1 files changed, 28 insertions, 0 deletions
diff --git a/js/src/threading/posix/CpuCount.cpp b/js/src/threading/posix/CpuCount.cpp
new file mode 100644
index 0000000000..b8fe1d3f66
--- /dev/null
+++ b/js/src/threading/posix/CpuCount.cpp
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <unistd.h>
+
+#include "threading/CpuCount.h"
+
+uint32_t js::GetCPUCount() {
+  static uint32_t ncpus = 0;
+
+  // _SC_NPROCESSORS_CONF and _SC_NPROCESSORS_ONLN are common, but not
+  // standard.
+  if (ncpus == 0) {
+#if defined(_SC_NPROCESSORS_CONF)
+    long n = sysconf(_SC_NPROCESSORS_CONF);
+    ncpus = (n > 0) ? uint32_t(n) : 1;
+#elif defined(_SC_NPROCESSORS_ONLN)
+    long n = sysconf(_SC_NPROCESSORS_ONLN);
+    ncpus = (n > 0) ? uint32_t(n) : 1;
+#else
+    ncpus = 1;
+#endif
+  }
+
+  return ncpus;
+}