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 qemu_gettimeofday(&tv);
93 ts.tv_sec = tv.tv_sec + 10;
98 while (TAILQ_EMPTY(&request_list) &&
99 !(ret == ETIMEDOUT)) {
100 ret = cond_timedwait(&cond, &lock, &ts);
103 if (ret == ETIMEDOUT)
106 aiocb = TAILQ_FIRST(&request_list);
107 TAILQ_REMOVE(&request_list, aiocb, node);
115 while (offset < aiocb->aio_nbytes) {
119 len = pwrite(aiocb->aio_fildes,
120 (const char *)aiocb->aio_buf + offset,
121 aiocb->aio_nbytes - offset,
122 aiocb->aio_offset + offset);
124 len = pread(aiocb->aio_fildes,
125 (char *)aiocb->aio_buf + offset,
126 aiocb->aio_nbytes - offset,
127 aiocb->aio_offset + offset);
129 if (len == -1 && errno == EINTR)
131 else if (len == -1) {
145 if (kill(getpid(), aiocb->ev_signo)) die("kill failed");
155 static void spawn_thread(void)
163 ret = pthread_attr_init(&attr);
164 if (ret) die2 (ret, "pthread_attr_init");
165 ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
166 if (ret) die2 (ret, "pthread_attr_setdetachstate");
167 thread_create(&thread_id, &attr, aio_thread, NULL);
168 ret = pthread_attr_destroy(&attr);
169 if (ret) die2 (ret, "pthread_attr_destroy");
172 int qemu_paio_init(struct qemu_paioinit *aioinit)
174 TAILQ_INIT(&request_list);
179 static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write)
181 aiocb->is_write = is_write;
182 aiocb->ret = -EINPROGRESS;
185 if (idle_threads == 0 && cur_threads < max_threads)
187 TAILQ_INSERT_TAIL(&request_list, aiocb, node);
189 cond_broadcast(&cond);
194 int qemu_paio_read(struct qemu_paiocb *aiocb)
196 return qemu_paio_submit(aiocb, 0);
199 int qemu_paio_write(struct qemu_paiocb *aiocb)
201 return qemu_paio_submit(aiocb, 1);
204 ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
215 int qemu_paio_error(struct qemu_paiocb *aiocb)
217 ssize_t ret = qemu_paio_return(aiocb);
227 int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb)
232 if (!aiocb->active) {
233 TAILQ_REMOVE(&request_list, aiocb, node);
234 aiocb->ret = -ECANCELED;
235 ret = QEMU_PAIO_CANCELED;
236 } else if (aiocb->ret == -EINPROGRESS)
237 ret = QEMU_PAIO_NOTCANCELED;
239 ret = QEMU_PAIO_ALLDONE;