diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/thread_annotations.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/base/internal/thread_annotations.h | 271 |
1 files changed, 0 insertions, 271 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/thread_annotations.h b/third_party/abseil_cpp/absl/base/internal/thread_annotations.h deleted file mode 100644 index 4dab6a9c150a..000000000000 --- a/third_party/abseil_cpp/absl/base/internal/thread_annotations.h +++ /dev/null @@ -1,271 +0,0 @@ -// Copyright 2019 The Abseil Authors. -// -// 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 -// -// https://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. -// -// ----------------------------------------------------------------------------- -// File: thread_annotations.h -// ----------------------------------------------------------------------------- -// -// WARNING: This is a backwards compatible header and it will be removed after -// the migration to prefixed thread annotations is finished; please include -// "absl/base/thread_annotations.h". -// -// This header file contains macro definitions for thread safety annotations -// that allow developers to document the locking policies of multi-threaded -// code. The annotations can also help program analysis tools to identify -// potential thread safety issues. -// -// These annotations are implemented using compiler attributes. Using the macros -// defined here instead of raw attributes allow for portability and future -// compatibility. -// -// When referring to mutexes in the arguments of the attributes, you should -// use variable names or more complex expressions (e.g. my_object->mutex_) -// that evaluate to a concrete mutex object whenever possible. If the mutex -// you want to refer to is not in scope, you may use a member pointer -// (e.g. &MyClass::mutex_) to refer to a mutex in some (unknown) object. - -#ifndef ABSL_BASE_INTERNAL_THREAD_ANNOTATIONS_H_ -#define ABSL_BASE_INTERNAL_THREAD_ANNOTATIONS_H_ - -#if defined(__clang__) -#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x)) -#else -#define THREAD_ANNOTATION_ATTRIBUTE__(x) // no-op -#endif - -// GUARDED_BY() -// -// Documents if a shared field or global variable needs to be protected by a -// mutex. GUARDED_BY() allows the user to specify a particular mutex that -// should be held when accessing the annotated variable. -// -// Although this annotation (and PT_GUARDED_BY, below) cannot be applied to -// local variables, a local variable and its associated mutex can often be -// combined into a small class or struct, thereby allowing the annotation. -// -// Example: -// -// class Foo { -// Mutex mu_; -// int p1_ GUARDED_BY(mu_); -// ... -// }; -#define GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x)) - -// PT_GUARDED_BY() -// -// Documents if the memory location pointed to by a pointer should be guarded -// by a mutex when dereferencing the pointer. -// -// Example: -// class Foo { -// Mutex mu_; -// int *p1_ PT_GUARDED_BY(mu_); -// ... -// }; -// -// Note that a pointer variable to a shared memory location could itself be a -// shared variable. -// -// Example: -// -// // `q_`, guarded by `mu1_`, points to a shared memory location that is -// // guarded by `mu2_`: -// int *q_ GUARDED_BY(mu1_) PT_GUARDED_BY(mu2_); -#define PT_GUARDED_BY(x) THREAD_ANNOTATION_ATTRIBUTE__(pt_guarded_by(x)) - -// ACQUIRED_AFTER() / ACQUIRED_BEFORE() -// -// Documents the acquisition order between locks that can be held -// simultaneously by a thread. For any two locks that need to be annotated -// to establish an acquisition order, only one of them needs the annotation. -// (i.e. You don't have to annotate both locks with both ACQUIRED_AFTER -// and ACQUIRED_BEFORE.) -// -// As with GUARDED_BY, this is only applicable to mutexes that are shared -// fields or global variables. -// -// Example: -// -// Mutex m1_; -// Mutex m2_ ACQUIRED_AFTER(m1_); -#define ACQUIRED_AFTER(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(acquired_after(__VA_ARGS__)) - -#define ACQUIRED_BEFORE(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(acquired_before(__VA_ARGS__)) - -// EXCLUSIVE_LOCKS_REQUIRED() / SHARED_LOCKS_REQUIRED() -// -// Documents a function that expects a mutex to be held prior to entry. -// The mutex is expected to be held both on entry to, and exit from, the -// function. -// -// An exclusive lock allows read-write access to the guarded data member(s), and -// only one thread can acquire a lock exclusively at any one time. A shared lock -// allows read-only access, and any number of threads can acquire a shared lock -// concurrently. -// -// Generally, non-const methods should be annotated with -// EXCLUSIVE_LOCKS_REQUIRED, while const methods should be annotated with -// SHARED_LOCKS_REQUIRED. -// -// Example: -// -// Mutex mu1, mu2; -// int a GUARDED_BY(mu1); -// int b GUARDED_BY(mu2); -// -// void foo() EXCLUSIVE_LOCKS_REQUIRED(mu1, mu2) { ... } -// void bar() const SHARED_LOCKS_REQUIRED(mu1, mu2) { ... } -#define EXCLUSIVE_LOCKS_REQUIRED(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(__VA_ARGS__)) - -#define SHARED_LOCKS_REQUIRED(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(shared_locks_required(__VA_ARGS__)) - -// LOCKS_EXCLUDED() -// -// Documents the locks acquired in the body of the function. These locks -// cannot be held when calling this function (as Abseil's `Mutex` locks are -// non-reentrant). -#define LOCKS_EXCLUDED(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(locks_excluded(__VA_ARGS__)) - -// LOCK_RETURNED() -// -// Documents a function that returns a mutex without acquiring it. For example, -// a public getter method that returns a pointer to a private mutex should -// be annotated with LOCK_RETURNED. -#define LOCK_RETURNED(x) \ - THREAD_ANNOTATION_ATTRIBUTE__(lock_returned(x)) - -// LOCKABLE -// -// Documents if a class/type is a lockable type (such as the `Mutex` class). -#define LOCKABLE \ - THREAD_ANNOTATION_ATTRIBUTE__(lockable) - -// SCOPED_LOCKABLE -// -// Documents if a class does RAII locking (such as the `MutexLock` class). -// The constructor should use `LOCK_FUNCTION()` to specify the mutex that is -// acquired, and the destructor should use `UNLOCK_FUNCTION()` with no -// arguments; the analysis will assume that the destructor unlocks whatever the -// constructor locked. -#define SCOPED_LOCKABLE \ - THREAD_ANNOTATION_ATTRIBUTE__(scoped_lockable) - -// EXCLUSIVE_LOCK_FUNCTION() -// -// Documents functions that acquire a lock in the body of a function, and do -// not release it. -#define EXCLUSIVE_LOCK_FUNCTION(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(exclusive_lock_function(__VA_ARGS__)) - -// SHARED_LOCK_FUNCTION() -// -// Documents functions that acquire a shared (reader) lock in the body of a -// function, and do not release it. -#define SHARED_LOCK_FUNCTION(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(shared_lock_function(__VA_ARGS__)) - -// UNLOCK_FUNCTION() -// -// Documents functions that expect a lock to be held on entry to the function, -// and release it in the body of the function. -#define UNLOCK_FUNCTION(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(unlock_function(__VA_ARGS__)) - -// EXCLUSIVE_TRYLOCK_FUNCTION() / SHARED_TRYLOCK_FUNCTION() -// -// Documents functions that try to acquire a lock, and return success or failure -// (or a non-boolean value that can be interpreted as a boolean). -// The first argument should be `true` for functions that return `true` on -// success, or `false` for functions that return `false` on success. The second -// argument specifies the mutex that is locked on success. If unspecified, this -// mutex is assumed to be `this`. -#define EXCLUSIVE_TRYLOCK_FUNCTION(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(exclusive_trylock_function(__VA_ARGS__)) - -#define SHARED_TRYLOCK_FUNCTION(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(shared_trylock_function(__VA_ARGS__)) - -// ASSERT_EXCLUSIVE_LOCK() / ASSERT_SHARED_LOCK() -// -// Documents functions that dynamically check to see if a lock is held, and fail -// if it is not held. -#define ASSERT_EXCLUSIVE_LOCK(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(assert_exclusive_lock(__VA_ARGS__)) - -#define ASSERT_SHARED_LOCK(...) \ - THREAD_ANNOTATION_ATTRIBUTE__(assert_shared_lock(__VA_ARGS__)) - -// NO_THREAD_SAFETY_ANALYSIS -// -// Turns off thread safety checking within the body of a particular function. -// This annotation is used to mark functions that are known to be correct, but -// the locking behavior is more complicated than the analyzer can handle. -#define NO_THREAD_SAFETY_ANALYSIS \ - THREAD_ANNOTATION_ATTRIBUTE__(no_thread_safety_analysis) - -//------------------------------------------------------------------------------ -// Tool-Supplied Annotations -//------------------------------------------------------------------------------ - -// TS_UNCHECKED should be placed around lock expressions that are not valid -// C++ syntax, but which are present for documentation purposes. These -// annotations will be ignored by the analysis. -#define TS_UNCHECKED(x) "" - -// TS_FIXME is used to mark lock expressions that are not valid C++ syntax. -// It is used by automated tools to mark and disable invalid expressions. -// The annotation should either be fixed, or changed to TS_UNCHECKED. -#define TS_FIXME(x) "" - -// Like NO_THREAD_SAFETY_ANALYSIS, this turns off checking within the body of -// a particular function. However, this attribute is used to mark functions -// that are incorrect and need to be fixed. It is used by automated tools to -// avoid breaking the build when the analysis is updated. -// Code owners are expected to eventually fix the routine. -#define NO_THREAD_SAFETY_ANALYSIS_FIXME NO_THREAD_SAFETY_ANALYSIS - -// Similar to NO_THREAD_SAFETY_ANALYSIS_FIXME, this macro marks a GUARDED_BY -// annotation that needs to be fixed, because it is producing thread safety -// warning. It disables the GUARDED_BY. -#define GUARDED_BY_FIXME(x) - -// Disables warnings for a single read operation. This can be used to avoid -// warnings when it is known that the read is not actually involved in a race, -// but the compiler cannot confirm that. -#define TS_UNCHECKED_READ(x) thread_safety_analysis::ts_unchecked_read(x) - - -namespace thread_safety_analysis { - -// Takes a reference to a guarded data member, and returns an unguarded -// reference. -template <typename T> -inline const T& ts_unchecked_read(const T& v) NO_THREAD_SAFETY_ANALYSIS { - return v; -} - -template <typename T> -inline T& ts_unchecked_read(T& v) NO_THREAD_SAFETY_ANALYSIS { - return v; -} - -} // namespace thread_safety_analysis - -#endif // ABSL_BASE_INTERNAL_THREAD_ANNOTATIONS_H_ |