+++ /dev/null
-/*
- * 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_mod(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.
- * LTTNG_POLL_GETNB is always used after lttng_poll_wait, thus we can use the
- * current list for test compatibility purposes.
- */
-#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)->current.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_mod(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 */
projects / lttng-tools.git / blobdiff