[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.
 */
LTTNG_HIDDEN
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).
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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
 */
LTTNG_HIDDEN
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'.
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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().
 */
LTTNG_HIDDEN
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.
 */
LTTNG_HIDDEN
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
 */
LTTNG_HIDDEN
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	*/
db14a5c9 JR	125	LTTNG_HIDDEN
db14a5c9 JR	126	int compat_epoll_create(struct lttng_poll_event *events,
5eb91c98 DG	127	int size, int flags);
5eb91c98 DG	128	#define lttng_poll_create(events, size, flags) \
65b1b198	129	compat_epoll_create(events, size, flags)
5eb91c98	130
062fc3d8	131	#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
f263b7fd JD	132	static inline int compat_glibc_epoll_create(int size __attribute__((unused)),
	133	int flags)
	134	{
	135	return epoll_create1(flags);
	136	}
	137	#else
	138	static inline int compat_glibc_epoll_create(int size, int flags)
	139	{
	140	/*
	141	* epoll_create1 was added in glibc 2.9, but unfortunatly reverting to
	142	* epoll_create(..) also means that we lose the possibility to
	143	* directly set the EPOLL_CLOEXEC, so try and do it anyway but through
	144	* fcntl(..).
	145	*/
	146	int efd = epoll_create(size);
	147	assert(fcntl(efd, F_SETFD, flags) != -1);
	148	return efd;
	149	}
	150	#endif
	151
5eb91c98 DG	152	/*
	153	* Wait on epoll set with the number of fd registered to the lttng_poll_event
	154	* data structure (events).
	155	*/
db14a5c9 JR	156	LTTNG_HIDDEN
db14a5c9 JR	157	int compat_epoll_wait(struct lttng_poll_event *events, int timeout);
5eb91c98	158	#define lttng_poll_wait(events, timeout) \
65b1b198	159	compat_epoll_wait(events, timeout)
5eb91c98 DG	160
	161	/*
	162	* Add a fd to the epoll set and resize the epoll_event structure if needed.
	163	*/
db14a5c9 JR	164	LTTNG_HIDDEN
db14a5c9 JR	165	int compat_epoll_add(struct lttng_poll_event *events,
5eb91c98 DG	166	int fd, uint32_t req_events);
5eb91c98 DG	167	#define lttng_poll_add(events, fd, req_events) \
65b1b198	168	compat_epoll_add(events, fd, req_events)
5eb91c98 DG	169
	170	/*
	171	* Remove a fd from the epoll set.
	172	*/
db14a5c9 JR	173	LTTNG_HIDDEN
db14a5c9 JR	174	int compat_epoll_del(struct lttng_poll_event *events, int fd);
5eb91c98	175	#define lttng_poll_del(events, fd) \
65b1b198	176	compat_epoll_del(events, fd)
5eb91c98	177
f057dfc3 JG	178	/*
	179	* Modify an fd's events in the epoll set.
	180	*/
db14a5c9 JR	181	LTTNG_HIDDEN
db14a5c9 JR	182	int compat_epoll_mod(struct lttng_poll_event *events,
f057dfc3 JG	183	int fd, uint32_t req_events);
	184	#define lttng_poll_mod(events, fd, req_events) \
	185	compat_epoll_add(events, fd, req_events)
	186
5eb91c98 DG	187	/*
	188	* Set up the poll set limits variable poll_max_size
	189	*/
db14a5c9 JR	190	LTTNG_HIDDEN
db14a5c9 JR	191	int compat_epoll_set_max_size(void);
65b1b198 MD	192	#define lttng_poll_set_max_size() \
65b1b198 MD	193	compat_epoll_set_max_size()
5eb91c98 DG	194
	195	/*
	196	* This function memset with zero the structure since it can be reused at each
	197	* round of a main loop. Being in a loop and using a non static number of fds,
	198	* this function must be called to insure coherent events with associted fds.
	199	*/
	200	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	201	{
	202	if (events && events->events) {
	203	memset(events->events, 0,
	204	events->nb_fd * sizeof(struct epoll_event));
	205	}
	206	}
	207
6d737ce4 DG	208	/*
	209	* Initialize an already allocated poll event data structure. For epoll(), the
	210	* epfd is set to -1 to indicate that it's not usable.
	211	*/
	212	static inline void lttng_poll_init(struct lttng_poll_event *events)
	213	{
c5854b1c	214	memset(events, 0, sizeof(struct lttng_poll_event));
6d737ce4 DG	215	/* Set fd to -1 so if clean before created, we don't close 0. */
	216	events->epfd = -1;
	217	}
	218
5eb91c98 DG	219	/*
	220	* Clean the events structure of a lttng_poll_event. It's the caller
	221	* responsability to free the lttng_poll_event memory.
	222	*/
	223	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	224	{
76d7553f MD	225	int ret;
76d7553f MD	226
3cc04881 DG	227	if (!events) {
	228	return;
	229	}
	230
	231	if (events->epfd >= 0) {
76d7553f MD	232	ret = close(events->epfd);
76d7553f MD	233	if (ret) {
6f04ed72	234	PERROR("close");
76d7553f	235	}
5eb91c98	236	}
3cc04881 DG	237
3cc04881 DG	238	__lttng_poll_free((void *) events->events);
5eb91c98 DG	239	}
	240
	241	#else /* HAVE_EPOLL */
	242	/*
	243	* Fallback on poll(2) API
	244	*/
	245
	246	/* Needed for some poll event values */
	247	#ifndef __USE_XOPEN
	248	#define __USE_XOPEN
	249	#endif
	250
	251	/* Needed for some poll event values */
	252	#ifndef __USE_GNU
	253	#define __USE_GNU
	254	#endif
	255
	256	#include <poll.h>
	257	#include <stdint.h>
	258
	259	enum {
	260	/* Polling variables compatibility for poll */
	261	LPOLLIN = POLLIN,
	262	LPOLLPRI = POLLPRI,
	263	LPOLLOUT = POLLOUT,
	264	LPOLLRDNORM = POLLRDNORM,
	265	LPOLLRDBAND = POLLRDBAND,
	266	LPOLLWRNORM = POLLWRNORM,
	267	LPOLLWRBAND = POLLWRBAND,
1268b9d6	268	#if __linux__
5eb91c98	269	LPOLLMSG = POLLMSG,
1268b9d6	270	LPOLLRDHUP = POLLRDHUP,
a97dd6ce	271	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
1268b9d6 DG	272	LPOLLMSG = 0,
1268b9d6 DG	273	LPOLLRDHUP = 0,
b2c3836f MD	274	#else
b2c3836f MD	275	#error "Please add support for your OS."
1268b9d6	276	#endif /* __linux__ */
5eb91c98 DG	277	LPOLLERR = POLLERR,
5eb91c98 DG	278	LPOLLHUP = POLLHUP \| POLLNVAL,
5eb91c98 DG	279	/* Close on exec feature does not exist for poll(2) */
	280	LTTNG_CLOEXEC = 0xdead,
	281	};
	282
d21b0d71	283	struct compat_poll_event_array {
5eb91c98	284	uint32_t nb_fd; /* Current number of fd in events */
d21b0d71 DG	285	uint32_t alloc_size; /* Size of events array */
	286	/* Initial size of the pollset. We never shrink below that. */
	287	uint32_t init_size;
5eb91c98 DG	288	struct pollfd *events;
5eb91c98 DG	289	};
d21b0d71 DG	290
	291	struct compat_poll_event {
	292	/*
	293	* Modified by the wait action. Updated using current fields if the
	294	* need_update flag is set.
	295	*/
	296	struct compat_poll_event_array wait;
	297	/*
	298	* This is modified by add/del actions being the _current_ flow of
	299	* execution before a poll wait is done.
	300	*/
	301	struct compat_poll_event_array current;
dbe23f45	302
d21b0d71 DG	303	/* Indicate if wait.events need to be updated from current. */
	304	int need_update:1;
	305	};
5eb91c98 DG	306	#define lttng_poll_event compat_poll_event
5eb91c98 DG	307
beaad64c DG	308	static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events,
	309	int index, uint32_t nb_fd)
	310	{
	311	assert(events);
	312	assert(index != nb_fd);
	313
	314	if (index == 0 \|\| nb_fd == 0) {
	315	return -1;
	316	} else {
	317	return events->current.events[index - 1].fd;
	318	}
	319	}
	320
5eb91c98 DG	321	/*
	322	* For the following calls, consider 'e' to be a lttng_poll_event pointer and i
	323	* being the index of the events array.
	324	*/
d21b0d71 DG	325	#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
	326	#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
	327	#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
	328	#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size
beaad64c DG	329	#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
beaad64c DG	330	__lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd)
5eb91c98 DG	331
	332	/*
	333	* Create a pollfd structure of size 'size'.
	334	*/
db14a5c9 JR	335	LTTNG_HIDDEN
db14a5c9 JR	336	int compat_poll_create(struct lttng_poll_event *events, int size);
5eb91c98	337	#define lttng_poll_create(events, size, flags) \
65b1b198	338	compat_poll_create(events, size)
5eb91c98 DG	339
	340	/*
	341	* Wait on poll(2) event with nb_fd registered to the lttng_poll_event data
	342	* structure.
	343	*/
db14a5c9 JR	344	LTTNG_HIDDEN
db14a5c9 JR	345	int compat_poll_wait(struct lttng_poll_event *events, int timeout);
5eb91c98	346	#define lttng_poll_wait(events, timeout) \
65b1b198	347	compat_poll_wait(events, timeout)
5eb91c98 DG	348
	349	/*
	350	* Add the fd to the pollfd structure. Resize if needed.
	351	*/
db14a5c9 JR	352	LTTNG_HIDDEN
db14a5c9 JR	353	int compat_poll_add(struct lttng_poll_event *events,
5eb91c98 DG	354	int fd, uint32_t req_events);
5eb91c98 DG	355	#define lttng_poll_add(events, fd, req_events) \
65b1b198	356	compat_poll_add(events, fd, req_events)
5eb91c98 DG	357
	358	/*
	359	* Remove the fd from the pollfd. Memory allocation is done to recreate a new
	360	* pollfd, data is copied from the old pollfd to the new and, finally, the old
	361	* one is freed().
	362	*/
db14a5c9 JR	363	LTTNG_HIDDEN
db14a5c9 JR	364	int compat_poll_del(struct lttng_poll_event *events, int fd);
5eb91c98	365	#define lttng_poll_del(events, fd) \
65b1b198	366	compat_poll_del(events, fd)
5eb91c98	367
f057dfc3 JG	368	/*
	369	* Modify an fd's events in the epoll set.
	370	*/
db14a5c9 JR	371	LTTNG_HIDDEN
db14a5c9 JR	372	int compat_poll_mod(struct lttng_poll_event *events,
f057dfc3 JG	373	int fd, uint32_t req_events);
	374	#define lttng_poll_mod(events, fd, req_events) \
	375	compat_poll_add(events, fd, req_events)
	376
5eb91c98 DG	377	/*
	378	* Set up the poll set limits variable poll_max_size
	379	*/
db14a5c9 JR	380	LTTNG_HIDDEN
db14a5c9 JR	381	int compat_poll_set_max_size(void);
65b1b198 MD	382	#define lttng_poll_set_max_size() \
65b1b198 MD	383	compat_poll_set_max_size()
5eb91c98 DG	384
	385	/*
	386	* No need to reset a pollfd structure for poll(2)
	387	*/
	388	static inline void lttng_poll_reset(struct lttng_poll_event *events)
	389	{}
	390
6d737ce4 DG	391	/*
	392	* Initialize an already allocated poll event data structure.
	393	*/
	394	static inline void lttng_poll_init(struct lttng_poll_event *events)
	395	{
	396	memset(events, 0, sizeof(struct lttng_poll_event));
	397	}
	398
5eb91c98 DG	399	/*
	400	* Clean the events structure of a lttng_poll_event. It's the caller
	401	* responsability to free the lttng_poll_event memory.
	402	*/
	403	static inline void lttng_poll_clean(struct lttng_poll_event *events)
	404	{
	405	if (events) {
d21b0d71 DG	406	__lttng_poll_free((void *) events->wait.events);
d21b0d71 DG	407	__lttng_poll_free((void *) events->current.events);
5eb91c98 DG	408	}
	409	}
	410
	411	#endif /* HAVE_EPOLL */
	412
	413	#endif /* _LTT_POLL_H */