Remove unneeded book keeping for sub processes.

Since we are not using signals we no longer need some bookkeeping.

examples/async-execute.janet

@@ -0,0 +1,22 @@
+(defn dowork [name n]
+  (print name " starting work...")
+  (os/execute ["sleep" (string n)] :p)
+  (print name " finished work!"))
+
+# Will be done in parallel
+(print "starting group A")
+(ev/call dowork "A 2" 2)
+(ev/call dowork "A 1" 1)
+(ev/call dowork "A 3" 3)
+
+(ev/sleep 4)
+
+# Will also be done in parallel
+(print "starting group B")
+(ev/call dowork "B 2" 2)
+(ev/call dowork "B 1" 1)
+(ev/call dowork "B 3" 3)
+
+(ev/sleep 4)
+
+(print "all work done")

src/core/ev.c

@@ -897,7 +897,7 @@ static void janet_ev_handle_selfpipe(void) {
             default:
                 break;
             case JANET_SELFPIPE_PROC:
-                janet_schedule_pid(ev.as.proc.pid, ev.as.proc.status);
+                janet_schedule_proc(ev.as.proc.proc, ev.as.proc.status);
                 break;
         }
     }

src/core/os.c

@@ -345,21 +345,18 @@ typedef struct {
 
 #ifdef JANET_EV
 
-JANET_THREAD_LOCAL JanetProc **janet_vm_waiting_procs = NULL;
-JANET_THREAD_LOCAL size_t janet_vm_proc_count = 0;
-JANET_THREAD_LOCAL size_t janet_vm_proc_cap = 0;
-
 /* Structure used to initialize the thread used to call wait
  * on child processes */
 typedef struct {
-    pid_t pid;
     int write_pipe;
+    JanetProc *proc;
 } JanetReaperInit;
 
 static void *janet_thread_waiter(void *ptr) {
     JanetReaperInit *init = (JanetReaperInit *)ptr;
-    pid_t pid = init->pid;
+    JanetProc *proc = (JanetProc *) init->proc;
     int fd = init->write_pipe;
+    pid_t pid = proc->pid;
     free(init);
     for (;;) {
         int status = 0;
@@ -374,7 +371,7 @@ static void *janet_thread_waiter(void *ptr) {
             JanetSelfPipeEvent ev;
             ev.tag = JANET_SELFPIPE_PROC;
             ev.as.proc.status = status;
-            ev.as.proc.pid = which;
+            ev.as.proc.proc = proc;
             if (write(fd, &ev, sizeof(ev)) < 0) {
                 /* TODO failed to handle signal. */
                 fprintf(stderr, "failed to write event\n");
@@ -387,62 +384,30 @@ static void *janet_thread_waiter(void *ptr) {
 /* Map pids to JanetProc to allow for lookup after a call to
  * waitpid. */
 static void janet_add_waiting_proc(JanetProc *proc) {
-    if (janet_vm_proc_count == janet_vm_proc_cap) {
-        size_t newcap = (janet_vm_proc_count + 1) * 2;
-        if (newcap < 16) newcap = 16;
-        JanetProc **newprocs = realloc(janet_vm_waiting_procs, sizeof(JanetProc *) * newcap);
-        if (NULL == newprocs) {
-            JANET_OUT_OF_MEMORY;
-        }
-        janet_vm_waiting_procs = newprocs;
-        janet_vm_proc_cap = newcap;
-    }
-
-    /* Set proccess group for tracking purposes */
-    pid_t pid = proc->pid;
     JanetReaperInit *init = malloc(sizeof(JanetReaperInit));
     if (NULL == init) {
         JANET_OUT_OF_MEMORY;
     }
-    init->pid = pid;
     init->write_pipe = janet_vm_selfpipe[1];
+    init->proc = proc;
     pthread_attr_t attr;
     pthread_t waiter_thread;
     pthread_attr_init(&attr);
     pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN);
     int err = pthread_create(&waiter_thread, NULL, janet_thread_waiter, init);
     pthread_attr_destroy(&attr);
-    if (err) {
-        janet_panicf("%s", strerror(err));
-    }
+    if (err) janet_panicf("%s", strerror(err));
     pthread_detach(waiter_thread);
-
-    janet_vm_waiting_procs[janet_vm_proc_count++] = proc;
     janet_gcroot(janet_wrap_abstract(proc));
     janet_ev_inc_refcount();
 }
 
 static void janet_remove_waiting_proc(JanetProc *proc) {
-    for (size_t i = 0; i < janet_vm_proc_count; i++) {
-        if (janet_vm_waiting_procs[i] == proc) {
-            janet_vm_waiting_procs[i] = janet_vm_waiting_procs[--janet_vm_proc_count];
-            janet_gcunroot(janet_wrap_abstract(proc));
-            janet_ev_dec_refcount();
-            return;
-        }
-    }
+    janet_gcunroot(janet_wrap_abstract(proc));
+    janet_ev_dec_refcount();
 }
 
-static JanetProc *janet_lookup_proc(pid_t pid) {
-    for (size_t i = 0; i < janet_vm_proc_count; i++) {
-        if (janet_vm_waiting_procs[i]->pid == pid) {
-            return janet_vm_waiting_procs[i];
-        }
-    }
-    return NULL;
-}
-
-void janet_schedule_pid(pid_t pid, int status) {
+void janet_schedule_proc(void *ptr, int status) {
     /* Use POSIX shell semantics for interpreting signals */
     if (WIFEXITED(status)) {
         status = WEXITSTATUS(status);
@@ -451,29 +416,24 @@ void janet_schedule_pid(pid_t pid, int status) {
     } else {
         status = WTERMSIG(status) + 128;
     }
-    JanetProc *proc = janet_lookup_proc(pid);
+    JanetProc *proc = (JanetProc *)ptr;
     if (NULL == proc) return;
     proc->return_code = (int32_t) status;
     proc->flags |= JANET_PROC_WAITED;
     proc->flags &= ~JANET_PROC_WAITING;
+    janet_remove_waiting_proc(proc);
     if ((status != 0) && (proc->flags & JANET_PROC_ERROR_NONZERO)) {
         JanetString s = janet_formatc("command failed with non-zero exit code %d", status);
         janet_cancel(proc->fiber, janet_wrap_string(s));
     } else {
         janet_schedule(proc->fiber, janet_wrap_integer(status));
     }
-    janet_remove_waiting_proc(proc);
 }
 #endif
 
 static int janet_proc_gc(void *p, size_t s) {
     (void) s;
     JanetProc *proc = (JanetProc *) p;
-#ifdef JANET_EV
-    if (proc->flags & JANET_PROC_WAITING) {
-        janet_remove_waiting_proc(proc);
-    }
-#endif
 #ifdef JANET_WINDOWS
     if (!(proc->flags & JANET_PROC_CLOSED)) {
         CloseHandle(proc->pHandle);
@@ -2213,16 +2173,7 @@ static const JanetReg os_cfuns[] = {
     {NULL, NULL, NULL}
 };
 
-void janet_os_deinit(void) {
-#ifndef JANET_NO_PROCESSES
-#ifdef JANET_EV
-    free(janet_vm_waiting_procs);
-    janet_vm_waiting_procs = NULL;
-    janet_vm_proc_count = 0;
-    janet_vm_proc_cap = 0;
-#endif
-#endif
-}
+void janet_os_deinit(void) {}
 
 /* Module entry point */
 void janet_lib_os(JanetTable *env) {
@@ -2235,11 +2186,6 @@ void janet_lib_os(JanetTable *env) {
     }
 #endif
 #ifndef JANET_NO_PROCESSES
-#ifdef JANET_EV
-    janet_vm_waiting_procs = NULL;
-    janet_vm_proc_count = 0;
-    janet_vm_proc_cap = 0;
-#endif
 #endif
     janet_core_cfuns(env, NULL, os_cfuns);
 }

src/core/util.h

@@ -146,7 +146,7 @@ extern const JanetAbstractType janet_address_type;
 void janet_lib_ev(JanetTable *env);
 void janet_ev_mark(void);
 int janet_make_pipe(JanetHandle handles[2]);
-void janet_schedule_pid(pid_t pid, int status);
+void janet_schedule_proc(void *proc, int status);
 
 /* Single message that is written to self pipe. This is used
  * to communicate messages inside Janet to work with the event loop.
@@ -158,7 +158,7 @@ typedef struct {
     union {
         struct {
             int status;
-            pid_t pid;
+            void *proc;
         } proc;
     } as;
 } JanetSelfPipeEvent;