--- /dev/null
+/*
+ * Copyright (C) 2011 EfficiOS Inc.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#ifndef _LTT_POLL_H
+#define _LTT_POLL_H
+
+#include <string.h>
+#include <unistd.h>
+
+#include <common/common.hpp>
+
+/*
+ * 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.hpp>
+
+/* 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)
+{
+ LTTNG_ASSERT(events);
+ LTTNG_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. */
+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);
+ LTTNG_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,
+ bool interruptible);
+#define lttng_poll_wait(events, timeout) \
+ compat_epoll_wait(events, timeout, false)
+#define lttng_poll_wait_interruptible(events, timeout) \
+ compat_epoll_wait(events, timeout, true)
+
+/*
+ * 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,
+#ifdef __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)
+{
+ LTTNG_ASSERT(events);
+ LTTNG_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,
+ bool interruptible);
+#define lttng_poll_wait(events, timeout) \
+ compat_poll_wait(events, timeout, false)
+#define lttng_poll_wait_interruptible(events, timeout) \
+ compat_poll_wait(events, timeout, true)
+
+/*
+ * 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 poll 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 __attribute__((unused)))
+{}
+
+/*
+ * 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