Add basic infrastructure for protecting V8's heap when leaving the VM...

src/log.cc

Index: src/log.cc
===================================================================
--- src/log.cc	(revision 1577)
+++ src/log.cc	(working copy)
@@ -29,10 +29,12 @@
 
 #include "v8.h"
 
+#include "bootstrapper.h"
 #include "log.h"
+#include "macro-assembler.h"
 #include "platform.h"
+#include "serialize.h"
 #include "string-stream.h"
-#include "macro-assembler.h"
 
 namespace v8 { namespace internal {
 
@@ -1115,10 +1117,22 @@
 
   if (FLAG_log_state_changes) {
     LOG(UncheckedStringEvent("Entering", StateToString(state_)));
-    if (previous_) {
+    if (previous_ != NULL) {
       LOG(UncheckedStringEvent("From", StateToString(previous_->state_)));
     }
   }
+
+#ifdef ENABLE_HEAP_PROTECTION
+  if (FLAG_protect_heap && previous_ != NULL) {
+    if (state_ == EXTERNAL) {
+      // Are we leaving V8?

[Søren Thygesen Gjesse, 2009/03/24 11:43:55]

ASSERT that previous state was not EXTERNAL and likewise for the other state
changes to/from EXTERNAL.

+      if (previous_->state_ != EXTERNAL) Heap::Protect();
+    } else {
+      // Are we entering V8?
+      if (previous_->state_ == EXTERNAL) Heap::Unprotect();
+    }
+  }
+#endif
 }
 
 
@@ -1127,10 +1141,22 @@
 
   if (FLAG_log_state_changes) {
     LOG(UncheckedStringEvent("Leaving", StateToString(state_)));
-    if (previous_) {
+    if (previous_ != NULL) {
       LOG(UncheckedStringEvent("To", StateToString(previous_->state_)));
     }
   }
+
+#ifdef ENABLE_HEAP_PROTECTION
+  if (FLAG_protect_heap && previous_ != NULL) {
+    if (state_ == EXTERNAL) {
+      // Are we (re)entering V8?
+      if (previous_->state_ != EXTERNAL) Heap::Unprotect();
+    } else {
+      // Are we leaving V8?
+      if (previous_->state_ == EXTERNAL) Heap::Protect();
+    }
+  }
+#endif
 }
 #endif