xref: /aosp_15_r20/external/llvm/lib/Support/Unix/RWMutex.inc (revision 9880d6810fe72a1726cb53787c6711e909410d58)
1*9880d681SAndroid Build Coastguard Worker//= llvm/Support/Unix/RWMutex.inc - Unix Reader/Writer Mutual Exclusion Lock  =//
2*9880d681SAndroid Build Coastguard Worker//
3*9880d681SAndroid Build Coastguard Worker//                     The LLVM Compiler Infrastructure
4*9880d681SAndroid Build Coastguard Worker//
5*9880d681SAndroid Build Coastguard Worker// This file is distributed under the University of Illinois Open Source
6*9880d681SAndroid Build Coastguard Worker// License. See LICENSE.TXT for details.
7*9880d681SAndroid Build Coastguard Worker//
8*9880d681SAndroid Build Coastguard Worker//===----------------------------------------------------------------------===//
9*9880d681SAndroid Build Coastguard Worker//
10*9880d681SAndroid Build Coastguard Worker// This file implements the Unix specific (non-pthread) RWMutex class.
11*9880d681SAndroid Build Coastguard Worker//
12*9880d681SAndroid Build Coastguard Worker//===----------------------------------------------------------------------===//
13*9880d681SAndroid Build Coastguard Worker
14*9880d681SAndroid Build Coastguard Worker//===----------------------------------------------------------------------===//
15*9880d681SAndroid Build Coastguard Worker//=== WARNING: Implementation here must contain only generic UNIX code that
16*9880d681SAndroid Build Coastguard Worker//===          is guaranteed to work on *all* UNIX variants.
17*9880d681SAndroid Build Coastguard Worker//===----------------------------------------------------------------------===//
18*9880d681SAndroid Build Coastguard Worker
19*9880d681SAndroid Build Coastguard Worker#include "llvm/Support/Mutex.h"
20*9880d681SAndroid Build Coastguard Worker
21*9880d681SAndroid Build Coastguard Workernamespace llvm {
22*9880d681SAndroid Build Coastguard Worker
23*9880d681SAndroid Build Coastguard Workerusing namespace sys;
24*9880d681SAndroid Build Coastguard Worker
25*9880d681SAndroid Build Coastguard Worker// This naive implementation treats readers the same as writers.  This
26*9880d681SAndroid Build Coastguard Worker// will therefore deadlock if a thread tries to acquire a read lock
27*9880d681SAndroid Build Coastguard Worker// multiple times.
28*9880d681SAndroid Build Coastguard Worker
29*9880d681SAndroid Build Coastguard WorkerRWMutexImpl::RWMutexImpl() : data_(new MutexImpl(false)) { }
30*9880d681SAndroid Build Coastguard Worker
31*9880d681SAndroid Build Coastguard WorkerRWMutexImpl::~RWMutexImpl() {
32*9880d681SAndroid Build Coastguard Worker  delete static_cast<MutexImpl *>(data_);
33*9880d681SAndroid Build Coastguard Worker}
34*9880d681SAndroid Build Coastguard Worker
35*9880d681SAndroid Build Coastguard Workerbool RWMutexImpl::reader_acquire() {
36*9880d681SAndroid Build Coastguard Worker  return static_cast<MutexImpl *>(data_)->acquire();
37*9880d681SAndroid Build Coastguard Worker}
38*9880d681SAndroid Build Coastguard Worker
39*9880d681SAndroid Build Coastguard Workerbool RWMutexImpl::reader_release() {
40*9880d681SAndroid Build Coastguard Worker  return static_cast<MutexImpl *>(data_)->release();
41*9880d681SAndroid Build Coastguard Worker}
42*9880d681SAndroid Build Coastguard Worker
43*9880d681SAndroid Build Coastguard Workerbool RWMutexImpl::writer_acquire() {
44*9880d681SAndroid Build Coastguard Worker  return static_cast<MutexImpl *>(data_)->acquire();
45*9880d681SAndroid Build Coastguard Worker}
46*9880d681SAndroid Build Coastguard Worker
47*9880d681SAndroid Build Coastguard Workerbool RWMutexImpl::writer_release() {
48*9880d681SAndroid Build Coastguard Worker  return static_cast<MutexImpl *>(data_)->release();
49*9880d681SAndroid Build Coastguard Worker}
50*9880d681SAndroid Build Coastguard Worker
51*9880d681SAndroid Build Coastguard Worker}
52