/*
* 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 _GNU_SOURCE
+#include <assert.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <unistd.h>
#include <config.h>
-#include <common/lttngerr.h>
+#include <common/error.h>
+#include <common/defaults.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 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;
+ }
+ events->events = ptr;
+ events->alloc_size = new_size;
+
+ return 0;
+
+error:
+ return -1;
+}
+
/*
* Create epoll set and allocate returned events structure.
*/
}
/* Don't bust the limit here */
- if (size > poll_max_size) {
+ if (size > poll_max_size && poll_max_size != 0) {
size = poll_max_size;
}
ret = epoll_create1(flags);
if (ret < 0) {
/* At this point, every error is fatal */
- perror("epoll_create1");
+ PERROR("epoll_create1");
goto error;
}
/* 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");
+ PERROR("zmalloc epoll set");
goto error_close;
}
- events->events_size = size;
+ events->alloc_size = events->init_size = size;
events->nb_fd = 0;
return 0;
error_close:
- close(events->epfd);
+ ret = close(events->epfd);
+ if (ret) {
+ PERROR("close");
+ }
error:
return -1;
}
*/
int compat_epoll_add(struct lttng_poll_event *events, int fd, uint32_t req_events)
{
- int ret, new_size;
- struct epoll_event ev, *ptr;
+ int ret;
+ struct epoll_event ev;
if (events == NULL || events->events == NULL || fd < 0) {
ERR("Bad compat epoll add arguments");
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");
+ /* Print PERROR and goto end not failing. Show must go on. */
+ PERROR("epoll_ctl ADD");
goto end;
default:
- perror("epoll_ctl ADD fatal");
+ PERROR("epoll_ctl ADD fatal");
goto error;
}
}
events->nb_fd++;
- if (events->nb_fd >= events->events_size) {
- new_size = 2 * events->events_size;
- ptr = realloc(events->events, new_size * sizeof(struct epoll_event));
- if (ptr == NULL) {
- perror("realloc epoll add");
- goto error;
- }
- events->events = ptr;
- events->events_size = new_size;
- }
-
end:
return 0;
switch (errno) {
case ENOENT:
case EPERM:
- /* Print perror and goto end not failing. Show must go on. */
- perror("epoll_ctl DEL");
+ /* Print PERROR and goto end not failing. Show must go on. */
+ PERROR("epoll_ctl DEL");
goto end;
default:
- perror("epoll_ctl DEL fatal");
+ PERROR("epoll_ctl DEL fatal");
goto error;
}
- perror("epoll_ctl del");
- goto error;
}
events->nb_fd--;
int compat_epoll_wait(struct lttng_poll_event *events, int timeout)
{
int ret;
+ uint32_t new_size;
- if (events == NULL || events->events == NULL ||
- events->events_size < events->nb_fd) {
+ if (events == NULL || events->events == NULL) {
ERR("Wrong arguments in compat_epoll_wait");
goto error;
}
+ /*
+ * 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.
+ */
+ if (events->nb_fd > events->alloc_size) {
+ /* Expand if the nb_fd is higher than the actual size. */
+ new_size = max_t(uint32_t,
+ 1U << utils_get_count_order_u32(events->nb_fd),
+ events->alloc_size << 1UL);
+ } else if ((events->nb_fd << 1UL) <= events->alloc_size &&
+ events->nb_fd >= events->init_size) {
+ /* Shrink if nb_fd multiplied by two is <= than the actual size. */
+ new_size = max_t(uint32_t,
+ utils_get_count_order_u32(events->nb_fd) >> 1U,
+ events->alloc_size >> 1U);
+ } else {
+ /* Indicate that we don't want to resize. */
+ new_size = 0;
+ }
+
+ if (new_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 (ret == -1 && errno == EINTR);
if (ret < 0) {
/* At this point, every error is fatal */
- perror("epoll_wait");
+ 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:
void compat_epoll_set_max_size(void)
{
int ret, fd;
+ ssize_t size_ret;
char buf[64];
- poll_max_size = LTTNG_POLL_DEFAULT_SIZE;
+ poll_max_size = DEFAULT_POLL_SIZE;
- fd = open(LTTNG_EPOLL_PROC_PATH, O_RDONLY);
+ fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
if (fd < 0) {
return;
}
- ret = read(fd, buf, sizeof(buf));
- if (ret < 0) {
- perror("read set max size");
+ 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");
goto error;
}
+ buf[size_ret] = '\0';
poll_max_size = atoi(buf);
- if (poll_max_size <= 0) {
+ if (poll_max_size == 0) {
/* Extra precaution */
- poll_max_size = LTTNG_POLL_DEFAULT_SIZE;
+ poll_max_size = DEFAULT_POLL_SIZE;
}
DBG("epoll set max size is %d", poll_max_size);
error:
- close(fd);
+ ret = close(fd);
+ if (ret) {
+ PERROR("close");
+ }
}
projects / lttng-tools.git / blobdiff