X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=ltt-sessiond%2Fcompat%2Fcompat-poll.c;fp=ltt-sessiond%2Fcompat%2Fcompat-poll.c;h=cc4bb0f97585df5bcc71b8fb9c1fde43016518c7;hp=0000000000000000000000000000000000000000;hb=5eb91c9837a7b379a74e99358f0f9fb10011ef74;hpb=71615260f4e0d7a58bf64a837c081af2d155ef9d

diff --git a/ltt-sessiond/compat/compat-poll.c b/ltt-sessiond/compat/compat-poll.c
new file mode 100644
index 000000000..cc4bb0f97
--- /dev/null
+++ b/ltt-sessiond/compat/compat-poll.c
@@ -0,0 +1,195 @@
+/*
+ * 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("malloc 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("malloc 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);
+}