--- /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 as published by the Free
+ * Software Foundation; only version 2 of the License.
+ *
+ * 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.
+ */
+
+#include <stdlib.h>
+#include <sys/resource.h>
+#include <sys/time.h>
+
+#include <lttngerr.h>
+
+#include "poll.h"
+
+unsigned int poll_max_size;
+
+/*
+ * Create pollfd data structure.
+ */
+int compat_poll_create(struct lttng_poll_event *events, int size)
+{
+ if (events == NULL || size <= 0) {
+ ERR("Wrong arguments for poll create");
+ goto error;
+ }
+
+ /* Don't bust the limit here */
+ if (size > poll_max_size) {
+ size = poll_max_size;
+ }
+
+ /* This *must* be freed by using lttng_poll_free() */
+ events->events = zmalloc(size * sizeof(struct pollfd));
+ if (events->events == NULL) {
+ perror("zmalloc struct pollfd");
+ goto error;
+ }
+
+ events->events_size = size;
+ events->nb_fd = 0;
+
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Add fd to pollfd data structure with requested events.
+ */
+int compat_poll_add(struct lttng_poll_event *events, int fd,
+ uint32_t req_events)
+{
+ int new_size;
+ struct pollfd *ptr;
+
+ if (events == NULL || events->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");
+ 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++;
+
+ DBG("fd %d of %d added to pollfd", fd, events->nb_fd);
+
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Remove a fd from the pollfd structure.
+ */
+int compat_poll_del(struct lttng_poll_event *events, int fd)
+{
+ int new_size, i, count = 0;
+ struct pollfd *old = NULL, *new = NULL;
+
+ if (events == NULL || events->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;
+ }
+
+ for (i = 0; i < events->events_size; 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;
+ count++;
+ }
+ }
+
+ events->events_size = new_size;
+ events->events = new;
+ events->nb_fd--;
+
+ free(old);
+
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Wait on poll() with timeout. Blocking call.
+ */
+int compat_poll_wait(struct lttng_poll_event *events, int timeout)
+{
+ int ret;
+
+ if (events == NULL || events->events == NULL ||
+ events->events_size < events->nb_fd) {
+ ERR("poll wait arguments error");
+ goto error;
+ }
+
+ ret = poll(events->events, events->nb_fd, timeout);
+ if (ret < 0) {
+ /* At this point, every error is fatal */
+ perror("poll wait");
+ goto error;
+ }
+
+ return ret;
+
+error:
+ return -1;
+}
+
+/*
+ * Setup poll set maximum size.
+ */
+void compat_poll_set_max_size(void)
+{
+ int ret;
+ struct rlimit lim;
+
+ /* Default value */
+ poll_max_size = LTTNG_POLL_DEFAULT_SIZE;
+
+ ret = getrlimit(RLIMIT_NOFILE, &lim);
+ if (ret < 0) {
+ perror("getrlimit poll RLIMIT_NOFILE");
+ return;
+ }
+
+ poll_max_size = lim.rlim_cur;
+ if (poll_max_size <= 0) {
+ /* Extra precaution */
+ poll_max_size = LTTNG_POLL_DEFAULT_SIZE;
+ }
+
+ DBG("poll set max size set to %u", poll_max_size);
+}