Provide a helper function that can reset cgsems to zero.

util.c

@@ -2599,6 +2599,25 @@ int _cgsem_mswait(cgsem_t *cgsem, int ms, const char *file, const char *func, co
 	/* We don't reach here */
 	return 0;
 }
+
+/* Reset semaphore count back to zero */
+void cgsem_reset(cgsem_t *cgsem)
+{
+	int ret, fd;
+	fd_set rd;
+	char buf;
+
+	fd = cgsem->pipefd[0];
+	FD_ZERO(&rd);
+	FD_SET(fd, &rd);
+	do {
+		struct timeval timeout = {0, 0};
+
+		ret = select(fd + 1, &rd, NULL, NULL, &timeout);
+		if (ret > 0)
+			ret = read(fd, &buf, 1);
+	} while (ret > 0);
+}
 #else
 void _cgsem_init(cgsem_t *cgsem, const char *file, const char *func, const int line)
 {
@@ -2639,6 +2658,15 @@ int _cgsem_mswait(cgsem_t *cgsem, int ms, const char *file, const char *func, co
 	return 0;
 }
 
+void cgsem_reset(cgsem_t *cgsem)
+{
+	int ret;
+
+	do {
+		ret = sem_trywait(cgsem);
+	} while (!ret);
+}
+
 void cgsem_destroy(cgsem_t *cgsem)
 {
 	sem_destroy(cgsem);

util.h

@@ -138,6 +138,7 @@ void _cgsem_init(cgsem_t *cgsem, const char *file, const char *func, const int l
 void _cgsem_post(cgsem_t *cgsem, const char *file, const char *func, const int line);
 void _cgsem_wait(cgsem_t *cgsem, const char *file, const char *func, const int line);
 int _cgsem_mswait(cgsem_t *cgsem, int ms, const char *file, const char *func, const int line);
+void cgsem_reset(cgsem_t *cgsem);
 void cgsem_destroy(cgsem_t *cgsem);
 bool cg_completion_timeout(void *fn, void *fnarg, int timeout);