libc/src/pthread/pthread_mutexattr.h

   1 //===-- Declarations related mutex attribute objects  -----------*- 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_PTHREAD_PTHREAD_MUTEXATTR_H
  10 #define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_H
  11
  12 #include "src/__support/common.h"
  13
  14 #include <pthread.h>
  15
  16 namespace __llvm_libc {
  17
  18 enum class PThreadMutexAttrPos : unsigned int {
  19   TYPE_SHIFT = 0,
  20   TYPE_MASK = 0x3 << TYPE_SHIFT, // Type is encoded in 2 bits
  21
  22   ROBUST_SHIFT = 2,
  23   ROBUST_MASK = 0x1 << ROBUST_SHIFT,
  24
  25   PSHARED_SHIFT = 3,
  26   PSHARED_MASK = 0x1 << PSHARED_SHIFT,
  27
  28   // TODO: Add a mask for protocol and prioceiling when it is supported.
  29 };
  30
  31 constexpr pthread_mutexattr_t DEFAULT_MUTEXATTR =
  32     PTHREAD_MUTEX_DEFAULT << unsigned(PThreadMutexAttrPos::TYPE_SHIFT) |
  33     PTHREAD_MUTEX_STALLED << unsigned(PThreadMutexAttrPos::ROBUST_SHIFT) |
  34     PTHREAD_PROCESS_PRIVATE << unsigned(PThreadMutexAttrPos::PSHARED_SHIFT);
  35
  36 LIBC_INLINE int get_mutexattr_type(pthread_mutexattr_t attr) {
  37   return (attr & unsigned(PThreadMutexAttrPos::TYPE_MASK)) >>
  38          unsigned(PThreadMutexAttrPos::TYPE_SHIFT);
  39 }
  40
  41 LIBC_INLINE int get_mutexattr_robust(pthread_mutexattr_t attr) {
  42   return (attr & unsigned(PThreadMutexAttrPos::ROBUST_MASK)) >>
  43          unsigned(PThreadMutexAttrPos::ROBUST_SHIFT);
  44 }
  45
  46 } // namespace __llvm_libc
  47
  48 #endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_H