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Diffstat (limited to 'security/sandbox/chromium/base/threading/thread_collision_warner.h')
| -rw-r--r-- | security/sandbox/chromium/base/threading/thread_collision_warner.h | 245 |
1 files changed, 0 insertions, 245 deletions
diff --git a/security/sandbox/chromium/base/threading/thread_collision_warner.h b/security/sandbox/chromium/base/threading/thread_collision_warner.h deleted file mode 100644 index 4699a910d..000000000 --- a/security/sandbox/chromium/base/threading/thread_collision_warner.h +++ /dev/null @@ -1,245 +0,0 @@ -// Copyright (c) 2012 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#ifndef BASE_THREADING_THREAD_COLLISION_WARNER_H_ -#define BASE_THREADING_THREAD_COLLISION_WARNER_H_ - -#include <memory> - -#include "base/atomicops.h" -#include "base/base_export.h" -#include "base/compiler_specific.h" -#include "base/macros.h" - -// A helper class alongside macros to be used to verify assumptions about thread -// safety of a class. -// -// Example: Queue implementation non thread-safe but still usable if clients -// are synchronized somehow. -// -// In this case the macro DFAKE_SCOPED_LOCK has to be -// used, it checks that if a thread is inside the push/pop then -// noone else is still inside the pop/push -// -// class NonThreadSafeQueue { -// public: -// ... -// void push(int) { DFAKE_SCOPED_LOCK(push_pop_); ... } -// int pop() { DFAKE_SCOPED_LOCK(push_pop_); ... } -// ... -// private: -// DFAKE_MUTEX(push_pop_); -// }; -// -// -// Example: Queue implementation non thread-safe but still usable if clients -// are synchronized somehow, it calls a method to "protect" from -// a "protected" method -// -// In this case the macro DFAKE_SCOPED_RECURSIVE_LOCK -// has to be used, it checks that if a thread is inside the push/pop -// then noone else is still inside the pop/push -// -// class NonThreadSafeQueue { -// public: -// void push(int) { -// DFAKE_SCOPED_LOCK(push_pop_); -// ... -// } -// int pop() { -// DFAKE_SCOPED_RECURSIVE_LOCK(push_pop_); -// bar(); -// ... -// } -// void bar() { DFAKE_SCOPED_RECURSIVE_LOCK(push_pop_); ... } -// ... -// private: -// DFAKE_MUTEX(push_pop_); -// }; -// -// -// Example: Queue implementation not usable even if clients are synchronized, -// so only one thread in the class life cycle can use the two members -// push/pop. -// -// In this case the macro DFAKE_SCOPED_LOCK_THREAD_LOCKED pins the -// specified -// critical section the first time a thread enters push or pop, from -// that time on only that thread is allowed to execute push or pop. -// -// class NonThreadSafeQueue { -// public: -// ... -// void push(int) { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... } -// int pop() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(push_pop_); ... } -// ... -// private: -// DFAKE_MUTEX(push_pop_); -// }; -// -// -// Example: Class that has to be contructed/destroyed on same thread, it has -// a "shareable" method (with external synchronization) and a not -// shareable method (even with external synchronization). -// -// In this case 3 Critical sections have to be defined -// -// class ExoticClass { -// public: -// ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } -// ~ExoticClass() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } -// -// void Shareable() { DFAKE_SCOPED_LOCK(shareable_section_); ... } -// void NotShareable() { DFAKE_SCOPED_LOCK_THREAD_LOCKED(ctor_dtor_); ... } -// ... -// private: -// DFAKE_MUTEX(ctor_dtor_); -// DFAKE_MUTEX(shareable_section_); -// }; - - -#if !defined(NDEBUG) - -// Defines a class member that acts like a mutex. It is used only as a -// verification tool. -#define DFAKE_MUTEX(obj) \ - mutable base::ThreadCollisionWarner obj -// Asserts the call is never called simultaneously in two threads. Used at -// member function scope. -#define DFAKE_SCOPED_LOCK(obj) \ - base::ThreadCollisionWarner::ScopedCheck s_check_##obj(&obj) -// Asserts the call is never called simultaneously in two threads. Used at -// member function scope. Same as DFAKE_SCOPED_LOCK but allows recursive locks. -#define DFAKE_SCOPED_RECURSIVE_LOCK(obj) \ - base::ThreadCollisionWarner::ScopedRecursiveCheck sr_check_##obj(&obj) -// Asserts the code is always executed in the same thread. -#define DFAKE_SCOPED_LOCK_THREAD_LOCKED(obj) \ - base::ThreadCollisionWarner::Check check_##obj(&obj) - -#else - -#define DFAKE_MUTEX(obj) typedef void InternalFakeMutexType##obj -#define DFAKE_SCOPED_LOCK(obj) ((void)0) -#define DFAKE_SCOPED_RECURSIVE_LOCK(obj) ((void)0) -#define DFAKE_SCOPED_LOCK_THREAD_LOCKED(obj) ((void)0) - -#endif - -namespace base { - -// The class ThreadCollisionWarner uses an Asserter to notify the collision -// AsserterBase is the interfaces and DCheckAsserter is the default asserter -// used. During the unit tests is used another class that doesn't "DCHECK" -// in case of collision (check thread_collision_warner_unittests.cc) -struct BASE_EXPORT AsserterBase { - virtual ~AsserterBase() {} - virtual void warn() = 0; -}; - -struct BASE_EXPORT DCheckAsserter : public AsserterBase { - ~DCheckAsserter() override {} - void warn() override; -}; - -class BASE_EXPORT ThreadCollisionWarner { - public: - // The parameter asserter is there only for test purpose - explicit ThreadCollisionWarner(AsserterBase* asserter = new DCheckAsserter()) - : valid_thread_id_(0), - counter_(0), - asserter_(asserter) {} - - ~ThreadCollisionWarner() { - delete asserter_; - } - - // This class is meant to be used through the macro - // DFAKE_SCOPED_LOCK_THREAD_LOCKED - // it doesn't leave the critical section, as opposed to ScopedCheck, - // because the critical section being pinned is allowed to be used only - // from one thread - class BASE_EXPORT Check { - public: - explicit Check(ThreadCollisionWarner* warner) - : warner_(warner) { - warner_->EnterSelf(); - } - - ~Check() {} - - private: - ThreadCollisionWarner* warner_; - - DISALLOW_COPY_AND_ASSIGN(Check); - }; - - // This class is meant to be used through the macro - // DFAKE_SCOPED_LOCK - class BASE_EXPORT ScopedCheck { - public: - explicit ScopedCheck(ThreadCollisionWarner* warner) - : warner_(warner) { - warner_->Enter(); - } - - ~ScopedCheck() { - warner_->Leave(); - } - - private: - ThreadCollisionWarner* warner_; - - DISALLOW_COPY_AND_ASSIGN(ScopedCheck); - }; - - // This class is meant to be used through the macro - // DFAKE_SCOPED_RECURSIVE_LOCK - class BASE_EXPORT ScopedRecursiveCheck { - public: - explicit ScopedRecursiveCheck(ThreadCollisionWarner* warner) - : warner_(warner) { - warner_->EnterSelf(); - } - - ~ScopedRecursiveCheck() { - warner_->Leave(); - } - - private: - ThreadCollisionWarner* warner_; - - DISALLOW_COPY_AND_ASSIGN(ScopedRecursiveCheck); - }; - - private: - // This method stores the current thread identifier and does a DCHECK - // if a another thread has already done it, it is safe if same thread - // calls this multiple time (recursion allowed). - void EnterSelf(); - - // Same as EnterSelf but recursion is not allowed. - void Enter(); - - // Removes the thread_id stored in order to allow other threads to - // call EnterSelf or Enter. - void Leave(); - - // This stores the thread id that is inside the critical section, if the - // value is 0 then no thread is inside. - volatile subtle::Atomic32 valid_thread_id_; - - // Counter to trace how many time a critical section was "pinned" - // (when allowed) in order to unpin it when counter_ reaches 0. - volatile subtle::Atomic32 counter_; - - // Here only for class unit tests purpose, during the test I need to not - // DCHECK but notify the collision with something else. - AsserterBase* asserter_; - - DISALLOW_COPY_AND_ASSIGN(ThreadCollisionWarner); -}; - -} // namespace base - -#endif // BASE_THREADING_THREAD_COLLISION_WARNER_H_ |