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3d692649d1
Introduce a function to gracefully wake a coroutine sleeping in qemu_co_sleep_ns(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20191009084158.15614-2-vsementsov@virtuozzo.com> Signed-off-by: Eric Blake <eblake@redhat.com>
73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
/*
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* QEMU coroutine sleep
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*
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* Copyright IBM, Corp. 2011
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*
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* Authors:
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qemu/osdep.h"
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#include "qemu/coroutine.h"
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#include "qemu/coroutine_int.h"
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#include "qemu/timer.h"
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#include "block/aio.h"
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static const char *qemu_co_sleep_ns__scheduled = "qemu_co_sleep_ns";
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struct QemuCoSleepState {
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Coroutine *co;
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QEMUTimer *ts;
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QemuCoSleepState **user_state_pointer;
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};
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void qemu_co_sleep_wake(QemuCoSleepState *sleep_state)
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{
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/* Write of schedule protected by barrier write in aio_co_schedule */
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const char *scheduled = atomic_cmpxchg(&sleep_state->co->scheduled,
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qemu_co_sleep_ns__scheduled, NULL);
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assert(scheduled == qemu_co_sleep_ns__scheduled);
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if (sleep_state->user_state_pointer) {
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*sleep_state->user_state_pointer = NULL;
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}
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timer_del(sleep_state->ts);
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aio_co_wake(sleep_state->co);
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}
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static void co_sleep_cb(void *opaque)
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{
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qemu_co_sleep_wake(opaque);
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}
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void coroutine_fn qemu_co_sleep_ns_wakeable(QEMUClockType type, int64_t ns,
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QemuCoSleepState **sleep_state)
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{
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AioContext *ctx = qemu_get_current_aio_context();
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QemuCoSleepState state = {
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.co = qemu_coroutine_self(),
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.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &state),
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.user_state_pointer = sleep_state,
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};
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const char *scheduled = atomic_cmpxchg(&state.co->scheduled, NULL,
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qemu_co_sleep_ns__scheduled);
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if (scheduled) {
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fprintf(stderr,
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"%s: Co-routine was already scheduled in '%s'\n",
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__func__, scheduled);
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abort();
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}
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if (sleep_state) {
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*sleep_state = &state;
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}
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timer_mod(state.ts, qemu_clock_get_ns(type) + ns);
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qemu_coroutine_yield();
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timer_free(state.ts);
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}
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