Merge r10809 into 3.7 branch

src/platform-win32.cc

 // Copyright 2011 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 813 matching lines @@
   static size_t allocate_alignment = 0;
   if (allocate_alignment == 0) {
     SYSTEM_INFO info;
     GetSystemInfo(&info);
     allocate_alignment = info.dwAllocationGranularity;
   }
   return allocate_alignment;
 }
 
 
+intptr_t OS::CommitPageSize() {
+  return 4096;
+}
+
+
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
   // The address range used to randomize RWX allocations in OS::Allocate
   // Try not to map pages into the default range that windows loads DLLs
   // Use a multiple of 64k to prevent committing unused memory.
   // Note: This does not guarantee RWX regions will be within the
   // range kAllocationRandomAddressMin to kAllocationRandomAddressMax
 #ifdef V8_HOST_ARCH_64_BIT
   static const intptr_t kAllocationRandomAddressMin = 0x0000000080000000;
@@ skipping 630 matching lines @@
   int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
   if (NULL == VirtualAlloc(base, size, MEM_COMMIT, prot)) {
     return false;
   }
 
   UpdateAllocatedSpaceLimits(base, static_cast<int>(size));
   return true;
 }
 
 
+bool VirtualMemory::Guard(void* address) {
+  if (NULL == VirtualAlloc(address,
+                           OS::CommitPageSize(),
+                           MEM_COMMIT,
+                           PAGE_READONLY | PAGE_GUARD)) {
+    return false;
+  }
+  return true;
+}
+
+
 bool VirtualMemory::UncommitRegion(void* base, size_t size) {
   return VirtualFree(base, size, MEM_DECOMMIT) != 0;
 }
 
 
 bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
   return VirtualFree(base, 0, MEM_RELEASE) != 0;
 }
 
 
@@ skipping 539 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal