* Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
- * 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; only version 2
- * of the License.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
*
- * 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.
+ * 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.
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _GNU_SOURCE
#include <assert.h>
-#include <fcntl.h>
#include <poll.h>
#include <pthread.h>
#include <stdlib.h>
{
struct lttng_consumer_stream *stream;
+ rcu_read_lock();
stream = consumer_find_stream(key);
- if (stream)
+ if (stream) {
stream->key = -1;
+ /*
+ * We don't want the lookup to match, but we still need
+ * to iterate on this stream when iterating over the hash table. Just
+ * change the node key.
+ */
+ stream->node.key = -1;
+ }
+ rcu_read_unlock();
}
static struct lttng_consumer_channel *consumer_find_channel(int key)
{
struct lttng_consumer_channel *channel;
+ rcu_read_lock();
channel = consumer_find_channel(key);
- if (channel)
+ if (channel) {
channel->key = -1;
+ /*
+ * We don't want the lookup to match, but we still need
+ * to iterate on this channel when iterating over the hash table. Just
+ * change the node key.
+ */
+ channel->node.key = -1;
+ }
+ rcu_read_unlock();
+}
+
+static
+void consumer_free_stream(struct rcu_head *head)
+{
+ struct lttng_ht_node_ulong *node =
+ caa_container_of(head, struct lttng_ht_node_ulong, head);
+ struct lttng_consumer_stream *stream =
+ caa_container_of(node, struct lttng_consumer_stream, node);
+
+ free(stream);
}
/*
}
rcu_read_lock();
-
- /* Get stream node from hash table */
- lttng_ht_lookup(consumer_data.stream_ht,
- (void *)((unsigned long) stream->key), &iter);
- /* Remove stream node from hash table */
+ iter.iter.node = &stream->node.node;
ret = lttng_ht_del(consumer_data.stream_ht, &iter);
assert(!ret);
goto end;
}
if (stream->out_fd >= 0) {
- close(stream->out_fd);
+ ret = close(stream->out_fd);
+ if (ret) {
+ PERROR("close");
+ }
}
if (stream->wait_fd >= 0 && !stream->wait_fd_is_copy) {
- close(stream->wait_fd);
+ ret = close(stream->wait_fd);
+ if (ret) {
+ PERROR("close");
+ }
}
if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) {
- close(stream->shm_fd);
+ ret = close(stream->shm_fd);
+ if (ret) {
+ PERROR("close");
+ }
}
if (!--stream->chan->refcount)
free_chan = stream->chan;
- free(stream);
+
+ call_rcu(&stream->node.head, consumer_free_stream);
end:
consumer_data.need_update = 1;
pthread_mutex_unlock(&consumer_data.lock);
consumer_del_channel(free_chan);
}
-static void consumer_del_stream_rcu(struct rcu_head *head)
-{
- struct lttng_ht_node_ulong *node =
- caa_container_of(head, struct lttng_ht_node_ulong, head);
- struct lttng_consumer_stream *stream =
- caa_container_of(node, struct lttng_consumer_stream, node);
-
- consumer_del_stream(stream);
-}
-
struct lttng_consumer_stream *consumer_allocate_stream(
int channel_key, int stream_key,
int shm_fd, int wait_fd,
int consumer_add_stream(struct lttng_consumer_stream *stream)
{
int ret = 0;
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
pthread_mutex_lock(&consumer_data.lock);
/* Steal stream identifier, for UST */
consumer_steal_stream_key(stream->key);
rcu_read_lock();
+
+ lttng_ht_lookup(consumer_data.stream_ht,
+ (void *)((unsigned long) stream->key), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node != NULL) {
+ rcu_read_unlock();
+ /* Stream already exist. Ignore the insertion */
+ goto end;
+ }
+
lttng_ht_add_unique_ulong(consumer_data.stream_ht, &stream->node);
rcu_read_unlock();
consumer_data.stream_count++;
end:
pthread_mutex_unlock(&consumer_data.lock);
+
return ret;
}
pthread_mutex_unlock(&consumer_data.lock);
}
+static
+void consumer_free_channel(struct rcu_head *head)
+{
+ struct lttng_ht_node_ulong *node =
+ caa_container_of(head, struct lttng_ht_node_ulong, head);
+ struct lttng_consumer_channel *channel =
+ caa_container_of(node, struct lttng_consumer_channel, node);
+
+ free(channel);
+}
+
/*
* Remove a channel from the global list protected by a mutex. This
* function is also responsible for freeing its data structures.
}
rcu_read_lock();
-
- lttng_ht_lookup(consumer_data.channel_ht,
- (void *)((unsigned long) channel->key), &iter);
+ iter.iter.node = &channel->node.node;
ret = lttng_ht_del(consumer_data.channel_ht, &iter);
assert(!ret);
-
rcu_read_unlock();
if (channel->mmap_base != NULL) {
}
}
if (channel->wait_fd >= 0 && !channel->wait_fd_is_copy) {
- close(channel->wait_fd);
+ ret = close(channel->wait_fd);
+ if (ret) {
+ PERROR("close");
+ }
}
if (channel->shm_fd >= 0 && channel->wait_fd != channel->shm_fd) {
- close(channel->shm_fd);
+ ret = close(channel->shm_fd);
+ if (ret) {
+ PERROR("close");
+ }
}
- free(channel);
+
+ call_rcu(&channel->node.head, consumer_free_channel);
end:
pthread_mutex_unlock(&consumer_data.lock);
}
-static void consumer_del_channel_rcu(struct rcu_head *head)
-{
- struct lttng_ht_node_ulong *node =
- caa_container_of(head, struct lttng_ht_node_ulong, head);
- struct lttng_consumer_channel *channel=
- caa_container_of(node, struct lttng_consumer_channel, node);
-
- consumer_del_channel(channel);
-}
-
struct lttng_consumer_channel *consumer_allocate_channel(
int channel_key,
int shm_fd, int wait_fd,
*/
int consumer_add_channel(struct lttng_consumer_channel *channel)
{
+ struct lttng_ht_node_ulong *node;
+ struct lttng_ht_iter iter;
+
pthread_mutex_lock(&consumer_data.lock);
/* Steal channel identifier, for UST */
consumer_steal_channel_key(channel->key);
rcu_read_lock();
+
+ lttng_ht_lookup(consumer_data.channel_ht,
+ (void *)((unsigned long) channel->key), &iter);
+ node = lttng_ht_iter_get_node_ulong(&iter);
+ if (node != NULL) {
+ /* Channel already exist. Ignore the insertion */
+ goto end;
+ }
+
lttng_ht_add_unique_ulong(consumer_data.channel_ht, &channel->node);
+
+end:
rcu_read_unlock();
pthread_mutex_unlock(&consumer_data.lock);
+
return 0;
}
struct lttng_consumer_stream *stream;
DBG("Updating poll fd array");
+ rcu_read_lock();
cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, stream,
node.node) {
if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM) {
local_stream[i] = stream;
i++;
}
+ rcu_read_unlock();
/*
* Insert the consumer_poll_pipe at the end of the array and don't
* increment i so nb_fd is the number of real FD.
*/
(*pollfd)[i].fd = ctx->consumer_poll_pipe[0];
- (*pollfd)[i].events = POLLIN;
+ (*pollfd)[i].events = POLLIN | POLLPRI;
return i;
}
{
int num_rdy;
+restart:
num_rdy = poll(consumer_sockpoll, 2, -1);
if (num_rdy == -1) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ goto restart;
+ }
perror("Poll error");
goto exit;
}
- if (consumer_sockpoll[0].revents == POLLIN) {
+ if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) {
DBG("consumer_should_quit wake up");
goto exit;
}
*/
void lttng_consumer_cleanup(void)
{
- int ret;
struct lttng_ht_iter iter;
struct lttng_ht_node_ulong *node;
*/
cds_lfht_for_each_entry(consumer_data.stream_ht->ht, &iter.iter, node,
node) {
- ret = lttng_ht_del(consumer_data.stream_ht, &iter);
- assert(!ret);
- call_rcu(&node->head, consumer_del_stream_rcu);
+ struct lttng_consumer_stream *stream =
+ caa_container_of(node, struct lttng_consumer_stream, node);
+ consumer_del_stream(stream);
}
cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, node,
node) {
- ret = lttng_ht_del(consumer_data.channel_ht, &iter);
- assert(!ret);
- call_rcu(&node->head, consumer_del_channel_rcu);
+ struct lttng_consumer_channel *channel =
+ caa_container_of(node, struct lttng_consumer_channel, node);
+ consumer_del_channel(channel);
}
rcu_read_unlock();
+
+ lttng_ht_destroy(consumer_data.stream_ht);
+ lttng_ht_destroy(consumer_data.channel_ht);
}
/*
if (orig_offset < stream->chan->max_sb_size) {
return;
}
- sync_file_range(outfd, orig_offset - stream->chan->max_sb_size,
+ lttng_sync_file_range(outfd, orig_offset - stream->chan->max_sb_size,
stream->chan->max_sb_size,
SYNC_FILE_RANGE_WAIT_BEFORE
| SYNC_FILE_RANGE_WRITE
*/
struct lttng_consumer_local_data *lttng_consumer_create(
enum lttng_consumer_type type,
- int (*buffer_ready)(struct lttng_consumer_stream *stream,
+ ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
struct lttng_consumer_local_data *ctx),
int (*recv_channel)(struct lttng_consumer_channel *channel),
int (*recv_stream)(struct lttng_consumer_stream *stream),
goto error_poll_pipe;
}
+ /* set read end of the pipe to non-blocking */
+ ret = fcntl(ctx->consumer_poll_pipe[0], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ perror("fcntl O_NONBLOCK");
+ goto error_poll_fcntl;
+ }
+
+ /* set write end of the pipe to non-blocking */
+ ret = fcntl(ctx->consumer_poll_pipe[1], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ perror("fcntl O_NONBLOCK");
+ goto error_poll_fcntl;
+ }
+
ret = pipe(ctx->consumer_should_quit);
if (ret < 0) {
perror("Error creating recv pipe");
int err;
err = close(ctx->consumer_should_quit[i]);
- assert(!err);
+ if (err) {
+ PERROR("close");
+ }
}
+error_poll_fcntl:
error_quit_pipe:
for (i = 0; i < 2; i++) {
int err;
err = close(ctx->consumer_poll_pipe[i]);
- assert(!err);
+ if (err) {
+ PERROR("close");
+ }
}
error_poll_pipe:
free(ctx);
*/
void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
{
- close(ctx->consumer_error_socket);
- close(ctx->consumer_thread_pipe[0]);
- close(ctx->consumer_thread_pipe[1]);
- close(ctx->consumer_poll_pipe[0]);
- close(ctx->consumer_poll_pipe[1]);
- close(ctx->consumer_should_quit[0]);
- close(ctx->consumer_should_quit[1]);
+ int ret;
+
+ ret = close(ctx->consumer_error_socket);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_thread_pipe[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_thread_pipe[1]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_poll_pipe[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_poll_pipe[1]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_should_quit[0]);
+ if (ret) {
+ PERROR("close");
+ }
+ ret = close(ctx->consumer_should_quit[1]);
+ if (ret) {
+ PERROR("close");
+ }
unlink(ctx->consumer_command_sock_path);
free(ctx);
}
*
* Returns the number of bytes written
*/
-int lttng_consumer_on_read_subbuffer_mmap(
+ssize_t lttng_consumer_on_read_subbuffer_mmap(
struct lttng_consumer_local_data *ctx,
struct lttng_consumer_stream *stream, unsigned long len)
{
ERR("Unknown consumer_data type");
assert(0);
}
+
+ return 0;
}
/*
*
* Returns the number of bytes spliced.
*/
-int lttng_consumer_on_read_subbuffer_splice(
+ssize_t lttng_consumer_on_read_subbuffer_splice(
struct lttng_consumer_local_data *ctx,
struct lttng_consumer_stream *stream, unsigned long len)
{
struct lttng_consumer_stream **local_stream = NULL;
/* local view of consumer_data.fds_count */
int nb_fd = 0;
- char tmp;
- int tmp2;
struct lttng_consumer_local_data *ctx = data;
rcu_register_thread();
}
pthread_mutex_unlock(&consumer_data.lock);
+ /* No FDs and consumer_quit, consumer_cleanup the thread */
+ if (nb_fd == 0 && consumer_quit == 1) {
+ goto end;
+ }
/* poll on the array of fds */
+ restart:
DBG("polling on %d fd", nb_fd + 1);
num_rdy = poll(pollfd, nb_fd + 1, consumer_poll_timeout);
DBG("poll num_rdy : %d", num_rdy);
if (num_rdy == -1) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ goto restart;
+ }
perror("Poll error");
lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR);
goto end;
goto end;
}
- /* No FDs and consumer_quit, consumer_cleanup the thread */
- if (nb_fd == 0 && consumer_quit == 1) {
- goto end;
- }
-
/*
* If the consumer_poll_pipe triggered poll go
* directly to the beginning of the loop to update the
* array. We want to prioritize array update over
* low-priority reads.
*/
- if (pollfd[nb_fd].revents & POLLIN) {
+ if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) {
+ size_t pipe_readlen;
+ char tmp;
+
DBG("consumer_poll_pipe wake up");
- tmp2 = read(ctx->consumer_poll_pipe[0], &tmp, 1);
- if (tmp2 < 0) {
- perror("read consumer poll");
- }
+ /* Consume 1 byte of pipe data */
+ do {
+ pipe_readlen = read(ctx->consumer_poll_pipe[0], &tmp, 1);
+ } while (pipe_readlen == -1 && errno == EINTR);
continue;
}
/* Take care of high priority channels first. */
for (i = 0; i < nb_fd; i++) {
if (pollfd[i].revents & POLLPRI) {
+ ssize_t len;
+
DBG("Urgent read on fd %d", pollfd[i].fd);
high_prio = 1;
- ret = ctx->on_buffer_ready(local_stream[i], ctx);
+ len = ctx->on_buffer_ready(local_stream[i], ctx);
/* it's ok to have an unavailable sub-buffer */
- if (ret == EAGAIN) {
- ret = 0;
- }
- } else if (pollfd[i].revents & POLLERR) {
- ERR("Error returned in polling fd %d.", pollfd[i].fd);
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
- num_hup++;
- } else if (pollfd[i].revents & POLLNVAL) {
- ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
- num_hup++;
- } else if ((pollfd[i].revents & POLLHUP) &&
- !(pollfd[i].revents & POLLIN)) {
- if (consumer_data.type == LTTNG_CONSUMER32_UST
- || consumer_data.type == LTTNG_CONSUMER64_UST) {
- DBG("Polling fd %d tells it has hung up. Attempting flush and read.",
- pollfd[i].fd);
- if (!local_stream[i]->hangup_flush_done) {
- lttng_ustconsumer_on_stream_hangup(local_stream[i]);
- /* read after flush */
- do {
- ret = ctx->on_buffer_ready(local_stream[i], ctx);
- } while (ret == EAGAIN);
- }
- } else {
- DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
+ if (len < 0 && len != -EAGAIN) {
+ goto end;
+ } else if (len > 0) {
+ local_stream[i]->data_read = 1;
}
- rcu_read_lock();
- consumer_del_stream_rcu(&local_stream[i]->node.head);
- rcu_read_unlock();
- num_hup++;
}
}
- /* If every buffer FD has hung up, we end the read loop here */
- if (nb_fd > 0 && num_hup == nb_fd) {
- DBG("every buffer FD has hung up\n");
- if (consumer_quit == 1) {
- goto end;
- }
+ /*
+ * If we read high prio channel in this loop, try again
+ * for more high prio data.
+ */
+ if (high_prio) {
continue;
}
/* Take care of low priority channels. */
- if (high_prio == 0) {
- for (i = 0; i < nb_fd; i++) {
- if (pollfd[i].revents & POLLIN) {
- DBG("Normal read on fd %d", pollfd[i].fd);
- ret = ctx->on_buffer_ready(local_stream[i], ctx);
- /* it's ok to have an unavailable subbuffer */
- if (ret == EAGAIN) {
- ret = 0;
- }
+ for (i = 0; i < nb_fd; i++) {
+ if ((pollfd[i].revents & POLLIN) ||
+ local_stream[i]->hangup_flush_done) {
+ ssize_t len;
+
+ DBG("Normal read on fd %d", pollfd[i].fd);
+ len = ctx->on_buffer_ready(local_stream[i], ctx);
+ /* it's ok to have an unavailable sub-buffer */
+ if (len < 0 && len != -EAGAIN) {
+ goto end;
+ } else if (len > 0) {
+ local_stream[i]->data_read = 1;
}
}
}
+
+ /* Handle hangup and errors */
+ for (i = 0; i < nb_fd; i++) {
+ if (!local_stream[i]->hangup_flush_done
+ && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL))
+ && (consumer_data.type == LTTNG_CONSUMER32_UST
+ || consumer_data.type == LTTNG_CONSUMER64_UST)) {
+ DBG("fd %d is hup|err|nval. Attempting flush and read.",
+ pollfd[i].fd);
+ lttng_ustconsumer_on_stream_hangup(local_stream[i]);
+ /* Attempt read again, for the data we just flushed. */
+ local_stream[i]->data_read = 1;
+ }
+ /*
+ * If the poll flag is HUP/ERR/NVAL and we have
+ * read no data in this pass, we can remove the
+ * stream from its hash table.
+ */
+ if ((pollfd[i].revents & POLLHUP)) {
+ DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
+ if (!local_stream[i]->data_read) {
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ }
+ } else if (pollfd[i].revents & POLLERR) {
+ ERR("Error returned in polling fd %d.", pollfd[i].fd);
+ if (!local_stream[i]->data_read) {
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ }
+ } else if (pollfd[i].revents & POLLNVAL) {
+ ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
+ if (!local_stream[i]->data_read) {
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ }
+ }
+ local_stream[i]->data_read = 0;
+ }
}
end:
DBG("polling thread exiting");
*/
consumer_poll_timeout = LTTNG_CONSUMER_POLL_TIMEOUT;
- /* wake up the polling thread */
- ret = write(ctx->consumer_poll_pipe[1], "4", 1);
- if (ret < 0) {
- perror("poll pipe write");
- }
+ /*
+ * Wake-up the other end by writing a null byte in the pipe
+ * (non-blocking). Important note: Because writing into the
+ * pipe is non-blocking (and therefore we allow dropping wakeup
+ * data, as long as there is wakeup data present in the pipe
+ * buffer to wake up the other end), the other end should
+ * perform the following sequence for waiting:
+ * 1) empty the pipe (reads).
+ * 2) perform update operation.
+ * 3) wait on the pipe (poll).
+ */
+ do {
+ ret = write(ctx->consumer_poll_pipe[1], "", 1);
+ } while (ret == -1UL && errno == EINTR);
rcu_unregister_thread();
return NULL;
}
-int lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
+ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
struct lttng_consumer_local_data *ctx)
{
switch (consumer_data.type) {