+++ /dev/null
-/*
- * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
- *
- * 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_KCONSUMERD_H
-#define _LTTNG_KCONSUMERD_H
-
-#include <limits.h>
-#include <lttng/lttng.h>
-#include <poll.h>
-#include <urcu/list.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_KCONSUMERD_POLL_GRACE_PERIOD 2000
-
-/* Commands for kconsumerd */
-enum lttng_kconsumerd_command {
- ADD_STREAM,
- UPDATE_STREAM, /* pause, delete, active depending on fd state */
- STOP, /* inform the kconsumerd to quit when all fd has hang up */
-};
-
-/* State of each fd in consumerd */
-enum lttng_kconsumerd_fd_state {
- ACTIVE_FD,
- PAUSE_FD,
- DELETE_FD,
-};
-
-struct lttng_kconsumerd_fd_list {
- struct cds_list_head head;
-};
-
-/*
- * Internal representation of the FDs, sessiond_fd is used to identify uniquely
- * a fd
- */
-struct lttng_kconsumerd_fd {
- struct cds_list_head list;
- int sessiond_fd; /* used to identify uniquely a fd with sessiond */
- int consumerd_fd; /* fd to consume */
- 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_kconsumerd_fd_state state;
- unsigned long max_sb_size; /* the subbuffer size for this channel */
- void *mmap_base;
- size_t mmap_len;
- enum lttng_event_output output; /* splice or mmap */
-};
-
-/*
- * Kernel consumer local data to the program.
- */
-struct lttng_kconsumerd_local_data {
- /* function to call when data is available on a buffer */
- int (*on_buffer_ready)(struct lttng_kconsumerd_fd *kconsumerd_fd);
- /*
- * function to call when we receive a new fd, it receives a
- * newly allocated kconsumerd_fd, depending on the return code
- * of this function, the new FD 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_fd)(struct lttng_kconsumerd_fd *kconsumerd_fd);
- /*
- * function to call when a FD is getting updated by the session
- * daemon, this function receives the FD as seen by the session
- * daemon (sessiond_fd) and the new state, depending on the
- * return code of this function the update of state for the FD
- * 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_fd)(int sessiond_fd, uint32_t state);
- /* socket to communicate errors with sessiond */
- int kconsumerd_error_socket;
- /* socket to exchange commands with sessiond */
- char *kconsumerd_command_sock_path;
- /* communication with splice */
- int kconsumerd_thread_pipe[2];
- /* pipe to wake the poll thread when necessary */
- int kconsumerd_poll_pipe[2];
- /* to let the signal handler wake up the fd receiver thread */
- int kconsumerd_should_quit[2];
-};
-
-/*
- * 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 the function pointers to the on_buffer_ready, on_recv_fd, and
- * on_update_fd callbacks.
- *
- * Returns a pointer to the new context or NULL on error.
- */
-extern struct lttng_kconsumerd_local_data *lttng_kconsumerd_create(
- int (*buffer_ready)(struct lttng_kconsumerd_fd *kconsumerd_fd),
- int (*recv_fd)(struct lttng_kconsumerd_fd *kconsumerd_fd),
- int (*update_fd)(int sessiond_fd, uint32_t state));
-
-/*
- * Close all fds associated with the instance and free the context.
- */
-extern void lttng_kconsumerd_destroy(struct lttng_kconsumerd_local_data *ctx);
-
-/*
- * Mmap the ring buffer, read it and write the data to the tracefile.
- *
- * Returns the number of bytes written.
- */
-extern int lttng_kconsumerd_on_read_subbuffer_mmap(
- struct lttng_kconsumerd_local_data *ctx,
- struct lttng_kconsumerd_fd *kconsumerd_fd, unsigned long len);
-
-/*
- * Splice the data from the ring buffer to the tracefile.
- *
- * Returns the number of bytes spliced.
- */
-extern int lttng_kconsumerd_on_read_subbuffer_splice(
- struct lttng_kconsumerd_local_data *ctx,
- struct lttng_kconsumerd_fd *kconsumerd_fd, unsigned long len);
-
-/*
- * Take a snapshot for a specific fd
- *
- * Returns 0 on success, < 0 on error
- */
-int lttng_kconsumerd_take_snapshot(struct lttng_kconsumerd_local_data *ctx,
- struct lttng_kconsumerd_fd *kconsumerd_fd);
-
-/*
- * Get the produced position
- *
- * Returns 0 on success, < 0 on error
- */
-int lttng_kconsumerd_get_produced_snapshot(
- struct lttng_kconsumerd_local_data *ctx,
- struct lttng_kconsumerd_fd *kconsumerd_fd,
- unsigned long *pos);
-
-/*
- * Send return code to session daemon.
- *
- * Returns the return code of sendmsg : the number of bytes transmitted or -1
- * on error.
- */
-extern int lttng_kconsumerd_send_error(
- struct lttng_kconsumerd_local_data *ctx, int cmd);
-
-/*
- * 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_kconsumerd_poll_socket(struct pollfd *kconsumerd_sockpoll);
-
-/*
- * This thread polls the fds in the ltt_fd_list to consume the data and write
- * it to tracefile if necessary.
- */
-extern void *lttng_kconsumerd_thread_poll_fds(void *data);
-
-/*
- * This thread listens on the consumerd socket and receives the file
- * descriptors from ltt-sessiond.
- */
-extern void *lttng_kconsumerd_thread_receive_fds(void *data);
-
-/*
- * Called from signal handler to ensure a clean exit.
- */
-extern void lttng_kconsumerd_should_exit(
- struct lttng_kconsumerd_local_data *ctx);
-
-/*
- * Cleanup the daemon's socket on exit.
- */
-extern void lttng_kconsumerd_cleanup(void);
-
-/*
- * Set the error socket for communication with a session daemon.
- */
-extern void lttng_kconsumerd_set_error_sock(
- struct lttng_kconsumerd_local_data *ctx, int sock);
-
-/*
- * Set the command socket path for communication with a session daemon.
- */
-extern void lttng_kconsumerd_set_command_sock_path(
- struct lttng_kconsumerd_local_data *ctx, char *sock);
-
-#endif /* _LTTNG_KCONSUMERD_H */
projects / lttng-tools.git / blobdiff