unix: update timer if already active

uv_timer_start() no longer returns an error when the timer is already active,
now it just updates the timer. Consistent with the uv-win implementation.

Fixes #425.

src/unix/timer.c

@@ -52,11 +52,12 @@ int uv_timer_init(uv_loop_t* loop, uv_timer_t* timer) {
 }
 
 
-int uv_timer_start(uv_timer_t* timer, uv_timer_cb cb, int64_t timeout,
-    int64_t repeat) {
-  if (uv__is_active(timer)) {
-    return -1;
-  }
+int uv_timer_start(uv_timer_t* timer,
+                   uv_timer_cb cb,
+                   int64_t timeout,
+                   int64_t repeat) {
+  if (uv__is_active(timer))
+    uv_timer_stop(timer);
 
   timer->timer_cb = cb;
 

test/test-list.h

@@ -77,6 +77,7 @@ TEST_DECLARE   (callback_stack)
 TEST_DECLARE   (error_message)
 TEST_DECLARE   (timer)
 TEST_DECLARE   (timer_again)
+TEST_DECLARE   (timer_start_twice)
 TEST_DECLARE   (idle_starvation)
 TEST_DECLARE   (loop_handles)
 TEST_DECLARE   (get_loadavg)
@@ -266,6 +267,7 @@ TASK_LIST_START
 
   TEST_ENTRY  (timer)
   TEST_ENTRY  (timer_again)
+  TEST_ENTRY  (timer_start_twice)
 
   TEST_ENTRY  (idle_starvation)
 

test/test-timer.c

@@ -131,3 +131,22 @@ TEST_IMPL(timer) {
 
   return 0;
 }
+
+
+TEST_IMPL(timer_start_twice) {
+  uv_timer_t once;
+  int r;
+
+  r = uv_timer_init(uv_default_loop(), &once);
+  ASSERT(r == 0);
+  r = uv_timer_start(&once, never_cb, 86400 * 1000, 0);
+  ASSERT(r == 0);
+  r = uv_timer_start(&once, once_cb, 10, 0);
+  ASSERT(r == 0);
+  r = uv_run(uv_default_loop());
+  ASSERT(r == 0);
+
+  ASSERT(once_cb_called == 1);
+
+  return 0;
+}