| // Copyright 2016 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "android-qemu2-glue/emulation/VmLock.h" |
| |
| #include "android/base/Log.h" |
| |
| extern "C" { |
| #include "qemu/main-loop.h" |
| } // extern "C" |
| |
| namespace qemu2 { |
| |
| // TECHNICAL NOTE: |
| // |
| // This implementation needs to protect against recursive lock() calls |
| // which can happen because some code in AndroidEmu calls it, without |
| // knowing whether it's running in the thread that holds the BQL or not. |
| // |
| // What we want is to ensure that qemu_mutex_lock_iothread() is always true |
| // when we leave ::lock(), and that it will be false when ::unlock() has |
| // been called as often as ::lock() was. |
| |
| void VmLock::lock() { |
| qemu_mutex_lock_iothread(); |
| } |
| |
| void VmLock::unlock() { |
| qemu_mutex_unlock_iothread(); |
| } |
| |
| bool VmLock::isLockedBySelf() const { |
| return qemu_mutex_check_iothread(); |
| } |
| |
| } // namespace qemu2 |