1'st Init() { ... output[i].event_handle = CreateEvent(0, FALSE /* manual reset */, FALSE /* initial state */, 0); .. } After this ,the event_handle is nonsignaled state.

but in function:

int wait(struct buffer *buffer) { MMRESULT error; DWORD tick;

if (!buffer->playing) return 0;

tick = GetTickCount(); switch (WaitForSingleObject(buffer->event_handle, INFINITE)) { .. }

why the event_handle is signaled state?

I only find this time to setevent: void CALLBACK callback(HWAVEOUT handle, UINT message, DWORD data, DWORD param1, DWORD param2) { WAVEHDR *header; struct buffer *buffer;

switch (message) { case WOM_DONE: header = (WAVEHDR *) param1; buffer = (struct buffer *) header->dwUser; if (SetEvent(buffer->event_handle) == 0) {

... }