Add getloadavg(3).

Lets us build ninja with bionic.

Bug: N/A
Test: ran tests
Change-Id: I97eef1247d794b58a2b9aee4851551632e5a4e48

1 files changed, 44 insertions, 0 deletions

diff --git a/libc/bionic/getloadavg.cpp b/libc/bionic/getloadavg.cpp
new file mode 100644
index 000000000..28d316cfa
--- /dev/null
+++ b/libc/bionic/getloadavg.cpp
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stdlib.h>
+
+#include <sys/sysinfo.h>
+
+int getloadavg(double averages[], int n) {
+  if (n < 0) return -1;
+  if (n > 3) n = 3;
+
+  struct sysinfo si;
+  if (sysinfo(&si) == -1) return -1;
+
+  for (int i = 0; i < n; ++i) {
+    averages[i] = static_cast<double>(si.loads[i]) / static_cast<double>(1 << SI_LOAD_SHIFT);
+  }
+  return n;
+}