Changed the Unix implementation of sf::Sleep to a more robust one

src/SFML/System/Unix/Platform.cpp

@@ -26,6 +26,7 @@
 // Headers
 ////////////////////////////////////////////////////////////
 #include <SFML/System/Unix/Platform.hpp>
+#include <pthread.h>
 #include <unistd.h>
 #include <sys/time.h>
 
@@ -47,7 +48,35 @@ Uint64 Platform::GetSystemTime()
 ////////////////////////////////////////////////////////////
 void Platform::Sleep(Uint32 time)
 {
-    usleep(time * 1000);
+    // usleep is not reliable enough (it might block the
+    // whole process instead of just the current thread)
+    // so we must use pthread_cond_timedwait instead
+    // this implementation is inspired from Qt
+
+    // first get the current time
+    timeval tv;
+    gettimeofday(&tv, NULL);
+
+    // construct the time limit (current time + time to wait)
+    timespec ti;
+    ti.tv_nsec = (tv.tv_usec + (time % 1000) * 1000) * 1000;
+    ti.tv_sec = tv.tv_sec + (time / 1000) + (ti.tv_nsec / 1000000000);
+    ti.tv_nsec %= 1000000000;
+
+    // create a mutex and thread condition
+    pthread_mutex_t mutex;
+    pthread_mutex_init(&mutex, 0);
+    pthread_cond_t condition;
+    pthread_cond_init(&condition, 0);
+
+    // wait...
+    pthread_mutex_lock(&mutex);
+    pthread_cond_timedwait(&condition, &mutex, &ti);
+    pthread_mutex_unlock(&mutex);
+
+    // destroy the mutex and condition
+    pthread_cond_destroy(&condition);
+    pthread_mutex_destroy(&mutex);
 }
 
 } // namespace priv