liblttkconsumerd/liblttkconsumerd.h

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; only version 2
   7  * of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #ifndef _LIBLTTKCONSUMERD_H
  20 #define _LIBLTTKCONSUMERD_H
  21
  22 #include "lttng-kconsumerd.h"
  23 #include "liblttsessiondcomm.h"
  24
  25 /*
  26  * When the receiving thread dies, we need to have a way to make
  27  * the polling thread exit eventually.
  28  * If all FDs hang up (normal case when the ltt-sessiond stops),
  29  * we can exit cleanly, but if there is a problem and for whatever
  30  * reason some FDs remain open, the consumer should still exit eventually.
  31  *
  32  * If the timeout is reached, it means that during this period
  33  * no events occurred on the FDs so we need to force an exit.
  34  * This case should not happen but it is a safety to ensure we won't block
  35  * the consumer indefinitely.
  36  *
  37  * The value of 2 seconds is an arbitrary choice.
  38  */
  39 #define KCONSUMERD_POLL_GRACE_PERIOD 2000
  40
  41 struct kconsumerd_fd_list {
  42         struct cds_list_head head;
  43 };
  44
  45 /*
  46  * Internal representation of the FDs,
  47  * sessiond_fd is used to identify uniquely a fd
  48  */
  49 struct kconsumerd_fd {
  50         struct cds_list_head list;
  51         int sessiond_fd; /* used to identify uniquely a fd with sessiond */
  52         int consumerd_fd; /* fd to consume */
  53         int out_fd; /* output file to write the data */
  54         off_t out_fd_offset; /* write position in the output file descriptor */
  55         char path_name[PATH_MAX]; /* tracefile name */
  56         enum kconsumerd_fd_state state;
  57         unsigned long max_sb_size; /* the subbuffer size for this channel */
  58 };
  59
  60 int kconsumerd_init(void);
  61 int kconsumerd_send_error(enum lttcomm_return_code cmd);
  62 int kconsumerd_poll_socket(struct pollfd *kconsumerd_sockpoll);
  63 void *kconsumerd_thread_poll_fds(void *data);
  64 void *kconsumerd_thread_receive_fds(void *data);
  65 void kconsumerd_should_exit(void);
  66 void kconsumerd_cleanup(void);
  67 void kconsumerd_set_error_socket(int sock);
  68 void kconsumerd_set_command_socket_path(char *sock);
  69
  70 #endif /* _LIBLTTKCONSUMERD_H */