JavaScriptCore-521.tar.gz

[apple/javascriptcore.git] / wtf / RandomNumberSeed.h

diff --git a/wtf/RandomNumberSeed.h b/wtf/RandomNumberSeed.h
new file mode 100644 (file)
index 0000000..f994fd9
--- /dev/null
+++ b/wtf/RandomNumberSeed.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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. 
+ */
+
+#ifndef WTF_RandomNumberSeed_h
+#define WTF_RandomNumberSeed_h
+
+#include <stdlib.h>
+#include <time.h>
+
+#if HAVE(SYS_TIME_H)
+#include <sys/time.h>
+#endif
+
+#if PLATFORM(UNIX)
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+
+// Internal JavaScriptCore usage only
+namespace WTF {
+
+inline void initializeRandomNumberGenerator()
+{
+#if PLATFORM(DARWIN)
+    // On Darwin we use arc4random which initialises itself.
+#elif COMPILER(MSVC) && defined(_CRT_RAND_S)
+    // On Windows we use rand_s which intialises itself
+#elif PLATFORM(UNIX)
+    // srandomdev is not guaranteed to exist on linux so we use this poor seed, this should be improved
+    timeval time;
+    gettimeofday(&time, 0);
+    srandom(static_cast<unsigned>(time.tv_usec * getpid()));
+#else
+    srand(static_cast<unsigned>(time(0)));
+#endif
+}
+
+inline void initializeWeakRandomNumberGenerator()
+{
+#if COMPILER(MSVC) && defined(_CRT_RAND_S)
+    // We need to initialise windows rand() explicitly for Math.random
+    unsigned seed = 0;
+    rand_s(&seed);
+    srand(seed);
+#endif
+}
+}
+
+#endif