xref: /openbmc/qemu/util/qemu-co-timeout.c (revision d0bf492f)
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 }
90