From 06bdc5bf258dae4afd640ed4d1d6e4e7ed47ad7c Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Mon, 30 Jun 2008 02:43:22 +0000 Subject: introduce struct condition as a more correct version of Notify Start using it in the HTTP code git-svn-id: https://svn.musicpd.org/mpd/trunk@7395 09075e82-0dd4-0310-85a5-a0d7c8717e4f --- src/Makefile.am | 2 ++ src/condition.c | 84 +++++++++++++++++++++++++++++++++++++++++++++ src/condition.h | 76 +++++++++++++++++++++++++++++++++++++++++ src/inputStream_http.c | 93 ++++++++++++++++---------------------------------- 4 files changed, 191 insertions(+), 64 deletions(-) create mode 100644 src/condition.c create mode 100644 src/condition.h (limited to 'src') diff --git a/src/Makefile.am b/src/Makefile.am index a1809976a..d79bda29f 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -36,6 +36,7 @@ mpd_headers = \ buffer2array.h \ charConv.h \ command.h \ + condition.h \ conf.h \ dbUtils.h \ decode.h \ @@ -97,6 +98,7 @@ mpd_SOURCES = \ buffer2array.c \ charConv.c \ command.c \ + condition.c \ conf.c \ dbUtils.c \ decode.c \ diff --git a/src/condition.c b/src/condition.c new file mode 100644 index 000000000..e71dcdd88 --- /dev/null +++ b/src/condition.c @@ -0,0 +1,84 @@ +/* the Music Player Daemon (MPD) + * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com) + * Copyright (C) 2008 Max Kellermann + * This project's homepage is: http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include "condition.h" +#include "utils.h" +#include "log.h" + +void cond_init(struct condition *cond) +{ + xpthread_mutex_init(&cond->mutex, NULL); + xpthread_cond_init(&cond->cond, NULL); +} + +void cond_enter(struct condition *cond) +{ + pthread_mutex_lock(&cond->mutex); +} + +void cond_leave(struct condition *cond) +{ + pthread_mutex_unlock(&cond->mutex); +} + +void cond_wait(struct condition *cond) +{ + pthread_cond_wait(&cond->cond, &cond->mutex); +} + +static struct timespec * ts_timeout(struct timespec *ts, const long sec) +{ + struct timeval tv; + gettimeofday(&tv, NULL); + ts->tv_sec = tv.tv_sec + sec; + ts->tv_nsec = tv.tv_usec * 1000; + return ts; +} + +int cond_timedwait(struct condition *cond, const long sec) +{ + struct timespec ts; + int ret = pthread_cond_timedwait(&cond->cond, &cond->mutex, + ts_timeout(&ts, sec)); + if (!ret || ret == ETIMEDOUT) + return ret; + FATAL("cond_timedwait: %s\n", strerror(ret)); + return ret; +} + +int cond_signal_async(struct condition *cond) +{ + if (!pthread_mutex_trylock(&cond->mutex)) { + pthread_cond_signal(&cond->cond); + pthread_mutex_unlock(&cond->mutex); + return 0; + } + return EBUSY; +} + +void cond_signal_sync(struct condition *cond) +{ + pthread_cond_signal(&cond->cond); +} + +void cond_destroy(struct condition *cond) +{ + xpthread_cond_destroy(&cond->cond); + xpthread_mutex_destroy(&cond->mutex); +} diff --git a/src/condition.h b/src/condition.h new file mode 100644 index 000000000..576ff9dc3 --- /dev/null +++ b/src/condition.h @@ -0,0 +1,76 @@ +/* the Music Player Daemon (MPD) + * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com) + * Copyright (C) 2008 Max Kellermann + * This project's homepage is: http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef CONDITION_H +#define CONDITION_H + +#include "os_compat.h" + +struct condition { + pthread_mutex_t mutex; + pthread_cond_t cond; +}; + +void cond_init(struct condition *cond); + +/** + * The thread which shall be notified by this object must call this + * function before any cond_wait() invocation. It locks the mutex. + */ +void cond_enter(struct condition *cond); + +/** + * Neutralize cond_leave(). + */ +void cond_leave(struct condition *cond); + +/** + * Wait for a conditio. Return immediately if we have already + * been notified since we last returned from cond_wait(). + */ +void cond_wait(struct condition *cond); + +/** + * Wait for a condition with timeout + * + * @param sec number of seconds to wait for (subject to change) + * + * @return ETIMEDOUT if timed out, 0 if notification was received + */ +int cond_timedwait(struct condition *cond, const long sec); + +/** + * Notify the thread there is a waiter. This function never blocks. + * + * @return EBUSY if it was unable to lock the mutex, 0 on success + */ +int cond_signal_async(struct condition *cond); + +/** + * Notify the thread synchronously, i.e. wait until it can deliver + * the notification. + */ +void cond_signal_sync(struct condition *cond); + +/** + * cond_destroy - destroy the cond and internal structures + */ +void cond_destroy(struct condition *cond); + +#endif /* CONDITION_H */ diff --git a/src/inputStream_http.c b/src/inputStream_http.c index 64d4d5b64..f2dadf4e3 100644 --- a/src/inputStream_http.c +++ b/src/inputStream_http.c @@ -24,6 +24,7 @@ #include "conf.h" #include "os_compat.h" #include "ringbuf.h" +#include "condition.h" enum conn_state { /* only written by io thread, read by both */ CONN_STATE_NEW, /* just (re)initialized */ @@ -71,14 +72,9 @@ struct http_data { pthread_t io_thread; struct ringbuf *rb; - /* TODO: fix Notify so it doesn't use ugly "pending" flag */ - pthread_mutex_t full_lock; - pthread_cond_t full_cond; - pthread_mutex_t empty_lock; - pthread_cond_t empty_cond; - - pthread_mutex_t action_lock; - pthread_cond_t action_cond; + struct condition full_cond; + struct condition empty_cond; + struct condition action_cond; /* } */ int nr_redirect; @@ -112,12 +108,9 @@ static void init_http_data(struct http_data *data) data->icy_offset = 0; data->rb = ringbuf_create(buffer_size); - pthread_cond_init(&data->action_cond, NULL); - pthread_mutex_init(&data->action_lock, NULL); - pthread_cond_init(&data->full_cond, NULL); - pthread_mutex_init(&data->full_lock, NULL); - pthread_cond_init(&data->empty_cond, NULL); - pthread_mutex_init(&data->empty_lock, NULL); + cond_init(&data->action_cond); + cond_init(&data->full_cond); + cond_init(&data->empty_cond); } static struct http_data *new_http_data(void) @@ -135,12 +128,9 @@ static void free_http_data(struct http_data * data) if (data->proxy_auth) free(data->proxy_auth); if (data->http_auth) free(data->http_auth); - xpthread_cond_destroy(&data->action_cond); - xpthread_mutex_destroy(&data->action_lock); - xpthread_cond_destroy(&data->full_cond); - xpthread_mutex_destroy(&data->full_lock); - xpthread_cond_destroy(&data->empty_cond); - xpthread_mutex_destroy(&data->empty_lock); + cond_destroy(&data->action_cond); + cond_destroy(&data->full_cond); + cond_destroy(&data->empty_cond); xclose(data->pipe_fds[0]); xclose(data->pipe_fds[1]); @@ -242,15 +232,6 @@ static int parse_url(struct http_data * data, char *url) return 0; } -static struct timespec * ts_timeout(struct timespec *ts, const long sec) -{ - struct timeval tv; - gettimeofday(&tv, NULL); - ts->tv_sec = tv.tv_sec + sec; - ts->tv_nsec = tv.tv_usec * 1000; - return ts; -} - /* triggers an action and waits for completion */ static int trigger_action(struct http_data *data, enum conn_action action, @@ -259,7 +240,7 @@ static int trigger_action(struct http_data *data, int ret = -1; assert(!pthread_equal(data->io_thread, pthread_self())); - pthread_mutex_lock(&data->action_lock); + cond_enter(&data->action_cond); if (data->action != CONN_ACTION_NONE) goto out; data->action = action; @@ -270,17 +251,13 @@ static int trigger_action(struct http_data *data, data->action = CONN_ACTION_NONE; goto out; } - if (nonblocking) { - struct timespec ts; - pthread_cond_timedwait(&data->action_cond, - &data->action_lock, - ts_timeout(&ts, 1)); - } else { - pthread_cond_wait(&data->action_cond, &data->action_lock); - } + if (nonblocking) + cond_timedwait(&data->action_cond, 1); + else + cond_wait(&data->action_cond); ret = 0; out: - pthread_mutex_unlock(&data->action_lock); + cond_leave(&data->action_cond); return ret; } @@ -288,10 +265,10 @@ static int take_action(struct http_data *data) { assert(pthread_equal(data->io_thread, pthread_self())); - pthread_mutex_lock(&data->action_lock); + cond_enter(&data->action_cond); switch (data->action) { case CONN_ACTION_NONE: - pthread_mutex_unlock(&data->action_lock); + cond_leave(&data->action_cond); return 0; case CONN_ACTION_DOSEEK: data->state = CONN_STATE_NEW; @@ -302,8 +279,8 @@ static int take_action(struct http_data *data) xclose(data->fd); data->fd = -1; data->action = CONN_ACTION_NONE; - pthread_cond_signal(&data->action_cond); - pthread_mutex_unlock(&data->action_lock); + cond_signal_sync(&data->action_cond); + cond_leave(&data->action_cond); return 1; } @@ -450,7 +427,7 @@ static void await_buffer_space(struct http_data *data) { assert(pthread_equal(data->io_thread, pthread_self())); assert_state(CONN_STATE_BUFFER_FULL); - pthread_cond_wait(&data->full_cond, &data->full_lock); + cond_wait(&data->full_cond); if (ringbuf_write_space(data->rb) > 0) data->state = CONN_STATE_BUFFER; /* else spurious wakeup or action triggered ... */ @@ -459,32 +436,20 @@ static void await_buffer_space(struct http_data *data) static void feed_starved(struct http_data *data) { assert(pthread_equal(data->io_thread, pthread_self())); - - if (!pthread_mutex_trylock(&data->empty_lock)) { - pthread_cond_signal(&data->empty_cond); - pthread_mutex_unlock(&data->empty_lock); - } + cond_signal_async(&data->empty_cond); } static int starved_wait(struct http_data *data, const long sec) { - struct timespec ts; - assert(!pthread_equal(data->io_thread, pthread_self())); - return pthread_cond_timedwait(&data->empty_cond, - &data->empty_lock, - ts_timeout(&ts, sec)); + return cond_timedwait(&data->empty_cond, sec); } static int awaken_buffer_task(struct http_data *data) { assert(!pthread_equal(data->io_thread, pthread_self())); - if (!pthread_mutex_trylock(&data->full_lock)) { - pthread_cond_signal(&data->full_cond); - pthread_mutex_unlock(&data->full_lock); - return 1; - } - return 0; + + return ! cond_signal_async(&data->full_cond); } static ssize_t buffer_data(InputStream *is) @@ -741,7 +706,7 @@ static void * http_io_task(void *arg) InputStream *is = (InputStream *) arg; struct http_data *data = (struct http_data *) is->data; - pthread_mutex_lock(&data->full_lock); + cond_enter(&data->full_cond); while (1) { take_action(data); switch (data->state) { @@ -782,7 +747,7 @@ err: err_close(data); closed: assert_state(CONN_STATE_CLOSED); - pthread_mutex_unlock(&data->full_lock); + cond_leave(&data->full_cond); return NULL; } @@ -813,7 +778,7 @@ int inputStream_httpOpen(InputStream * is, char *url) if (pthread_create(&data->io_thread, &attr, http_io_task, is)) FATAL("failed to spawn http_io_task: %s", strerror(errno)); - pthread_mutex_lock(&data->empty_lock); + cond_enter(&data->empty_cond); /* httpClose will leave this */ return 0; } @@ -982,7 +947,7 @@ int inputStream_httpClose(InputStream * is) while (data->state != CONN_STATE_CLOSED) trigger_action(data, CONN_ACTION_CLOSE, 1); pthread_join(data->io_thread, NULL); - pthread_mutex_unlock(&data->empty_lock); + cond_leave(&data->empty_cond); free_http_data(data); return 0; } -- cgit v1.2.3