target/mips/rel6_translate: Change license to GNU LGPL v2.1 (or later)
[qemu/ar7.git] / util / qemu-coroutine-sleep.c
blob8c4dac4fd75eeb12df3718b65f612de72dc7089c
1 /*
2 * QEMU coroutine sleep
4 * Copyright IBM, Corp. 2011
6 * Authors:
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
9 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
10 * See the COPYING.LIB file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include "qemu/coroutine.h"
16 #include "qemu/coroutine_int.h"
17 #include "qemu/timer.h"
18 #include "block/aio.h"
20 static const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns";
22 struct QemuCoSleepState {
23 Coroutine *co;
24 QEMUTimer *ts;
25 QemuCoSleepState **user_state_pointer;
28 void qemu_co_sleep_wake(QemuCoSleepState *sleep_state)
30 /* Write of schedule protected by barrier write in aio_co_schedule */
31 const char *scheduled = qatomic_cmpxchg(&sleep_state->co->scheduled,
32 qemu_co_sleep_ns__scheduled, NULL);
34 assert(scheduled == qemu_co_sleep_ns__scheduled);
35 if (sleep_state->user_state_pointer) {
36 *sleep_state->user_state_pointer = NULL;
38 timer_del(sleep_state->ts);
39 aio_co_wake(sleep_state->co);
42 static void co_sleep_cb(void *opaque)
44 qemu_co_sleep_wake(opaque);
47 void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
48 QemuCoSleepState **sleep_state)
50 AioContext *ctx = qemu_get_current_aio_context();
51 QemuCoSleepState state = {
52 .co = qemu_coroutine_self(),
53 .ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &state),
54 .user_state_pointer = sleep_state,
57 const char *scheduled = qatomic_cmpxchg(&state.co->scheduled, NULL,
58 qemu_co_sleep_ns__scheduled);
59 if (scheduled) {
60 fprintf(stderr,
61 "%s: Co-routine was already scheduled in '%s'\n",
62 __func__, scheduled);
63 abort();
66 if (sleep_state) {
67 *sleep_state = &state;
69 timer_mod(state.ts, qemu_clock_get_ns(type) + ns);
70 qemu_coroutine_yield();
71 if (sleep_state) {
73 * Note that *sleep_state is cleared during qemu_co_sleep_wake
74 * before resuming this coroutine.
76 assert(*sleep_state == NULL);
78 timer_free(state.ts);