blob: 43e188fb34a8444ac14d5fe7a15c7f99ec637a58 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
#if !defined(THREADED_RTS) /* to the end */
/*
* Wait/check for external events. Periodically, the
* Scheduler checks for the completion of external operations,
* like the expiration of timers, completion of I/O requests
* issued by Haskell threads.
*
* If the Scheduler is otherwise out of work, it'll block
* herein waiting for external events to occur.
*
* This file mirrors the select()-based functionality
* for POSIX / Unix platforms in rts/Select.c, but for
* Win32.
*
*/
#include "Rts.h"
#include "Schedule.h"
#include "AwaitEvent.h"
#include <windows.h>
#include "win32/AsyncIO.h"
// Used to avoid calling abandonRequestWait() if we don't need to.
// Protected by sched_mutex.
static nat workerWaitingForRequests = 0;
void
awaitEvent(rtsBool wait)
{
int ret;
do {
/* Try to de-queue completed IO requests
*/
workerWaitingForRequests = 1;
ret = awaitRequests(wait);
workerWaitingForRequests = 0;
if (!ret) {
return; /* still hold the lock */
}
// Return to the scheduler if:
//
// - we were interrupted
// - new threads have arrived
} while (wait
&& sched_state == SCHED_RUNNING
&& emptyRunQueue(&MainCapability)
);
}
#endif
|