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git.proxmox.com Git - qemu.git/blob - qemu-coroutine-lock.c
abaa1f796702736e64e0823ea068b0d69632c7fe
2 * coroutine queues and locks
4 * Copyright (c) 2011 Kevin Wolf <kwolf@redhat.com>
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 #include "qemu-common.h"
26 #include "qemu-coroutine.h"
27 #include "qemu-coroutine-int.h"
28 #include "qemu-queue.h"
31 static QTAILQ_HEAD(, Coroutine
) unlock_bh_queue
=
32 QTAILQ_HEAD_INITIALIZER(unlock_bh_queue
);
38 static void qemu_co_queue_next_bh(void *opaque
)
40 struct unlock_bh
*unlock_bh
= opaque
;
43 trace_qemu_co_queue_next_bh();
44 while ((next
= QTAILQ_FIRST(&unlock_bh_queue
))) {
45 QTAILQ_REMOVE(&unlock_bh_queue
, next
, co_queue_next
);
46 qemu_coroutine_enter(next
, NULL
);
49 qemu_bh_delete(unlock_bh
->bh
);
53 void qemu_co_queue_init(CoQueue
*queue
)
55 QTAILQ_INIT(&queue
->entries
);
58 void coroutine_fn
qemu_co_queue_wait(CoQueue
*queue
)
60 Coroutine
*self
= qemu_coroutine_self();
61 QTAILQ_INSERT_TAIL(&queue
->entries
, self
, co_queue_next
);
62 qemu_coroutine_yield();
63 assert(qemu_in_coroutine());
66 bool qemu_co_queue_next(CoQueue
*queue
)
68 struct unlock_bh
*unlock_bh
;
71 next
= QTAILQ_FIRST(&queue
->entries
);
73 QTAILQ_REMOVE(&queue
->entries
, next
, co_queue_next
);
74 QTAILQ_INSERT_TAIL(&unlock_bh_queue
, next
, co_queue_next
);
75 trace_qemu_co_queue_next(next
);
77 unlock_bh
= qemu_malloc(sizeof(*unlock_bh
));
78 unlock_bh
->bh
= qemu_bh_new(qemu_co_queue_next_bh
, unlock_bh
);
79 qemu_bh_schedule(unlock_bh
->bh
);
82 return (next
!= NULL
);
85 bool qemu_co_queue_empty(CoQueue
*queue
)
87 return (QTAILQ_FIRST(&queue
->entries
) == NULL
);
90 void qemu_co_mutex_init(CoMutex
*mutex
)
92 memset(mutex
, 0, sizeof(*mutex
));
93 qemu_co_queue_init(&mutex
->queue
);
96 void coroutine_fn
qemu_co_mutex_lock(CoMutex
*mutex
)
98 Coroutine
*self
= qemu_coroutine_self();
100 trace_qemu_co_mutex_lock_entry(mutex
, self
);
102 while (mutex
->locked
) {
103 qemu_co_queue_wait(&mutex
->queue
);
106 mutex
->locked
= true;
108 trace_qemu_co_mutex_lock_return(mutex
, self
);
111 void coroutine_fn
qemu_co_mutex_unlock(CoMutex
*mutex
)
113 Coroutine
*self
= qemu_coroutine_self();
115 trace_qemu_co_mutex_unlock_entry(mutex
, self
);
117 assert(mutex
->locked
== true);
118 assert(qemu_in_coroutine());
120 mutex
->locked
= false;
121 qemu_co_queue_next(&mutex
->queue
);
123 trace_qemu_co_mutex_unlock_return(mutex
, self
);