/*
* 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 as published by the Free
- * Software Foundation; only version 2 of the License.
+ * 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., 59 Temple
- * Place - Suite 330, Boston, MA 02111-1307, USA.
+ * 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.
*/
+#define _LGPL_SOURCE
+#include <assert.h>
#include <stdlib.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <common/defaults.h>
#include <common/error.h>
+#include <common/macros.h>
+#include <common/utils.h>
#include "poll.h"
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.
*/
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() */
- events->events = zmalloc(size * sizeof(struct pollfd));
- if (events->events == NULL) {
- perror("zmalloc struct pollfd");
+ wait->events = zmalloc(size * sizeof(struct pollfd));
+ if (wait->events == NULL) {
+ PERROR("zmalloc struct pollfd");
goto error;
}
- events->events_size = size;
- events->nb_fd = 0;
+ 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;
int compat_poll_add(struct lttng_poll_event *events, int fd,
uint32_t req_events)
{
- int new_size;
- struct pollfd *ptr;
+ int new_size, ret, i;
+ struct compat_poll_event_array *current;
- if (events == NULL || events->events == NULL || fd < 0) {
+ if (events == NULL || events->current.events == NULL || fd < 0) {
ERR("Bad compat poll add arguments");
goto error;
}
- /* Reallocate pollfd structure by a factor of 2 if needed. */
- if (events->nb_fd >= events->events_size) {
- new_size = 2 * events->events_size;
- ptr = realloc(events->events, new_size * sizeof(struct pollfd));
- if (ptr == NULL) {
- perror("realloc poll add");
+ 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;
}
- events->events = ptr;
- events->events_size = new_size;
}
- events->events[events->nb_fd].fd = fd;
- events->events[events->nb_fd].events = req_events;
- events->nb_fd++;
+ /* 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;
+ }
+ }
- DBG("fd %d of %d added to pollfd", fd, events->nb_fd);
+ 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;
*/
int compat_poll_del(struct lttng_poll_event *events, int fd)
{
- int new_size, i, count = 0;
- struct pollfd *old = NULL, *new = NULL;
+ int new_size, i, count = 0, ret;
+ struct compat_poll_event_array *current;
- if (events == NULL || events->events == NULL || fd < 0) {
+ if (events == NULL || events->current.events == NULL || fd < 0) {
ERR("Wrong arguments for poll del");
goto error;
}
- old = events->events;
- new_size = events->events_size - 1;
-
- /* Safety check on size */
- if (new_size > poll_max_size) {
- new_size = poll_max_size;
- }
-
- new = zmalloc(new_size * sizeof(struct pollfd));
- if (new == NULL) {
- perror("zmalloc poll del");
- goto error;
- }
+ /* Ease our life a bit. */
+ current = &events->current;
- for (i = 0; i < events->events_size; i++) {
+ for (i = 0; i < current->nb_fd; i++) {
/* Don't put back the fd we want to delete */
- if (old[i].fd != fd) {
- new[count].fd = old[i].fd;
- new[count].events = old[i].events;
+ if (current->events[i].fd != fd) {
+ current->events[count].fd = current->events[i].fd;
+ current->events[count].events = current->events[i].events;
count++;
}
}
+ /* 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) {
+ ret = resize_poll_event(current, new_size);
+ if (ret < 0) {
+ goto error;
+ }
+ }
- events->events_size = new_size;
- events->events = new;
- events->nb_fd--;
-
- free(old);
+ events->need_update = 1;
return 0;
{
int ret;
- if (events == NULL || events->events == NULL ||
- events->events_size < events->nb_fd) {
+ if (events == NULL || events->current.events == NULL) {
ERR("poll wait arguments error");
goto error;
}
+ assert(events->current.nb_fd >= 0);
- ret = poll(events->events, events->nb_fd, timeout);
+ 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 (ret == -1 && errno == EINTR);
if (ret < 0) {
/* At this point, every error is fatal */
- perror("poll wait");
+ PERROR("poll wait");
goto error;
}
- return ret;
+ /*
+ * poll() should always iterate on all FDs since we handle the pollset in
+ * user space and after poll returns, we have to try every fd for a match.
+ */
+ return events->wait.nb_fd;
error:
return -1;
/*
* Setup poll set maximum size.
*/
-void compat_poll_set_max_size(void)
+int compat_poll_set_max_size(void)
{
- int ret;
+ int ret, retval = 0;
struct rlimit lim;
- /* Default value */
- poll_max_size = DEFAULT_POLL_SIZE;
-
ret = getrlimit(RLIMIT_NOFILE, &lim);
if (ret < 0) {
- perror("getrlimit poll RLIMIT_NOFILE");
- return;
+ PERROR("getrlimit poll RLIMIT_NOFILE");
+ retval = -1;
+ goto end;
}
poll_max_size = lim.rlim_cur;
- if (poll_max_size <= 0) {
- /* Extra precaution */
+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;
}
projects / lttng-tools.git / blobdiff