Introduce a random entropy source which can optionally be provided at initialization.

src/v8.cc

Index: src/v8.cc
===================================================================
--- src/v8.cc	(revision 8657)
+++ src/v8.cc	(working copy)
@@ -50,7 +50,10 @@
 bool V8::has_fatal_error_ = false;
 bool V8::use_crankshaft_ = true;
 
+static Mutex* entropy_mutex = OS::CreateMutex();
+static EntropySource entropy_source;
 
+
 bool V8::Initialize(Deserializer* des) {
   InitializeOncePerProcess();
 
@@ -102,8 +105,14 @@
 
 static void seed_random(uint32_t* state) {
   for (int i = 0; i < 2; ++i) {
-    state[i] = FLAG_random_seed;
-    while (state[i] == 0) {
+    if (FLAG_random_seed != NULL)

[Mads Ager (chromium), 2011/07/17 09:11:39]

Please consistently use braces around the body. Also, FLAG_random_seem is not a
pointer but an int, so the test should be '0' instead of 'NULL'. I'll fix these
too.

+      state[i] = FLAG_random_seed;
+    else if (entropy_source != NULL) {
+      uint32_t val;
+      ScopedLock lock(entropy_mutex);
+      entropy_source(reinterpret_cast<unsigned char*>(&val), sizeof(uint32_t));
+      state[i] = val;
+    } else {
       state[i] = random();
     }
   }
@@ -124,6 +133,11 @@
 }
 
 
+void V8::SetEntropySource(EntropySource source) {
+  entropy_source = source;
+}
+
+
 // Used by JavaScript APIs
 uint32_t V8::Random(Isolate* isolate) {
   ASSERT(isolate == Isolate::Current());