| // Copyright (c) 2014, 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/verified_memory.h" |
| |
| namespace dart { |
| |
| #if defined(DEBUG) |
| |
| DEFINE_FLAG(bool, verified_mem, false, |
| "Enable write-barrier verification mode (slow, DEBUG only)."); |
| DEFINE_FLAG(int, verified_mem_max_reserve_mb, (kWordSize <= 4) ? 16 : 32, |
| "When verified_mem is true, largest supported reservation (MB)."); |
| |
| |
| VirtualMemory* VerifiedMemory::ReserveInternal(intptr_t size) { |
| if (size > offset()) { |
| FATAL1("Requested reservation of %" Pd " bytes exceeds the limit. " |
| "Use --verified_mem_max_reserve_mb to increase it.", size); |
| } |
| VirtualMemory* result = VirtualMemory::Reserve(size + offset()); |
| if (result != NULL) { |
| // Commit the offset part of the reservation (writable, not executable). |
| result->Commit(result->start() + offset(), size, /* executable = */ false); |
| // Truncate without unmapping, so that the returned object looks like |
| // a normal 'size' bytes reservation (but VirtualMemory will correctly |
| // unmap the entire original reservation on destruction). |
| result->Truncate(size, /* try_unmap = */ false); |
| } |
| return result; |
| } |
| |
| #endif // DEBUG |
| |
| } // namespace dart |
