* 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.
*
- * 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>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
+#include <inttypes.h>
#include <unistd.h>
+#include <sys/stat.h>
#include <common/common.h>
#include <common/kernel-ctl/kernel-ctl.h>
#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/sessiond-comm/relayd.h>
+#include <common/compat/fcntl.h>
+#include <common/pipe.h>
+#include <common/relayd/relayd.h>
+#include <common/utils.h>
#include "kernel-consumer.h"
extern int consumer_poll_timeout;
extern volatile int consumer_quit;
-/*
- * Mmap the ring buffer, read it and write the data to the tracefile.
- *
- * Returns the number of bytes written
- */
-ssize_t lttng_kconsumer_on_read_subbuffer_mmap(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream, unsigned long len)
-{
- unsigned long mmap_offset;
- ssize_t ret = 0;
- off_t orig_offset = stream->out_fd_offset;
- int fd = stream->wait_fd;
- int outfd = stream->out_fd;
-
- /* get the offset inside the fd to mmap */
- ret = kernctl_get_mmap_read_offset(fd, &mmap_offset);
- if (ret != 0) {
- errno = -ret;
- perror("kernctl_get_mmap_read_offset");
- goto end;
- }
-
- while (len > 0) {
- ret = write(outfd, stream->mmap_base + mmap_offset, len);
- if (ret >= len) {
- len = 0;
- } else if (ret < 0) {
- errno = -ret;
- perror("Error in file write");
- goto end;
- }
- /* This won't block, but will start writeout asynchronously */
- sync_file_range(outfd, stream->out_fd_offset, ret,
- SYNC_FILE_RANGE_WRITE);
- stream->out_fd_offset += ret;
- }
-
- lttng_consumer_sync_trace_file(stream, orig_offset);
-
- goto end;
-
-end:
- return ret;
-}
-
-/*
- * Splice the data from the ring buffer to the tracefile.
- *
- * Returns the number of bytes spliced.
- */
-ssize_t lttng_kconsumer_on_read_subbuffer_splice(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream, unsigned long len)
-{
- ssize_t ret = 0;
- loff_t offset = 0;
- off_t orig_offset = stream->out_fd_offset;
- int fd = stream->wait_fd;
- int outfd = stream->out_fd;
-
- while (len > 0) {
- DBG("splice chan to pipe offset %lu (fd : %d)",
- (unsigned long)offset, fd);
- ret = splice(fd, &offset, ctx->consumer_thread_pipe[1], NULL, len,
- SPLICE_F_MOVE | SPLICE_F_MORE);
- DBG("splice chan to pipe ret %ld", ret);
- if (ret < 0) {
- errno = -ret;
- perror("Error in relay splice");
- goto splice_error;
- }
-
- ret = splice(ctx->consumer_thread_pipe[0], NULL, outfd, NULL, ret,
- SPLICE_F_MOVE | SPLICE_F_MORE);
- DBG("splice pipe to file %ld", ret);
- if (ret < 0) {
- errno = -ret;
- perror("Error in file splice");
- goto splice_error;
- }
- len -= ret;
- /* This won't block, but will start writeout asynchronously */
- sync_file_range(outfd, stream->out_fd_offset, ret,
- SYNC_FILE_RANGE_WRITE);
- stream->out_fd_offset += ret;
- }
- lttng_consumer_sync_trace_file(stream, orig_offset);
-
- goto end;
-
-splice_error:
- /* send the appropriate error description to sessiond */
- switch(ret) {
- case EBADF:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF);
- break;
- case EINVAL:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EINVAL);
- break;
- case ENOMEM:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ENOMEM);
- break;
- case ESPIPE:
- lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ESPIPE);
- break;
- }
-
-end:
- return ret;
-}
-
/*
* Take a snapshot for a specific fd
*
* Returns 0 on success, < 0 on error
*/
-int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream)
+int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
{
int ret = 0;
int infd = stream->wait_fd;
*
* Returns 0 on success, < 0 on error
*/
-int lttng_kconsumer_get_produced_snapshot(
- struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_stream *stream,
+int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
unsigned long *pos)
{
int ret;
int sock, struct pollfd *consumer_sockpoll)
{
ssize_t ret;
+ enum lttng_error_code ret_code = LTTNG_OK;
struct lttcomm_consumer_msg msg;
ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
if (ret != sizeof(msg)) {
- lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_CMD);
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
return ret;
}
if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
+ /*
+ * Notify the session daemon that the command is completed.
+ *
+ * On transport layer error, the function call will print an error
+ * message so handling the returned code is a bit useless since we
+ * return an error code anyway.
+ */
+ (void) consumer_send_status_msg(sock, ret_code);
return -ENOENT;
}
+ /* relayd needs RCU read-side protection */
+ rcu_read_lock();
+
switch (msg.cmd_type) {
+ case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
+ {
+ /* Session daemon status message are handled in the following call. */
+ ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
+ msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
+ &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
+ goto end_nosignal;
+ }
case LTTNG_CONSUMER_ADD_CHANNEL:
{
struct lttng_consumer_channel *new_channel;
+ int ret_recv;
- DBG("consumer_add_channel %d", msg.u.channel.channel_key);
+ /* First send a status message before receiving the fds. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ DBG("consumer_add_channel %" PRIu64, msg.u.channel.channel_key);
new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
- -1, -1,
- msg.u.channel.mmap_len,
- msg.u.channel.max_sb_size);
+ msg.u.channel.session_id, msg.u.channel.pathname,
+ msg.u.channel.name, msg.u.channel.uid, msg.u.channel.gid,
+ msg.u.channel.relayd_id, msg.u.channel.output,
+ msg.u.channel.tracefile_size,
+ msg.u.channel.tracefile_count);
if (new_channel == NULL) {
- lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
goto end_nosignal;
}
+ new_channel->nb_init_stream_left = msg.u.channel.nb_init_streams;
+
+ /* Translate and save channel type. */
+ switch (msg.u.channel.type) {
+ case CONSUMER_CHANNEL_TYPE_DATA:
+ case CONSUMER_CHANNEL_TYPE_METADATA:
+ new_channel->type = msg.u.channel.type;
+ break;
+ default:
+ assert(0);
+ goto end_nosignal;
+ };
+
if (ctx->on_recv_channel != NULL) {
- ret = ctx->on_recv_channel(new_channel);
- if (ret == 0) {
- consumer_add_channel(new_channel);
- } else if (ret < 0) {
+ ret_recv = ctx->on_recv_channel(new_channel);
+ if (ret_recv == 0) {
+ ret = consumer_add_channel(new_channel, ctx);
+ } else if (ret_recv < 0) {
goto end_nosignal;
}
} else {
- consumer_add_channel(new_channel);
+ ret = consumer_add_channel(new_channel, ctx);
+ }
+
+ /* If we received an error in add_channel, we need to report it. */
+ if (ret != 0) {
+ consumer_send_status_msg(sock, ret);
+ goto end_nosignal;
}
+
goto end_nosignal;
}
case LTTNG_CONSUMER_ADD_STREAM:
{
- struct lttng_consumer_stream *new_stream;
int fd;
+ struct lttng_pipe *stream_pipe;
+ struct consumer_relayd_sock_pair *relayd = NULL;
+ struct lttng_consumer_stream *new_stream;
+ struct lttng_consumer_channel *channel;
+ int alloc_ret = 0;
+
+ /*
+ * Get stream's channel reference. Needed when adding the stream to the
+ * global hash table.
+ */
+ channel = consumer_find_channel(msg.u.stream.channel_key);
+ if (!channel) {
+ /*
+ * We could not find the channel. Can happen if cpu hotplug
+ * happens while tearing down.
+ */
+ ERR("Unable to find channel key %" PRIu64, msg.u.stream.channel_key);
+ ret_code = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
+ }
+
+ /* First send a status message before receiving the fds. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0 || ret_code != LTTNG_OK) {
+ /*
+ * Somehow, the session daemon is not responding anymore or the
+ * channel was not found.
+ */
+ goto end_nosignal;
+ }
/* block */
if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
+ rcu_read_unlock();
return -EINTR;
}
+
+ /* Get stream file descriptor from socket */
ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
if (ret != sizeof(fd)) {
- lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
+ rcu_read_unlock();
return ret;
}
- DBG("consumer_add_stream %s (%d)", msg.u.stream.path_name,
- fd);
- new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
- msg.u.stream.stream_key,
- fd, fd,
- msg.u.stream.state,
- msg.u.stream.mmap_len,
- msg.u.stream.output,
- msg.u.stream.path_name,
- msg.u.stream.uid,
- msg.u.stream.gid);
+ /*
+ * Send status code to session daemon only if the recv works. If the
+ * above recv() failed, the session daemon is notified through the
+ * error socket and the teardown is eventually done.
+ */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
+ new_stream = consumer_allocate_stream(channel->key,
+ fd,
+ LTTNG_CONSUMER_ACTIVE_STREAM,
+ channel->name,
+ channel->uid,
+ channel->gid,
+ channel->relayd_id,
+ channel->session_id,
+ msg.u.stream.cpu,
+ &alloc_ret,
+ channel->type);
if (new_stream == NULL) {
- lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
- goto end;
+ switch (alloc_ret) {
+ case -ENOMEM:
+ case -EINVAL:
+ default:
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
+ break;
+ }
+ goto end_nosignal;
+ }
+ new_stream->chan = channel;
+ new_stream->wait_fd = fd;
+
+ /* Metadata chan refcount is increment in add_metadata_stream */
+ if (new_stream->chan->type != CONSUMER_CHANNEL_TYPE_METADATA) {
+ /* Update channel refcount */
+ uatomic_inc(&new_stream->chan->refcount);
+ }
+
+ /*
+ * The buffer flush is done on the session daemon side for the kernel
+ * so no need for the stream "hangup_flush_done" variable to be
+ * tracked. This is important for a kernel stream since we don't rely
+ * on the flush state of the stream to read data. It's not the case for
+ * user space tracing.
+ */
+ new_stream->hangup_flush_done = 0;
+
+ /* The stream is not metadata. Get relayd reference if exists. */
+ relayd = consumer_find_relayd(new_stream->net_seq_idx);
+ if (relayd != NULL) {
+ /* Add stream on the relayd */
+ pthread_mutex_lock(&relayd->ctrl_sock_mutex);
+ ret = relayd_add_stream(&relayd->control_sock,
+ new_stream->name, new_stream->chan->pathname,
+ &new_stream->relayd_stream_id,
+ new_stream->chan->tracefile_size,
+ new_stream->chan->tracefile_count);
+ pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
+ if (ret < 0) {
+ consumer_del_stream(new_stream, NULL);
+ goto end_nosignal;
+ }
+ } else if (new_stream->net_seq_idx != (uint64_t) -1ULL) {
+ ERR("Network sequence index %" PRIu64 " unknown. Not adding stream.",
+ new_stream->net_seq_idx);
+ consumer_del_stream(new_stream, NULL);
+ goto end_nosignal;
}
- if (ctx->on_recv_stream != NULL) {
+
+ if (ctx->on_recv_stream) {
ret = ctx->on_recv_stream(new_stream);
- if (ret == 0) {
- consumer_add_stream(new_stream);
- } else if (ret < 0) {
- goto end;
+ if (ret < 0) {
+ consumer_del_stream(new_stream, NULL);
+ goto end_nosignal;
}
+ }
+
+ /* Get the right pipe where the stream will be sent. */
+ if (new_stream->metadata_flag) {
+ stream_pipe = ctx->consumer_metadata_pipe;
} else {
- consumer_add_stream(new_stream);
+ stream_pipe = ctx->consumer_data_pipe;
+ }
+
+ ret = lttng_pipe_write(stream_pipe, &new_stream, sizeof(new_stream));
+ if (ret < 0) {
+ ERR("Consumer write %s stream to pipe %d",
+ new_stream->metadata_flag ? "metadata" : "data",
+ lttng_pipe_get_writefd(stream_pipe));
+ consumer_del_stream(new_stream, NULL);
+ goto end_nosignal;
}
+
+ DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64,
+ new_stream->name, fd, new_stream->relayd_stream_id);
break;
}
case LTTNG_CONSUMER_UPDATE_STREAM:
{
- if (ctx->on_update_stream != NULL) {
- ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state);
- if (ret == 0) {
- consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state);
- } else if (ret < 0) {
- goto end;
- }
- } else {
- consumer_change_stream_state(msg.u.stream.stream_key,
- msg.u.stream.state);
+ rcu_read_unlock();
+ return -ENOSYS;
+ }
+ case LTTNG_CONSUMER_DESTROY_RELAYD:
+ {
+ uint64_t index = msg.u.destroy_relayd.net_seq_idx;
+ struct consumer_relayd_sock_pair *relayd;
+
+ DBG("Kernel consumer destroying relayd %" PRIu64, index);
+
+ /* Get relayd reference if exists. */
+ relayd = consumer_find_relayd(index);
+ if (relayd == NULL) {
+ DBG("Unable to find relayd %" PRIu64, index);
+ ret_code = LTTNG_ERR_NO_CONSUMER;
}
- break;
+
+ /*
+ * Each relayd socket pair has a refcount of stream attached to it
+ * which tells if the relayd is still active or not depending on the
+ * refcount value.
+ *
+ * This will set the destroy flag of the relayd object and destroy it
+ * if the refcount reaches zero when called.
+ *
+ * The destroy can happen either here or when a stream fd hangs up.
+ */
+ if (relayd) {
+ consumer_flag_relayd_for_destroy(relayd);
+ }
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
+ goto end_nosignal;
}
- default:
+ case LTTNG_CONSUMER_DATA_PENDING:
+ {
+ int32_t ret;
+ uint64_t id = msg.u.data_pending.session_id;
+
+ DBG("Kernel consumer data pending command for id %" PRIu64, id);
+
+ ret = consumer_data_pending(id);
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+ if (ret < 0) {
+ PERROR("send data pending ret code");
+ }
+
+ /*
+ * No need to send back a status message since the data pending
+ * returned value is the response.
+ */
break;
}
-end:
- /* signal the poll thread */
- ret = write(ctx->consumer_poll_pipe[1], "4", 1);
- if (ret < 0) {
- perror("write consumer poll");
+ default:
+ goto end_nosignal;
}
+
end_nosignal:
- return 0;
+ rcu_read_unlock();
+
+ /*
+ * Return 1 to indicate success since the 0 value can be a socket
+ * shutdown during the recv() or send() call.
+ */
+ return 1;
}
/*
ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
struct lttng_consumer_local_data *ctx)
{
- unsigned long len;
+ unsigned long len, subbuf_size, padding;
int err;
ssize_t ret = 0;
int infd = stream->wait_fd;
/* Get the next subbuffer */
err = kernctl_get_next_subbuf(infd);
if (err != 0) {
+ ret = err;
/*
* This is a debug message even for single-threaded consumer,
* because poll() have more relaxed criterions than get subbuf,
goto end;
}
- switch (stream->output) {
- case LTTNG_EVENT_SPLICE:
- /* read the whole subbuffer */
- err = kernctl_get_padded_subbuf_size(infd, &len);
- if (err != 0) {
- errno = -ret;
- perror("Getting sub-buffer len failed.");
- goto end;
- }
+ /* Get the full subbuffer size including padding */
+ err = kernctl_get_padded_subbuf_size(infd, &len);
+ if (err != 0) {
+ errno = -err;
+ perror("Getting sub-buffer len failed.");
+ ret = err;
+ goto end;
+ }
- /* splice the subbuffer to the tracefile */
- ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len);
- if (ret < 0) {
- /*
- * display the error but continue processing to try
- * to release the subbuffer
- */
- ERR("Error splicing to tracefile");
- }
- break;
- case LTTNG_EVENT_MMAP:
- /* read the used subbuffer size */
- err = kernctl_get_padded_subbuf_size(infd, &len);
- if (err != 0) {
- errno = -ret;
- perror("Getting sub-buffer len failed.");
- goto end;
- }
- /* write the subbuffer to the tracefile */
- ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
- if (ret < 0) {
- /*
- * display the error but continue processing to try
- * to release the subbuffer
- */
- ERR("Error writing to tracefile");
- }
- break;
- default:
- ERR("Unknown output method");
- ret = -1;
+ switch (stream->chan->output) {
+ case LTTNG_EVENT_SPLICE:
+
+ /*
+ * XXX: The lttng-modules splice "actor" does not handle copying
+ * partial pages hence only using the subbuffer size without the
+ * padding makes the splice fail.
+ */
+ subbuf_size = len;
+ padding = 0;
+
+ /* splice the subbuffer to the tracefile */
+ ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, subbuf_size,
+ padding);
+ /*
+ * XXX: Splice does not support network streaming so the return value
+ * is simply checked against subbuf_size and not like the mmap() op.
+ */
+ if (ret != subbuf_size) {
+ /*
+ * display the error but continue processing to try
+ * to release the subbuffer
+ */
+ ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
+ ret, subbuf_size);
+ }
+ break;
+ case LTTNG_EVENT_MMAP:
+ /* Get subbuffer size without padding */
+ err = kernctl_get_subbuf_size(infd, &subbuf_size);
+ if (err != 0) {
+ errno = -err;
+ perror("Getting sub-buffer len failed.");
+ ret = err;
+ goto end;
+ }
+
+ /* Make sure the tracer is not gone mad on us! */
+ assert(len >= subbuf_size);
+
+ padding = len - subbuf_size;
+
+ /* write the subbuffer to the tracefile */
+ ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size,
+ padding);
+ /*
+ * The mmap operation should write subbuf_size amount of data when
+ * network streaming or the full padding (len) size when we are _not_
+ * streaming.
+ */
+ if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
+ (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
+ /*
+ * Display the error but continue processing to try to release the
+ * subbuffer
+ */
+ ERR("Error writing to tracefile "
+ "(ret: %zd != len: %lu != subbuf_size: %lu)",
+ ret, len, subbuf_size);
+ }
+ break;
+ default:
+ ERR("Unknown output method");
+ ret = -1;
}
err = kernctl_put_next_subbuf(infd);
if (err != 0) {
- errno = -ret;
+ errno = -err;
if (errno == EFAULT) {
perror("Error in unreserving sub buffer\n");
} else if (errno == EIO) {
/* Should never happen with newer LTTng versions */
perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
}
+
+ ret = -err;
goto end;
}
{
int ret;
- /* Opening the tracefile in write mode */
- if (stream->path_name != NULL) {
- ret = run_as_open(stream->path_name,
- O_WRONLY|O_CREAT|O_TRUNC,
- S_IRWXU|S_IRWXG|S_IRWXO,
+ assert(stream);
+
+ /* Don't create anything if this is set for streaming. */
+ if (stream->net_seq_idx == (uint64_t) -1ULL) {
+ ret = utils_create_stream_file(stream->chan->pathname, stream->name,
+ stream->chan->tracefile_size, stream->tracefile_count_current,
stream->uid, stream->gid);
if (ret < 0) {
- ERR("Opening %s", stream->path_name);
- perror("open");
goto error;
}
stream->out_fd = ret;
+ stream->tracefile_size_current = 0;
}
if (stream->output == LTTNG_EVENT_MMAP) {
ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
if (ret != 0) {
errno = -ret;
- perror("kernctl_get_mmap_len");
+ PERROR("kernctl_get_mmap_len");
goto error_close_fd;
}
stream->mmap_len = (size_t) mmap_len;
- stream->mmap_base = mmap(NULL, stream->mmap_len,
- PROT_READ, MAP_PRIVATE, stream->wait_fd, 0);
+ stream->mmap_base = mmap(NULL, stream->mmap_len, PROT_READ,
+ MAP_PRIVATE, stream->wait_fd, 0);
if (stream->mmap_base == MAP_FAILED) {
- perror("Error mmaping");
+ PERROR("Error mmaping");
ret = -1;
goto error_close_fd;
}
return ret;
}
+/*
+ * Check if data is still being extracted from the buffers for a specific
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
+ *
+ * Return 1 if the traced data are still getting read else 0 meaning that the
+ * data is available for trace viewer reading.
+ */
+int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ assert(stream);
+
+ ret = kernctl_get_next_subbuf(stream->wait_fd);
+ if (ret == 0) {
+ /* There is still data so let's put back this subbuffer. */
+ ret = kernctl_put_subbuf(stream->wait_fd);
+ assert(ret == 0);
+ ret = 1; /* Data is pending */
+ goto end;
+ }
+
+ /* Data is NOT pending and ready to be read. */
+ ret = 0;
+
+end:
+ return ret;
+}
projects / lttng-tools.git / blobdiff