src/lxc/monitor.h

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23 #ifndef __LXC_MONITOR_H
  24 #define __LXC_MONITOR_H
  25
  26 #include <limits.h>
  27 #include <poll.h>
  28 #include <sys/param.h>
  29 #include <sys/un.h>
  30
  31 typedef enum {
  32         lxc_msg_state,
  33         lxc_msg_priority,
  34         lxc_msg_exit_code,
  35 } lxc_msg_type_t;
  36
  37 struct lxc_msg {
  38         lxc_msg_type_t type;
  39         char name[NAME_MAX+1];
  40         int value;
  41 };
  42
  43 extern int lxc_monitor_sock_name(const char *lxcpath, struct sockaddr_un *addr);
  44 extern int lxc_monitor_fifo_name(const char *lxcpath, char *fifo_path,
  45                                  size_t fifo_path_sz, int do_mkdirp);
  46 extern void lxc_monitor_send_state(const char *name, lxc_state_t state,
  47                             const char *lxcpath);
  48 extern void lxc_monitor_send_exit_code(const char *name, int exit_code,
  49                             const char *lxcpath);
  50 extern int lxc_monitord_spawn(const char *lxcpath);
  51
  52 /*
  53  * Open the monitoring mechanism for a specific container
  54  * The function will return an fd corresponding to the events
  55  * Returns a file descriptor on success, < 0 otherwise
  56  */
  57 extern int lxc_monitor_open(const char *lxcpath);
  58
  59 /*
  60  * Blocking read for the next container state change
  61  * @fd  : the file descriptor provided by lxc_monitor_open
  62  * @msg : the variable which will be filled with the state
  63  * Returns 0 if the monitored container has exited, > 0 if
  64  * data was read, < 0 otherwise
  65  */
  66 extern int lxc_monitor_read(int fd, struct lxc_msg *msg);
  67
  68 /*
  69  * Blocking read for the next container state change with timeout
  70  * @fd      : the file descriptor provided by lxc_monitor_open
  71  * @msg     : the variable which will be filled with the state
  72  * @timeout : the timeout in seconds to wait for a state change
  73  * Returns 0 if the monitored container has exited, > 0 if
  74  * data was read, < 0 otherwise
  75  */
  76 extern int lxc_monitor_read_timeout(int fd, struct lxc_msg *msg, int timeout);
  77
  78 /*
  79  * Blocking read from multiple monitors for the next container state
  80  * change with timeout
  81  * @fds     : struct pollfd describing the fds to use
  82  * @nfds    : the number of entries in fds
  83  * @msg     : the variable which will be filled with the state
  84  * @timeout : the timeout in seconds to wait for a state change
  85  * Returns 0 if the monitored container has exited, > 0 if
  86  * data was read, < 0 otherwise
  87  */
  88 extern int lxc_monitor_read_fdset(struct pollfd *fds, nfds_t nfds, struct lxc_msg *msg,
  89                            int timeout);
  90
  91
  92 #endif