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author | Josh Gao <jmgao@google.com> | 2016-05-17 19:23:39 -0700 |
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committer | gitbuildkicker <android-build@google.com> | 2016-07-21 17:35:58 -0700 |
commit | 014b1592fd10ef5733a943325cf20cb6c1cdf187 (patch) | |
tree | b5cb187e122f468693d679ed0b1ec50c4ca62520 /adb/sysdeps/mutex.h | |
parent | 3c28cda5d0120eb7bf7a49b36b96f45c0a588232 (diff) | |
download | system_core-014b1592fd10ef5733a943325cf20cb6c1cdf187.zip system_core-014b1592fd10ef5733a943325cf20cb6c1cdf187.tar.gz system_core-014b1592fd10ef5733a943325cf20cb6c1cdf187.tar.bz2 |
adb: switch the socket list mutex to a recursive_mutex.
sockets.cpp was branching on whether a socket close function was
local_socket_close in order to avoid a potential deadlock if the socket
list lock was held while closing a peer socket.
Bug: http://b/28347842
Change-Id: I5e56f17fa54275284787f0f1dc150d1960256ab3
(functionally a cherrypick of 903b749f + 9b587dec, with windows disabled)
Diffstat (limited to 'adb/sysdeps/mutex.h')
-rw-r--r-- | adb/sysdeps/mutex.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/adb/sysdeps/mutex.h b/adb/sysdeps/mutex.h new file mode 100644 index 0000000..ef5d9b1 --- /dev/null +++ b/adb/sysdeps/mutex.h @@ -0,0 +1,143 @@ +#pragma once + +/* + * Copyright (C) 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. + */ + +#if defined(_WIN32) + +#include <windows.h> + +#include <android-base/macros.h> + +#include "adb.h" + +// The prebuilt version of mingw we use doesn't support mutex or recursive_mutex. +// Therefore, implement our own using the Windows primitives. +// Put them directly into the std namespace, so that when they're actually available, the build +// breaks until they're removed. + +#include <mutex> +namespace std { + +// CRITICAL_SECTION is recursive, so just wrap it in a Mutex-compatible class. +class recursive_mutex { + public: + recursive_mutex() { + InitializeCriticalSection(&mutex_); + } + + ~recursive_mutex() { + DeleteCriticalSection(&mutex_); + } + + void lock() { + EnterCriticalSection(&mutex_); + } + + bool try_lock() { + return TryEnterCriticalSection(&mutex_); + } + + void unlock() { + LeaveCriticalSection(&mutex_); + } + + private: + CRITICAL_SECTION mutex_; + + DISALLOW_COPY_AND_ASSIGN(recursive_mutex); +}; + +class mutex { + public: + mutex() { + } + + ~mutex() { + } + + void lock() { + mutex_.lock(); + if (++lock_count_ != 1) { + fatal("non-recursive mutex locked reentrantly"); + } + } + + void unlock() { + if (--lock_count_ != 0) { + fatal("non-recursive mutex unlock resulted in unexpected lock count: %d", lock_count_); + } + mutex_.unlock(); + } + + bool try_lock() { + if (!mutex_.try_lock()) { + return false; + } + + if (lock_count_ != 0) { + mutex_.unlock(); + return false; + } + + ++lock_count_; + return true; + } + + private: + recursive_mutex mutex_; + size_t lock_count_ = 0; +}; + +} + +#elif defined(__BIONIC__) + +// On M, the recovery image uses parts of adb that depends on recursive_mutex, and uses libstdc++, +// which lacks it. + +#include <pthread.h> +#include <mutex> + +#include <base/macros.h> + +class recursive_mutex { + public: + recursive_mutex() { + } + + ~recursive_mutex() { + } + + void lock() { + pthread_mutex_lock(&mutex_); + } + + bool try_lock() { + return pthread_mutex_trylock(&mutex_); + } + + void unlock() { + pthread_mutex_unlock(&mutex_); + } + + private: + pthread_mutex_t mutex_ = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; + + DISALLOW_COPY_AND_ASSIGN(recursive_mutex); +}; + +#endif |