libc/src/__support/threads/gpu/mutex.h

   1 //===--- Implementation of a GPU mutex class --------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_GPU_MUTEX_H
  10 #define LLVM_LIBC_SRC___SUPPORT_THREADS_GPU_MUTEX_H
  11
  12 #include "src/__support/macros/attributes.h"
  13 #include "src/__support/macros/config.h"
  14 #include "src/__support/threads/mutex_common.h"
  15
  16 namespace LIBC_NAMESPACE_DECL {
  17
  18 /// Implementation of a simple passthrough mutex which guards nothing. A
  19 /// complete Mutex locks in general cannot be implemented on the GPU. We simply
  20 /// define the Mutex interface and require that only a single thread executes
  21 /// code requiring a mutex lock.
  22 struct Mutex {
  23   LIBC_INLINE constexpr Mutex(bool, bool, bool, bool) {}
  24
  25   LIBC_INLINE MutexError lock() { return MutexError::NONE; }
  26   LIBC_INLINE MutexError unlock() { return MutexError::NONE; }
  27   LIBC_INLINE MutexError reset() { return MutexError::NONE; }
  28 };
  29
  30 } // namespace LIBC_NAMESPACE_DECL
  31
  32 #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_GPU_MUTEX_H