[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 <assert.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)
{
	free(events);
}

/*
 * epoll(7) implementation.
 */
#ifdef HAVE_EPOLL
#include <sys/epoll.h>
#include <stdio.h>
#include <features.h>
#include <common/compat/fcntl.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 */
#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
	LTTNG_CLOEXEC = EPOLL_CLOEXEC,
#else
	/*
	 * EPOLL_CLOEXEC was added in glibc 2.8 (usually used in conjunction with
	 * epoll_create1(..)), but since neither EPOLL_CLOEXEC exists nor
	 * epoll_create1(..), we set it to FD_CLOEXEC so that we can pass it
	 * directly to fcntl(..) instead.
	 */
	LTTNG_CLOEXEC = FD_CLOEXEC,
#endif
};

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

static inline int __lttng_epoll_get_prev_fd(struct lttng_poll_event *events,
		int index, uint32_t nb_fd)
{
	assert(events);
	assert(index != nb_fd);

	if (index == 0 || nb_fd == 0) {
		return -1;
	} else {
		return events->events[index - 1].data.fd;
	}
}

/*
 * 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
#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
	__lttng_epoll_get_prev_fd(LTTNG_REF(e), i, nb_fd)

/*
 * 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)

#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
static inline int compat_glibc_epoll_create(int size __attribute__((unused)),
		int flags)
{
	return epoll_create1(flags);
}
#else
static inline int compat_glibc_epoll_create(int size, int flags)
{
	/*
	 * epoll_create1 was added in glibc 2.9, but unfortunatly reverting to
	 * epoll_create(..) also means that we lose the possibility to
	 * directly set the EPOLL_CLOEXEC, so try and do it anyway but through
	 * fcntl(..).
	 */
	int efd = epoll_create(size);
	assert(fcntl(efd, F_SETFD, flags) != -1);
	return efd;
}
#endif

/*
 * 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)

/*
 * Modify an fd's events in the epoll set.
 */
extern int compat_epoll_mod(struct lttng_poll_event *events,
		int fd, uint32_t req_events);
#define lttng_poll_mod(events, fd, req_events) \
	compat_epoll_add(events, fd, req_events)

/*
 * Set up the poll set limits variable poll_max_size
 */
extern int 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));
	}
}

/*
 * Initialize an already allocated poll event data structure. For epoll(), the
 * epfd is set to -1 to indicate that it's not usable.
 */
static inline void lttng_poll_init(struct lttng_poll_event *events)
{
	memset(events, 0, sizeof(struct lttng_poll_event));
	/* Set fd to -1 so if clean before created, we don't close 0. */
	events->epfd = -1;
}

/*
 * 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) {
		return;
	}

	if (events->epfd >= 0) {
		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__) || defined(__sun__) || defined(__APPLE__))
	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 need to be updated from current. */
	int need_update:1;
};
#define lttng_poll_event compat_poll_event

static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events,
		int index, uint32_t nb_fd)
{
	assert(events);
	assert(index != nb_fd);

	if (index == 0 || nb_fd == 0) {
		return -1;
	} else {
		return events->current.events[index - 1].fd;
	}
}

/*
 * 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
#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
	__lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd)

/*
 * 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)

/*
 * Modify an fd's events in the epoll set.
 */
extern int compat_poll_mod(struct lttng_poll_event *events,
		int fd, uint32_t req_events);
#define lttng_poll_mod(events, fd, req_events) \
	compat_poll_add(events, fd, req_events)

/*
 * Set up the poll set limits variable poll_max_size
 */
extern int 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)
{}

/*
 * Initialize an already allocated poll event data structure.
 */
static inline void lttng_poll_init(struct lttng_poll_event *events)
{
	memset(events, 0, sizeof(struct lttng_poll_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)
{
	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
beaad64c	21	#include <assert.h>
5eb91c98 DG	22	#include <string.h>
	23	#include <unistd.h>
	24
990570ed	25	#include <common/common.h>
5eb91c98 DG	26
	27	/*
	28	* Maximum number of fd we can monitor.
	29	*
	30	* For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will
	31	* be used for the maximum size of the poll set. If this interface is not
	32	* available, according to the manpage, the max_user_watches value is 1/25 (4%)
	33	* of the available low memory divided by the registration cost in bytes which
	34	* is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel.
	35	*
	36	* For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
	37	* getrlimit(2).
	38	*/
	39	extern unsigned int poll_max_size;
	40
	41	/*
	42	* Used by lttng_poll_clean to free the events structure in a lttng_poll_event.
	43	*/
	44	static inline void __lttng_poll_free(void *events)
	45	{
0e428499	46	free(events);
5eb91c98 DG	47	}
	48
	49	/*
	50	* epoll(7) implementation.
	51	*/
	52	#ifdef HAVE_EPOLL
	53	#include <sys/epoll.h>
76d7553f	54	#include <stdio.h>
f263b7fd JD	55	#include <features.h>
f263b7fd JD	56	#include <common/compat/fcntl.h>
5eb91c98 DG	57
5eb91c98 DG	58	/* See man epoll(7) for this define path */
990570ed	59	#define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches"
5eb91c98 DG	60
	61	enum {
	62	/* Polling variables compatibility for epoll */
	63	LPOLLIN = EPOLLIN,
	64	LPOLLPRI = EPOLLPRI,
	65	LPOLLOUT = EPOLLOUT,
	66	LPOLLRDNORM = EPOLLRDNORM,
	67	LPOLLRDBAND = EPOLLRDBAND,
	68	LPOLLWRNORM = EPOLLWRNORM,
	69	LPOLLWRBAND = EPOLLWRBAND,
	70	LPOLLMSG = EPOLLMSG,
	71	LPOLLERR = EPOLLERR,
	72	LPOLLHUP = EPOLLHUP,
	73	LPOLLNVAL = EPOLLHUP,
	74	LPOLLRDHUP = EPOLLRDHUP,
	75	/* Close on exec feature of epoll */
062fc3d8	76	#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
5eb91c98	77	LTTNG_CLOEXEC = EPOLL_CLOEXEC,
f263b7fd JD	78	#else
	79	/*
	80	* EPOLL_CLOEXEC was added in glibc 2.8 (usually used in conjunction with
	81	* epoll_create1(..)), but since neither EPOLL_CLOEXEC exists nor
	82	* epoll_create1(..), we set it to FD_CLOEXEC so that we can pass it
	83	* directly to fcntl(..) instead.
	84	*/
	85	LTTNG_CLOEXEC = FD_CLOEXEC,
	86	#endif
5eb91c98 DG	87	};
	88
	89	struct compat_epoll_event {
	90	int epfd;
	91	uint32_t nb_fd; /* Current number of fd in events */
d21b0d71 DG	92	uint32_t alloc_size; /* Size of events array */
d21b0d71 DG	93	uint32_t init_size; /* Initial size of events array */
5eb91c98 DG	94	struct epoll_event *events;
	95	};
	96	#define lttng_poll_event compat_epoll_event
	97
beaad64c DG	98	static inline int __lttng_epoll_get_prev_fd(struct lttng_poll_event *events,
	99	int index, uint32_t nb_fd)
	100	{
	101	assert(events);
	102	assert(index != nb_fd);
	103
	104	if (index == 0 \|\| nb_fd == 0) {
	105	return -1;
	106	} else {
	107	return events->events[index - 1].data.fd;
	108	}
	109	}
	110
5eb91c98 DG	111	/*
	112	* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
	113	* being the index of the events array.
	114	*/
	115	#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd
	116	#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events
	117	#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
	118	#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size
beaad64c DG	119	#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
beaad64c DG	120	__lttng_epoll_get_prev_fd(LTTNG_REF(e), i, nb_fd)
5eb91c98 DG	121
	122	/*
	123	* Create the epoll set. No memory allocation is done here.
	124	*/
	125	extern int compat_epoll_create(struct lttng_poll_event *events,
	126	int size, int flags);
	127	#define lttng_poll_create(events, size, flags) \
65b1b198	128	compat_epoll_create(events, size, flags)
5eb91c98	129
062fc3d8	130	#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
f263b7fd JD	131	static inline int compat_glibc_epoll_create(int size __attribute__((unused)),
	132	int flags)
	133	{
	134	return epoll_create1(flags);
	135	}
	136	#else
	137	static inline int compat_glibc_epoll_create(int size, int flags)
	138	{
	139	/*
	140	* epoll_create1 was added in glibc 2.9, but unfortunatly reverting to
	141	* epoll_create(..) also means that we lose the possibility to
	142	* directly set the EPOLL_CLOEXEC, so try and do it anyway but through
	143	* fcntl(..).
	144	*/
	145	int efd = epoll_create(size);
	146	assert(fcntl(efd, F_SETFD, flags) != -1);
	147	return efd;
	148	}
	149	#endif
	150
5eb91c98 DG	151	/*
	152	* Wait on epoll set with the number of fd registered to the lttng_poll_event
	153	* data structure (events).
	154	*/
	155	extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout);
	156	#define lttng_poll_wait(events, timeout) \
65b1b198	157	compat_epoll_wait(events, timeout)
5eb91c98 DG	158
	159	/*
	160	* Add a fd to the epoll set and resize the epoll_event structure if needed.
	161	*/
	162	extern int compat_epoll_add(struct lttng_poll_event *events,
	163	int fd, uint32_t req_events);
	164	#define lttng_poll_add(events, fd, req_events) \
65b1b198	165	compat_epoll_add(events, fd, req_events)
5eb91c98 DG	166
	167	/*
	168	* Remove a fd from the epoll set.
	169	*/
	170	extern int compat_epoll_del(struct lttng_poll_event *events, int fd);
	171	#define lttng_poll_del(events, fd) \
65b1b198	172	compat_epoll_del(events, fd)
5eb91c98	173
f057dfc3 JG	174	/*
	175	* Modify an fd's events in the epoll set.
	176	*/
	177	extern int compat_epoll_mod(struct lttng_poll_event *events,
	178	int fd, uint32_t req_events);
	179	#define lttng_poll_mod(events, fd, req_events) \
	180	compat_epoll_add(events, fd, req_events)
	181
5eb91c98 DG	182	/*
	183	* Set up the poll set limits variable poll_max_size
	184	*/
dbe23f45	185	extern int compat_epoll_set_max_size(void);
65b1b198 MD	186	#define lttng_poll_set_max_size() \
65b1b198 MD	187	compat_epoll_set_max_size()
5eb91c98 DG	188
	189	/*
	190	* This function memset with zero the structure since it can be reused at each
	191	* round of a main loop. Being in a loop and using a non static number of fds,
	192	* this function must be called to insure coherent events with associted fds.
	193	*/
	194	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	195	{
	196	if (events && events->events) {
	197	memset(events->events, 0,
	198	events->nb_fd * sizeof(struct epoll_event));
	199	}
	200	}
	201
6d737ce4 DG	202	/*
	203	* Initialize an already allocated poll event data structure. For epoll(), the
	204	* epfd is set to -1 to indicate that it's not usable.
	205	*/
	206	static inline void lttng_poll_init(struct lttng_poll_event *events)
	207	{
c5854b1c	208	memset(events, 0, sizeof(struct lttng_poll_event));
6d737ce4 DG	209	/* Set fd to -1 so if clean before created, we don't close 0. */
	210	events->epfd = -1;
	211	}
	212
5eb91c98 DG	213	/*
	214	* Clean the events structure of a lttng_poll_event. It's the caller
	215	* responsability to free the lttng_poll_event memory.
	216	*/
	217	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	218	{
76d7553f MD	219	int ret;
76d7553f MD	220
3cc04881 DG	221	if (!events) {
	222	return;
	223	}
	224
	225	if (events->epfd >= 0) {
76d7553f MD	226	ret = close(events->epfd);
76d7553f MD	227	if (ret) {
6f04ed72	228	PERROR("close");
76d7553f	229	}
5eb91c98	230	}
3cc04881 DG	231
3cc04881 DG	232	__lttng_poll_free((void *) events->events);
5eb91c98 DG	233	}
	234
	235	#else /* HAVE_EPOLL */
	236	/*
	237	* Fallback on poll(2) API
	238	*/
	239
	240	/* Needed for some poll event values */
	241	#ifndef __USE_XOPEN
	242	#define __USE_XOPEN
	243	#endif
	244
	245	/* Needed for some poll event values */
	246	#ifndef __USE_GNU
	247	#define __USE_GNU
	248	#endif
	249
	250	#include <poll.h>
	251	#include <stdint.h>
	252
	253	enum {
	254	/* Polling variables compatibility for poll */
	255	LPOLLIN = POLLIN,
	256	LPOLLPRI = POLLPRI,
	257	LPOLLOUT = POLLOUT,
	258	LPOLLRDNORM = POLLRDNORM,
	259	LPOLLRDBAND = POLLRDBAND,
	260	LPOLLWRNORM = POLLWRNORM,
	261	LPOLLWRBAND = POLLWRBAND,
1268b9d6	262	#if __linux__
5eb91c98	263	LPOLLMSG = POLLMSG,
1268b9d6	264	LPOLLRDHUP = POLLRDHUP,
a97dd6ce	265	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
1268b9d6 DG	266	LPOLLMSG = 0,
1268b9d6 DG	267	LPOLLRDHUP = 0,
b2c3836f MD	268	#else
b2c3836f MD	269	#error "Please add support for your OS."
1268b9d6	270	#endif /* __linux__ */
5eb91c98 DG	271	LPOLLERR = POLLERR,
5eb91c98 DG	272	LPOLLHUP = POLLHUP \| POLLNVAL,
5eb91c98 DG	273	/* Close on exec feature does not exist for poll(2) */
	274	LTTNG_CLOEXEC = 0xdead,
	275	};
	276
d21b0d71	277	struct compat_poll_event_array {
5eb91c98	278	uint32_t nb_fd; /* Current number of fd in events */
d21b0d71 DG	279	uint32_t alloc_size; /* Size of events array */
	280	/* Initial size of the pollset. We never shrink below that. */
	281	uint32_t init_size;
5eb91c98 DG	282	struct pollfd *events;
5eb91c98 DG	283	};
d21b0d71 DG	284
	285	struct compat_poll_event {
	286	/*
	287	* Modified by the wait action. Updated using current fields if the
	288	* need_update flag is set.
	289	*/
	290	struct compat_poll_event_array wait;
	291	/*
	292	* This is modified by add/del actions being the _current_ flow of
	293	* execution before a poll wait is done.
	294	*/
	295	struct compat_poll_event_array current;
dbe23f45	296
d21b0d71 DG	297	/* Indicate if wait.events need to be updated from current. */
	298	int need_update:1;
	299	};
5eb91c98 DG	300	#define lttng_poll_event compat_poll_event
5eb91c98 DG	301
beaad64c DG	302	static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events,
	303	int index, uint32_t nb_fd)
	304	{
	305	assert(events);
	306	assert(index != nb_fd);
	307
	308	if (index == 0 \|\| nb_fd == 0) {
	309	return -1;
	310	} else {
	311	return events->current.events[index - 1].fd;
	312	}
	313	}
	314
5eb91c98 DG	315	/*
	316	* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
	317	* being the index of the events array.
	318	*/
d21b0d71 DG	319	#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
	320	#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
	321	#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
	322	#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size
beaad64c DG	323	#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
beaad64c DG	324	__lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd)
5eb91c98 DG	325
	326	/*
	327	* Create a pollfd structure of size 'size'.
	328	*/
	329	extern int compat_poll_create(struct lttng_poll_event *events, int size);
	330	#define lttng_poll_create(events, size, flags) \
65b1b198	331	compat_poll_create(events, size)
5eb91c98 DG	332
	333	/*
	334	* Wait on poll(2) event with nb_fd registered to the lttng_poll_event data
	335	* structure.
	336	*/
	337	extern int compat_poll_wait(struct lttng_poll_event *events, int timeout);
	338	#define lttng_poll_wait(events, timeout) \
65b1b198	339	compat_poll_wait(events, timeout)
5eb91c98 DG	340
	341	/*
	342	* Add the fd to the pollfd structure. Resize if needed.
	343	*/
	344	extern int compat_poll_add(struct lttng_poll_event *events,
	345	int fd, uint32_t req_events);
	346	#define lttng_poll_add(events, fd, req_events) \
65b1b198	347	compat_poll_add(events, fd, req_events)
5eb91c98 DG	348
	349	/*
	350	* Remove the fd from the pollfd. Memory allocation is done to recreate a new
	351	* pollfd, data is copied from the old pollfd to the new and, finally, the old
	352	* one is freed().
	353	*/
	354	extern int compat_poll_del(struct lttng_poll_event *events, int fd);
	355	#define lttng_poll_del(events, fd) \
65b1b198	356	compat_poll_del(events, fd)
5eb91c98	357
f057dfc3 JG	358	/*
	359	* Modify an fd's events in the epoll set.
	360	*/
	361	extern int compat_poll_mod(struct lttng_poll_event *events,
	362	int fd, uint32_t req_events);
	363	#define lttng_poll_mod(events, fd, req_events) \
	364	compat_poll_add(events, fd, req_events)
	365
5eb91c98 DG	366	/*
	367	* Set up the poll set limits variable poll_max_size
	368	*/
dbe23f45	369	extern int compat_poll_set_max_size(void);
65b1b198 MD	370	#define lttng_poll_set_max_size() \
65b1b198 MD	371	compat_poll_set_max_size()
5eb91c98 DG	372
	373	/*
	374	* No need to reset a pollfd structure for poll(2)
	375	*/
	376	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	377	{}
	378
6d737ce4 DG	379	/*
	380	* Initialize an already allocated poll event data structure.
	381	*/
	382	static inline void lttng_poll_init(struct lttng_poll_event *events)
	383	{
	384	memset(events, 0, sizeof(struct lttng_poll_event));
	385	}
	386
5eb91c98 DG	387	/*
	388	* Clean the events structure of a lttng_poll_event. It's the caller
	389	* responsability to free the lttng_poll_event memory.
	390	*/
	391	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	392	{
	393	if (events) {
d21b0d71 DG	394	__lttng_poll_free((void *) events->wait.events);
d21b0d71 DG	395	__lttng_poll_free((void *) events->current.events);
5eb91c98 DG	396	}
	397	}
	398
	399	#endif /* HAVE_EPOLL */
	400
	401	#endif /* _LTT_POLL_H */