bin: compile lttng-sessiond as C++

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

diff --git a/src/bin/lttng-sessiond/fd-limit.cpp b/src/bin/lttng-sessiond/fd-limit.cpp
new file mode 100644 (file)
index 0000000..833b647
--- /dev/null
+++ b/src/bin/lttng-sessiond/fd-limit.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <urcu/uatomic.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <stdio.h>
+#include "fd-limit.h"
+#include <common/error.h>
+#include <common/compat/errno.h>
+
+/* total count of fd. */
+static long fd_count;
+
+/*
+ * threshold in % of number of fd allowed.
+ */
+static long fd_threshold[LTTNG_FD_NR_TYPES] = {
+       75, /* LTTNG_FD_APPS */
+};
+
+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;
+}