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authorbigbiff bigbiff <bigbiff@teamw.in>2013-01-09 15:09:08 +0100
committerbigbiff bigbiff <bigbiff@teamw.in>2013-01-09 15:09:08 +0100
commit9c754053b07a724bdd98d039f34899d6a49115b7 (patch)
tree464885db361a12d83d60cf152142c765562bb92d /fuse/fuse_loop_mt.c
parentAdd Samsung TouchWiz decryption (diff)
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Diffstat (limited to 'fuse/fuse_loop_mt.c')
-rw-r--r--fuse/fuse_loop_mt.c246
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