--- /dev/null
+/*
+ * 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 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.
+ */
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <lttng-kernel-ctl.h>
+#include <lttng-sessiond-comm.h>
+#include <lttng/lttng-consumer.h>
+#include <lttng/lttng-kconsumer.h>
+#include <lttng/lttng-ustconsumer.h>
+#include <lttngerr.h>
+
+struct lttng_consumer_global_data consumer_data = {
+ .stream_list.head = CDS_LIST_HEAD_INIT(consumer_data.stream_list.head),
+ .channel_list.head = CDS_LIST_HEAD_INIT(consumer_data.channel_list.head),
+ .stream_count = 0,
+ .need_update = 1,
+ .type = LTTNG_CONSUMER_UNKNOWN,
+};
+
+/* timeout parameter, to control the polling thread grace period. */
+int consumer_poll_timeout = -1;
+
+/*
+ * Flag to inform the polling thread to quit when all fd hung up. Updated by
+ * the consumer_thread_receive_fds when it notices that all fds has hung up.
+ * Also updated by the signal handler (consumer_should_exit()). Read by the
+ * polling threads.
+ */
+volatile int consumer_quit = 0;
+
+/*
+ * Find a stream. The consumer_data.lock must be locked during this
+ * call.
+ */
+static struct lttng_consumer_stream *consumer_find_stream(int key)
+{
+ struct lttng_consumer_stream *iter;
+
+ cds_list_for_each_entry(iter, &consumer_data.stream_list.head, list) {
+ if (iter->key == key) {
+ DBG("Found stream key %d", key);
+ return iter;
+ }
+ }
+ return NULL;
+}
+
+static struct lttng_consumer_channel *consumer_find_channel(int key)
+{
+ struct lttng_consumer_channel *iter;
+
+ cds_list_for_each_entry(iter, &consumer_data.channel_list.head, list) {
+ if (iter->key == key) {
+ DBG("Found channel key %d", key);
+ return iter;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * Remove a stream from the global list protected by a mutex. This
+ * function is also responsible for freeing its data structures.
+ */
+void consumer_del_stream(struct lttng_consumer_stream *stream)
+{
+ int ret;
+ struct lttng_consumer_channel *free_chan = NULL;
+
+ pthread_mutex_lock(&consumer_data.lock);
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ if (stream->mmap_base != NULL) {
+ ret = munmap(stream->mmap_base, stream->mmap_len);
+ if (ret != 0) {
+ perror("munmap");
+ }
+ }
+ break;
+ case LTTNG_CONSUMER_UST:
+ lttng_ustconsumer_del_stream(stream);
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+
+ cds_list_del(&stream->list);
+ if (consumer_data.stream_count <= 0) {
+ goto end;
+ }
+ consumer_data.stream_count--;
+ if (!stream) {
+ goto end;
+ }
+ if (stream->out_fd >= 0) {
+ close(stream->out_fd);
+ }
+ if (stream->wait_fd >= 0) {
+ close(stream->wait_fd);
+ }
+ if (stream->shm_fd >= 0 && stream->wait_fd != stream->shm_fd) {
+ close(stream->shm_fd);
+ }
+ if (!--stream->chan->refcount)
+ free_chan = stream->chan;
+ free(stream);
+end:
+ consumer_data.need_update = 1;
+ pthread_mutex_unlock(&consumer_data.lock);
+
+ if (free_chan)
+ consumer_del_channel(free_chan);
+}
+
+struct lttng_consumer_stream *consumer_allocate_stream(
+ int channel_key, int stream_key,
+ int shm_fd, int wait_fd,
+ enum lttng_consumer_stream_state state,
+ uint64_t mmap_len,
+ enum lttng_event_output output,
+ const char *path_name)
+{
+ struct lttng_consumer_stream *stream;
+ int ret;
+
+ stream = malloc(sizeof(*stream));
+ if (stream == NULL) {
+ perror("malloc struct lttng_consumer_stream");
+ goto end;
+ }
+ stream->chan = consumer_find_channel(channel_key);
+ if (!stream->chan) {
+ perror("Unable to find channel key");
+ goto end;
+ }
+ stream->chan->refcount++;
+ stream->key = stream_key;
+ stream->shm_fd = shm_fd;
+ stream->wait_fd = wait_fd;
+ stream->out_fd = -1;
+ stream->out_fd_offset = 0;
+ stream->state = state;
+ stream->mmap_len = mmap_len;
+ stream->mmap_base = NULL;
+ stream->output = output;
+ strncpy(stream->path_name, path_name, PATH_MAX - 1);
+ stream->path_name[PATH_MAX - 1] = '\0';
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ break;
+ case LTTNG_CONSUMER_UST:
+ ret = lttng_ustconsumer_allocate_stream(stream);
+ if (ret) {
+ free(stream);
+ return NULL;
+ }
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+ DBG("Allocated stream %s (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, out_fd %d)",
+ stream->path_name, stream->key,
+ stream->shm_fd,
+ stream->wait_fd,
+ (unsigned long long) stream->mmap_len,
+ stream->out_fd);
+end:
+ return stream;
+}
+
+/*
+ * Add a stream to the global list protected by a mutex.
+ */
+int consumer_add_stream(struct lttng_consumer_stream *stream)
+{
+ int ret = 0;
+
+ pthread_mutex_lock(&consumer_data.lock);
+ /* Check if already exist */
+ if (consumer_find_stream(stream->key)) {
+ ret = -1;
+ goto end;
+ }
+ cds_list_add(&stream->list, &consumer_data.stream_list.head);
+ consumer_data.stream_count++;
+ consumer_data.need_update = 1;
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ break;
+ case LTTNG_CONSUMER_UST:
+ /* Streams are in CPU number order (we rely on this) */
+ stream->cpu = stream->chan->nr_streams++;
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+
+end:
+ pthread_mutex_unlock(&consumer_data.lock);
+ return ret;
+}
+
+/*
+ * Update a stream according to what we just received.
+ */
+void consumer_change_stream_state(int stream_key,
+ enum lttng_consumer_stream_state state)
+{
+ struct lttng_consumer_stream *stream;
+
+ pthread_mutex_lock(&consumer_data.lock);
+ stream = consumer_find_stream(stream_key);
+ if (stream) {
+ stream->state = state;
+ }
+ consumer_data.need_update = 1;
+ pthread_mutex_unlock(&consumer_data.lock);
+}
+
+/*
+ * Remove a channel from the global list protected by a mutex. This
+ * function is also responsible for freeing its data structures.
+ */
+void consumer_del_channel(struct lttng_consumer_channel *channel)
+{
+ int ret;
+
+ pthread_mutex_lock(&consumer_data.lock);
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ break;
+ case LTTNG_CONSUMER_UST:
+ lttng_ustconsumer_del_channel(channel);
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+
+ cds_list_del(&channel->list);
+ if (channel->mmap_base != NULL) {
+ ret = munmap(channel->mmap_base, channel->mmap_len);
+ if (ret != 0) {
+ perror("munmap");
+ }
+ }
+ if (channel->wait_fd >= 0) {
+ close(channel->wait_fd);
+ }
+ if (channel->shm_fd >= 0 && channel->wait_fd != channel->shm_fd) {
+ close(channel->shm_fd);
+ }
+ free(channel);
+end:
+ pthread_mutex_unlock(&consumer_data.lock);
+}
+
+struct lttng_consumer_channel *consumer_allocate_channel(
+ int channel_key,
+ int shm_fd, int wait_fd,
+ uint64_t mmap_len,
+ uint64_t max_sb_size)
+{
+ struct lttng_consumer_channel *channel;
+ int ret;
+
+ channel = malloc(sizeof(*channel));
+ if (channel == NULL) {
+ perror("malloc struct lttng_consumer_channel");
+ goto end;
+ }
+ channel->key = channel_key;
+ channel->shm_fd = shm_fd;
+ channel->wait_fd = wait_fd;
+ channel->mmap_len = mmap_len;
+ channel->max_sb_size = max_sb_size;
+ channel->refcount = 0;
+ channel->nr_streams = 0;
+
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ channel->mmap_base = NULL;
+ channel->mmap_len = 0;
+ break;
+ case LTTNG_CONSUMER_UST:
+ ret = lttng_ustconsumer_allocate_channel(channel);
+ if (ret) {
+ free(channel);
+ return NULL;
+ }
+ break;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ goto end;
+ }
+ DBG("Allocated channel (key %d, shm_fd %d, wait_fd %d, mmap_len %llu, max_sb_size %llu)",
+ channel->key,
+ channel->shm_fd,
+ channel->wait_fd,
+ (unsigned long long) channel->mmap_len,
+ (unsigned long long) channel->max_sb_size);
+end:
+ return channel;
+}
+
+/*
+ * Add a channel to the global list protected by a mutex.
+ */
+int consumer_add_channel(struct lttng_consumer_channel *channel)
+{
+ int ret = 0;
+
+ pthread_mutex_lock(&consumer_data.lock);
+ /* Check if already exist */
+ if (consumer_find_channel(channel->key)) {
+ ret = -1;
+ goto end;
+ }
+ cds_list_add(&channel->list, &consumer_data.channel_list.head);
+end:
+ pthread_mutex_unlock(&consumer_data.lock);
+ return ret;
+}
+
+/*
+ * Allocate the pollfd structure and the local view of the out fds to avoid
+ * doing a lookup in the linked list and concurrency issues when writing is
+ * needed. Called with consumer_data.lock held.
+ *
+ * Returns the number of fds in the structures.
+ */
+int consumer_update_poll_array(
+ struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
+ struct lttng_consumer_stream **local_stream)
+{
+ struct lttng_consumer_stream *iter;
+ int i = 0;
+
+ DBG("Updating poll fd array");
+ cds_list_for_each_entry(iter, &consumer_data.stream_list.head, list) {
+ if (iter->state != LTTNG_CONSUMER_ACTIVE_STREAM) {
+ continue;
+ }
+ DBG("Active FD %d", iter->wait_fd);
+ (*pollfd)[i].fd = iter->wait_fd;
+ (*pollfd)[i].events = POLLIN | POLLPRI;
+ local_stream[i] = iter;
+ i++;
+ }
+
+ /*
+ * 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;
+ return i;
+}
+
+/*
+ * Poll on the should_quit pipe and the command socket return -1 on error and
+ * should exit, 0 if data is available on the command socket
+ */
+int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll)
+{
+ int num_rdy;
+
+ num_rdy = poll(consumer_sockpoll, 2, -1);
+ if (num_rdy == -1) {
+ perror("Poll error");
+ goto exit;
+ }
+ if (consumer_sockpoll[0].revents == POLLIN) {
+ DBG("consumer_should_quit wake up");
+ goto exit;
+ }
+ return 0;
+
+exit:
+ return -1;
+}
+
+/*
+ * Set the error socket.
+ */
+void lttng_consumer_set_error_sock(
+ struct lttng_consumer_local_data *ctx, int sock)
+{
+ ctx->consumer_error_socket = sock;
+}
+
+/*
+ * Set the command socket path.
+ */
+
+void lttng_consumer_set_command_sock_path(
+ struct lttng_consumer_local_data *ctx, char *sock)
+{
+ ctx->consumer_command_sock_path = sock;
+}
+
+/*
+ * Send return code to the session daemon.
+ * If the socket is not defined, we return 0, it is not a fatal error
+ */
+int lttng_consumer_send_error(
+ struct lttng_consumer_local_data *ctx, int cmd)
+{
+ if (ctx->consumer_error_socket > 0) {
+ return lttcomm_send_unix_sock(ctx->consumer_error_socket, &cmd,
+ sizeof(enum lttcomm_sessiond_command));
+ }
+
+ return 0;
+}
+
+/*
+ * Close all the tracefiles and stream fds, should be called when all instances
+ * are destroyed.
+ */
+void lttng_consumer_cleanup(void)
+{
+ struct lttng_consumer_stream *iter, *tmp;
+ struct lttng_consumer_channel *citer, *ctmp;
+
+ /*
+ * close all outfd. Called when there are no more threads
+ * running (after joining on the threads), no need to protect
+ * list iteration with mutex.
+ */
+ cds_list_for_each_entry_safe(iter, tmp,
+ &consumer_data.stream_list.head, list) {
+ consumer_del_stream(iter);
+ }
+ cds_list_for_each_entry_safe(citer, ctmp,
+ &consumer_data.channel_list.head, list) {
+ consumer_del_channel(citer);
+ }
+}
+
+/*
+ * Called from signal handler.
+ */
+void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ consumer_quit = 1;
+ ret = write(ctx->consumer_should_quit[1], "4", 1);
+ if (ret < 0) {
+ perror("write consumer quit");
+ }
+}
+
+void lttng_consumer_sync_trace_file(
+ struct lttng_consumer_stream *stream, off_t orig_offset)
+{
+ int outfd = stream->out_fd;
+
+ /*
+ * This does a blocking write-and-wait on any page that belongs to the
+ * subbuffer prior to the one we just wrote.
+ * Don't care about error values, as these are just hints and ways to
+ * limit the amount of page cache used.
+ */
+ if (orig_offset < stream->chan->max_sb_size) {
+ return;
+ }
+ 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
+ | SYNC_FILE_RANGE_WAIT_AFTER);
+ /*
+ * Give hints to the kernel about how we access the file:
+ * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
+ * we write it.
+ *
+ * We need to call fadvise again after the file grows because the
+ * kernel does not seem to apply fadvise to non-existing parts of the
+ * file.
+ *
+ * Call fadvise _after_ having waited for the page writeback to
+ * complete because the dirty page writeback semantic is not well
+ * defined. So it can be expected to lead to lower throughput in
+ * streaming.
+ */
+ posix_fadvise(outfd, orig_offset - stream->chan->max_sb_size,
+ stream->chan->max_sb_size, POSIX_FADV_DONTNEED);
+}
+
+/*
+ * Initialise the necessary environnement :
+ * - create a new context
+ * - create the poll_pipe
+ * - create the should_quit pipe (for signal handler)
+ * - create the thread pipe (for splice)
+ *
+ * Takes a function pointer as argument, this function is called when data is
+ * available on a buffer. This function is responsible to do the
+ * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
+ * buffer configuration and then kernctl_put_next_subbuf at the end.
+ *
+ * Returns a pointer to the new context or NULL on error.
+ */
+struct lttng_consumer_local_data *lttng_consumer_create(
+ enum lttng_consumer_type type,
+ int (*buffer_ready)(struct lttng_consumer_stream *stream),
+ int (*recv_channel)(struct lttng_consumer_channel *channel),
+ int (*recv_stream)(struct lttng_consumer_stream *stream),
+ int (*update_stream)(int stream_key, uint32_t state))
+{
+ int ret, i;
+ struct lttng_consumer_local_data *ctx;
+
+ assert(consumer_data.type == LTTNG_CONSUMER_UNKNOWN ||
+ consumer_data.type == type);
+ consumer_data.type = type;
+
+ ctx = malloc(sizeof(struct lttng_consumer_local_data));
+ if (ctx == NULL) {
+ perror("allocating context");
+ goto error;
+ }
+
+ ctx->consumer_error_socket = -1;
+ /* assign the callbacks */
+ ctx->on_buffer_ready = buffer_ready;
+ ctx->on_recv_channel = recv_channel;
+ ctx->on_recv_stream = recv_stream;
+ ctx->on_update_stream = update_stream;
+
+ ret = pipe(ctx->consumer_poll_pipe);
+ if (ret < 0) {
+ perror("Error creating poll pipe");
+ goto error_poll_pipe;
+ }
+
+ ret = pipe(ctx->consumer_should_quit);
+ if (ret < 0) {
+ perror("Error creating recv pipe");
+ goto error_quit_pipe;
+ }
+
+ ret = pipe(ctx->consumer_thread_pipe);
+ if (ret < 0) {
+ perror("Error creating thread pipe");
+ goto error_thread_pipe;
+ }
+
+ return ctx;
+
+
+error_thread_pipe:
+ for (i = 0; i < 2; i++) {
+ int err;
+
+ err = close(ctx->consumer_should_quit[i]);
+ assert(!err);
+ }
+error_quit_pipe:
+ for (i = 0; i < 2; i++) {
+ int err;
+
+ err = close(ctx->consumer_poll_pipe[i]);
+ assert(!err);
+ }
+error_poll_pipe:
+ free(ctx);
+error:
+ return NULL;
+}
+
+/*
+ * Close all fds associated with the instance and free the context.
+ */
+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]);
+ unlink(ctx->consumer_command_sock_path);
+ free(ctx);
+}
+
+/*
+ * Mmap the ring buffer, read it and write the data to the tracefile.
+ *
+ * Returns the number of bytes written
+ */
+int lttng_consumer_on_read_subbuffer_mmap(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream, unsigned long len)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_on_read_subbuffer_mmap(ctx, stream, len);
+ case LTTNG_CONSUMER_UST:
+ return lttng_ustconsumer_on_read_subbuffer_mmap(ctx, stream, len);
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ }
+}
+
+/*
+ * Splice the data from the ring buffer to the tracefile.
+ *
+ * Returns the number of bytes spliced.
+ */
+int lttng_consumer_on_read_subbuffer_splice(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream, unsigned long len)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_on_read_subbuffer_splice(ctx, stream, len);
+ case LTTNG_CONSUMER_UST:
+ return -ENOSYS;
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ return -ENOSYS;
+ }
+
+}
+
+/*
+ * Take a snapshot for a specific fd
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_take_snapshot(ctx, stream);
+ case LTTNG_CONSUMER_UST:
+ return lttng_ustconsumer_take_snapshot(ctx, stream);
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ return -ENOSYS;
+ }
+
+}
+
+/*
+ * Get the produced position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_consumer_get_produced_snapshot(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream,
+ unsigned long *pos)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_get_produced_snapshot(ctx, stream, pos);
+ case LTTNG_CONSUMER_UST:
+ return lttng_ustconsumer_get_produced_snapshot(ctx, stream, pos);
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ return -ENOSYS;
+ }
+}
+
+int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
+ int sock, struct pollfd *consumer_sockpoll)
+{
+ switch (consumer_data.type) {
+ case LTTNG_CONSUMER_KERNEL:
+ return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
+ case LTTNG_CONSUMER_UST:
+ return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
+ default:
+ ERR("Unknown consumer_data type");
+ assert(0);
+ return -ENOSYS;
+ }
+}
+
+/*
+ * This thread polls the fds in the ltt_fd_list to consume the data and write
+ * it to tracefile if necessary.
+ */
+void *lttng_consumer_thread_poll_fds(void *data)
+{
+ int num_rdy, num_hup, high_prio, ret, i;
+ struct pollfd *pollfd = NULL;
+ /* local view of the streams */
+ 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;
+
+ local_stream = malloc(sizeof(struct lttng_consumer_stream));
+
+ while (1) {
+ high_prio = 0;
+ num_hup = 0;
+
+ /*
+ * the ltt_fd_list has been updated, we need to update our
+ * local array as well
+ */
+ pthread_mutex_lock(&consumer_data.lock);
+ if (consumer_data.need_update) {
+ if (pollfd != NULL) {
+ free(pollfd);
+ pollfd = NULL;
+ }
+ if (local_stream != NULL) {
+ free(local_stream);
+ local_stream = NULL;
+ }
+
+ /* allocate for all fds + 1 for the consumer_poll_pipe */
+ pollfd = malloc((consumer_data.stream_count + 1) * sizeof(struct pollfd));
+ if (pollfd == NULL) {
+ perror("pollfd malloc");
+ pthread_mutex_unlock(&consumer_data.lock);
+ goto end;
+ }
+
+ /* allocate for all fds + 1 for the consumer_poll_pipe */
+ local_stream = malloc((consumer_data.stream_count + 1) *
+ sizeof(struct lttng_consumer_stream));
+ if (local_stream == NULL) {
+ perror("local_stream malloc");
+ pthread_mutex_unlock(&consumer_data.lock);
+ goto end;
+ }
+ ret = consumer_update_poll_array(ctx, &pollfd, local_stream);
+ if (ret < 0) {
+ ERR("Error in allocating pollfd or local_outfds");
+ lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR);
+ pthread_mutex_unlock(&consumer_data.lock);
+ goto end;
+ }
+ nb_fd = ret;
+ consumer_data.need_update = 0;
+ }
+ pthread_mutex_unlock(&consumer_data.lock);
+
+ /* poll on the array of fds */
+ 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) {
+ perror("Poll error");
+ lttng_consumer_send_error(ctx, CONSUMERD_POLL_ERROR);
+ goto end;
+ } else if (num_rdy == 0) {
+ DBG("Polling thread timed out");
+ goto end;
+ }
+
+ /* No FDs and consumer_quit, kconsumer_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) {
+ DBG("consumer_poll_pipe wake up");
+ tmp2 = read(ctx->consumer_poll_pipe[0], &tmp, 1);
+ if (tmp2 < 0) {
+ perror("read kconsumer poll");
+ }
+ continue;
+ }
+
+ /* Take care of high priority channels first. */
+ for (i = 0; i < nb_fd; i++) {
+ switch(pollfd[i].revents) {
+ case POLLERR:
+ ERR("Error returned in polling fd %d.", pollfd[i].fd);
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ break;
+ case POLLHUP:
+ DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ break;
+ case POLLNVAL:
+ ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
+ consumer_del_stream(local_stream[i]);
+ num_hup++;
+ break;
+ case POLLPRI:
+ DBG("Urgent read on fd %d", pollfd[i].fd);
+ high_prio = 1;
+ ret = ctx->on_buffer_ready(local_stream[i]);
+ /* it's ok to have an unavailable sub-buffer */
+ if (ret == EAGAIN) {
+ ret = 0;
+ }
+ break;
+ }
+ }
+
+ /* 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;
+ }
+ 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]);
+ /* it's ok to have an unavailable subbuffer */
+ if (ret == EAGAIN) {
+ ret = 0;
+ }
+ }
+ }
+ }
+ }
+end:
+ DBG("polling thread exiting");
+ if (pollfd != NULL) {
+ free(pollfd);
+ pollfd = NULL;
+ }
+ if (local_stream != NULL) {
+ free(local_stream);
+ local_stream = NULL;
+ }
+ return NULL;
+}
+
+/*
+ * This thread listens on the consumerd socket and receives the file
+ * descriptors from the session daemon.
+ */
+void *lttng_consumer_thread_receive_fds(void *data)
+{
+ int sock, client_socket, ret;
+ /*
+ * structure to poll for incoming data on communication socket avoids
+ * making blocking sockets.
+ */
+ struct pollfd consumer_sockpoll[2];
+ struct lttng_consumer_local_data *ctx = data;
+
+ DBG("Creating command socket %s", ctx->consumer_command_sock_path);
+ unlink(ctx->consumer_command_sock_path);
+ client_socket = lttcomm_create_unix_sock(ctx->consumer_command_sock_path);
+ if (client_socket < 0) {
+ ERR("Cannot create command socket");
+ goto end;
+ }
+
+ ret = lttcomm_listen_unix_sock(client_socket);
+ if (ret < 0) {
+ goto end;
+ }
+
+ DBG("Sending ready command to ltt-sessiond");
+ ret = lttng_consumer_send_error(ctx, CONSUMERD_COMMAND_SOCK_READY);
+ /* return < 0 on error, but == 0 is not fatal */
+ if (ret < 0) {
+ ERR("Error sending ready command to ltt-sessiond");
+ goto end;
+ }
+
+ ret = fcntl(client_socket, F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ perror("fcntl O_NONBLOCK");
+ goto end;
+ }
+
+ /* prepare the FDs to poll : to client socket and the should_quit pipe */
+ consumer_sockpoll[0].fd = ctx->consumer_should_quit[0];
+ consumer_sockpoll[0].events = POLLIN | POLLPRI;
+ consumer_sockpoll[1].fd = client_socket;
+ consumer_sockpoll[1].events = POLLIN | POLLPRI;
+
+ if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
+ goto end;
+ }
+ DBG("Connection on client_socket");
+
+ /* Blocking call, waiting for transmission */
+ sock = lttcomm_accept_unix_sock(client_socket);
+ if (sock <= 0) {
+ WARN("On accept");
+ goto end;
+ }
+ ret = fcntl(sock, F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ perror("fcntl O_NONBLOCK");
+ goto end;
+ }
+
+ /* update the polling structure to poll on the established socket */
+ consumer_sockpoll[1].fd = sock;
+ consumer_sockpoll[1].events = POLLIN | POLLPRI;
+
+ while (1) {
+ if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
+ goto end;
+ }
+ DBG("Incoming command on sock");
+ ret = lttng_consumer_recv_cmd(ctx, sock, consumer_sockpoll);
+ if (ret == -ENOENT) {
+ DBG("Received STOP command");
+ goto end;
+ }
+ if (ret < 0) {
+ ERR("Communication interrupted on command socket");
+ goto end;
+ }
+ if (consumer_quit) {
+ DBG("consumer_thread_receive_fds received quit from signal");
+ goto end;
+ }
+ DBG("received fds on sock");
+ }
+end:
+ DBG("consumer_thread_receive_fds exiting");
+
+ /*
+ * when all fds have hung up, the polling thread
+ * can exit cleanly
+ */
+ consumer_quit = 1;
+
+ /*
+ * 2s of grace period, if no polling events occur during
+ * this period, the polling thread will exit even if there
+ * are still open FDs (should not happen, but safety mechanism).
+ */
+ 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");
+ }
+ return NULL;
+}
projects / lttng-tools.git / blobdiff