diff options
Diffstat (limited to 'fuse/fuse_loop_mt.c')
| -rw-r--r-- | fuse/fuse_loop_mt.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/fuse/fuse_loop_mt.c b/fuse/fuse_loop_mt.c new file mode 100644 index 000000000..a73c399b7 --- /dev/null +++ b/fuse/fuse_loop_mt.c @@ -0,0 +1,246 @@ +/* + FUSE: Filesystem in Userspace + Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu> + + This program can be distributed under the terms of the GNU LGPLv2. + See the file COPYING.LIB. +*/ + +#include "fuse_lowlevel.h" +#include "fuse_misc.h" +#include "fuse_kernel.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <signal.h> +#include <semaphore.h> +#include <errno.h> +#include <sys/time.h> + +#ifdef __MULTI_THREAD + +/* Environment var controlling the thread stack size */ +#define ENVNAME_THREAD_STACK "FUSE_THREAD_STACK" + +struct fuse_worker { + struct fuse_worker *prev; + struct fuse_worker *next; + pthread_t thread_id; + size_t bufsize; + char *buf; + struct fuse_mt *mt; +}; + +struct fuse_mt { + pthread_mutex_t lock; + int numworker; + int numavail; + struct fuse_session *se; + struct fuse_chan *prevch; + struct fuse_worker main; + sem_t finish; + int exit; + int error; +}; + +static void list_add_worker(struct fuse_worker *w, struct fuse_worker *next) +{ + struct fuse_worker *prev = next->prev; + w->next = next; + w->prev = prev; + prev->next = w; + next->prev = w; +} + +static void list_del_worker(struct fuse_worker *w) +{ + struct fuse_worker *prev = w->prev; + struct fuse_worker *next = w->next; + prev->next = next; + next->prev = prev; +} + +#define PTHREAD_CANCEL_ENABLE 0 +#define PTHREAD_CANCEL_DISABLE 1 + +static int fuse_start_thread(struct fuse_mt *mt); + +static void *fuse_do_work(void *data) +{ + struct fuse_worker *w = (struct fuse_worker *) data; + struct fuse_mt *mt = w->mt; + + while (!fuse_session_exited(mt->se)) { + int isforget = 0; + struct fuse_chan *ch = mt->prevch; + int res; + + pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); + res = fuse_chan_recv(&ch, w->buf, w->bufsize); + pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL); + if (res == -EINTR) + continue; + if (res <= 0) { + if (res < 0) { + fuse_session_exit(mt->se); + mt->error = -1; + } + break; + } + + pthread_mutex_lock(&mt->lock); + if (mt->exit) { + pthread_mutex_unlock(&mt->lock); + return NULL; + } + + /* + * This disgusting hack is needed so that zillions of threads + * are not created on a burst of FORGET messages + */ + if (((struct fuse_in_header *) w->buf)->opcode == FUSE_FORGET) + isforget = 1; + + if (!isforget) + mt->numavail--; + if (mt->numavail == 0) + fuse_start_thread(mt); + pthread_mutex_unlock(&mt->lock); + + fuse_session_process(mt->se, w->buf, res, ch); + + pthread_mutex_lock(&mt->lock); + if (!isforget) + mt->numavail++; + if (mt->numavail > 10) { + if (mt->exit) { + pthread_mutex_unlock(&mt->lock); + return NULL; + } + list_del_worker(w); + mt->numavail--; + mt->numworker--; + pthread_mutex_unlock(&mt->lock); + + pthread_detach(w->thread_id); + free(w->buf); + free(w); + return NULL; + } + pthread_mutex_unlock(&mt->lock); + } + + sem_post(&mt->finish); + pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL); + pause(); + + return NULL; +} + +static int fuse_start_thread(struct fuse_mt *mt) +{ + sigset_t oldset; + sigset_t newset; + int res; + pthread_attr_t attr; + char *stack_size; + struct fuse_worker *w = malloc(sizeof(struct fuse_worker)); + if (!w) { + fprintf(stderr, "fuse: failed to allocate worker structure\n"); + return -1; + } + memset(w, 0, sizeof(struct fuse_worker)); + w->bufsize = fuse_chan_bufsize(mt->prevch); + w->buf = malloc(w->bufsize); + w->mt = mt; + if (!w->buf) { + fprintf(stderr, "fuse: failed to allocate read buffer\n"); + free(w); + return -1; + } + + /* Override default stack size */ + pthread_attr_init(&attr); + stack_size = getenv(ENVNAME_THREAD_STACK); + if (stack_size && pthread_attr_setstacksize(&attr, atoi(stack_size))) + fprintf(stderr, "fuse: invalid stack size: %s\n", stack_size); + + /* Disallow signal reception in worker threads */ + sigemptyset(&newset); + sigaddset(&newset, SIGTERM); + sigaddset(&newset, SIGINT); + sigaddset(&newset, SIGHUP); + sigaddset(&newset, SIGQUIT); + pthread_sigmask(SIG_BLOCK, &newset, &oldset); + res = pthread_create(&w->thread_id, &attr, fuse_do_work, w); + pthread_sigmask(SIG_SETMASK, &oldset, NULL); + pthread_attr_destroy(&attr); + if (res != 0) { + fprintf(stderr, "fuse: error creating thread: %s\n", + strerror(res)); + free(w->buf); + free(w); + return -1; + } + list_add_worker(w, &mt->main); + mt->numavail ++; + mt->numworker ++; + + return 0; +} + +static void fuse_join_worker(struct fuse_mt *mt, struct fuse_worker *w) +{ + pthread_join(w->thread_id, NULL); + pthread_mutex_lock(&mt->lock); + list_del_worker(w); + pthread_mutex_unlock(&mt->lock); + free(w->buf); + free(w); +} + +int fuse_session_loop_mt(struct fuse_session *se) +{ + int err; + struct fuse_mt mt; + struct fuse_worker *w; + + memset(&mt, 0, sizeof(struct fuse_mt)); + mt.se = se; + mt.prevch = fuse_session_next_chan(se, NULL); + mt.error = 0; + mt.numworker = 0; + mt.numavail = 0; + mt.main.thread_id = pthread_self(); + mt.main.prev = mt.main.next = &mt.main; + sem_init(&mt.finish, 0, 0); + fuse_mutex_init(&mt.lock); + + pthread_mutex_lock(&mt.lock); + err = fuse_start_thread(&mt); + pthread_mutex_unlock(&mt.lock); + if (!err) { + /* sem_wait() is interruptible */ + while (!fuse_session_exited(se)) + sem_wait(&mt.finish); + + for (w = mt.main.next; w != &mt.main; w = w->next) + pthread_cancel(w->thread_id); + mt.exit = 1; + pthread_mutex_unlock(&mt.lock); + + while (mt.main.next != &mt.main) + fuse_join_worker(&mt, mt.main.next); + + err = mt.error; + } + + pthread_mutex_destroy(&mt.lock); + sem_destroy(&mt.finish); + fuse_session_reset(se); + return err; +} + +#endif |