2 * QEMU posix-aio emulation
4 * Copyright IBM, Corp. 2008
7 * Anthony Liguori <aliguori@us.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
20 #include "posix-aio-compat.h"
22 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
23 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
24 static pthread_t thread_id;
25 static int max_threads = 64;
26 static int cur_threads = 0;
27 static int idle_threads = 0;
28 static TAILQ_HEAD(, qemu_paiocb) request_list;
30 static void *aio_thread(void *unused)
34 /* block all signals */
36 sigprocmask(SIG_BLOCK, &set, NULL);
39 struct qemu_paiocb *aiocb;
43 pthread_mutex_lock(&lock);
45 while (TAILQ_EMPTY(&request_list) &&
46 !(ret == ETIMEDOUT)) {
47 struct timespec ts = { 0 };
50 qemu_gettimeofday(&tv);
51 ts.tv_sec = tv.tv_sec + 10;
52 ret = pthread_cond_timedwait(&cond, &lock, &ts);
58 aiocb = TAILQ_FIRST(&request_list);
59 TAILQ_REMOVE(&request_list, aiocb, node);
65 pthread_mutex_unlock(&lock);
67 while (offset < aiocb->aio_nbytes) {
71 len = pwrite(aiocb->aio_fildes,
72 (const char *)aiocb->aio_buf + offset,
73 aiocb->aio_nbytes - offset,
74 aiocb->aio_offset + offset);
76 len = pread(aiocb->aio_fildes,
77 (char *)aiocb->aio_buf + offset,
78 aiocb->aio_nbytes - offset,
79 aiocb->aio_offset + offset);
81 if (len == -1 && errno == EINTR)
92 pthread_mutex_lock(&lock);
95 pthread_mutex_unlock(&lock);
98 aiocb->aio_sigevent.sigev_signo,
99 aiocb->aio_sigevent.sigev_value);
104 pthread_mutex_unlock(&lock);
109 static int spawn_thread(void)
117 pthread_attr_init(&attr);
118 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
119 ret = pthread_create(&thread_id, &attr, aio_thread, NULL);
120 pthread_attr_destroy(&attr);
125 int qemu_paio_init(struct qemu_paioinit *aioinit)
127 TAILQ_INIT(&request_list);
132 static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write)
134 aiocb->is_write = is_write;
135 aiocb->ret = -EINPROGRESS;
137 pthread_mutex_lock(&lock);
138 if (idle_threads == 0 && cur_threads < max_threads)
140 TAILQ_INSERT_TAIL(&request_list, aiocb, node);
141 pthread_mutex_unlock(&lock);
142 pthread_cond_broadcast(&cond);
147 int qemu_paio_read(struct qemu_paiocb *aiocb)
149 return qemu_paio_submit(aiocb, 0);
152 int qemu_paio_write(struct qemu_paiocb *aiocb)
154 return qemu_paio_submit(aiocb, 1);
157 ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
161 pthread_mutex_lock(&lock);
163 pthread_mutex_unlock(&lock);
168 int qemu_paio_error(struct qemu_paiocb *aiocb)
170 ssize_t ret = qemu_paio_return(aiocb);
180 int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb)
184 pthread_mutex_lock(&lock);
185 if (!aiocb->active) {
186 TAILQ_REMOVE(&request_list, aiocb, node);
187 aiocb->ret = -ECANCELED;
188 ret = QEMU_PAIO_CANCELED;
189 } else if (aiocb->ret == -EINPROGRESS)
190 ret = QEMU_PAIO_NOTCANCELED;
192 ret = QEMU_PAIO_ALLDONE;
193 pthread_mutex_unlock(&lock);