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

src/log.cc

 // Copyright 2006-2008 the V8 project authors. 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
@@ skipping 11 matching lines @@
 // 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 <stdarg.h>
 
 #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 {
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 //
 // Sliding state window.  Updates counters to keep track of the last
 // window of kBufferSize states.  This is useful to track where we
 // spent our time.
 //
@@ skipping 1062 matching lines @@
   }
 }
 
 VMState::VMState(StateTag state) {
   state_ = state;
   previous_ = Logger::current_state_;
   Logger::current_state_ = this;
 
   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
 }
 
 
 VMState::~VMState() {
   Logger::current_state_ = previous_;
 
   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
 
 } }  // namespace v8::internal