better thread management

1 files changed, 111 insertions, 0 deletions

diff --git a/lib/fuse_mt.c b/lib/fuse_mt.c
new file mode 100644
index 0000000..ac616fe
--- /dev/null
+++ b/lib/fuse_mt.c
@@ -0,0 +1,111 @@
+/*
+    FUSE: Filesystem in Userspace
+    Copyright (C) 2001  Miklos Szeredi (mszeredi@inf.bme.hu)
+
+    This program can be distributed under the terms of the GNU GPL.
+    See the file COPYING.
+*/
+
+#include "fuse.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/time.h>
+
+
+struct thread_common {
+    struct fuse *f;
+    struct fuse_cmd *cmd;
+    pthread_mutex_t lock;
+    pthread_cond_t cond;
+    int avail;
+};
+
+/* Called with c->lock held */
+static void *do_work(void *data)
+{
+    struct thread_common *c = (struct thread_common *) data;
+    struct fuse *f = c->f;
+
+    c->avail ++;
+    while(1) {
+        int res;
+        struct timespec timeout;
+        struct timeval now;
+        struct fuse_cmd *cmd;
+
+        gettimeofday(&now, NULL);
+        timeout.tv_sec = now.tv_sec + 1;
+        timeout.tv_nsec = now.tv_usec * 1000;
+        
+        res = 0;
+        while(c->cmd == NULL && res != ETIMEDOUT) 
+            res = pthread_cond_timedwait(&c->cond, &c->lock, &timeout);
+        if(res == ETIMEDOUT)
+            break;
+
+        cmd = c->cmd;
+        c->cmd = NULL;
+        c->avail --;
+        pthread_mutex_unlock(&c->lock);
+        __fuse_process_cmd(f, cmd);
+        pthread_mutex_lock(&c->lock);
+        c->avail ++;
+    }
+
+    c->avail --;
+    pthread_mutex_unlock(&c->lock);
+    return NULL;
+}
+
+static void start_thread(struct thread_common *c)
+{
+    pthread_attr_t attr;
+    pthread_t thrid;
+    sigset_t oldset;
+    sigset_t newset;
+    int res;
+    
+    pthread_attr_init(&attr);
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+    
+    /* Disallow signal reception in worker threads */
+    sigfillset(&newset);
+    sigprocmask(SIG_SETMASK, &newset, &oldset);
+    res = pthread_create(&thrid, &attr, do_work, c);
+    sigprocmask(SIG_SETMASK, &oldset, NULL);
+    pthread_mutex_lock(&c->lock);
+    if(res != 0) {
+        fprintf(stderr, "Error creating thread: %s\n", strerror(res));
+        exit(1);
+    }
+}
+
+void fuse_loop_mt(struct fuse *f)
+{
+    struct thread_common *c;
+
+    c = (struct thread_common *) malloc(sizeof(struct thread_common));
+    c->f = f;
+    c->cmd = NULL;
+    pthread_cond_init(&c->cond, NULL);
+    pthread_mutex_init(&c->lock, NULL);
+    c->avail = 0;
+
+    while(1) {
+        struct fuse_cmd *cmd = __fuse_read_cmd(f);
+        if(cmd == NULL)
+            exit(1);
+
+        pthread_mutex_lock(&c->lock);
+        c->cmd = cmd;
+        while(c->avail == 0)
+            start_thread(c);
+        pthread_cond_signal(&c->cond);
+        pthread_mutex_unlock(&c->lock);
+    }
+}