2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU LGPLv2.
6 See the file COPYING.LIB.
9 #include "fuse_lowlevel.h"
10 #include "fuse_misc.h"
11 #include "fuse_kernel.h"
19 #include <semaphore.h>
23 /* Environment var controlling the thread stack size */
24 #define ENVNAME_THREAD_STACK "FUSE_THREAD_STACK"
27 struct fuse_worker *prev;
28 struct fuse_worker *next;
39 struct fuse_session *se;
40 struct fuse_chan *prevch;
41 struct fuse_worker main;
47 static void list_add_worker(struct fuse_worker *w, struct fuse_worker *next)
49 struct fuse_worker *prev = next->prev;
56 static void list_del_worker(struct fuse_worker *w)
58 struct fuse_worker *prev = w->prev;
59 struct fuse_worker *next = w->next;
64 static int fuse_loop_start_thread(struct fuse_mt *mt);
66 static void *fuse_do_work(void *data)
68 struct fuse_worker *w = (struct fuse_worker *) data;
69 struct fuse_mt *mt = w->mt;
71 while (!fuse_session_exited(mt->se)) {
73 struct fuse_chan *ch = mt->prevch;
74 struct fuse_buf fbuf = {
80 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
81 res = fuse_session_receive_buf(mt->se, &fbuf, &ch);
82 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
87 fuse_session_exit(mt->se);
93 pthread_mutex_lock(&mt->lock);
95 pthread_mutex_unlock(&mt->lock);
100 * This disgusting hack is needed so that zillions of threads
101 * are not created on a burst of FORGET messages
103 if (!(fbuf.flags & FUSE_BUF_IS_FD)) {
104 struct fuse_in_header *in = fbuf.mem;
106 if (in->opcode == FUSE_FORGET ||
107 in->opcode == FUSE_BATCH_FORGET)
113 if (mt->numavail == 0)
114 fuse_loop_start_thread(mt);
115 pthread_mutex_unlock(&mt->lock);
117 fuse_session_process_buf(mt->se, &fbuf, ch);
119 pthread_mutex_lock(&mt->lock);
122 if (mt->numavail > 10) {
124 pthread_mutex_unlock(&mt->lock);
130 pthread_mutex_unlock(&mt->lock);
132 pthread_detach(w->thread_id);
137 pthread_mutex_unlock(&mt->lock);
140 sem_post(&mt->finish);
145 int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg)
153 /* Override default stack size */
154 pthread_attr_init(&attr);
155 stack_size = getenv(ENVNAME_THREAD_STACK);
156 if (stack_size && pthread_attr_setstacksize(&attr, atoi(stack_size)))
157 fprintf(stderr, "fuse: invalid stack size: %s\n", stack_size);
159 /* Disallow signal reception in worker threads */
160 sigemptyset(&newset);
161 sigaddset(&newset, SIGTERM);
162 sigaddset(&newset, SIGINT);
163 sigaddset(&newset, SIGHUP);
164 sigaddset(&newset, SIGQUIT);
165 pthread_sigmask(SIG_BLOCK, &newset, &oldset);
166 res = pthread_create(thread_id, &attr, func, arg);
167 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
168 pthread_attr_destroy(&attr);
170 fprintf(stderr, "fuse: error creating thread: %s\n",
178 static int fuse_loop_start_thread(struct fuse_mt *mt)
181 struct fuse_worker *w = malloc(sizeof(struct fuse_worker));
183 fprintf(stderr, "fuse: failed to allocate worker structure\n");
186 memset(w, 0, sizeof(struct fuse_worker));
187 w->bufsize = fuse_chan_bufsize(mt->prevch);
188 w->buf = malloc(w->bufsize);
191 fprintf(stderr, "fuse: failed to allocate read buffer\n");
196 res = fuse_start_thread(&w->thread_id, fuse_do_work, w);
202 list_add_worker(w, &mt->main);
209 static void fuse_join_worker(struct fuse_mt *mt, struct fuse_worker *w)
211 pthread_join(w->thread_id, NULL);
212 pthread_mutex_lock(&mt->lock);
214 pthread_mutex_unlock(&mt->lock);
219 int fuse_session_loop_mt(struct fuse_session *se)
223 struct fuse_worker *w;
225 memset(&mt, 0, sizeof(struct fuse_mt));
227 mt.prevch = fuse_session_next_chan(se, NULL);
231 mt.main.thread_id = pthread_self();
232 mt.main.prev = mt.main.next = &mt.main;
233 sem_init(&mt.finish, 0, 0);
234 fuse_mutex_init(&mt.lock);
236 pthread_mutex_lock(&mt.lock);
237 err = fuse_loop_start_thread(&mt);
238 pthread_mutex_unlock(&mt.lock);
240 /* sem_wait() is interruptible */
241 while (!fuse_session_exited(se))
242 sem_wait(&mt.finish);
244 for (w = mt.main.next; w != &mt.main; w = w->next)
245 pthread_cancel(w->thread_id);
248 while (mt.main.next != &mt.main)
249 fuse_join_worker(&mt, mt.main.next);
254 pthread_mutex_destroy(&mt.lock);
255 sem_destroy(&mt.finish);
256 fuse_session_reset(se);