fixed segfault when starting and stoping the event hook too quickly, it was a data race

event/goEvent.h

@@ -16,6 +16,9 @@
 #include <stdlib.h>
 #include "pub.h"
 #include "../chan/eb_chan.h"
+
+void dispatch_proc(iohook_event * const event);
+
 eb_chan events;
 
 void go_send(char*);
@@ -24,10 +27,15 @@ void go_sleep(void);
 bool sending = false;
 
 void startev(){
+	// puts("start_ev");
     events = eb_chan_create(1024);
     eb_chan_retain(events);
 	sending = true;
-	add_event("q");
+	// add_event("q");	
+	hook_set_logger(&loggerProc);
+	hook_set_dispatch_proc(&dispatch_proc);
+	hook_run();
+	// puts("done_ev");
 }
 
 void pollEv(){
@@ -116,89 +124,6 @@ void dispatch_proc(iohook_event * const event) {
 	// fprintf(stdout, "----%s\n",	 buffer);
 }
 
-int add_event(char *key_event) {
-	cevent = key_event;
-	// Set the logger callback for library output.
-	hook_set_logger(&loggerProc);
-
-	// Set the event callback for IOhook events.
-	hook_set_dispatch_proc(&dispatch_proc);
-	// Start the hook and block.
-	// NOTE If EVENT_HOOK_ENABLED was delivered, the status will always succeed.
-	int status = hook_run();
-
-	switch (status) {
-		case IOHOOK_SUCCESS:
-			// Everything is ok.
-			break;
-
-		// System level errors.
-		case IOHOOK_ERROR_OUT_OF_MEMORY:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to allocate memory. (%#X)", status);
-			break;
-
-
-		// X11 specific errors.
-		case IOHOOK_ERROR_X_OPEN_DISPLAY:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to open X11 display. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_X_RECORD_NOT_FOUND:
-			loggerProc(LOG_LEVEL_ERROR, "Unable to locate XRecord extension. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_X_RECORD_ALLOC_RANGE:
-			loggerProc(LOG_LEVEL_ERROR, "Unable to allocate XRecord range. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_X_RECORD_CREATE_CONTEXT:
-			loggerProc(LOG_LEVEL_ERROR, "Unable to allocate XRecord context. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_X_RECORD_ENABLE_CONTEXT:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to enable XRecord context. (%#X)", status);
-			break;
-
-
-		// Windows specific errors.
-		case IOHOOK_ERROR_SET_WINDOWS_HOOK_EX:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to register low level windows hook. (%#X)", status);
-			break;
-
-
-		// Darwin specific errors.
-		case IOHOOK_ERROR_AXAPI_DISABLED:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to enable access for assistive devices. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_CREATE_EVENT_PORT:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to create apple event port. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_CREATE_RUN_LOOP_SOURCE:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to create apple run loop source. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_GET_RUNLOOP:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to acquire apple run loop. (%#X)", status);
-			break;
-
-		case IOHOOK_ERROR_CREATE_OBSERVER:
-			loggerProc(LOG_LEVEL_ERROR, "Failed to create apple run loop observer. (%#X)", status);
-			break;
-
-		// Default error.
-		case IOHOOK_FAILURE:
-		default:
-			loggerProc(LOG_LEVEL_ERROR, "An unknown hook error occurred. (%#X)", status);
-			break;
-	}
-
-	// return status;
-	// printf("%d\n", status);
-	return cstatus;
-}
-
 int stop_event(){
 	int status = hook_stop();
 	switch (status) {

extern.go

@@ -28,6 +28,7 @@ func go_send(s *C.char) {
 	if err != nil {
 		log.Fatal(err)
 	}
+	// log.Print("sending stuff")
 	//todo: maybe make non-bloking
 	ev <- out
 }

hook.go

@@ -77,6 +77,7 @@ var (
 	keys    = map[int][]uint16{}
 	cbs     = map[int]func(Event){}
 	events  = map[uint8][]int{}
+	grOn    = 0
 )
 
 //from robotgo
@@ -213,11 +214,15 @@ func Process(EvChan <-chan Event) (out chan bool) {
 				pressed[ev.Keycode] = false
 			}
 			for _, v := range events[ev.Kind] {
+				if !asyncon {
+					break
+				}
 				if allPressed(pressed, keys[v]...) {
 					cbs[v](ev)
 				}
 			}
 		}
+		// fmt.Println("exiting after end (process)")
 		out <- true
 	}()
 	return out
@@ -264,16 +269,32 @@ func KeychartoRawcode(kc string) uint16 {
 // Adds global event hook to OS
 // returns event channel
 func Start() chan Event {
-	asyncon = true
+	for grOn != 0 {
+		// fmt.Println("wating for goroutines to end")
+		time.After(50 * time.Millisecond)
+	}
 	ev = make(chan Event, 1024)
-	go C.startev()
+
 	go func() {
+		grOn += 1
+		C.startev()
+		grOn -= 1
+		// fmt.Println("exiting after end (C.startev)")
+	}()
+	// fmt.Println("started ev")
+	asyncon = true
+	go func() {
+		grOn += 1
 		for {
-			C.pollEv()
-			time.Sleep(time.Millisecond * 50)
-			//todo: find smallest time that does not destroy the cpu utilization
 			if !asyncon {
+				// fmt.Println("exiting after end (start)")
+				grOn -= 1
 				return
+			} else {
+				// fmt.Println("polling events")
+				C.pollEv()
+				time.Sleep(time.Millisecond * 50)
+				//todo: find smallest time that does not destroy the cpu utilization
 			}
 		}
 	}()
@@ -282,13 +303,21 @@ func Start() chan Event {
 
 // End removes global event hook
 func End() {
+	asyncon = false
 	C.endPoll()
 	C.stop_event()
 	for len(ev) != 0 {
 		<-ev
 	}
 	close(ev)
-	asyncon = false
+	pressed = make(map[uint16]bool, 256)
+	used = []int{}
+	keys = map[int][]uint16{}
+	cbs = map[int]func(Event){}
+	events = map[uint8][]int{}
+	// for grOn != 0 {
+	// 	time.After(time.Millisecond * 50)
+	// }
 }
 
 // AddEvent add event listener