Implement a cksem_trywait function

src/libckpool.c

@@ -399,6 +399,15 @@ void _cksem_wait(sem_t *sem, const char *file, const char *func, const int line)
 	}
 }
 
+int _cksem_trywait(sem_t *sem, const char *file, const char *func, const int line)
+{
+	int ret = sem_trywait(sem);
+
+	if (unlikely(ret && errno != EAGAIN && errno != EINTR))
+		quitfrom(1, file, func, line, "Failed to sem_trywait errno=%d sem=0x%p", errno, sem);
+	return ret;
+}
+
 int _cksem_mswait(sem_t *sem, int ms, const char *file, const char *func, const int line)
 {
 	ts_t abs_timeout, ts_now;

src/libckpool.h

@@ -452,12 +452,14 @@ void cklock_destroy(cklock_t *lock);
 void _cksem_init(sem_t *sem, const char *file, const char *func, const int line);
 void _cksem_post(sem_t *sem, const char *file, const char *func, const int line);
 void _cksem_wait(sem_t *sem, const char *file, const char *func, const int line);
+int _cksem_trywait(sem_t *sem, const char *file, const char *func, const int line);
 int _cksem_mswait(sem_t *sem, int ms, const char *file, const char *func, const int line);
 void _cksem_destroy(sem_t *sem, const char *file, const char *func, const int line);
 
 #define cksem_init(SEM) _cksem_init(SEM, __FILE__, __func__, __LINE__)
 #define cksem_post(SEM) _cksem_post(SEM, __FILE__, __func__, __LINE__)
 #define cksem_wait(SEM) _cksem_wait(SEM, __FILE__, __func__, __LINE__)
+#define cksem_trywait(SEM) _cksem_trywait(SEM, __FILE__, __func__, __LINE__)
 #define cksem_mswait(SEM, _timeout) _cksem_mswait(SEM, _timeout, __FILE__, __func__, __LINE__)
 #define cksem_destroy(SEM) _cksem_destroy(SEM, __FILE__, __func__, __LINE__)