LXR qemu/util/qemu-co-timeout.c

   1/*
   2 * Helper functionality for distributing a fixed total amount of
   3 * an abstract resource among multiple coroutines.
   4 *
   5 * Copyright (c) 2022 Virtuozzo International GmbH
   6 *
   7 * Permission is hereby granted, free of charge, to any person obtaining a copy
   8 * of this software and associated documentation files (the "Software"), to deal
   9 * in the Software without restriction, including without limitation the rights
  10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 * copies of the Software, and to permit persons to whom the Software is
  12 * furnished to do so, subject to the following conditions:
  13 *
  14 * The above copyright notice and this permission notice shall be included in
  15 * all copies or substantial portions of the Software.
  16 *
  17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23 * THE SOFTWARE.
  24 */
  25
  26#include "qemu/osdep.h"
  27#include "qemu/coroutine.h"
  28#include "block/aio.h"
  29
  30typedef struct QemuCoTimeoutState {
  31    CoroutineEntry *entry;
  32    void *opaque;
  33    QemuCoSleep sleep_state;
  34    bool marker;
  35    CleanupFunc *clean;
  36} QemuCoTimeoutState;
  37
  38static void coroutine_fn qemu_co_timeout_entry(void *opaque)
  39{
  40    QemuCoTimeoutState *s = opaque;
  41
  42    s->entry(s->opaque);
  43
  44    if (s->marker) {
  45        assert(!s->sleep_state.to_wake);
  46        /* .marker set by qemu_co_timeout, it have been failed */
  47        if (s->clean) {
  48            s->clean(s->opaque);
  49        }
  50        g_free(s);
  51    } else {
  52        s->marker = true;
  53        qemu_co_sleep_wake(&s->sleep_state);
  54    }
  55}
  56
  57int coroutine_fn qemu_co_timeout(CoroutineEntry *entry, void *opaque,
  58                                 uint64_t timeout_ns, CleanupFunc clean)
  59{
  60    QemuCoTimeoutState *s;
  61    Coroutine *co;
  62
  63    if (timeout_ns == 0) {
  64        entry(opaque);
  65        return 0;
  66    }
  67
  68    s = g_new(QemuCoTimeoutState, 1);
  69    *s = (QemuCoTimeoutState) {
  70        .entry = entry,
  71        .opaque = opaque,
  72        .clean = clean
  73    };
  74
  75    co = qemu_coroutine_create(qemu_co_timeout_entry, s);
  76
  77    aio_co_enter(qemu_get_current_aio_context(), co);
  78    qemu_co_sleep_ns_wakeable(&s->sleep_state, QEMU_CLOCK_REALTIME, timeout_ns);
  79
  80    if (s->marker) {
  81        /* .marker set by qemu_co_timeout_entry, success */
  82        g_free(s);
  83        return 0;
  84    }
  85
  86    /* Don't free s, as we can't cancel qemu_co_timeout_entry execution */
  87    s->marker = true;
  88    return -ETIMEDOUT;
  89}
  90