Keep track of FD used for UST applications (v2)

[lttng-tools.git] / src / bin / lttng-sessiond / fd-limit.c

diff --git a/src/bin/lttng-sessiond/fd-limit.c b/src/bin/lttng-sessiond/fd-limit.c
new file mode 100644 (file)
index 0000000..a886d33
--- /dev/null
+++ b/src/bin/lttng-sessiond/fd-limit.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include <urcu/uatomic.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <errno.h>
+#include <stdio.h>
+#include "fd-limit.h"
+
+/* total count of fd. */
+static long fd_count;
+
+/*
+ * threshold in % of number of fd allowed.
+ */
+static long fd_threshold[LTTNG_FD_NR_TYPES] = {
+       [LTTNG_FD_APPS] = 75,
+};
+
+static rlim_t max_nr_fd;
+
+int lttng_fd_get(enum lttng_fd_type type, unsigned int nr)
+{
+       long newval;
+
+       if (type >= LTTNG_FD_NR_TYPES) {
+               return -EINVAL;
+       }
+
+       newval = uatomic_add_return(&fd_count, (long) nr);
+       if ((long) (newval * 100)
+                       - (long) (max_nr_fd * fd_threshold[type]) > 0) {
+               uatomic_sub(&fd_count, (long) nr);
+               return -EPERM;
+       }
+       return 0;
+}
+
+void lttng_fd_put(enum lttng_fd_type type, unsigned int nr)
+{
+       uatomic_sub(&fd_count, (long) nr);
+}
+
+void lttng_fd_init(void)
+{
+       struct rlimit rlim;
+       int ret;
+
+       ret = getrlimit(RLIMIT_NOFILE, &rlim);
+       if (ret < 0) {
+               perror("getrlimit");
+       }
+       max_nr_fd = rlim.rlim_cur;
+}