Merge pull request #3235 from xinhua9569/master

[mirror_lxc.git] / src / lxc / monitor.h

/* SPDX-License-Identifier: LGPL-2.1+ */

#ifndef __LXC_MONITOR_H
#define __LXC_MONITOR_H

#include <limits.h>
#include <poll.h>
#include <sys/param.h>
#include <sys/un.h>

typedef enum {
	lxc_msg_state,
	lxc_msg_priority,
	lxc_msg_exit_code,
} lxc_msg_type_t;

struct lxc_msg {
	lxc_msg_type_t type;
	char name[NAME_MAX+1];
	int value;
};

extern int lxc_monitor_sock_name(const char *lxcpath, struct sockaddr_un *addr);
extern int lxc_monitor_fifo_name(const char *lxcpath, char *fifo_path,
				 size_t fifo_path_sz, int do_mkdirp);
extern void lxc_monitor_send_state(const char *name, lxc_state_t state,
			    const char *lxcpath);
extern void lxc_monitor_send_exit_code(const char *name, int exit_code,
			    const char *lxcpath);
extern int lxc_monitord_spawn(const char *lxcpath);

/*
 * Open the monitoring mechanism for a specific container
 * The function will return an fd corresponding to the events
 * Returns a file descriptor on success, < 0 otherwise
 */
extern int lxc_monitor_open(const char *lxcpath);

/*
 * Blocking read for the next container state change
 * @fd  : the file descriptor provided by lxc_monitor_open
 * @msg : the variable which will be filled with the state
 * Returns 0 if the monitored container has exited, > 0 if
 * data was read, < 0 otherwise
 */
extern int lxc_monitor_read(int fd, struct lxc_msg *msg);

/*
 * Blocking read for the next container state change with timeout
 * @fd      : the file descriptor provided by lxc_monitor_open
 * @msg     : the variable which will be filled with the state
 * @timeout : the timeout in seconds to wait for a state change
 * Returns 0 if the monitored container has exited, > 0 if
 * data was read, < 0 otherwise
 */
extern int lxc_monitor_read_timeout(int fd, struct lxc_msg *msg, int timeout);

/*
 * Blocking read from multiple monitors for the next container state
 * change with timeout
 * @fds     : struct pollfd describing the fds to use
 * @nfds    : the number of entries in fds
 * @msg     : the variable which will be filled with the state
 * @timeout : the timeout in seconds to wait for a state change
 * Returns 0 if the monitored container has exited, > 0 if
 * data was read, < 0 otherwise
 */
extern int lxc_monitor_read_fdset(struct pollfd *fds, nfds_t nfds, struct lxc_msg *msg,
			   int timeout);


#endif