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 #include "src/__support/macros/config.h"
  14
  15 #include <pthread.h>
  16
  17 namespace LIBC_NAMESPACE_DECL {
  18
  19 enum class PThreadMutexAttrPos : unsigned int {
  20   TYPE_SHIFT = 0,
  21   TYPE_MASK = 0x3 << TYPE_SHIFT, // Type is encoded in 2 bits
  22
  23   ROBUST_SHIFT = 2,
  24   ROBUST_MASK = 0x1 << ROBUST_SHIFT,
  25
  26   PSHARED_SHIFT = 3,
  27   PSHARED_MASK = 0x1 << PSHARED_SHIFT,
  28
  29   // TODO: Add a mask for protocol and prioceiling when it is supported.
  30 };
  31
  32 constexpr pthread_mutexattr_t DEFAULT_MUTEXATTR =
  33     PTHREAD_MUTEX_DEFAULT << unsigned(PThreadMutexAttrPos::TYPE_SHIFT) |
  34     PTHREAD_MUTEX_STALLED << unsigned(PThreadMutexAttrPos::ROBUST_SHIFT) |
  35     PTHREAD_PROCESS_PRIVATE << unsigned(PThreadMutexAttrPos::PSHARED_SHIFT);
  36
  37 LIBC_INLINE int get_mutexattr_type(pthread_mutexattr_t attr) {
  38   return (attr & unsigned(PThreadMutexAttrPos::TYPE_MASK)) >>
  39          unsigned(PThreadMutexAttrPos::TYPE_SHIFT);
  40 }
  41
  42 LIBC_INLINE int get_mutexattr_robust(pthread_mutexattr_t attr) {
  43   return (attr & unsigned(PThreadMutexAttrPos::ROBUST_MASK)) >>
  44          unsigned(PThreadMutexAttrPos::ROBUST_SHIFT);
  45 }
  46
  47 LIBC_INLINE int get_mutexattr_pshared(pthread_mutexattr_t attr) {
  48   return (attr & unsigned(PThreadMutexAttrPos::PSHARED_MASK)) >>
  49          unsigned(PThreadMutexAttrPos::PSHARED_SHIFT);
  50 }
  51
  52 } // namespace LIBC_NAMESPACE_DECL
  53
  54 #endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_H