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authorEric Wong <normalperson@yhbt.net>2008-06-30 02:43:22 +0000
committerEric Wong <normalperson@yhbt.net>2008-06-30 02:43:22 +0000
commit06bdc5bf258dae4afd640ed4d1d6e4e7ed47ad7c (patch)
treeeeb6f4f96bae2093e600cad5355947462ca82251 /src
parentd82a4aff2524e68ad56efca68723792296950713 (diff)
downloadmpd-06bdc5bf258dae4afd640ed4d1d6e4e7ed47ad7c.tar.gz
mpd-06bdc5bf258dae4afd640ed4d1d6e4e7ed47ad7c.tar.xz
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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
Diffstat (limited to 'src')
-rw-r--r--src/Makefile.am2
-rw-r--r--src/condition.c84
-rw-r--r--src/condition.h76
-rw-r--r--src/inputStream_http.c93
4 files changed, 191 insertions, 64 deletions
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 <max@duempel.org>
+ * 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 <max@duempel.org>
+ * 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;
}