Author: [EMAIL PROTECTED]
Date: Tue Sep 9 23:59:41 2008
New Revision: 246
Modified:
branches/bleeding_edge/src/platform-linux.cc
branches/bleeding_edge/src/platform-macos.cc
branches/bleeding_edge/src/platform-win32.cc
Log:
Fix issue http://code.google.com/p/v8/issues/detail?id=58:
- Prevent a clipping of values when converting a double to an unsigned int
for use as the random generator's seed value.
Review URL: http://codereview.chromium.org/1887
Modified: branches/bleeding_edge/src/platform-linux.cc
==============================================================================
--- branches/bleeding_edge/src/platform-linux.cc (original)
+++ branches/bleeding_edge/src/platform-linux.cc Tue Sep 9 23:59:41 2008
@@ -67,7 +67,12 @@
void OS::Setup() {
// Seed the random number generator.
- srandom(static_cast<unsigned int>(TimeCurrentMillis()));
+ // Convert the current time to a 64-bit integer first, before converting
it
+ // to an unsigned. Going directly can cause an overflow and the seed to
be
+ // set to all ones. The seed will be identical for different instances
that
+ // call this setup code within the same millisecond.
+ uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
+ srandom(static_cast<unsigned int>(seed));
}
Modified: branches/bleeding_edge/src/platform-macos.cc
==============================================================================
--- branches/bleeding_edge/src/platform-macos.cc (original)
+++ branches/bleeding_edge/src/platform-macos.cc Tue Sep 9 23:59:41 2008
@@ -73,7 +73,12 @@
void OS::Setup() {
// Seed the random number generator.
- srandom(static_cast<unsigned int>(TimeCurrentMillis()));
+ // Convert the current time to a 64-bit integer first, before converting
it
+ // to an unsigned. Going directly will cause an overflow and the seed to
be
+ // set to all ones. The seed will be identical for different instances
that
+ // call this setup code within the same millisecond.
+ uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
+ srandom(static_cast<unsigned int>(seed));
}
Modified: branches/bleeding_edge/src/platform-win32.cc
==============================================================================
--- branches/bleeding_edge/src/platform-win32.cc (original)
+++ branches/bleeding_edge/src/platform-win32.cc Tue Sep 9 23:59:41 2008
@@ -493,7 +493,12 @@
void OS::Setup() {
// Seed the random number generator.
- srand(static_cast<unsigned int>(TimeCurrentMillis()));
+ // Convert the current time to a 64-bit integer first, before converting
it
+ // to an unsigned. Going directly can cause an overflow and the seed to
be
+ // set to all ones. The seed will be identical for different instances
that
+ // call this setup code within the same millisecond.
+ uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
+ srand(static_cast<unsigned int>(seed));
}
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