Cleanup: simplify 'poll' wrapper build
authorMichael Jeanson <mjeanson@efficios.com>
Wed, 26 Aug 2020 15:39:15 +0000 (11:39 -0400)
committerJérémie Galarneau <jeremie.galarneau@efficios.com>
Tue, 27 Oct 2020 14:06:11 +0000 (10:06 -0400)
Remove the AM conditionnal and merge the sources in single files like the
other wrappers. This removes a special case from the build system.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I6078f6013e52c3bc7c74cb8937f3741453c65874

configure.ac
src/common/compat/Makefile.am
src/common/compat/compat-epoll.c [deleted file]
src/common/compat/compat-poll.c [deleted file]
src/common/compat/poll.c [new file with mode: 0644]
src/common/fd-tracker/Makefile.am
src/common/fd-tracker/utils-epoll.c [deleted file]
src/common/fd-tracker/utils-poll.c

index 36f00de2a941c0e4c5920f36a1c6241628177f9b..2d4fcb7b96a594575a5ccea3817caa9ab3b5c9d0 100644 (file)
@@ -621,10 +621,8 @@ AX_HAVE_EPOLL(
 )
 AX_CONFIG_FEATURE(
        [epoll], [This platform supports epoll(7)],
-       [HAVE_EPOLL], [This platform supports epoll(7).],
-       [enable_epoll="yes"], [enable_epoll="no"]
+       [HAVE_EPOLL], [This platform supports epoll(7).]
 )
-AM_CONDITIONAL([COMPAT_EPOLL], [ test "$enable_epoll" = "yes" ])
 
 AS_IF([test "x$ac_cv_func_dirfd" = "xyes"],
        [AX_CONFIG_FEATURE_ENABLE(dirfd)],
index 0878b00c25c348239b38366e83df9de2517b7ffa..299a956b99883bd631afb63ed256711f4374a3e3 100644 (file)
@@ -2,13 +2,7 @@
 
 noinst_LTLIBRARIES = libcompat.la
 
-if COMPAT_EPOLL
-COMPAT=compat-epoll.c
-else
-COMPAT=compat-poll.c
-endif
-
-libcompat_la_SOURCES = poll.h fcntl.h endian.h mman.h dirent.h \
+libcompat_la_SOURCES = poll.c poll.h fcntl.h endian.h mman.h dirent.h \
                socket.h compat-fcntl.c tid.h \
-               getenv.h string.h paths.h pthread.h netdb.h $(COMPAT) \
+               getenv.h string.h paths.h pthread.h netdb.h \
                time.h directory-handle.h directory-handle.c path.h
diff --git a/src/common/compat/compat-epoll.c b/src/common/compat/compat-epoll.c
deleted file mode 100644 (file)
index 9055f51..0000000
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-#include <assert.h>
-#include <fcntl.h>
-#include <limits.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <stdbool.h>
-
-#include <common/error.h>
-#include <common/defaults.h>
-#include <common/macros.h>
-#include <common/utils.h>
-
-#include "poll.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.
- *
- */
-static unsigned int poll_max_size;
-
-/*
- * Resize the epoll events structure of the new size.
- *
- * Return 0 on success or else -1 with the current events pointer untouched.
- */
-static int resize_poll_event(struct lttng_poll_event *events,
-               uint32_t new_size)
-{
-       struct epoll_event *ptr;
-
-       assert(events);
-
-       ptr = realloc(events->events, new_size * sizeof(*ptr));
-       if (ptr == NULL) {
-               PERROR("realloc epoll add");
-               goto error;
-       }
-       if (new_size > events->alloc_size) {
-               /* Zero newly allocated memory */
-               memset(ptr + events->alloc_size, 0,
-                       (new_size - events->alloc_size) * sizeof(*ptr));
-       }
-       events->events = ptr;
-       events->alloc_size = new_size;
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Create epoll set and allocate returned events structure.
- */
-LTTNG_HIDDEN
-int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
-{
-       int ret;
-
-       if (events == NULL || size <= 0) {
-               goto error;
-       }
-
-       if (!poll_max_size) {
-               if (lttng_poll_set_max_size()) {
-                       goto error;
-               }
-       }
-
-       /* Don't bust the limit here */
-       if (size > poll_max_size) {
-               size = poll_max_size;
-       }
-
-       ret = compat_glibc_epoll_create(size, flags);
-       if (ret < 0) {
-               /* At this point, every error is fatal */
-               PERROR("epoll_create1");
-               goto error;
-       }
-
-       events->epfd = ret;
-
-       /* This *must* be freed by using lttng_poll_free() */
-       events->events = zmalloc(size * sizeof(struct epoll_event));
-       if (events->events == NULL) {
-               PERROR("zmalloc epoll set");
-               goto error_close;
-       }
-
-       events->alloc_size = events->init_size = size;
-       events->nb_fd = 0;
-
-       return 0;
-
-error_close:
-       ret = close(events->epfd);
-       if (ret) {
-               PERROR("close");
-       }
-error:
-       return -1;
-}
-
-/*
- * Add a fd to the epoll set with requesting events.
- */
-LTTNG_HIDDEN
-int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
-{
-       int ret;
-       struct epoll_event ev;
-
-       if (events == NULL || events->events == NULL || fd < 0) {
-               ERR("Bad compat epoll add arguments");
-               goto error;
-       }
-
-       /*
-        * Zero struct epoll_event to ensure all representations of its
-        * union are zeroed.
-        */
-       memset(&ev, 0, sizeof(ev));
-       ev.events = req_events;
-       ev.data.fd = fd;
-
-       ret = epoll_ctl(events->epfd, EPOLL_CTL_ADD, fd, &ev);
-       if (ret < 0) {
-               switch (errno) {
-               case EEXIST:
-                       /* If exist, it's OK. */
-                       goto end;
-               case ENOSPC:
-               case EPERM:
-                       /* Print PERROR and goto end not failing. Show must go on. */
-                       PERROR("epoll_ctl ADD");
-                       goto end;
-               default:
-                       PERROR("epoll_ctl ADD fatal");
-                       goto error;
-               }
-       }
-
-       events->nb_fd++;
-
-end:
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Remove a fd from the epoll set.
- */
-LTTNG_HIDDEN
-int compat_epoll_del(struct lttng_poll_event *events, int fd)
-{
-       int ret;
-
-       if (events == NULL || fd < 0 || events->nb_fd == 0) {
-               goto error;
-       }
-
-       ret = epoll_ctl(events->epfd, EPOLL_CTL_DEL, fd, NULL);
-       if (ret < 0) {
-               switch (errno) {
-               case ENOENT:
-               case EPERM:
-                       /* Print PERROR and goto end not failing. Show must go on. */
-                       PERROR("epoll_ctl DEL");
-                       goto end;
-               default:
-                       PERROR("epoll_ctl DEL fatal");
-                       goto error;
-               }
-       }
-
-       events->nb_fd--;
-
-end:
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Set an fd's events.
- */
-LTTNG_HIDDEN
-int compat_epoll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events)
-{
-       int ret;
-       struct epoll_event ev;
-
-       if (events == NULL || fd < 0 || events->nb_fd == 0) {
-               goto error;
-       }
-
-       /*
-        * Zero struct epoll_event to ensure all representations of its
-        * union are zeroed.
-        */
-       memset(&ev, 0, sizeof(ev));
-       ev.events = req_events;
-       ev.data.fd = fd;
-
-       ret = epoll_ctl(events->epfd, EPOLL_CTL_MOD, fd, &ev);
-       if (ret < 0) {
-               switch (errno) {
-               case ENOENT:
-               case EPERM:
-                       /* Print PERROR and goto end not failing. Show must go on. */
-                       PERROR("epoll_ctl MOD");
-                       goto end;
-               default:
-                       PERROR("epoll_ctl MOD fatal");
-                       goto error;
-               }
-       }
-
-end:
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Wait on epoll set. This is a blocking call of timeout value.
- */
-LTTNG_HIDDEN
-int compat_epoll_wait(struct lttng_poll_event *events, int timeout,
-               bool interruptible)
-{
-       int ret;
-       uint32_t new_size;
-
-       if (events == NULL || events->events == NULL) {
-               ERR("Wrong arguments in compat_epoll_wait");
-               goto error;
-       }
-
-       if (events->nb_fd == 0) {
-               errno = EINVAL;
-               return -1;
-       }
-
-       /*
-        * Resize if needed before waiting. We could either expand the array or
-        * shrink it down. It's important to note that after this step, we are
-        * ensured that the events argument of the epoll_wait call will be large
-        * enough to hold every possible returned events.
-        */
-       new_size = 1U << utils_get_count_order_u32(events->nb_fd);
-       if (new_size != events->alloc_size && new_size >= events->init_size) {
-               ret = resize_poll_event(events, new_size);
-               if (ret < 0) {
-                       /* ENOMEM problem at this point. */
-                       goto error;
-               }
-       }
-
-       do {
-               ret = epoll_wait(events->epfd, events->events, events->nb_fd, timeout);
-       } while (!interruptible && ret == -1 && errno == EINTR);
-       if (ret < 0) {
-               if (errno != EINTR) {
-                       PERROR("epoll_wait");
-               }
-               goto error;
-       }
-
-       /*
-        * Since the returned events are set sequentially in the "events" structure
-        * we only need to return the epoll_wait value and iterate over it.
-        */
-       return ret;
-
-error:
-       return -1;
-}
-
-/*
- * Setup poll set maximum size.
- */
-LTTNG_HIDDEN
-int compat_epoll_set_max_size(void)
-{
-       int ret, fd, retval = 0;
-       ssize_t size_ret;
-       char buf[64];
-
-       fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
-       if (fd < 0) {
-               /*
-                * Failing on opening [1] is not an error per see. [1] was
-                * introduced in Linux 2.6.28 but epoll is available since
-                * 2.5.44. Hence, goto end and set a default value without
-                * setting an error return value.
-                *
-                * [1] /proc/sys/fs/epoll/max_user_watches
-                */
-               retval = 0;
-               goto end;
-       }
-
-       size_ret = lttng_read(fd, buf, sizeof(buf));
-       /*
-        * Allow reading a file smaller than buf, but keep space for
-        * final \0.
-        */
-       if (size_ret < 0 || size_ret >= sizeof(buf)) {
-               PERROR("read set max size");
-               retval = -1;
-               goto end_read;
-       }
-       buf[size_ret] = '\0';
-       poll_max_size = atoi(buf);
-end_read:
-       ret = close(fd);
-       if (ret) {
-               PERROR("close");
-       }
-end:
-       if (!poll_max_size) {
-               poll_max_size = DEFAULT_POLL_SIZE;
-       }
-       DBG("epoll set max size is %d", poll_max_size);
-       return retval;
-}
diff --git a/src/common/compat/compat-poll.c b/src/common/compat/compat-poll.c
deleted file mode 100644 (file)
index 0c59e98..0000000
+++ /dev/null
@@ -1,394 +0,0 @@
-/*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- * Copyright (C) 2019 Yannick Lamarre <ylamarre@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-#include <assert.h>
-#include <stdlib.h>
-#include <sys/resource.h>
-#include <sys/time.h>
-#include <stdbool.h>
-
-#include <common/defaults.h>
-#include <common/error.h>
-#include <common/macros.h>
-#include <common/utils.h>
-
-#include "poll.h"
-
-
-/*
- * Maximum number of fd we can monitor.
- *
- * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
- * getrlimit(2).
- */
-static unsigned int poll_max_size;
-
-/*
- * Resize the epoll events structure of the new size.
- *
- * Return 0 on success or else -1 with the current events pointer untouched.
- */
-static int resize_poll_event(struct compat_poll_event_array *array,
-               uint32_t new_size)
-{
-       struct pollfd *ptr;
-
-       assert(array);
-
-       /* Refuse to resize the array more than the max size. */
-       if (new_size > poll_max_size) {
-               goto error;
-       }
-
-       ptr = realloc(array->events, new_size * sizeof(*ptr));
-       if (ptr == NULL) {
-               PERROR("realloc epoll add");
-               goto error;
-       }
-       if (new_size > array->alloc_size) {
-               /* Zero newly allocated memory */
-               memset(ptr + array->alloc_size, 0,
-                       (new_size - array->alloc_size) * sizeof(*ptr));
-       }
-       array->events = ptr;
-       array->alloc_size = new_size;
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Update events with the current events object.
- */
-static int update_current_events(struct lttng_poll_event *events)
-{
-       int ret;
-       struct compat_poll_event_array *current, *wait;
-
-       assert(events);
-
-       current = &events->current;
-       wait = &events->wait;
-
-       wait->nb_fd = current->nb_fd;
-       if (current->alloc_size != wait->alloc_size) {
-               ret = resize_poll_event(wait, current->alloc_size);
-               if (ret < 0) {
-                       goto error;
-               }
-       }
-       memcpy(wait->events, current->events,
-                       current->nb_fd * sizeof(*current->events));
-
-       /* Update is done. */
-       events->need_update = 0;
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Create pollfd data structure.
- */
-LTTNG_HIDDEN
-int compat_poll_create(struct lttng_poll_event *events, int size)
-{
-       struct compat_poll_event_array *current, *wait;
-
-       if (events == NULL || size <= 0) {
-               ERR("Wrong arguments for poll create");
-               goto error;
-       }
-
-       if (!poll_max_size) {
-               if (lttng_poll_set_max_size()) {
-                       goto error;
-               }
-       }
-
-       /* Don't bust the limit here */
-       if (size > poll_max_size) {
-               size = poll_max_size;
-       }
-
-       /* Reset everything before begining the allocation. */
-       memset(events, 0, sizeof(struct lttng_poll_event));
-
-       current = &events->current;
-       wait = &events->wait;
-
-       /* This *must* be freed by using lttng_poll_free() */
-       wait->events = zmalloc(size * sizeof(struct pollfd));
-       if (wait->events == NULL) {
-               PERROR("zmalloc struct pollfd");
-               goto error;
-       }
-
-       wait->alloc_size = wait->init_size = size;
-
-       current->events = zmalloc(size * sizeof(struct pollfd));
-       if (current->events == NULL) {
-               PERROR("zmalloc struct current pollfd");
-               goto error;
-       }
-
-       current->alloc_size = current->init_size = size;
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Add fd to pollfd data structure with requested events.
- */
-LTTNG_HIDDEN
-int compat_poll_add(struct lttng_poll_event *events, int fd,
-               uint32_t req_events)
-{
-       int new_size, ret, i;
-       struct compat_poll_event_array *current;
-
-       if (events == NULL || events->current.events == NULL || fd < 0) {
-               ERR("Bad compat poll add arguments");
-               goto error;
-       }
-
-       current = &events->current;
-
-       /* Check if fd we are trying to add is already there. */
-       for (i = 0; i < current->nb_fd; i++) {
-               if (current->events[i].fd == fd) {
-                       errno = EEXIST;
-                       goto error;
-               }
-       }
-
-       /* Resize array if needed. */
-       new_size = 1U << utils_get_count_order_u32(current->nb_fd + 1);
-       if (new_size != current->alloc_size && new_size >= current->init_size) {
-               ret = resize_poll_event(current, new_size);
-               if (ret < 0) {
-                       goto error;
-               }
-       }
-
-       current->events[current->nb_fd].fd = fd;
-       current->events[current->nb_fd].events = req_events;
-       current->nb_fd++;
-       events->need_update = 1;
-
-       DBG("fd %d of %d added to pollfd", fd, current->nb_fd);
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Modify an fd's events..
- */
-LTTNG_HIDDEN
-int compat_poll_mod(struct lttng_poll_event *events, int fd,
-               uint32_t req_events)
-{
-       int i;
-       struct compat_poll_event_array *current;
-
-       if (events == NULL || events->current.nb_fd == 0 ||
-                       events->current.events == NULL || fd < 0) {
-               ERR("Bad compat poll mod arguments");
-               goto error;
-       }
-
-       current = &events->current;
-
-       for (i = 0; i < current->nb_fd; i++) {
-               if (current->events[i].fd == fd) {
-                       current->events[i].events = req_events;
-                       events->need_update = 1;
-                       break;
-               }
-       }
-
-       /*
-        * The epoll flavor doesn't flag modifying a non-included FD as an
-        * error.
-        */
-
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Remove a fd from the pollfd structure.
- */
-LTTNG_HIDDEN
-int compat_poll_del(struct lttng_poll_event *events, int fd)
-{
-       int i, count = 0, ret;
-       uint32_t new_size;
-       struct compat_poll_event_array *current;
-
-       if (events == NULL || events->current.nb_fd == 0 ||
-                       events->current.events == NULL || fd < 0) {
-               goto error;
-       }
-
-       /* Ease our life a bit. */
-       current = &events->current;
-
-       for (i = 0; i < current->nb_fd; i++) {
-               /* Don't put back the fd we want to delete */
-               if (current->events[i].fd != fd) {
-                       current->events[count].fd = current->events[i].fd;
-                       current->events[count].events = current->events[i].events;
-                       count++;
-               }
-       }
-
-       /* The fd was not in our set, return no error as with epoll. */
-       if (current->nb_fd == count) {
-               goto end;
-       }
-
-       /* No fd duplicate should be ever added into array. */
-       assert(current->nb_fd - 1 == count);
-       current->nb_fd = count;
-
-       /* Resize array if needed. */
-       new_size = 1U << utils_get_count_order_u32(current->nb_fd);
-       if (new_size != current->alloc_size && new_size >= current->init_size
-                       && current->nb_fd != 0) {
-               ret = resize_poll_event(current, new_size);
-               if (ret < 0) {
-                       goto error;
-               }
-       }
-
-       events->need_update = 1;
-
-end:
-       return 0;
-
-error:
-       return -1;
-}
-
-/*
- * Wait on poll() with timeout. Blocking call.
- */
-LTTNG_HIDDEN
-int compat_poll_wait(struct lttng_poll_event *events, int timeout,
-               bool interruptible)
-{
-       int ret, active_fd_count;
-       int idle_pfd_index = 0;
-       size_t i;
-
-       if (events == NULL || events->current.events == NULL) {
-               ERR("poll wait arguments error");
-               goto error;
-       }
-
-       if (events->current.nb_fd == 0) {
-               /* Return an invalid error to be consistent with epoll. */
-               errno = EINVAL;
-               events->wait.nb_fd = 0;
-               goto error;
-       }
-
-       if (events->need_update) {
-               ret = update_current_events(events);
-               if (ret < 0) {
-                       errno = ENOMEM;
-                       goto error;
-               }
-       }
-
-       do {
-               ret = poll(events->wait.events, events->wait.nb_fd, timeout);
-       } while (!interruptible && ret == -1 && errno == EINTR);
-       if (ret < 0) {
-               if (errno != EINTR) {
-                       PERROR("poll wait");
-               }
-               goto error;
-       }
-
-       active_fd_count = ret;
-
-       /*
-        * Swap all active pollfd structs to the beginning of the
-        * array to emulate compat-epoll behaviour. This algorithm takes
-        * advantage of poll's returned value and the burst nature of active
-        * events on the file descriptors. The while loop guarantees that
-        * idle_pfd will always point to an idle fd.
-        */
-       if (active_fd_count == events->wait.nb_fd) {
-               goto end;
-       }
-       while (idle_pfd_index < active_fd_count &&
-                       events->wait.events[idle_pfd_index].revents != 0) {
-               idle_pfd_index++;
-       }
-
-       for (i = idle_pfd_index + 1; idle_pfd_index < active_fd_count;
-                       i++) {
-               struct pollfd swap_pfd;
-               struct pollfd *idle_pfd = &events->wait.events[idle_pfd_index];
-               struct pollfd *current_pfd = &events->wait.events[i];
-
-               if (idle_pfd->revents != 0) {
-                       swap_pfd = *current_pfd;
-                       *current_pfd = *idle_pfd;
-                       *idle_pfd = swap_pfd;
-                       idle_pfd_index++;
-               }
-       }
-
-end:
-       return ret;
-
-error:
-       return -1;
-}
-
-/*
- * Setup poll set maximum size.
- */
-LTTNG_HIDDEN
-int compat_poll_set_max_size(void)
-{
-       int ret, retval = 0;
-       struct rlimit lim;
-
-       ret = getrlimit(RLIMIT_NOFILE, &lim);
-       if (ret < 0) {
-               PERROR("getrlimit poll RLIMIT_NOFILE");
-               retval = -1;
-               goto end;
-       }
-
-       poll_max_size = lim.rlim_cur;
-end:
-       if (poll_max_size == 0) {
-               poll_max_size = DEFAULT_POLL_SIZE;
-       }
-       DBG("poll set max size set to %u", poll_max_size);
-       return retval;
-}
diff --git a/src/common/compat/poll.c b/src/common/compat/poll.c
new file mode 100644 (file)
index 0000000..d9acd90
--- /dev/null
@@ -0,0 +1,731 @@
+/*
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2019 Yannick Lamarre <ylamarre@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <assert.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include <common/defaults.h>
+#include <common/error.h>
+#include <common/macros.h>
+#include <common/utils.h>
+
+#include "poll.h"
+
+#if HAVE_EPOLL
+
+#include <fcntl.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.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.
+ *
+ */
+static unsigned int poll_max_size;
+
+/*
+ * Resize the epoll events structure of the new size.
+ *
+ * Return 0 on success or else -1 with the current events pointer untouched.
+ */
+static int resize_poll_event(struct lttng_poll_event *events,
+               uint32_t new_size)
+{
+       struct epoll_event *ptr;
+
+       assert(events);
+
+       ptr = realloc(events->events, new_size * sizeof(*ptr));
+       if (ptr == NULL) {
+               PERROR("realloc epoll add");
+               goto error;
+       }
+       if (new_size > events->alloc_size) {
+               /* Zero newly allocated memory */
+               memset(ptr + events->alloc_size, 0,
+                       (new_size - events->alloc_size) * sizeof(*ptr));
+       }
+       events->events = ptr;
+       events->alloc_size = new_size;
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Create epoll set and allocate returned events structure.
+ */
+LTTNG_HIDDEN
+int compat_epoll_create(struct lttng_poll_event *events, int size, int flags)
+{
+       int ret;
+
+       if (events == NULL || size <= 0) {
+               goto error;
+       }
+
+       if (!poll_max_size) {
+               if (lttng_poll_set_max_size()) {
+                       goto error;
+               }
+       }
+
+       /* Don't bust the limit here */
+       if (size > poll_max_size) {
+               size = poll_max_size;
+       }
+
+       ret = compat_glibc_epoll_create(size, flags);
+       if (ret < 0) {
+               /* At this point, every error is fatal */
+               PERROR("epoll_create1");
+               goto error;
+       }
+
+       events->epfd = ret;
+
+       /* This *must* be freed by using lttng_poll_free() */
+       events->events = zmalloc(size * sizeof(struct epoll_event));
+       if (events->events == NULL) {
+               PERROR("zmalloc epoll set");
+               goto error_close;
+       }
+
+       events->alloc_size = events->init_size = size;
+       events->nb_fd = 0;
+
+       return 0;
+
+error_close:
+       ret = close(events->epfd);
+       if (ret) {
+               PERROR("close");
+       }
+error:
+       return -1;
+}
+
+/*
+ * Add a fd to the epoll set with requesting events.
+ */
+LTTNG_HIDDEN
+int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
+{
+       int ret;
+       struct epoll_event ev;
+
+       if (events == NULL || events->events == NULL || fd < 0) {
+               ERR("Bad compat epoll add arguments");
+               goto error;
+       }
+
+       /*
+        * Zero struct epoll_event to ensure all representations of its
+        * union are zeroed.
+        */
+       memset(&ev, 0, sizeof(ev));
+       ev.events = req_events;
+       ev.data.fd = fd;
+
+       ret = epoll_ctl(events->epfd, EPOLL_CTL_ADD, fd, &ev);
+       if (ret < 0) {
+               switch (errno) {
+               case EEXIST:
+                       /* If exist, it's OK. */
+                       goto end;
+               case ENOSPC:
+               case EPERM:
+                       /* Print PERROR and goto end not failing. Show must go on. */
+                       PERROR("epoll_ctl ADD");
+                       goto end;
+               default:
+                       PERROR("epoll_ctl ADD fatal");
+                       goto error;
+               }
+       }
+
+       events->nb_fd++;
+
+end:
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Remove a fd from the epoll set.
+ */
+LTTNG_HIDDEN
+int compat_epoll_del(struct lttng_poll_event *events, int fd)
+{
+       int ret;
+
+       if (events == NULL || fd < 0 || events->nb_fd == 0) {
+               goto error;
+       }
+
+       ret = epoll_ctl(events->epfd, EPOLL_CTL_DEL, fd, NULL);
+       if (ret < 0) {
+               switch (errno) {
+               case ENOENT:
+               case EPERM:
+                       /* Print PERROR and goto end not failing. Show must go on. */
+                       PERROR("epoll_ctl DEL");
+                       goto end;
+               default:
+                       PERROR("epoll_ctl DEL fatal");
+                       goto error;
+               }
+       }
+
+       events->nb_fd--;
+
+end:
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Set an fd's events.
+ */
+LTTNG_HIDDEN
+int compat_epoll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events)
+{
+       int ret;
+       struct epoll_event ev;
+
+       if (events == NULL || fd < 0 || events->nb_fd == 0) {
+               goto error;
+       }
+
+       /*
+        * Zero struct epoll_event to ensure all representations of its
+        * union are zeroed.
+        */
+       memset(&ev, 0, sizeof(ev));
+       ev.events = req_events;
+       ev.data.fd = fd;
+
+       ret = epoll_ctl(events->epfd, EPOLL_CTL_MOD, fd, &ev);
+       if (ret < 0) {
+               switch (errno) {
+               case ENOENT:
+               case EPERM:
+                       /* Print PERROR and goto end not failing. Show must go on. */
+                       PERROR("epoll_ctl MOD");
+                       goto end;
+               default:
+                       PERROR("epoll_ctl MOD fatal");
+                       goto error;
+               }
+       }
+
+end:
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Wait on epoll set. This is a blocking call of timeout value.
+ */
+LTTNG_HIDDEN
+int compat_epoll_wait(struct lttng_poll_event *events, int timeout,
+               bool interruptible)
+{
+       int ret;
+       uint32_t new_size;
+
+       if (events == NULL || events->events == NULL) {
+               ERR("Wrong arguments in compat_epoll_wait");
+               goto error;
+       }
+
+       if (events->nb_fd == 0) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       /*
+        * Resize if needed before waiting. We could either expand the array or
+        * shrink it down. It's important to note that after this step, we are
+        * ensured that the events argument of the epoll_wait call will be large
+        * enough to hold every possible returned events.
+        */
+       new_size = 1U << utils_get_count_order_u32(events->nb_fd);
+       if (new_size != events->alloc_size && new_size >= events->init_size) {
+               ret = resize_poll_event(events, new_size);
+               if (ret < 0) {
+                       /* ENOMEM problem at this point. */
+                       goto error;
+               }
+       }
+
+       do {
+               ret = epoll_wait(events->epfd, events->events, events->nb_fd, timeout);
+       } while (!interruptible && ret == -1 && errno == EINTR);
+       if (ret < 0) {
+               if (errno != EINTR) {
+                       PERROR("epoll_wait");
+               }
+               goto error;
+       }
+
+       /*
+        * Since the returned events are set sequentially in the "events" structure
+        * we only need to return the epoll_wait value and iterate over it.
+        */
+       return ret;
+
+error:
+       return -1;
+}
+
+/*
+ * Setup poll set maximum size.
+ */
+LTTNG_HIDDEN
+int compat_epoll_set_max_size(void)
+{
+       int ret, fd, retval = 0;
+       ssize_t size_ret;
+       char buf[64];
+
+       fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
+       if (fd < 0) {
+               /*
+                * Failing on opening [1] is not an error per see. [1] was
+                * introduced in Linux 2.6.28 but epoll is available since
+                * 2.5.44. Hence, goto end and set a default value without
+                * setting an error return value.
+                *
+                * [1] /proc/sys/fs/epoll/max_user_watches
+                */
+               retval = 0;
+               goto end;
+       }
+
+       size_ret = lttng_read(fd, buf, sizeof(buf));
+       /*
+        * Allow reading a file smaller than buf, but keep space for
+        * final \0.
+        */
+       if (size_ret < 0 || size_ret >= sizeof(buf)) {
+               PERROR("read set max size");
+               retval = -1;
+               goto end_read;
+       }
+       buf[size_ret] = '\0';
+       poll_max_size = atoi(buf);
+end_read:
+       ret = close(fd);
+       if (ret) {
+               PERROR("close");
+       }
+end:
+       if (!poll_max_size) {
+               poll_max_size = DEFAULT_POLL_SIZE;
+       }
+       DBG("epoll set max size is %d", poll_max_size);
+       return retval;
+}
+
+#else /* HAVE_EPOLL */
+
+#include <sys/resource.h>
+#include <sys/time.h>
+
+/*
+ * Maximum number of fd we can monitor.
+ *
+ * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by
+ * getrlimit(2).
+ */
+static unsigned int poll_max_size;
+
+/*
+ * Resize the epoll events structure of the new size.
+ *
+ * Return 0 on success or else -1 with the current events pointer untouched.
+ */
+static int resize_poll_event(struct compat_poll_event_array *array,
+               uint32_t new_size)
+{
+       struct pollfd *ptr;
+
+       assert(array);
+
+       /* Refuse to resize the array more than the max size. */
+       if (new_size > poll_max_size) {
+               goto error;
+       }
+
+       ptr = realloc(array->events, new_size * sizeof(*ptr));
+       if (ptr == NULL) {
+               PERROR("realloc epoll add");
+               goto error;
+       }
+       if (new_size > array->alloc_size) {
+               /* Zero newly allocated memory */
+               memset(ptr + array->alloc_size, 0,
+                       (new_size - array->alloc_size) * sizeof(*ptr));
+       }
+       array->events = ptr;
+       array->alloc_size = new_size;
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Update events with the current events object.
+ */
+static int update_current_events(struct lttng_poll_event *events)
+{
+       int ret;
+       struct compat_poll_event_array *current, *wait;
+
+       assert(events);
+
+       current = &events->current;
+       wait = &events->wait;
+
+       wait->nb_fd = current->nb_fd;
+       if (current->alloc_size != wait->alloc_size) {
+               ret = resize_poll_event(wait, current->alloc_size);
+               if (ret < 0) {
+                       goto error;
+               }
+       }
+       memcpy(wait->events, current->events,
+                       current->nb_fd * sizeof(*current->events));
+
+       /* Update is done. */
+       events->need_update = 0;
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Create pollfd data structure.
+ */
+LTTNG_HIDDEN
+int compat_poll_create(struct lttng_poll_event *events, int size)
+{
+       struct compat_poll_event_array *current, *wait;
+
+       if (events == NULL || size <= 0) {
+               ERR("Wrong arguments for poll create");
+               goto error;
+       }
+
+       if (!poll_max_size) {
+               if (lttng_poll_set_max_size()) {
+                       goto error;
+               }
+       }
+
+       /* Don't bust the limit here */
+       if (size > poll_max_size) {
+               size = poll_max_size;
+       }
+
+       /* Reset everything before begining the allocation. */
+       memset(events, 0, sizeof(struct lttng_poll_event));
+
+       current = &events->current;
+       wait = &events->wait;
+
+       /* This *must* be freed by using lttng_poll_free() */
+       wait->events = zmalloc(size * sizeof(struct pollfd));
+       if (wait->events == NULL) {
+               PERROR("zmalloc struct pollfd");
+               goto error;
+       }
+
+       wait->alloc_size = wait->init_size = size;
+
+       current->events = zmalloc(size * sizeof(struct pollfd));
+       if (current->events == NULL) {
+               PERROR("zmalloc struct current pollfd");
+               goto error;
+       }
+
+       current->alloc_size = current->init_size = size;
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Add fd to pollfd data structure with requested events.
+ */
+LTTNG_HIDDEN
+int compat_poll_add(struct lttng_poll_event *events, int fd,
+               uint32_t req_events)
+{
+       int new_size, ret, i;
+       struct compat_poll_event_array *current;
+
+       if (events == NULL || events->current.events == NULL || fd < 0) {
+               ERR("Bad compat poll add arguments");
+               goto error;
+       }
+
+       current = &events->current;
+
+       /* Check if fd we are trying to add is already there. */
+       for (i = 0; i < current->nb_fd; i++) {
+               if (current->events[i].fd == fd) {
+                       errno = EEXIST;
+                       goto error;
+               }
+       }
+
+       /* Resize array if needed. */
+       new_size = 1U << utils_get_count_order_u32(current->nb_fd + 1);
+       if (new_size != current->alloc_size && new_size >= current->init_size) {
+               ret = resize_poll_event(current, new_size);
+               if (ret < 0) {
+                       goto error;
+               }
+       }
+
+       current->events[current->nb_fd].fd = fd;
+       current->events[current->nb_fd].events = req_events;
+       current->nb_fd++;
+       events->need_update = 1;
+
+       DBG("fd %d of %d added to pollfd", fd, current->nb_fd);
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Modify an fd's events..
+ */
+LTTNG_HIDDEN
+int compat_poll_mod(struct lttng_poll_event *events, int fd,
+               uint32_t req_events)
+{
+       int i;
+       struct compat_poll_event_array *current;
+
+       if (events == NULL || events->current.nb_fd == 0 ||
+                       events->current.events == NULL || fd < 0) {
+               ERR("Bad compat poll mod arguments");
+               goto error;
+       }
+
+       current = &events->current;
+
+       for (i = 0; i < current->nb_fd; i++) {
+               if (current->events[i].fd == fd) {
+                       current->events[i].events = req_events;
+                       events->need_update = 1;
+                       break;
+               }
+       }
+
+       /*
+        * The epoll flavor doesn't flag modifying a non-included FD as an
+        * error.
+        */
+
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Remove a fd from the pollfd structure.
+ */
+LTTNG_HIDDEN
+int compat_poll_del(struct lttng_poll_event *events, int fd)
+{
+       int i, count = 0, ret;
+       uint32_t new_size;
+       struct compat_poll_event_array *current;
+
+       if (events == NULL || events->current.nb_fd == 0 ||
+                       events->current.events == NULL || fd < 0) {
+               goto error;
+       }
+
+       /* Ease our life a bit. */
+       current = &events->current;
+
+       for (i = 0; i < current->nb_fd; i++) {
+               /* Don't put back the fd we want to delete */
+               if (current->events[i].fd != fd) {
+                       current->events[count].fd = current->events[i].fd;
+                       current->events[count].events = current->events[i].events;
+                       count++;
+               }
+       }
+
+       /* The fd was not in our set, return no error as with epoll. */
+       if (current->nb_fd == count) {
+               goto end;
+       }
+
+       /* No fd duplicate should be ever added into array. */
+       assert(current->nb_fd - 1 == count);
+       current->nb_fd = count;
+
+       /* Resize array if needed. */
+       new_size = 1U << utils_get_count_order_u32(current->nb_fd);
+       if (new_size != current->alloc_size && new_size >= current->init_size
+                       && current->nb_fd != 0) {
+               ret = resize_poll_event(current, new_size);
+               if (ret < 0) {
+                       goto error;
+               }
+       }
+
+       events->need_update = 1;
+
+end:
+       return 0;
+
+error:
+       return -1;
+}
+
+/*
+ * Wait on poll() with timeout. Blocking call.
+ */
+LTTNG_HIDDEN
+int compat_poll_wait(struct lttng_poll_event *events, int timeout,
+               bool interruptible)
+{
+       int ret, active_fd_count;
+       int idle_pfd_index = 0;
+       size_t i;
+
+       if (events == NULL || events->current.events == NULL) {
+               ERR("poll wait arguments error");
+               goto error;
+       }
+
+       if (events->current.nb_fd == 0) {
+               /* Return an invalid error to be consistent with epoll. */
+               errno = EINVAL;
+               events->wait.nb_fd = 0;
+               goto error;
+       }
+
+       if (events->need_update) {
+               ret = update_current_events(events);
+               if (ret < 0) {
+                       errno = ENOMEM;
+                       goto error;
+               }
+       }
+
+       do {
+               ret = poll(events->wait.events, events->wait.nb_fd, timeout);
+       } while (!interruptible && ret == -1 && errno == EINTR);
+       if (ret < 0) {
+               if (errno != EINTR) {
+                       PERROR("poll wait");
+               }
+               goto error;
+       }
+
+       active_fd_count = ret;
+
+       /*
+        * Swap all active pollfd structs to the beginning of the
+        * array to emulate compat-epoll behaviour. This algorithm takes
+        * advantage of poll's returned value and the burst nature of active
+        * events on the file descriptors. The while loop guarantees that
+        * idle_pfd will always point to an idle fd.
+        */
+       if (active_fd_count == events->wait.nb_fd) {
+               goto end;
+       }
+       while (idle_pfd_index < active_fd_count &&
+                       events->wait.events[idle_pfd_index].revents != 0) {
+               idle_pfd_index++;
+       }
+
+       for (i = idle_pfd_index + 1; idle_pfd_index < active_fd_count;
+                       i++) {
+               struct pollfd swap_pfd;
+               struct pollfd *idle_pfd = &events->wait.events[idle_pfd_index];
+               struct pollfd *current_pfd = &events->wait.events[i];
+
+               if (idle_pfd->revents != 0) {
+                       swap_pfd = *current_pfd;
+                       *current_pfd = *idle_pfd;
+                       *idle_pfd = swap_pfd;
+                       idle_pfd_index++;
+               }
+       }
+
+end:
+       return ret;
+
+error:
+       return -1;
+}
+
+/*
+ * Setup poll set maximum size.
+ */
+LTTNG_HIDDEN
+int compat_poll_set_max_size(void)
+{
+       int ret, retval = 0;
+       struct rlimit lim;
+
+       ret = getrlimit(RLIMIT_NOFILE, &lim);
+       if (ret < 0) {
+               PERROR("getrlimit poll RLIMIT_NOFILE");
+               retval = -1;
+               goto end;
+       }
+
+       poll_max_size = lim.rlim_cur;
+end:
+       if (poll_max_size == 0) {
+               poll_max_size = DEFAULT_POLL_SIZE;
+       }
+       DBG("poll set max size set to %u", poll_max_size);
+       return retval;
+}
+
+#endif /* !HAVE_EPOLL */
index 864772725067965061762eec96be063c52ca6f1c..05ca8e84ba93ca88844cd148fd2c398630cb90e7 100644 (file)
@@ -2,13 +2,7 @@
 
 noinst_LTLIBRARIES = libfd-tracker.la
 
-if COMPAT_EPOLL
-COMPAT=utils-epoll.c
-else
-COMPAT=utils-poll.c
-endif
-
 libfd_tracker_la_SOURCES = fd-tracker.h fd-tracker.c \
                            utils.h utils.c \
                            inode.h inode.c \
-                           $(COMPAT)
+                           utils-poll.c
diff --git a/src/common/fd-tracker/utils-epoll.c b/src/common/fd-tracker/utils-epoll.c
deleted file mode 100644 (file)
index f31dd2b..0000000
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#include <common/compat/poll.h>
-
-#include "utils.h"
-
-struct create_args {
-       struct lttng_poll_event *events;
-       int size;
-       int flags;
-};
-
-static int open_epoll(void *data, int *out_fd)
-{
-       int ret;
-       struct create_args *args = data;
-
-       ret = lttng_poll_create(args->events, args->size, args->flags);
-       if (ret < 0) {
-               goto end;
-       }
-
-       *out_fd = args->events->epfd;
-end:
-       return ret;
-}
-
-static int close_epoll(void *data, int *in_fd)
-{
-       /* Will close the epfd. */
-       lttng_poll_clean((struct lttng_poll_event *) data);
-       return 0;
-}
-
-/*
- * The epoll variant of the poll compat layer creates an unsuspendable fd which
- * must be tracked.
- */
-int fd_tracker_util_poll_create(struct fd_tracker *tracker,
-               const char *name,
-               struct lttng_poll_event *events,
-               int size,
-               int flags)
-{
-       int out_fd;
-       struct create_args create_args = {
-               .events = events,
-               .size = size,
-               .flags = flags,
-       };
-
-       return fd_tracker_open_unsuspendable_fd(
-                       tracker, &out_fd, &name, 1, open_epoll, &create_args);
-}
-
-int fd_tracker_util_poll_clean(
-               struct fd_tracker *tracker, struct lttng_poll_event *events)
-{
-       return fd_tracker_close_unsuspendable_fd(
-                       tracker, &events->epfd, 1, close_epoll, events);
-}
index fa957432d01945e397f49c7d0836ba4338182b59..17349a45ff252972d2607260ffb7bb08248a0be8 100644 (file)
@@ -9,6 +9,66 @@
 
 #include "utils.h"
 
+#if HAVE_EPOLL
+
+struct create_args {
+       struct lttng_poll_event *events;
+       int size;
+       int flags;
+};
+
+static int open_epoll(void *data, int *out_fd)
+{
+       int ret;
+       struct create_args *args = data;
+
+       ret = lttng_poll_create(args->events, args->size, args->flags);
+       if (ret < 0) {
+               goto end;
+       }
+
+       *out_fd = args->events->epfd;
+end:
+       return ret;
+}
+
+static int close_epoll(void *data, int *in_fd)
+{
+       /* Will close the epfd. */
+       lttng_poll_clean((struct lttng_poll_event *) data);
+       return 0;
+}
+
+/*
+ * The epoll variant of the poll compat layer creates an unsuspendable fd which
+ * must be tracked.
+ */
+int fd_tracker_util_poll_create(struct fd_tracker *tracker,
+               const char *name,
+               struct lttng_poll_event *events,
+               int size,
+               int flags)
+{
+       int out_fd;
+       struct create_args create_args = {
+               .events = events,
+               .size = size,
+               .flags = flags,
+       };
+
+       return fd_tracker_open_unsuspendable_fd(
+                       tracker, &out_fd, &name, 1, open_epoll, &create_args);
+}
+
+int fd_tracker_util_poll_clean(
+               struct fd_tracker *tracker, struct lttng_poll_event *events)
+{
+       return fd_tracker_close_unsuspendable_fd(
+                       tracker, &events->epfd, 1, close_epoll, events);
+}
+
+#else /* HAVE_EPOLL */
+
 /*
  * The epoll variant of the poll compat layer creates an unsuspendable fd which
  * must be tracked.
@@ -28,3 +88,5 @@ int fd_tracker_util_poll_clean(
        lttng_poll_clean(events);
        return 0;
 }
+
+#endif /* !HAVE_EPOLL */
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