/* Copyright (c) 2008-2012 Red Hat, Inc. This file is part of GlusterFS. This file is licensed to you under your choice of the GNU Lesser General Public License, version 3 or any later version (LGPLv3 or later), or the GNU General Public License, version 2 (GPLv2), in all cases as published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include "logging.h" #include "gf-event.h" #include "mem-pool.h" #include "common-utils.h" #include "libglusterfs-messages.h" #include "syscall.h" struct event_pool * event_pool_new (int count, int eventthreadcount) { struct event_pool *event_pool = NULL; extern struct event_ops event_ops_poll; #ifdef HAVE_SYS_EPOLL_H extern struct event_ops event_ops_epoll; event_pool = event_ops_epoll.new (count, eventthreadcount); if (event_pool) { event_pool->ops = &event_ops_epoll; } else { gf_msg ("event", GF_LOG_WARNING, 0, LG_MSG_FALLBACK_TO_POLL, "falling back to poll based event handling"); } #endif if (!event_pool) { event_pool = event_ops_poll.new (count, eventthreadcount); if (event_pool) event_pool->ops = &event_ops_poll; } return event_pool; } int event_register (struct event_pool *event_pool, int fd, event_handler_t handler, void *data, int poll_in, int poll_out) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = event_pool->ops->event_register (event_pool, fd, handler, data, poll_in, poll_out); out: return ret; } int event_unregister (struct event_pool *event_pool, int fd, int idx) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = event_pool->ops->event_unregister (event_pool, fd, idx); out: return ret; } int event_unregister_close (struct event_pool *event_pool, int fd, int idx) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = event_pool->ops->event_unregister_close (event_pool, fd, idx); out: return ret; } int event_select_on (struct event_pool *event_pool, int fd, int idx_hint, int poll_in, int poll_out) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = event_pool->ops->event_select_on (event_pool, fd, idx_hint, poll_in, poll_out); out: return ret; } int event_dispatch (struct event_pool *event_pool) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = event_pool->ops->event_dispatch (event_pool); if (ret) goto out; out: return ret; } int event_reconfigure_threads (struct event_pool *event_pool, int value) { int ret = -1; GF_VALIDATE_OR_GOTO ("event", event_pool, out); /* call event refresh function */ ret = event_pool->ops->event_reconfigure_threads (event_pool, value); out: return ret; } int event_pool_destroy (struct event_pool *event_pool) { int ret = -1; int destroy = 0, activethreadcount = 0; GF_VALIDATE_OR_GOTO ("event", event_pool, out); pthread_mutex_lock (&event_pool->mutex); { destroy = event_pool->destroy; activethreadcount = event_pool->activethreadcount; } pthread_mutex_unlock (&event_pool->mutex); if (!destroy || (activethreadcount > 0)) { goto out; } ret = event_pool->ops->event_pool_destroy (event_pool); out: return ret; } int poller_destroy_handler (int fd, int idx, int gen, void *data, int poll_out, int poll_in, int poll_err) { struct event_destroy_data *destroy = NULL; int readfd = -1, ret = -1; char buf = '\0'; destroy = data; readfd = destroy->readfd; if (readfd < 0) { goto out; } while (sys_read (readfd, &buf, 1) > 0) { } ret = 0; out: event_handled (destroy->pool, fd, idx, gen); return ret; } /* This function destroys all the poller threads. * Note: to be called before event_pool_destroy is called. * The order in which cleaning is performed: * - Register a pipe fd(this is for waking threads in poll()/epoll_wait()) * - Set the destroy mode, which this no new event registration will succeed * - Reconfigure the thread count to 0(this will succeed only in destroy mode) * - Wake up all the threads in poll() or epoll_wait(), so that they can * destroy themselves. * - Wait for the thread to join(which will happen only after all the other * threads are destroyed) */ int event_dispatch_destroy (struct event_pool *event_pool) { int ret = -1, threadcount = 0; int fd[2] = {-1}; int idx = -1; int flags = 0; struct timespec sleep_till = {0, }; struct event_destroy_data data = {0, }; GF_VALIDATE_OR_GOTO ("event", event_pool, out); ret = pipe (fd); if (ret < 0) goto out; /* Make the read end of the pipe nonblocking */ flags = fcntl(fd[0], F_GETFL); flags |= O_NONBLOCK; ret = fcntl(fd[0], F_SETFL, flags); if (ret < 0) goto out; /* Make the write end of the pipe nonblocking */ flags = fcntl(fd[1], F_GETFL); flags |= O_NONBLOCK; ret = fcntl(fd[1], F_SETFL, flags); if (ret < 0) goto out; data.pool = event_pool; data.readfd = fd[1]; /* From the main thread register an event on the pipe fd[0], */ idx = event_register (event_pool, fd[0], poller_destroy_handler, &data, 1, 0); if (idx < 0) goto out; /* Enter the destroy mode first, set this before reconfiguring to 0 * threads, to prevent further reconfigure to thread count > 0. */ pthread_mutex_lock (&event_pool->mutex); { threadcount = event_pool->eventthreadcount; event_pool->destroy = 1; } pthread_mutex_unlock (&event_pool->mutex); ret = event_reconfigure_threads (event_pool, 0); if (ret < 0) goto out; /* Write something onto the write end of the pipe(fd[1]) so that * poll wakes up and calls the handler, poller_destroy_handler() */ pthread_mutex_lock (&event_pool->mutex); { /* Write to pipe(fd[1]) and then wait for 1 second or until * a poller thread that is dying, broadcasts. Make sure we * do not loop forever by limiting to 10 retries */ int retry = 0; while (event_pool->activethreadcount > 0 && (retry++ < (threadcount + 10))) { if (sys_write (fd[1], "dummy", 6) == -1) { break; } sleep_till.tv_sec = time (NULL) + 1; ret = pthread_cond_timedwait (&event_pool->cond, &event_pool->mutex, &sleep_till); } } pthread_mutex_unlock (&event_pool->mutex); ret = event_unregister (event_pool, fd[0], idx); out: if (fd[0] != -1) sys_close (fd[0]); if (fd[1] != -1) sys_close (fd[1]); return ret; } int event_handled (struct event_pool *event_pool, int fd, int idx, int gen) { int ret = 0; if (event_pool->ops->event_handled) ret = event_pool->ops->event_handled (event_pool, fd, idx, gen); return ret; }