+// ===========================================================================
+// wxSemaphore implementation
+// ===========================================================================
+
+// ---------------------------------------------------------------------------
+// wxSemaphoreInternal
+// ---------------------------------------------------------------------------
+
+// we implement the semaphores using mutexes and conditions instead of using
+// the sem_xxx() POSIX functions because they're not widely available and also
+// because it's impossible to implement WaitTimeout() using them
+class wxSemaphoreInternal