Changeset 77260 in webkit

Timestamp:

Feb 1, 2011 10:50:17 AM (13 years ago)

Author:

dbates@webkit.org

Message:

2011-02-01 Daniel Bates <​dbates@rim.com>

Reviewed by Antonio Gomes.

Modify RandomNumberSeed.h to use USE(MERSENNE_TWISTER_19937)
​https://bugs.webkit.org/show_bug.cgi?id=53506

Currently, use of the Mersenne Twister pseudorandom number generator
is hardcoded to the Windows CE port. With the passing of bug #53253,
we can generalize support for this PRNG to all ports that use srand(3)
and rand(3), including Windows CE.

• wtf/RandomNumberSeed.h: (WTF::initializeRandomNumberGenerator):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• wtf/RandomNumberSeed.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-02-01  Daniel Bates  <dbates@rim.com>
+
+        Reviewed by Antonio Gomes.
+
+        Modify RandomNumberSeed.h to use USE(MERSENNE_TWISTER_19937)
+        https://bugs.webkit.org/show_bug.cgi?id=53506
+
+        Currently, use of the Mersenne Twister pseudorandom number generator
+        is hardcoded to the Windows CE port. With the passing of bug #53253,
+        we can generalize support for this PRNG to all ports that use srand(3)
+        and rand(3), including Windows CE.
+
+        * wtf/RandomNumberSeed.h:
+        (WTF::initializeRandomNumberGenerator):
+
 2011-02-01  Dave Tapuska  <dtapuska@rim.com>
 

trunk/Source/JavaScriptCore/wtf/RandomNumberSeed.h

@@ -39 +39 @@
 #endif
 
-#if OS(WINCE)
+#if USE(MERSENNE_TWISTER_19937)
 extern "C" {
 void init_by_array(unsigned long init_key[],int key_length);
@@ -55 +55 @@
     // initialize rand()
     srand(GetTickCount());
-
-    // use rand() to initialize the real RNG
-    unsigned long initializationBuffer[4];
-    initializationBuffer[0] = (rand() << 16) | rand();
-    initializationBuffer[1] = (rand() << 16) | rand();
-    initializationBuffer[2] = (rand() << 16) | rand();
-    initializationBuffer[3] = (rand() << 16) | rand();
-    init_by_array(initializationBuffer, 4);
 #elif COMPILER(MSVC) && defined(_CRT_RAND_S)
     // On Windows we use rand_s which initialises itself
@@ -75 +67 @@
     srand(static_cast<unsigned>(time(0)));
 #endif
+
+#if USE(MERSENNE_TWISTER_19937)
+    // use rand() to initialize the Mersenne Twister random number generator.
+    unsigned long initializationBuffer[4];
+    initializationBuffer[0] = (rand() << 16) | rand();
+    initializationBuffer[1] = (rand() << 16) | rand();
+    initializationBuffer[2] = (rand() << 16) | rand();
+    initializationBuffer[3] = (rand() << 16) | rand();
+    init_by_array(initializationBuffer, 4);
+#endif
 }