Uses an object pool on x64

runtime/vm/code_patcher.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 
 namespace dart {
@@ skipping 11 matching lines @@
   // The buffer is not executed. No need to flush.
 }
 
 
 // The patch code buffer contains the jmp code which will be inserted at
 // entry point.
 void CodePatcher::PatchEntry(const Code& code) {
   const uword patch_addr = code.GetPcForDeoptId(Isolate::kNoDeoptId,
                                                 PcDescriptors::kEntryPatch);
   ASSERT(patch_addr != 0);
-  JumpPattern jmp_entry(patch_addr);
+  JumpPattern jmp_entry(patch_addr, code);
   ASSERT(!jmp_entry.IsValid());
   const uword patch_buffer = code.GetPatchCodePc();
   ASSERT(patch_buffer != 0);
-  JumpPattern jmp_patch(patch_buffer);
+  JumpPattern jmp_patch(patch_buffer, code);
   ASSERT(jmp_patch.IsValid());
   const uword jump_target = jmp_patch.TargetAddress();
   SwapCode(jmp_patch.pattern_length_in_bytes(),
            reinterpret_cast<char*>(patch_addr),
            reinterpret_cast<char*>(patch_buffer));
   jmp_entry.SetTargetAddress(jump_target);
 }
 
 
 // The entry point is a jmp instruction, the patch code buffer contains
 // original code, the entry point contains the jump instruction.
 void CodePatcher::RestoreEntry(const Code& code) {
   const uword patch_addr = code.GetPcForDeoptId(Isolate::kNoDeoptId,
                                                 PcDescriptors::kEntryPatch);
   ASSERT(patch_addr != 0);
-  JumpPattern jmp_entry(patch_addr);
+  JumpPattern jmp_entry(patch_addr, code);
   ASSERT(jmp_entry.IsValid());
   const uword jump_target = jmp_entry.TargetAddress();
   const uword patch_buffer = code.GetPatchCodePc();
   ASSERT(patch_buffer != 0);
   // 'patch_buffer' contains original entry code.
-  JumpPattern jmp_patch(patch_buffer);
+  JumpPattern jmp_patch(patch_buffer, code);
   ASSERT(!jmp_patch.IsValid());
   SwapCode(jmp_patch.pattern_length_in_bytes(),
            reinterpret_cast<char*>(patch_addr),
            reinterpret_cast<char*>(patch_buffer));
   ASSERT(jmp_patch.IsValid());
   jmp_patch.SetTargetAddress(jump_target);
 }
 
 
 bool CodePatcher::CodeIsPatchable(const Code& code) {
   const uword patch_addr = code.GetPcForDeoptId(Isolate::kNoDeoptId,
                                                 PcDescriptors::kEntryPatch);
   // kEntryPatch may not exist which means the function is not patchable.
   if (patch_addr == 0) {
     return true;
   }
-  JumpPattern jmp_entry(patch_addr);
+  JumpPattern jmp_entry(patch_addr, code);
   if (code.Size() < (jmp_entry.pattern_length_in_bytes() * 2)) {
     return false;
   }
   const uword limit = patch_addr + jmp_entry.pattern_length_in_bytes();
   // Check no object stored between patch_addr .. limit.
   for (intptr_t i = 0; i < code.pointer_offsets_length(); i++) {
     const uword obj_start = code.GetPointerOffsetAt(i) + code.EntryPoint();
     const uword obj_end  = obj_start + kWordSize;
     if ((obj_start < limit) && (obj_end > patch_addr)) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace dart