[lttng-tools.git] / src / common / compat / poll.h

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef _LTT_POLL_H
#define _LTT_POLL_H

#include <string.h>
#include <unistd.h>

#include <common/common.h>

/*
 * Maximum number of fd we can monitor.
 *
 * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will
 * be used for the maximum size of the poll set. If this interface is not
 * available, according to the manpage, the max_user_watches value is 1/25 (4%)
 * of the available low memory divided by the registration cost in bytes which
 * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel.
 *
 * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
 * getrlimit(2).
 */
extern unsigned int poll_max_size;

/*
 * Used by lttng_poll_clean to free the events structure in a lttng_poll_event.
 */
static inline void __lttng_poll_free(void *events)
{
	if (events) {
		free(events);
	}
}

/*
 * epoll(7) implementation.
 */
#ifdef HAVE_EPOLL
#include <sys/epoll.h>
#include <stdio.h>

/* See man epoll(7) for this define path */
#define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches"

enum {
	/* Polling variables compatibility for epoll */
	LPOLLIN = EPOLLIN,
	LPOLLPRI = EPOLLPRI,
	LPOLLOUT = EPOLLOUT,
	LPOLLRDNORM = EPOLLRDNORM,
	LPOLLRDBAND = EPOLLRDBAND,
	LPOLLWRNORM = EPOLLWRNORM,
	LPOLLWRBAND = EPOLLWRBAND,
	LPOLLMSG = EPOLLMSG,
	LPOLLERR = EPOLLERR,
	LPOLLHUP = EPOLLHUP,
	LPOLLNVAL = EPOLLHUP,
	LPOLLRDHUP = EPOLLRDHUP,
	/* Close on exec feature of epoll */
	LTTNG_CLOEXEC = EPOLL_CLOEXEC,
};

struct compat_epoll_event {
	int epfd;
	uint32_t nb_fd;       /* Current number of fd in events */
	uint32_t alloc_size; /* Size of events array */
	uint32_t init_size;	/* Initial size of events array */
	struct epoll_event *events;
};
#define lttng_poll_event compat_epoll_event

/*
 * For the following calls, consider 'e' to be a lttng_poll_event pointer and i
 * being the index of the events array.
 */
#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd
#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events
#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size

/*
 * Create the epoll set. No memory allocation is done here.
 */
extern int compat_epoll_create(struct lttng_poll_event *events,
		int size, int flags);
#define lttng_poll_create(events, size, flags) \
	compat_epoll_create(events, size, flags)

/*
 * Wait on epoll set with the number of fd registered to the lttng_poll_event
 * data structure (events).
 */
extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout);
#define lttng_poll_wait(events, timeout) \
	compat_epoll_wait(events, timeout)

/*
 * Add a fd to the epoll set and resize the epoll_event structure if needed.
 */
extern int compat_epoll_add(struct lttng_poll_event *events,
		int fd, uint32_t req_events);
#define lttng_poll_add(events, fd, req_events) \
	compat_epoll_add(events, fd, req_events)

/*
 * Remove a fd from the epoll set.
 */
extern int compat_epoll_del(struct lttng_poll_event *events, int fd);
#define lttng_poll_del(events, fd) \
	compat_epoll_del(events, fd)

/*
 * Set up the poll set limits variable poll_max_size
 */
extern void compat_epoll_set_max_size(void);
#define lttng_poll_set_max_size() \
	compat_epoll_set_max_size()

/*
 * This function memset with zero the structure since it can be reused at each
 * round of a main loop. Being in a loop and using a non static number of fds,
 * this function must be called to insure coherent events with associted fds.
 */
static inline void lttng_poll_reset(struct lttng_poll_event *events)
{
	if (events && events->events) {
		memset(events->events, 0,
				events->nb_fd * sizeof(struct epoll_event));
	}
}

/*
 * Clean the events structure of a lttng_poll_event. It's the caller
 * responsability to free the lttng_poll_event memory.
 */
static inline void lttng_poll_clean(struct lttng_poll_event *events)
{
	int ret;

	if (events) {
		ret = close(events->epfd);
		if (ret) {
			perror("close");
		}
		__lttng_poll_free((void *) events->events);
	}
}

#else	/* HAVE_EPOLL */
/*
 * Fallback on poll(2) API
 */

/* Needed for some poll event values */
#ifndef __USE_XOPEN
#define __USE_XOPEN
#endif

/* Needed for some poll event values */
#ifndef __USE_GNU
#define __USE_GNU
#endif

#include <poll.h>
#include <stdint.h>

enum {
	/* Polling variables compatibility for poll */
	LPOLLIN = POLLIN,
	LPOLLPRI = POLLPRI,
	LPOLLOUT = POLLOUT,
	LPOLLRDNORM = POLLRDNORM,
	LPOLLRDBAND = POLLRDBAND,
	LPOLLWRNORM = POLLWRNORM,
	LPOLLWRBAND = POLLWRBAND,
#if __linux__
	LPOLLMSG = POLLMSG,
	LPOLLRDHUP = POLLRDHUP,
#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
	LPOLLMSG = 0,
	LPOLLRDHUP = 0,
#else
#error "Please add support for your OS."
#endif /* __linux__ */
	LPOLLERR = POLLERR,
	LPOLLHUP = POLLHUP | POLLNVAL,
	/* Close on exec feature does not exist for poll(2) */
	LTTNG_CLOEXEC = 0xdead,
};

struct compat_poll_event_array {
	uint32_t nb_fd;       /* Current number of fd in events */
	uint32_t alloc_size; /* Size of events array */
	/* Initial size of the pollset. We never shrink below that. */
	uint32_t init_size;
	struct pollfd *events;
};

struct compat_poll_event {
	/*
	 * Modified by the wait action. Updated using current fields if the
	 * need_update flag is set.
	 */
	struct compat_poll_event_array wait;
	/*
	 * This is modified by add/del actions being the _current_ flow of
	 * execution before a poll wait is done.
	 */
	struct compat_poll_event_array current;
	/* Indicate if wait.events needs to be realloc. */
	int need_realloc:1;
	/* Indicate if wait.events need to be updated from current. */
	int need_update:1;
};
#define lttng_poll_event compat_poll_event

/*
 * For the following calls, consider 'e' to be a lttng_poll_event pointer and i
 * being the index of the events array.
 */
#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size

/*
 * Create a pollfd structure of size 'size'.
 */
extern int compat_poll_create(struct lttng_poll_event *events, int size);
#define lttng_poll_create(events, size, flags) \
	compat_poll_create(events, size)

/*
 * Wait on poll(2) event with nb_fd registered to the lttng_poll_event data
 * structure.
 */
extern int compat_poll_wait(struct lttng_poll_event *events, int timeout);
#define lttng_poll_wait(events, timeout) \
	compat_poll_wait(events, timeout)

/*
 * Add the fd to the pollfd structure. Resize if needed.
 */
extern int compat_poll_add(struct lttng_poll_event *events,
		int fd, uint32_t req_events);
#define lttng_poll_add(events, fd, req_events) \
	compat_poll_add(events, fd, req_events)

/*
 * Remove the fd from the pollfd. Memory allocation is done to recreate a new
 * pollfd, data is copied from the old pollfd to the new and, finally, the old
 * one is freed().
 */
extern int compat_poll_del(struct lttng_poll_event *events, int fd);
#define lttng_poll_del(events, fd) \
	compat_poll_del(events, fd)

/*
 * Set up the poll set limits variable poll_max_size
 */
extern void compat_poll_set_max_size(void);
#define lttng_poll_set_max_size() \
	compat_poll_set_max_size()

/*
 * No need to reset a pollfd structure for poll(2)
 */
static inline void lttng_poll_reset(struct lttng_poll_event *events)
{}

/*
 * Clean the events structure of a lttng_poll_event. It's the caller
 * responsability to free the lttng_poll_event memory.
 */
static inline void lttng_poll_clean(struct lttng_poll_event *events)
{
	if (events) {
		__lttng_poll_free((void *) events->wait.events);
		__lttng_poll_free((void *) events->current.events);
	}
}

#endif /* HAVE_EPOLL */

#endif /* _LTT_POLL_H */
Commit	Line	Data
5eb91c98 DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	3	*
d14d33bf AM	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
5eb91c98 DG	7	*
	8	* This program is distributed in the hope that it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
d14d33bf AM	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
5eb91c98 DG	16	*/
	17
	18	#ifndef _LTT_POLL_H
	19	#define _LTT_POLL_H
	20
	21	#include <string.h>
	22	#include <unistd.h>
	23
990570ed	24	#include <common/common.h>
5eb91c98 DG	25
	26	/*
	27	* Maximum number of fd we can monitor.
	28	*
	29	* For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will
	30	* be used for the maximum size of the poll set. If this interface is not
	31	* available, according to the manpage, the max_user_watches value is 1/25 (4%)
	32	* of the available low memory divided by the registration cost in bytes which
	33	* is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel.
	34	*
	35	* For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
	36	* getrlimit(2).
	37	*/
	38	extern unsigned int poll_max_size;
	39
	40	/*
	41	* Used by lttng_poll_clean to free the events structure in a lttng_poll_event.
	42	*/
	43	static inline void __lttng_poll_free(void *events)
	44	{
b3066218 DG	45	if (events) {
	46	free(events);
	47	}
5eb91c98 DG	48	}
	49
	50	/*
	51	* epoll(7) implementation.
	52	*/
	53	#ifdef HAVE_EPOLL
	54	#include <sys/epoll.h>
76d7553f	55	#include <stdio.h>
5eb91c98 DG	56
5eb91c98 DG	57	/* See man epoll(7) for this define path */
990570ed	58	#define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches"
5eb91c98 DG	59
	60	enum {
	61	/* Polling variables compatibility for epoll */
	62	LPOLLIN = EPOLLIN,
	63	LPOLLPRI = EPOLLPRI,
	64	LPOLLOUT = EPOLLOUT,
	65	LPOLLRDNORM = EPOLLRDNORM,
	66	LPOLLRDBAND = EPOLLRDBAND,
	67	LPOLLWRNORM = EPOLLWRNORM,
	68	LPOLLWRBAND = EPOLLWRBAND,
	69	LPOLLMSG = EPOLLMSG,
	70	LPOLLERR = EPOLLERR,
	71	LPOLLHUP = EPOLLHUP,
	72	LPOLLNVAL = EPOLLHUP,
	73	LPOLLRDHUP = EPOLLRDHUP,
	74	/* Close on exec feature of epoll */
	75	LTTNG_CLOEXEC = EPOLL_CLOEXEC,
	76	};
	77
	78	struct compat_epoll_event {
	79	int epfd;
	80	uint32_t nb_fd; /* Current number of fd in events */
d21b0d71 DG	81	uint32_t alloc_size; /* Size of events array */
d21b0d71 DG	82	uint32_t init_size; /* Initial size of events array */
5eb91c98 DG	83	struct epoll_event *events;
	84	};
	85	#define lttng_poll_event compat_epoll_event
	86
	87	/*
	88	* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
	89	* being the index of the events array.
	90	*/
	91	#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd
	92	#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events
	93	#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
	94	#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size
	95
	96	/*
	97	* Create the epoll set. No memory allocation is done here.
	98	*/
	99	extern int compat_epoll_create(struct lttng_poll_event *events,
	100	int size, int flags);
	101	#define lttng_poll_create(events, size, flags) \
65b1b198	102	compat_epoll_create(events, size, flags)
5eb91c98 DG	103
	104	/*
	105	* Wait on epoll set with the number of fd registered to the lttng_poll_event
	106	* data structure (events).
	107	*/
	108	extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout);
	109	#define lttng_poll_wait(events, timeout) \
65b1b198	110	compat_epoll_wait(events, timeout)
5eb91c98 DG	111
	112	/*
	113	* Add a fd to the epoll set and resize the epoll_event structure if needed.
	114	*/
	115	extern int compat_epoll_add(struct lttng_poll_event *events,
	116	int fd, uint32_t req_events);
	117	#define lttng_poll_add(events, fd, req_events) \
65b1b198	118	compat_epoll_add(events, fd, req_events)
5eb91c98 DG	119
	120	/*
	121	* Remove a fd from the epoll set.
	122	*/
	123	extern int compat_epoll_del(struct lttng_poll_event *events, int fd);
	124	#define lttng_poll_del(events, fd) \
65b1b198	125	compat_epoll_del(events, fd)
5eb91c98 DG	126
	127	/*
	128	* Set up the poll set limits variable poll_max_size
	129	*/
	130	extern void compat_epoll_set_max_size(void);
65b1b198 MD	131	#define lttng_poll_set_max_size() \
65b1b198 MD	132	compat_epoll_set_max_size()
5eb91c98 DG	133
	134	/*
	135	* This function memset with zero the structure since it can be reused at each
	136	* round of a main loop. Being in a loop and using a non static number of fds,
	137	* this function must be called to insure coherent events with associted fds.
	138	*/
	139	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	140	{
	141	if (events && events->events) {
	142	memset(events->events, 0,
	143	events->nb_fd * sizeof(struct epoll_event));
	144	}
	145	}
	146
	147	/*
	148	* Clean the events structure of a lttng_poll_event. It's the caller
	149	* responsability to free the lttng_poll_event memory.
	150	*/
	151	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	152	{
76d7553f MD	153	int ret;
76d7553f MD	154
5eb91c98	155	if (events) {
76d7553f MD	156	ret = close(events->epfd);
	157	if (ret) {
	158	perror("close");
	159	}
5eb91c98 DG	160	__lttng_poll_free((void *) events->events);
	161	}
	162	}
	163
	164	#else /* HAVE_EPOLL */
	165	/*
	166	* Fallback on poll(2) API
	167	*/
	168
	169	/* Needed for some poll event values */
	170	#ifndef __USE_XOPEN
	171	#define __USE_XOPEN
	172	#endif
	173
	174	/* Needed for some poll event values */
	175	#ifndef __USE_GNU
	176	#define __USE_GNU
	177	#endif
	178
	179	#include <poll.h>
	180	#include <stdint.h>
	181
	182	enum {
	183	/* Polling variables compatibility for poll */
	184	LPOLLIN = POLLIN,
	185	LPOLLPRI = POLLPRI,
	186	LPOLLOUT = POLLOUT,
	187	LPOLLRDNORM = POLLRDNORM,
	188	LPOLLRDBAND = POLLRDBAND,
	189	LPOLLWRNORM = POLLWRNORM,
	190	LPOLLWRBAND = POLLWRBAND,
1268b9d6	191	#if __linux__
5eb91c98	192	LPOLLMSG = POLLMSG,
1268b9d6	193	LPOLLRDHUP = POLLRDHUP,
3247be18	194	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__))
1268b9d6 DG	195	LPOLLMSG = 0,
1268b9d6 DG	196	LPOLLRDHUP = 0,
b2c3836f MD	197	#else
b2c3836f MD	198	#error "Please add support for your OS."
1268b9d6	199	#endif /* __linux__ */
5eb91c98 DG	200	LPOLLERR = POLLERR,
5eb91c98 DG	201	LPOLLHUP = POLLHUP \| POLLNVAL,
5eb91c98 DG	202	/* Close on exec feature does not exist for poll(2) */
	203	LTTNG_CLOEXEC = 0xdead,
	204	};
	205
d21b0d71	206	struct compat_poll_event_array {
5eb91c98	207	uint32_t nb_fd; /* Current number of fd in events */
d21b0d71 DG	208	uint32_t alloc_size; /* Size of events array */
	209	/* Initial size of the pollset. We never shrink below that. */
	210	uint32_t init_size;
5eb91c98 DG	211	struct pollfd *events;
5eb91c98 DG	212	};
d21b0d71 DG	213
	214	struct compat_poll_event {
	215	/*
	216	* Modified by the wait action. Updated using current fields if the
	217	* need_update flag is set.
	218	*/
	219	struct compat_poll_event_array wait;
	220	/*
	221	* This is modified by add/del actions being the _current_ flow of
	222	* execution before a poll wait is done.
	223	*/
	224	struct compat_poll_event_array current;
	225	/* Indicate if wait.events needs to be realloc. */
	226	int need_realloc:1;
	227	/* Indicate if wait.events need to be updated from current. */
	228	int need_update:1;
	229	};
5eb91c98 DG	230	#define lttng_poll_event compat_poll_event
	231
	232	/*
	233	* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
	234	* being the index of the events array.
	235	*/
d21b0d71 DG	236	#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
	237	#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
	238	#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
	239	#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size
5eb91c98 DG	240
	241	/*
	242	* Create a pollfd structure of size 'size'.
	243	*/
	244	extern int compat_poll_create(struct lttng_poll_event *events, int size);
	245	#define lttng_poll_create(events, size, flags) \
65b1b198	246	compat_poll_create(events, size)
5eb91c98 DG	247
	248	/*
	249	* Wait on poll(2) event with nb_fd registered to the lttng_poll_event data
	250	* structure.
	251	*/
	252	extern int compat_poll_wait(struct lttng_poll_event *events, int timeout);
	253	#define lttng_poll_wait(events, timeout) \
65b1b198	254	compat_poll_wait(events, timeout)
5eb91c98 DG	255
	256	/*
	257	* Add the fd to the pollfd structure. Resize if needed.
	258	*/
	259	extern int compat_poll_add(struct lttng_poll_event *events,
	260	int fd, uint32_t req_events);
	261	#define lttng_poll_add(events, fd, req_events) \
65b1b198	262	compat_poll_add(events, fd, req_events)
5eb91c98 DG	263
	264	/*
	265	* Remove the fd from the pollfd. Memory allocation is done to recreate a new
	266	* pollfd, data is copied from the old pollfd to the new and, finally, the old
	267	* one is freed().
	268	*/
	269	extern int compat_poll_del(struct lttng_poll_event *events, int fd);
	270	#define lttng_poll_del(events, fd) \
65b1b198	271	compat_poll_del(events, fd)
5eb91c98 DG	272
	273	/*
	274	* Set up the poll set limits variable poll_max_size
	275	*/
	276	extern void compat_poll_set_max_size(void);
65b1b198 MD	277	#define lttng_poll_set_max_size() \
65b1b198 MD	278	compat_poll_set_max_size()
5eb91c98 DG	279
	280	/*
	281	* No need to reset a pollfd structure for poll(2)
	282	*/
	283	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	284	{}
	285
	286	/*
	287	* Clean the events structure of a lttng_poll_event. It's the caller
	288	* responsability to free the lttng_poll_event memory.
	289	*/
	290	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	291	{
	292	if (events) {
d21b0d71 DG	293	__lttng_poll_free((void *) events->wait.events);
d21b0d71 DG	294	__lttng_poll_free((void *) events->current.events);
5eb91c98 DG	295	}
	296	}
	297
	298	#endif /* HAVE_EPOLL */
	299
	300	#endif /* _LTT_POLL_H */