--- /dev/null
+/*
+ * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
+ * Copyright (C) 2011 - 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.
+ */
+
+#ifndef _LTTNG_CONSUMER_H
+#define _LTTNG_CONSUMER_H
+
+#include <limits.h>
+#include <poll.h>
+#include <urcu/list.h>
+#include <lttng/lttng.h>
+
+/*
+ * When the receiving thread dies, we need to have a way to make the polling
+ * thread exit eventually. If all FDs hang up (normal case when the
+ * ltt-sessiond stops), we can exit cleanly, but if there is a problem and for
+ * whatever reason some FDs remain open, the consumer should still exit
+ * eventually.
+ *
+ * If the timeout is reached, it means that during this period no events
+ * occurred on the FDs so we need to force an exit. This case should not happen
+ * but it is a safety to ensure we won't block the consumer indefinitely.
+ *
+ * The value of 2 seconds is an arbitrary choice.
+ */
+#define LTTNG_CONSUMER_POLL_TIMEOUT 2000
+
+/* Commands for consumer */
+enum lttng_consumer_command {
+ LTTNG_CONSUMER_ADD_CHANNEL,
+ LTTNG_CONSUMER_ADD_STREAM,
+ /* pause, delete, active depending on fd state */
+ LTTNG_CONSUMER_UPDATE_STREAM,
+ /* inform the consumer to quit when all fd has hang up */
+ LTTNG_CONSUMER_STOP,
+};
+
+/* State of each fd in consumer */
+enum lttng_consumer_stream_state {
+ LTTNG_CONSUMER_ACTIVE_STREAM,
+ LTTNG_CONSUMER_PAUSE_STREAM,
+ LTTNG_CONSUMER_DELETE_STREAM,
+};
+
+struct lttng_consumer_channel_list {
+ struct cds_list_head head;
+};
+
+struct lttng_consumer_stream_list {
+ struct cds_list_head head;
+};
+
+enum lttng_consumer_type {
+ LTTNG_CONSUMER_UNKNOWN = 0,
+ LTTNG_CONSUMER_KERNEL,
+ LTTNG_CONSUMER_UST,
+};
+
+struct lttng_consumer_channel {
+ struct cds_list_head list;
+ int key;
+ uint64_t max_sb_size; /* the subbuffer size for this channel */
+ int refcount; /* Number of streams referencing this channel */
+ /* For UST */
+ int shm_fd;
+ int wait_fd;
+ void *mmap_base;
+ size_t mmap_len;
+ struct shm_handle *handle;
+ int nr_streams;
+};
+
+/* Forward declaration for UST. */
+struct lib_ring_buffer;
+
+/*
+ * Internal representation of the streams, sessiond_key is used to identify
+ * uniquely a stream.
+ */
+struct lttng_consumer_stream {
+ struct cds_list_head list;
+ struct lttng_consumer_channel *chan; /* associated channel */
+ /*
+ * key is the key used by the session daemon to refer to the
+ * object in the consumer daemon.
+ */
+ int key;
+ int shm_fd;
+ int wait_fd;
+ int out_fd; /* output file to write the data */
+ off_t out_fd_offset; /* write position in the output file descriptor */
+ char path_name[PATH_MAX]; /* tracefile name */
+ enum lttng_consumer_stream_state state;
+ size_t shm_len;
+ void *mmap_base;
+ size_t mmap_len;
+ enum lttng_event_output output; /* splice or mmap */
+ /* For UST */
+ struct lib_ring_buffer *buf;
+ int cpu;
+};
+
+/*
+ * UST consumer local data to the program. One or more instance per
+ * process.
+ */
+struct lttng_consumer_local_data {
+ /* function to call when data is available on a buffer */
+ int (*on_buffer_ready)(struct lttng_consumer_stream *stream);
+ /*
+ * function to call when we receive a new channel, it receives a
+ * newly allocated channel, depending on the return code of this
+ * function, the new channel will be handled by the application
+ * or the library.
+ *
+ * Returns:
+ * > 0 (success, FD is kept by application)
+ * == 0 (success, FD is left to library)
+ * < 0 (error)
+ */
+ int (*on_recv_channel)(struct lttng_consumer_channel *channel);
+ /*
+ * function to call when we receive a new stream, it receives a
+ * newly allocated stream, depending on the return code of this
+ * function, the new stream will be handled by the application
+ * or the library.
+ *
+ * Returns:
+ * > 0 (success, FD is kept by application)
+ * == 0 (success, FD is left to library)
+ * < 0 (error)
+ */
+ int (*on_recv_stream)(struct lttng_consumer_stream *stream);
+ /*
+ * function to call when a stream is getting updated by the session
+ * daemon, this function receives the sessiond key and the new
+ * state, depending on the return code of this function the
+ * update of state for the stream is handled by the application
+ * or the library.
+ *
+ * Returns:
+ * > 0 (success, FD is kept by application)
+ * == 0 (success, FD is left to library)
+ * < 0 (error)
+ */
+ int (*on_update_stream)(int sessiond_key, uint32_t state);
+ /* socket to communicate errors with sessiond */
+ int consumer_error_socket;
+ /* socket to exchange commands with sessiond */
+ char *consumer_command_sock_path;
+ /* communication with splice */
+ int consumer_thread_pipe[2];
+ /* pipe to wake the poll thread when necessary */
+ int consumer_poll_pipe[2];
+ /* to let the signal handler wake up the fd receiver thread */
+ int consumer_should_quit[2];
+};
+
+/*
+ * Library-level data. One instance per process.
+ */
+struct lttng_consumer_global_data {
+ /*
+ * consumer_data.lock protects consumer_data.fd_list,
+ * consumer_data.stream_count, and consumer_data.need_update. It
+ * ensures the count matches the number of items in the fd_list.
+ * It ensures the list updates *always* trigger an fd_array
+ * update (therefore need to make list update vs
+ * consumer_data.need_update flag update atomic, and also flag
+ * read, fd array and flag clear atomic).
+ */
+ pthread_mutex_t lock;
+ /*
+ * Number of streams in the list below. Protected by
+ * consumer_data.lock.
+ */
+ int stream_count;
+ /*
+ * Lists of streams and channels. Protected by consumer_data.lock.
+ */
+ struct lttng_consumer_stream_list stream_list;
+ struct lttng_consumer_channel_list channel_list;
+ /*
+ * Flag specifying if the local array of FDs needs update in the
+ * poll function. Protected by consumer_data.lock.
+ */
+ unsigned int need_update;
+ enum lttng_consumer_type type;
+};
+
+/*
+ * Set the error socket for communication with a session daemon.
+ */
+extern void lttng_consumer_set_error_sock(
+ struct lttng_consumer_local_data *ctx, int sock);
+
+/*
+ * Set the command socket path for communication with a session daemon.
+ */
+extern void lttng_consumer_set_command_sock_path(
+ struct lttng_consumer_local_data *ctx, char *sock);
+
+/*
+ * Send return code to session daemon.
+ *
+ * Returns the return code of sendmsg : the number of bytes transmitted or -1
+ * on error.
+ */
+extern int lttng_consumer_send_error(
+ struct lttng_consumer_local_data *ctx, int cmd);
+
+/*
+ * Called from signal handler to ensure a clean exit.
+ */
+extern void lttng_consumer_should_exit(
+ struct lttng_consumer_local_data *ctx);
+
+/*
+ * Cleanup the daemon's socket on exit.
+ */
+extern void lttng_consumer_cleanup(void);
+
+/*
+ * Flush pending writes to trace output disk file.
+ */
+extern void lttng_consumer_sync_trace_file(
+ struct lttng_consumer_stream *stream, off_t orig_offset);
+
+/*
+ * 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
+ */
+extern int lttng_consumer_poll_socket(struct pollfd *kconsumer_sockpoll);
+
+extern int consumer_update_poll_array(
+ struct lttng_consumer_local_data *ctx, struct pollfd **pollfd,
+ struct lttng_consumer_stream **local_consumer_streams);
+
+extern 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);
+extern int consumer_add_stream(struct lttng_consumer_stream *stream);
+extern void consumer_del_stream(struct lttng_consumer_stream *stream);
+extern void consumer_change_stream_state(int stream_key,
+ enum lttng_consumer_stream_state state);
+extern void consumer_del_channel(struct lttng_consumer_channel *channel);
+extern 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);
+int consumer_add_channel(struct lttng_consumer_channel *channel);
+
+extern 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 sessiond_key, uint32_t state));
+extern void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx);
+extern int lttng_consumer_on_read_subbuffer_mmap(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream, unsigned long len);
+extern int lttng_consumer_on_read_subbuffer_splice(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream, unsigned long len);
+extern int lttng_consumer_take_snapshot(struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream);
+extern int lttng_consumer_get_produced_snapshot(
+ struct lttng_consumer_local_data *ctx,
+ struct lttng_consumer_stream *stream,
+ unsigned long *pos);
+extern void *lttng_consumer_thread_poll_fds(void *data);
+extern void *lttng_consumer_thread_receive_fds(void *data);
+extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
+ int sock, struct pollfd *consumer_sockpoll);
+
+#endif /* _LTTNG_CONSUMER_H */
projects / lttng-tools.git / blobdiff