From cad810f21b803229eb11403f9209855525a25d57 Mon Sep 17 00:00:00 2001
From: Steve Block <steveblock@google.com>
Date: Fri, 6 May 2011 11:45:16 +0100
Subject: Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84
---
 Source/JavaScriptCore/wtf/RandomNumber.cpp | 123 +++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 Source/JavaScriptCore/wtf/RandomNumber.cpp

(limited to 'Source/JavaScriptCore/wtf/RandomNumber.cpp')

diff --git a/Source/JavaScriptCore/wtf/RandomNumber.cpp b/Source/JavaScriptCore/wtf/RandomNumber.cpp
new file mode 100644
index 0000000..0c45416
--- /dev/null
+++ b/Source/JavaScriptCore/wtf/RandomNumber.cpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
+ *           (C) 2008, 2009 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. 
+ */
+
+#include "config.h"
+#include "RandomNumber.h"
+
+#include "RandomNumberSeed.h"
+
+#include <limits>
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#if OS(WINCE)
+extern "C" {
+#include "wince/mt19937ar.c"
+}
+#endif
+
+#if PLATFORM(BREWMP)
+#include <AEEAppGen.h>
+#include <AEESource.h>
+#include <AEEStdLib.h>
+#include <wtf/brew/RefPtrBrew.h>
+#include <wtf/brew/ShellBrew.h>
+#endif
+
+namespace WTF {
+
+double randomNumber()
+{
+#if !ENABLE(JSC_MULTIPLE_THREADS)
+    static bool s_initialized = false;
+    if (!s_initialized) {
+        initializeRandomNumberGenerator();
+        s_initialized = true;
+    }
+#endif
+    
+#if COMPILER(MSVC) && defined(_CRT_RAND_S)
+    uint32_t bits;
+    rand_s(&bits);
+    return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0);
+#elif OS(DARWIN)
+    uint32_t bits = arc4random();
+    return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0);
+#elif OS(UNIX)
+    uint32_t part1 = random() & (RAND_MAX - 1);
+    uint32_t part2 = random() & (RAND_MAX - 1);
+    // random only provides 31 bits
+    uint64_t fullRandom = part1;
+    fullRandom <<= 31;
+    fullRandom |= part2;
+
+    // Mask off the low 53bits
+    fullRandom &= (1LL << 53) - 1;
+    return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53);
+#elif OS(WINCE)
+    return genrand_res53();
+#elif OS(WINDOWS)
+    uint32_t part1 = rand() & (RAND_MAX - 1);
+    uint32_t part2 = rand() & (RAND_MAX - 1);
+    uint32_t part3 = rand() & (RAND_MAX - 1);
+    uint32_t part4 = rand() & (RAND_MAX - 1);
+    // rand only provides 15 bits on Win32
+    uint64_t fullRandom = part1;
+    fullRandom <<= 15;
+    fullRandom |= part2;
+    fullRandom <<= 15;
+    fullRandom |= part3;
+    fullRandom <<= 15;
+    fullRandom |= part4;
+
+    // Mask off the low 53bits
+    fullRandom &= (1LL << 53) - 1;
+    return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53);
+#elif PLATFORM(BREWMP)
+    uint32_t bits;
+    RefPtr<ISource> randomSource = createRefPtrInstance<ISource>(AEECLSID_RANDOM);
+    ISOURCE_Read(randomSource.get(), reinterpret_cast<char*>(&bits), 4);
+
+    return static_cast<double>(bits) / (static_cast<double>(std::numeric_limits<uint32_t>::max()) + 1.0);
+#else
+    uint32_t part1 = rand() & (RAND_MAX - 1);
+    uint32_t part2 = rand() & (RAND_MAX - 1);
+    // rand only provides 31 bits, and the low order bits of that aren't very random
+    // so we take the high 26 bits of part 1, and the high 27 bits of part2.
+    part1 >>= 5; // drop the low 5 bits
+    part2 >>= 4; // drop the low 4 bits
+    uint64_t fullRandom = part1;
+    fullRandom <<= 27;
+    fullRandom |= part2;
+
+    // Mask off the low 53bits
+    fullRandom &= (1LL << 53) - 1;
+    return static_cast<double>(fullRandom)/static_cast<double>(1LL << 53);
+#endif
+}
+
+}
-- 
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