Add JANET_ASYNC_EVENT_CANCEL

also fix bug that could cause event loop to hang.

src/core/ev.c

@@ -403,7 +403,10 @@ void janet_schedule(JanetFiber *fiber, Janet value) {
 
 void janet_fiber_did_resume(JanetFiber *fiber) {
     /* Cancel any pending fibers */
-    if (fiber->waiting) janet_unlisten(fiber->waiting);
+    if (fiber->waiting) {
+        fiber->waiting->machine(fiber->waiting, JANET_ASYNC_EVENT_CANCEL);
+        janet_unlisten(fiber->waiting);
+    }
 }
 
 /* Mark all pending tasks */
@@ -786,8 +789,10 @@ void janet_loop1(void) {
         while ((has_timeout = peek_timeout(&to)) && to.fiber->sched_id != to.sched_id) {
             pop_timeout(0);
         }
-        /* Run polling implementation */
-        janet_loop1_impl(has_timeout, to.when);
+        /* Run polling implementation only if pending timeouts or pending events */
+        if (janet_vm_tq_count || janet_vm_listener_count) {
+            janet_loop1_impl(has_timeout, to.when);
+        }
     }
 }
 

src/include/janet.h

@@ -517,7 +517,7 @@ typedef enum {
     JANET_ASYNC_EVENT_HUP,
     JANET_ASYNC_EVENT_READ,
     JANET_ASYNC_EVENT_WRITE,
-    JANET_ASYNC_EVENT_TIMEOUT,
+    JANET_ASYNC_EVENT_CANCEL,
     JANET_ASYNC_EVENT_COMPLETE, /* Used on windows for IOCP */
     JANET_ASYNC_EVENT_USER
 } JanetAsyncEvent;

test/suite0009.janet

@@ -65,4 +65,13 @@
   (ev/close writer)
   (ev/take chan))
 
+(var result nil)
+(def fiber
+  (ev/spawn 
+    (set result (protect (ev/sleep 0.4)))
+    (assert (= result '(false "boop")) "ev/cancel 1")))
+(ev/sleep 0.1)
+(ev/cancel fiber "boop")
+(ev/sleep 0.1)
+
 (end-suite)