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.
23 #include "posix-aio-compat.h"
25 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
26 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
27 static pthread_t thread_id;
28 static int max_threads = 64;
29 static int cur_threads = 0;
30 static int idle_threads = 0;
31 static TAILQ_HEAD(, qemu_paiocb) request_list;
33 static void die2(int err, const char *what)
35 fprintf(stderr, "%s failed: %s\n", what, strerror(err));
39 static void die(const char *what)
44 static void mutex_lock(pthread_mutex_t *mutex)
46 int ret = pthread_mutex_lock(mutex);
47 if (ret) die2(ret, "pthread_mutex_lock");
50 static void mutex_unlock(pthread_mutex_t *mutex)
52 int ret = pthread_mutex_unlock(mutex);
53 if (ret) die2(ret, "pthread_mutex_unlock");
56 static int cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
59 int ret = pthread_cond_timedwait(cond, mutex, ts);
60 if (ret && ret != ETIMEDOUT) die2(ret, "pthread_cond_timedwait");
64 static void cond_broadcast(pthread_cond_t *cond)
66 int ret = pthread_cond_broadcast(cond);
67 if (ret) die2(ret, "pthread_cond_broadcast");
70 static void thread_create(pthread_t *thread, pthread_attr_t *attr,
71 void *(*start_routine)(void*), void *arg)
73 int ret = pthread_create(thread, attr, start_routine, arg);
74 if (ret) die2(ret, "pthread_create");
77 static void *aio_thread(void *unused)
81 /* block all signals */
82 if (sigfillset(&set)) die("sigfillset");
83 if (sigprocmask(SIG_BLOCK, &set, NULL)) die("sigprocmask");
86 struct qemu_paiocb *aiocb;
92 while (TAILQ_EMPTY(&request_list) &&
93 !(ret == ETIMEDOUT)) {
94 struct timespec ts = { 0 };
97 qemu_gettimeofday(&tv);
98 ts.tv_sec = tv.tv_sec + 10;
99 ret = cond_timedwait(&cond, &lock, &ts);
102 if (ret == ETIMEDOUT)
105 aiocb = TAILQ_FIRST(&request_list);
106 TAILQ_REMOVE(&request_list, aiocb, node);
114 while (offset < aiocb->aio_nbytes) {
118 len = pwrite(aiocb->aio_fildes,
119 (const char *)aiocb->aio_buf + offset,
120 aiocb->aio_nbytes - offset,
121 aiocb->aio_offset + offset);
123 len = pread(aiocb->aio_fildes,
124 (char *)aiocb->aio_buf + offset,
125 aiocb->aio_nbytes - offset,
126 aiocb->aio_offset + offset);
128 if (len == -1 && errno == EINTR)
130 else if (len == -1) {
144 if (kill(getpid(), aiocb->ev_signo)) die("kill failed");
154 static void spawn_thread(void)
162 ret = pthread_attr_init(&attr);
163 if (ret) die2 (ret, "pthread_attr_init");
164 ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
165 if (ret) die2 (ret, "pthread_attr_setdetachstate");
166 thread_create(&thread_id, &attr, aio_thread, NULL);
167 ret = pthread_attr_destroy(&attr);
168 if (ret) die2 (ret, "pthread_attr_destroy");
171 int qemu_paio_init(struct qemu_paioinit *aioinit)
173 TAILQ_INIT(&request_list);
178 static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write)
180 aiocb->is_write = is_write;
181 aiocb->ret = -EINPROGRESS;
184 if (idle_threads == 0 && cur_threads < max_threads)
186 TAILQ_INSERT_TAIL(&request_list, aiocb, node);
188 cond_broadcast(&cond);
193 int qemu_paio_read(struct qemu_paiocb *aiocb)
195 return qemu_paio_submit(aiocb, 0);
198 int qemu_paio_write(struct qemu_paiocb *aiocb)
200 return qemu_paio_submit(aiocb, 1);
203 ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
214 int qemu_paio_error(struct qemu_paiocb *aiocb)
216 ssize_t ret = qemu_paio_return(aiocb);
226 int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb)
231 if (!aiocb->active) {
232 TAILQ_REMOVE(&request_list, aiocb, node);
233 aiocb->ret = -ECANCELED;
234 ret = QEMU_PAIO_CANCELED;
235 } else if (aiocb->ret == -EINPROGRESS)
236 ret = QEMU_PAIO_NOTCANCELED;
238 ret = QEMU_PAIO_ALLDONE;