JANET_FUNCTION)) {
janet_panicf("expected function|fiber, got %v", fiberv);
}
JanetFunction *func = janet_unwrap_function(fiberv);
if (func->def->min_arity > 1) {
janet_panicf("thread function must accept 0 or 1 arguments");
}
fiber = janet_fiber(func, 64, func->def->min_arity, &value);
fiber->flags |=
JANET_FIBER_MASK_ERROR |
JANET_FIBER_MASK_USER0 |
JANET_FIBER_MASK_USER1 |
JANET_FIBER_MASK_USER2 |
JANET_FIBER_MASK_USER3 |
JANET_FIBER_MASK_USER4;
} else {
fiber = janet_unwrap_fiber(fiberv);
}
fiber->supervisor_channel = janet_vm.user;
janet_schedule(fiber, value);
janet_loop();
args.tag = JANET_EV_TCTAG_NIL;
} else {
void *supervisor = janet_vm.user;
if (NULL != supervisor) {
/* Got a supervisor, write error there */
Janet pair[] = {
janet_ckeywordv("error"),
tstate.payload
};
janet_channel_push((JanetChannel *)supervisor,
janet_wrap_tuple(janet_tuple_n(pair, 2)), 2);
} else if (flags & 0x1) {
/* No wait, just print to stderr */
janet_eprintf("thread start failure: %v\n", tstate.payload);
} else {
/* Make ev/thread call from parent thread error */
if (janet_checktype(tstate.payload, JANET_STRING)) {
args.tag = JANET_EV_TCTAG_ERR_STRINGF;
args.argp = strdup((const char *) janet_unwrap_string(tstate.payload));
} else {
args.tag = JANET_EV_TCTAG_ERR_STRING;
args.argp = "failed to start thread";
}
}
}
janet_restore(&tstate);
janet_buffer_deinit(buffer);
janet_free(buffer);
janet_deinit();
return args;
}
JANET_CORE_FN(cfun_ev_thread,
"(ev/thread main &opt value flags supervisor)",
"Run `main` in a new operating system thread, optionally passing `value` "
"to resume with. The parameter `main` can either be a fiber, or a function that accepts "
"0 or 1 arguments. "
"Unlike `ev/go`, this function will suspend the current fiber until the thread is complete. "
"If you want to run the thread without waiting for a result, pass the `:n` flag to return nil immediately. "
"Otherwise, returns nil. Available flags:\n\n"
"* `:n` - return immediately\n"
"* `:a` - don't copy abstract registry to new thread (performance optimization)\n"
"* `:c` - don't copy cfunction registry to new thread (performance optimization)") {
janet_arity(argc, 1, 4);
Janet value = argc >= 2 ? argv[1] : janet_wrap_nil();
if (!janet_checktype(argv[0], JANET_FUNCTION)) janet_getfiber(argv, 0);
uint64_t flags = 0;
if (argc >= 3) {
flags = janet_getflags(argv, 2, "nac");
}
void *supervisor = janet_optabstract(argv, argc, 3, &janet_channel_type, janet_vm.root_fiber->supervisor_channel);
if (NULL != supervisor) flags |= 0x8;
/* Marshal arguments for the new thread. */
JanetBuffer *buffer = janet_malloc(sizeof(JanetBuffer));
if (NULL == buffer) {
JANET_OUT_OF_MEMORY;
}
janet_buffer_init(buffer, 0);
if (!(flags & 0x2)) {
janet_marshal(buffer, janet_wrap_table(janet_vm.abstract_registry), NULL, JANET_MARSHAL_UNSAFE);
}
if (flags & 0x8) {
janet_marshal(buffer, janet_wrap_abstract(supervisor), NULL, JANET_MARSHAL_UNSAFE);
}
if (!(flags & 0x4)) {
janet_assert(janet_vm.registry_count <= INT32_MAX, "assert failed size check");
uint32_t temp = (uint32_t) janet_vm.registry_count;
janet_buffer_push_bytes(buffer, (uint8_t *) &temp, sizeof(temp));
janet_buffer_push_bytes(buffer, (uint8_t *) janet_vm.registry, (int32_t) janet_vm.registry_count * sizeof(JanetCFunRegistry));
}
janet_marshal(buffer, argv[0], NULL, JANET_MARSHAL_UNSAFE);
janet_marshal(buffer, value, NULL, JANET_MARSHAL_UNSAFE);
if (flags & 0x1) {
/* Return immediately */
JanetEVGenericMessage arguments;
memset(&arguments, 0, sizeof(arguments));
arguments.tag = (uint32_t) flags;
arguments.argi = argc;
arguments.argp = buffer;
arguments.fiber = NULL;
janet_ev_threaded_call(janet_go_thread_subr, arguments, janet_ev_default_threaded_callback);
return janet_wrap_nil();
} else {
janet_ev_threaded_await(janet_go_thread_subr, (uint32_t) flags, argc, buffer);
}
}
JANET_CORE_FN(cfun_ev_give_supervisor,
"(ev/give-supervisor tag & payload)",
"Send a message to the current supervior channel if there is one. The message will be a "
"tuple of all of the arguments combined into a single message, where the first element is tag. "
"By convention, tag should be a keyword indicating the type of message. Returns nil.") {
janet_arity(argc, 1, -1);
void *chanv = janet_vm.root_fiber->supervisor_channel;
if (NULL != chanv) {
JanetChannel *chan = janet_channel_unwrap(chanv);
if (janet_channel_push(chan, janet_wrap_tuple(janet_tuple_n(argv, argc)), 0)) {
janet_await();
}
}
return janet_wrap_nil();
}
JANET_NO_RETURN void janet_sleep_await(double sec) {
JanetTimeout to;
to.when = ts_delta(ts_now(), sec);
to.fiber = janet_vm.root_fiber;
to.is_error = 0;
to.sched_id = to.fiber->sched_id;
to.curr_fiber = NULL;
add_timeout(to);
janet_await();
}
JANET_CORE_FN(cfun_ev_sleep,
"(ev/sleep sec)",
"Suspend the current fiber for sec seconds without blocking the event loop.") {
janet_fixarity(argc, 1);
double sec = janet_getnumber(argv, 0);
janet_sleep_await(sec);
}
JANET_CORE_FN(cfun_ev_deadline,
"(ev/deadline sec &opt tocancel tocheck)",
"Set a deadline for a fiber `tocheck`. If `tocheck` is not finished after `sec` seconds, "
"`tocancel` will be canceled as with `ev/cancel`. "
"If `tocancel` and `tocheck` are not given, they default to `(fiber/root)` and "
"`(fiber/current)` respectively. Returns `tocancel`.") {
janet_arity(argc, 1, 3);
double sec = janet_getnumber(argv, 0);
JanetFiber *tocancel = janet_optfiber(argv, argc, 1, janet_vm.root_fiber);
JanetFiber *tocheck = janet_optfiber(argv, argc, 2, janet_vm.fiber);
JanetTimeout to;
to.when = ts_delta(ts_now(), sec);
to.fiber = tocancel;
to.curr_fiber = tocheck;
to.is_error = 0;
to.sched_id = to.fiber->sched_id;
add_timeout(to);
return janet_wrap_fiber(tocancel);
}
JANET_CORE_FN(cfun_ev_cancel,
"(ev/cancel fiber err)",
"Cancel a suspended fiber in the event loop. Differs from cancel in that it returns the canceled fiber immediately.") {
janet_fixarity(argc, 2);
JanetFiber *fiber = janet_getfiber(argv, 0);
Janet err = argv[1];
janet_cancel(fiber, err);
return argv[0];
}
JANET_CORE_FN(janet_cfun_stream_close,
"(ev/close stream)",
"Close a stream. This should be the same as calling (:close stream) for all streams.") {
janet_fixarity(argc, 1);
JanetStream *stream = janet_getabstract(argv, 0, &janet_stream_type);
janet_stream_close(stream);
return argv[0];
}
JANET_CORE_FN(janet_cfun_stream_read,
"(ev/read stream n &opt buffer timeout)",
"Read up to n bytes into a buffer asynchronously from a stream. `n` can also be the keyword "
"`:all` to read into the buffer until end of stream. "
"Optionally provide a buffer to write into "
"as well as a timeout in seconds after which to cancel the operation and raise an error. "
"Returns the buffer if the read was successful or nil if end-of-stream reached. Will raise an "
"error if there are problems with the IO operation.") {
janet_arity(argc, 2, 4);
JanetStream *stream = janet_getabstract(argv, 0, &janet_stream_type);
janet_stream_flags(stream, JANET_STREAM_READABLE);
JanetBuffer *buffer = janet_optbuffer(argv, argc, 2, 10);
double to = janet_optnumber(argv, argc, 3, INFINITY);
if (janet_keyeq(argv[1], "all")) {
if (to != INFINITY) janet_addtimeout(to);
janet_ev_readchunk(stream, buffer, INT32_MAX);
} else {
int32_t n = janet_getnat(argv, 1);
if (to != INFINITY) janet_addtimeout(to);
janet_ev_read(stream, buffer, n);
}
janet_await();
}
JANET_CORE_FN(janet_cfun_stream_chunk,
"(ev/chunk stream n &opt buffer timeout)",
"Same as ev/read, but will not return early if less than n bytes are available. If an end of "
"stream is reached, will also return early with the collected bytes.") {
janet_arity(argc, 2, 4);
JanetStream *stream = janet_getabstract(argv, 0, &janet_stream_type);
janet_stream_flags(stream, JANET_STREAM_READABLE);
int32_t n = janet_getnat(argv, 1);
JanetBuffer *buffer = janet_optbuffer(argv, argc, 2, 10);
double to = janet_optnumber(argv, argc, 3, INFINITY);
if (to != INFINITY) janet_addtimeout(to);
janet_ev_readchunk(stream, buffer, n);
janet_await();
}
JANET_CORE_FN(janet_cfun_stream_write,
"(ev/write stream data &opt timeout)",
"Write data to a stream, suspending the current fiber until the write "
"completes. Takes an optional timeout in seconds, after which will return nil. "
"Returns nil, or raises an error if the write failed.") {
janet_arity(argc, 2, 3);
JanetStream *stream = janet_getabstract(argv, 0, &janet_stream_type);
janet_stream_flags(stream, JANET_STREAM_WRITABLE);
double to = janet_optnumber(argv, argc, 2, INFINITY);
if (janet_checktype(argv[1], JANET_BUFFER)) {
if (to != INFINITY) janet_addtimeout(to);
janet_ev_write_buffer(stream, janet_getbuffer(argv, 1));
} else {
JanetByteView bytes = janet_getbytes(argv, 1);
if (to != INFINITY) janet_addtimeout(to);
janet_ev_write_string(stream, bytes.bytes);
}
janet_await();
}
void janet_lib_ev(JanetTable *env) {
JanetRegExt ev_cfuns_ext[] = {
JANET_CORE_REG("ev/give", cfun_channel_push),
JANET_CORE_REG("ev/take", cfun_channel_pop),
JANET_CORE_REG("ev/full", cfun_channel_full),
JANET_CORE_REG("ev/capacity", cfun_channel_capacity),
JANET_CORE_REG("ev/count", cfun_channel_count),
JANET_CORE_REG("ev/select", cfun_channel_choice),
JANET_CORE_REG("ev/rselect", cfun_channel_rchoice),
JANET_CORE_REG("ev/chan", cfun_channel_new),
JANET_CORE_REG("ev/thread-chan", cfun_channel_new_threaded),
JANET_CORE_REG("ev/chan-close", cfun_channel_close),
JANET_CORE_REG("ev/go", cfun_ev_go),
JANET_CORE_REG("ev/thread", cfun_ev_thread),
JANET_CORE_REG("ev/give-supervisor", cfun_ev_give_supervisor),
JANET_CORE_REG("ev/sleep", cfun_ev_sleep),
JANET_CORE_REG("ev/deadline", cfun_ev_deadline),
JANET_CORE_REG("ev/cancel", cfun_ev_cancel),
JANET_CORE_REG("ev/close", janet_cfun_stream_close),
JANET_CORE_REG("ev/read", janet_cfun_stream_read),
JANET_CORE_REG("ev/chunk", janet_cfun_stream_chunk),
JANET_CORE_REG("ev/write", janet_cfun_stream_write),
JANET_REG_END
};
janet_core_cfuns_ext(env, NULL, ev_cfuns_ext);
janet_register_abstract_type(&janet_stream_type);
janet_register_abstract_type(&janet_channel_type);
}
#endif
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