]> git.itanic.dy.fi Git - rrdd/blobdiff - process.c
onewire_parser.c: Fix compiler warnings about string lengths
[rrdd] / process.c
index 98033f0a5f4bc5a0650c4f7e94cc54a9fa2ef310..f7477b532697fa257c79e22927629a7974c717c7 100644 (file)
--- a/process.c
+++ b/process.c
@@ -53,6 +53,8 @@ struct mutex work_stats_mutex = {
 static int workers_active;
 static int worker_count;
 
+static int job_notify_fd[2];
+
 static int run_work_on_queue(struct work_queue *queue)
 {
        struct work_struct *work;
@@ -83,8 +85,7 @@ static int run_work_on_queue(struct work_queue *queue)
 
 static void *worker_thread(void *arg)
 {
-       int stop_working = 0;
-       int work_done = 0;
+       int ret;
        char name[16];
 
        mutex_lock(&work_stats_mutex);
@@ -97,38 +98,55 @@ static void *worker_thread(void *arg)
 
        pr_info("Worker started\n");
 
-       while (!stop_working) {
-               while (1) {
-                       int prio;
-
-                       /*
-                        * Execute as much work from the high priority
-                        * queue as possible. Once there are no more
-                        * high prio work left, break out the loop and
-                        * see if we still need this many workers.
-                        */
-                       for (prio = 0; prio < WORK_PRIORITIES_NUM; prio++) {
-                               work_done =
-                                       run_work_on_queue(&work_queues[prio]);
-                               if (work_done)
-                                       break;
-                       }
+       /* Execute all high priority work from the queue */
+       while (run_work_on_queue(&work_queues[WORK_PRIORITY_HIGH]))
+               ;
+       /*
+        * All high priority work is now done, see if we have enough
+        * workers executing low priority worl. Continue from there if
+        * needed.
+        */
+       mutex_lock(&work_stats_mutex);
+       if (workers_active > max_jobs)
+               goto out_unlock;
 
-                       if (!work_done || prio != WORK_PRIORITY_HIGH)
-                               break;
-               }
+       mutex_unlock(&work_stats_mutex);
 
-               mutex_lock(&work_stats_mutex);
-               if (workers_active > max_jobs || !work_done) {
-                       workers_active--;
-                       pr_info("Worker exiting, %d left active\n",
-                               workers_active);
-                       if (!workers_active)
-                               worker_count = 0;
-                       stop_working = 1;
-               }
-               mutex_unlock(&work_stats_mutex);
-       }
+       /*
+        * Start executing the low priority work. Drop the nice value
+        * as this really is low priority stuff
+        */
+       ret = nice(19);
+       pr_info("Worker priority dropped to %d\n", ret);
+
+       while (run_work_on_queue(&work_queues[WORK_PRIORITY_LOW]))
+               ;
+
+       /* All done, exit */
+       mutex_lock(&work_stats_mutex);
+out_unlock:
+       workers_active--;
+       pr_info("Worker exiting, %d left active\n",
+               workers_active);
+
+       /*
+        * Last exiting worker zeroes the worker_count. This
+        * ensures next time we start spawning worker threads
+        * the first thread will have number zero on its name.
+        */
+       if (!workers_active)
+               worker_count = 0;
+
+       /*
+        * Kick the job poller. If all jobs were active at this point
+        * the scheduler thread will wait indefinitely until someone
+        * tells it to do something. We may now know when next job is
+        * available, so it is better for the scheduler to recalculate
+        * its sleep time.
+        */
+       notify_job_request();
+
+       mutex_unlock(&work_stats_mutex);
 
        return NULL;
 }
@@ -189,6 +207,18 @@ int queue_work(unsigned int priority, char *name,
        return 0;
 }
 
+static int job_notify_handler(struct event_handler *h)
+{
+       int ret;
+       char buf[64];
+
+       ret = read(job_notify_fd[0], buf, sizeof(buf));
+       if (ret < 0)
+               pr_err("Failed to read: %m\n");
+
+       return 0;
+}
+
 /*
  * Initialize the jobcontrol.
  *
@@ -198,6 +228,7 @@ int queue_work(unsigned int priority, char *name,
  */
 int init_jobcontrol(int max_jobs_requested)
 {
+       static struct event_handler ev;
        FILE *file;
        int ret;
        char buf[256];
@@ -238,6 +269,18 @@ int init_jobcontrol(int max_jobs_requested)
                        max_jobs++;
        }
 
+       ret = pipe(job_notify_fd);
+       if (ret) {
+               pr_err("pipe() failed: %m\n");
+               return ret;
+       }
+
+       ev.fd = job_notify_fd[0];
+       ev.events = EPOLLIN;
+       ev.handle_event = job_notify_handler;
+       ev.name = "job_notify";
+       register_event_handler(&ev, EPOLL_CTL_ADD);
+
 open_fail:
 read_fail:
        fclose(file);
@@ -297,6 +340,18 @@ out:
        return ret;
 }
 
+int notify_job_request(void)
+{
+       int ret;
+       char byte = 0;
+
+       ret = write(job_notify_fd[1], &byte, sizeof(byte));
+       if (ret < 0)
+               pr_err("Failed to write: %m\n");
+
+       return 0;
+}
+
 int do_fork(void)
 {
        int child;
@@ -369,12 +424,12 @@ int run_piped(const char *cmd, char *const argv[],
 
        if (stdoutfd && pipe(ofd)) {
                pr_err("pipe() failed: %m\n");
-               return -1;
+               goto close_ifd;
        }
 
        if (stderrfd && pipe(efd)) {
                pr_err("pipe() failed: %m\n");
-               return -1;
+               goto close_ofd;
        }
 
        pid = do_fork();
@@ -418,6 +473,19 @@ int run_piped(const char *cmd, char *const argv[],
        exit(1);
 
        return 0;
+
+close_ofd:
+       if (stdoutfd) {
+               close(ofd[0]);
+               close(ofd[1]);
+       }
+close_ifd:
+       if (stdinfd) {
+               close(ifd[0]);
+               close(ifd[1]);
+       }
+
+       return -1;
 }
 
 /*
@@ -448,7 +516,7 @@ int run_piped_stream(const char *cmd, char *const argv[],
        pid = run_piped(cmd, argv, i, o, e);
 
        if (stdinf) {
-               *stdinf = fdopen(ifd, "r");
+               *stdinf = fdopen(ifd, "w");
                if (*stdinf == NULL) {
                        pr_err("Error opening file stream for fd %d: %m\n",
                               ifd);
@@ -567,10 +635,11 @@ print:
        return 0;
 }
 
-int register_event_handler(struct event_handler *handler)
+int register_event_handler(struct event_handler *handler, int op)
 {
        struct epoll_event ev;
        int ret;
+       const char *str;
 
        if (handler->fd <= 0) {
                pr_err("Invalid file descriptor of %d\n", handler->fd);
@@ -582,15 +651,33 @@ int register_event_handler(struct event_handler *handler)
                return -1;
        }
 
-       pr_info("Registering handler for %s, fd %d\n",
+       switch (op) {
+       case EPOLL_CTL_ADD:
+               str = "register";
+               break;
+
+       case EPOLL_CTL_MOD:
+               str = "modify";
+               break;
+
+       case EPOLL_CTL_DEL:
+               str = "deregister";
+               break;
+
+       default:
+               pr_err("Invalid op %d\n", op);
+               return -1;
+       }
+
+       pr_info("Doing a epoll %s for handler %s, fd %d\n", str,
                handler->name, handler->fd);
 
        ev.data.fd = handler->fd;
        ev.data.ptr = handler;
        ev.events = handler->events;
-       ret = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, handler->fd, &ev);
+       ret = epoll_ctl(epoll_fd, op, handler->fd, &ev);
        if (ret) {
-               pr_err("Failed to add epoll_fd: %m\n");
+               pr_err("Failed to do epoll_ctl %s: %m\n", str);
                return -1;
        }
 
@@ -601,24 +688,32 @@ void _mutex_lock_acquired(struct mutex *lock, char *file, int line)
 {
        lock->line = line;
        lock->file = file;
+       pthread_getname_np(pthread_self(),
+                       lock->owner_name, sizeof(lock->owner_name));
 }
 
 int _mutex_lock(struct mutex *lock, char *file, int line)
 {
        int ret = 0;
+       int contended = 0;
 
        if (!pthread_mutex_trylock(&lock->lock))
                goto out_lock;
 
-       pr_info("Lock contention on lock %s on %s:%d\n",
-               lock->name, lock->file, lock->line);
+       contended = 1;
+       pr_debug("Lock contention at %s:%d on lock %s acquired by %s at %s:%d\n",
+               file, line, lock->name,
+               lock->owner_name, lock->file, lock->line);
 
        ret = pthread_mutex_lock(&lock->lock);
        if (ret)
-               pr_err("Acquirin lock %s failed: %m, acquired %s:%d\n",
+               pr_err("Acquirin lock %s failed: %m, acquired on %s:%d\n",
                        lock->name, lock->file, lock->line);
 
 out_lock:
+       if (contended)
+               pr_debug("Lock %s acquired at %s:%d after contention\n",
+                       lock->name, file, line);
        _mutex_lock_acquired(lock, file, line);
        return ret;
 }