waitUntil
Waits until either @cond is signalled or @end_time has passed.
As with g_cond_wait() it is possible that a spurious or stolen wakeup could occur. For that reason, waiting on a condition variable should always be in a loop, based on an explicitly-checked predicate.
true is returned if the condition variable was signalled (or in the case of a spurious wakeup). false is returned if @end_time has passed.
The following code shows how to correctly perform a timed wait on a condition variable (extending the example presented in the documentation for #GCond):
|[ gpointer pop_data_timed (void) { gint64 end_time; gpointer data;
g_mutex_lock (&data_mutex);
end_time = g_get_monotonic_time () + 5 * G_TIME_SPAN_SECOND; while (!current_data) if (!g_cond_wait_until (&data_cond, &data_mutex, end_time)) { // timeout has passed. g_mutex_unlock (&data_mutex); return NULL; }
// there is data for us data = current_data; current_data = NULL;
g_mutex_unlock (&data_mutex);
return data; } ]|
Notice that the end time is calculated once, before entering the loop and reused. This is the motivation behind the use of absolute time on this API -- if a relative time of 5 seconds were passed directly to the call and a spurious wakeup occurred, the program would have to start over waiting again (which would lead to a total wait time of more than 5 seconds).
Return
true on a signal, false on a timeout
Since
2.32
Parameters
a #GMutex that is currently locked
the monotonic time to wait until