Add chrome to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@15 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 72 insertions, 0 deletions

diff --git a/chrome/common/rand_util.cc b/chrome/common/rand_util.cc
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+++ b/chrome/common/rand_util.cc
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+// Copyright 2008, Google Inc.
+// 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.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// 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 "chrome/common/rand_util.h"
+
+#include <stdlib.h>
+#include <time.h>
+
+#include "base/logging.h"
+#include "base/thread_local_storage.h"
+#include "base/win_util.h"
+
+namespace rand_util {
+
+// Using TLS since srand() needs to be called once in each thread.
+int g_tls_index = ThreadLocalStorage::Alloc();
+
+int RandInt(int min, int max) {
+  if (ThreadLocalStorage::Get(g_tls_index) == 0) {
+    ThreadLocalStorage::Set(g_tls_index, reinterpret_cast<void*>(1));
+    srand(static_cast<unsigned int>(time(0)));
+  }
+
+  // From the rand man page, use this instead of just rand() % max, so that the
+  // higher bits are used.
+  return min + static_cast<int>(static_cast<double>(max - min + 1) *
+    (::rand() / (RAND_MAX + 1.0)));
+}
+
+int RandIntSecure(int min, int max) {
+  if (win_util::GetWinVersion() < win_util::WINVERSION_XP) {
+    // rand_s needs XP and later.
+    return RandInt(min, max);
+  }
+
+  unsigned int number;
+  errno_t rv = rand_s(&number);
+  DCHECK(rv == 0) << "rand_s failed with error " << rv;
+
+  // From the rand man page, use this instead of just rand() % max, so that the
+  // higher bits are used.
+  return min + static_cast<int>(static_cast<double>(max - min + 1.0) *
+      (number / (UINT_MAX + 1.0)));
+}
+
+}  // namespace rand_util