Bugfix: Avoid cancelling threads while locks are held

- Hopefully this fixes a semi-rare deadlock on exit
- All direct-stdout logging now disables async cancel temporarily
- Only mining_thread and RPC API are asynchronously cancellable ever
- Curses getch() is wrapped to always be asynchronously cancellable

cgminer.c

@@ -1398,6 +1398,24 @@ static bool curses_active_locked(void)
 		unlock_curses();
 	return ret;
 }
+
+// Cancellable getch
+int my_cancellable_getch(void)
+{
+	// This only works because the macro only hits direct getch() calls
+	typedef int (*real_getch_t)(void);
+	const real_getch_t real_getch = __real_getch;
+
+	int type, rv;
+	bool sct;
+
+	sct = !pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &type);
+	rv = real_getch();
+	if (sct)
+		pthread_setcanceltype(type, &type);
+
+	return rv;
+}
 #endif
 
 void tailsprintf(char *f, const char *fmt, ...)
@@ -2789,7 +2807,6 @@ static void *stage_thread(void *userdata)
 	bool ok = true;
 
 	rename_thr("bfg-stage");
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
 	while (ok) {
 		struct work *work = NULL;
@@ -3408,7 +3425,6 @@ retry:
 static void *input_thread(void __maybe_unused *userdata)
 {
 	rename_thr("bfg-input");
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
 	if (!curses_active)
 		return NULL;
@@ -3445,7 +3461,6 @@ static void *workio_thread(void *userdata)
 	bool ok = true;
 
 	rename_thr("bfg-workio");
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
 	while (ok) {
 		struct workio_cmd *wc;
@@ -4546,7 +4561,6 @@ static void reap_curl(struct pool *pool)
 static void *watchpool_thread(void __maybe_unused *userdata)
 {
 	rename_thr("bfg-watchpool");
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
 	while (42) {
 		struct timeval now;
@@ -4613,7 +4627,6 @@ static void *watchdog_thread(void __maybe_unused *userdata)
 	struct timeval zero_tv;
 
 	rename_thr("bfg-watchdog");
-	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
 
 	memset(&zero_tv, 0, sizeof(struct timeval));
 	gettimeofday(&rotate_tv, NULL);

logging.c

@@ -31,12 +31,17 @@ static void my_log_curses(__maybe_unused int prio, char *f, va_list ap)
 #endif
 	{
 		int len = strlen(f);
+		int cancelstate;
+		bool scs;
 
 		strcpy(f + len - 1, "                    \n");
 
+		scs = !pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancelstate);
 		mutex_lock(&console_lock);
 		vprintf(f, ap);
 		mutex_unlock(&console_lock);
+		if (scs)
+			pthread_setcancelstate(cancelstate, &cancelstate);
 	}
 }
 

miner.h

@@ -159,6 +159,21 @@ void *alloca (size_t);
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 #endif
 
+#ifdef HAVE_CURSES
+#	ifdef getch
+		// getch() is a macro
+		static int __maybe_unused __real_getch(void) {
+			return getch();
+		}
+#		undef getch
+#		define getch()  my_cancellable_getch()
+#	else
+		// getch() is a real function
+#		define __real_getch  getch
+#		define getch()  my_cancellable_getch()
+#	endif
+#endif
+
 enum alive {
 	LIFE_WELL,
 	LIFE_SICK,