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
  30 typedef struct QemuCoTimeoutState {
  31     CoroutineEntry *entry;
  32     void *opaque;
  33     QemuCoSleep sleep_state;
  34     bool marker;
  35     CleanupFunc *clean;
  36 } QemuCoTimeoutState;
  37
  38 static 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
  57 int 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 }