Remove the advertising clause from the slirp license
[qemu.git] / posix-aio-compat.c
blobf141cd9e1a3b215b1fa975bf335049b31f336295
1 /*
2 * QEMU posix-aio emulation
4 * Copyright IBM, Corp. 2008
6 * Authors:
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.
14 #include <pthread.h>
15 #include <unistd.h>
16 #include <errno.h>
17 #include <sys/time.h>
18 #include "osdep.h"
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)
32 sigset_t set;
34 /* block all signals */
35 sigfillset(&set);
36 sigprocmask(SIG_BLOCK, &set, NULL);
38 while (1) {
39 struct qemu_paiocb *aiocb;
40 size_t offset;
41 int ret = 0;
43 pthread_mutex_lock(&lock);
45 while (TAILQ_EMPTY(&request_list) &&
46 !(ret == ETIMEDOUT)) {
47 struct timespec ts = { 0 };
48 qemu_timeval tv;
50 qemu_gettimeofday(&tv);
51 ts.tv_sec = tv.tv_sec + 10;
52 ret = pthread_cond_timedwait(&cond, &lock, &ts);
55 if (ret == ETIMEDOUT)
56 break;
58 aiocb = TAILQ_FIRST(&request_list);
59 TAILQ_REMOVE(&request_list, aiocb, node);
61 offset = 0;
62 aiocb->active = 1;
64 idle_threads--;
65 pthread_mutex_unlock(&lock);
67 while (offset < aiocb->aio_nbytes) {
68 ssize_t len;
70 if (aiocb->is_write)
71 len = pwrite(aiocb->aio_fildes,
72 (const char *)aiocb->aio_buf + offset,
73 aiocb->aio_nbytes - offset,
74 aiocb->aio_offset + offset);
75 else
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)
82 continue;
83 else if (len == -1) {
84 offset = -errno;
85 break;
86 } else if (len == 0)
87 break;
89 offset += len;
92 pthread_mutex_lock(&lock);
93 aiocb->ret = offset;
94 idle_threads++;
95 pthread_mutex_unlock(&lock);
97 kill(getpid(), aiocb->ev_signo);
100 idle_threads--;
101 cur_threads--;
102 pthread_mutex_unlock(&lock);
104 return NULL;
107 static int spawn_thread(void)
109 pthread_attr_t attr;
110 int ret;
112 cur_threads++;
113 idle_threads++;
115 pthread_attr_init(&attr);
116 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
117 ret = pthread_create(&thread_id, &attr, aio_thread, NULL);
118 pthread_attr_destroy(&attr);
120 return ret;
123 int qemu_paio_init(struct qemu_paioinit *aioinit)
125 TAILQ_INIT(&request_list);
127 return 0;
130 static int qemu_paio_submit(struct qemu_paiocb *aiocb, int is_write)
132 aiocb->is_write = is_write;
133 aiocb->ret = -EINPROGRESS;
134 aiocb->active = 0;
135 pthread_mutex_lock(&lock);
136 if (idle_threads == 0 && cur_threads < max_threads)
137 spawn_thread();
138 TAILQ_INSERT_TAIL(&request_list, aiocb, node);
139 pthread_mutex_unlock(&lock);
140 pthread_cond_broadcast(&cond);
142 return 0;
145 int qemu_paio_read(struct qemu_paiocb *aiocb)
147 return qemu_paio_submit(aiocb, 0);
150 int qemu_paio_write(struct qemu_paiocb *aiocb)
152 return qemu_paio_submit(aiocb, 1);
155 ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
157 ssize_t ret;
159 pthread_mutex_lock(&lock);
160 ret = aiocb->ret;
161 pthread_mutex_unlock(&lock);
163 return ret;
166 int qemu_paio_error(struct qemu_paiocb *aiocb)
168 ssize_t ret = qemu_paio_return(aiocb);
170 if (ret < 0)
171 ret = -ret;
172 else
173 ret = 0;
175 return ret;
178 int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb)
180 int ret;
182 pthread_mutex_lock(&lock);
183 if (!aiocb->active) {
184 TAILQ_REMOVE(&request_list, aiocb, node);
185 aiocb->ret = -ECANCELED;
186 ret = QEMU_PAIO_CANCELED;
187 } else if (aiocb->ret == -EINPROGRESS)
188 ret = QEMU_PAIO_NOTCANCELED;
189 else
190 ret = QEMU_PAIO_ALLDONE;
191 pthread_mutex_unlock(&lock);
193 return ret;