[llvm-commits] [llvm] r73545 - in /llvm/trunk: include/llvm/System/RWMutex.h lib/System/RWMutex.cpp lib/System/Unix/RWMutex.inc lib/System/Win32/Mutex.inc lib/System/Win32/RWMutex.inc
Owen Anderson
resistor at mac.com
Tue Jun 16 13:19:28 PDT 2009
Author: resistor
Date: Tue Jun 16 15:19:28 2009
New Revision: 73545
URL: http://llvm.org/viewvc/llvm-project?rev=73545&view=rev
Log:
Add a portable wrapper for reader-writer locks.
Added:
llvm/trunk/include/llvm/System/RWMutex.h
llvm/trunk/lib/System/RWMutex.cpp
llvm/trunk/lib/System/Unix/RWMutex.inc
llvm/trunk/lib/System/Win32/RWMutex.inc
Modified:
llvm/trunk/lib/System/Win32/Mutex.inc
Added: llvm/trunk/include/llvm/System/RWMutex.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/System/RWMutex.h?rev=73545&view=auto
==============================================================================
--- llvm/trunk/include/llvm/System/RWMutex.h (added)
+++ llvm/trunk/include/llvm/System/RWMutex.h Tue Jun 16 15:19:28 2009
@@ -0,0 +1,84 @@
+//===- RWMutex.h - Reader/Writer Mutual Exclusion Lock ----------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the llvm::sys::RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_MUTEX_H
+#define LLVM_SYSTEM_MUTEX_H
+
+namespace llvm
+{
+ namespace sys
+ {
+ /// @brief Platform agnostic Mutex class.
+ class RWMutex
+ {
+ /// @name Constructors
+ /// @{
+ public:
+
+ /// Initializes the lock but doesn't acquire it.
+ /// @brief Default Constructor.
+ explicit RWMutex();
+
+ /// Releases and removes the lock
+ /// @brief Destructor
+ ~RWMutex();
+
+ /// @}
+ /// @name Methods
+ /// @{
+ public:
+
+ /// Attempts to unconditionally acquire the lock in reader mode. If the
+ /// lock is held by a writer, this method will wait until it can acquire
+ /// the lock.
+ /// @returns false if any kind of error occurs, true otherwise.
+ /// @brief Unconditionally acquire the lock in reader mode.
+ bool reader_acquire();
+
+ /// Attempts to release the lock in reader mode.
+ /// @returns false if any kind of error occurs, true otherwise.
+ /// @brief Unconditionally release the lock in reader mode.
+ bool reader_release();
+
+ /// Attempts to unconditionally acquire the lock in reader mode. If the
+ /// lock is held by any readers, this method will wait until it can
+ /// acquire the lock.
+ /// @returns false if any kind of error occurs, true otherwise.
+ /// @brief Unconditionally acquire the lock in writer mode.
+ bool writer_acquire();
+
+ /// Attempts to release the lock in writer mode.
+ /// @returns false if any kind of error occurs, true otherwise.
+ /// @brief Unconditionally release the lock in write mode.
+ bool writer_release();
+
+ //@}
+ /// @name Platform Dependent Data
+ /// @{
+ private:
+#ifdef ENABLE_THREADS
+ void* data_; ///< We don't know what the data will be
+#endif
+
+ /// @}
+ /// @name Do Not Implement
+ /// @{
+ private:
+ RWMutex(const RWMutex & original);
+ void operator=(const RWMutex &);
+ /// @}
+ };
+ }
+}
+
+#endif
Added: llvm/trunk/lib/System/RWMutex.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/System/RWMutex.cpp?rev=73545&view=auto
==============================================================================
--- llvm/trunk/lib/System/RWMutex.cpp (added)
+++ llvm/trunk/lib/System/RWMutex.cpp Tue Jun 16 15:19:28 2009
@@ -0,0 +1,169 @@
+//===- RWMutex.cpp - Reader/Writer Mutual Exclusion Lock --------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the llvm::sys::RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Config/config.h"
+#include "llvm/System/RWMutex.h"
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//=== independent code.
+//===----------------------------------------------------------------------===//
+
+#if !defined(ENABLE_THREADS) || ENABLE_THREADS == 0
+// Define all methods as no-ops if threading is explicitly disabled
+namespace llvm {
+using namespace sys;
+RWMutex::RWMutex( bool recursive) { }
+RWMutex::~RWMutex() { }
+bool RWMutex::reader_acquire() { return true; }
+bool RWMutex::reader_release() { return true; }
+bool RWMutex::writer_acquire() { return true; }
+bool RWMutex::writer_release() { return true; }
+}
+#else
+
+#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_RWLOCK_INIT)
+
+#include <cassert>
+#include <pthread.h>
+#include <stdlib.h>
+
+namespace llvm {
+using namespace sys;
+
+
+// This variable is useful for situations where the pthread library has been
+// compiled with weak linkage for its interface symbols. This allows the
+// threading support to be turned off by simply not linking against -lpthread.
+// In that situation, the value of pthread_mutex_init will be 0 and
+// consequently pthread_enabled will be false. In such situations, all the
+// pthread operations become no-ops and the functions all return false. If
+// pthread_rwlock_init does have an address, then rwlock support is enabled.
+// Note: all LLVM tools will link against -lpthread if its available since it
+// is configured into the LIBS variable.
+// Note: this line of code generates a warning if pthread_rwlock_init is not
+// declared with weak linkage. It's safe to ignore the warning.
+static const bool pthread_enabled = true;
+
+// Construct a RWMutex using pthread calls
+RWMutex::RWMutex()
+ : data_(0)
+{
+ if (pthread_enabled)
+ {
+ // Declare the pthread_rwlock data structures
+ pthread_rwlock_t* rwlock =
+ static_cast<pthread_rwlock_t*>(malloc(sizeof(pthread_rwlock_t)));
+ pthread_rwlockattr_t attr;
+
+ // Initialize the rwlock attributes
+ int errorcode = pthread_rwlockattr_init(&attr);
+ assert(errorcode == 0);
+
+#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
+ // Make it a process local rwlock
+ errorcode = pthread_rwlockattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
+#endif
+
+ // Initialize the rwlock
+ errorcode = pthread_rwlock_init(rwlock, &attr);
+ assert(errorcode == 0);
+
+ // Destroy the attributes
+ errorcode = pthread_rwlockattr_destroy(&attr);
+ assert(errorcode == 0);
+
+ // Assign the data member
+ data_ = rwlock;
+ }
+}
+
+// Destruct a RWMutex
+RWMutex::~RWMutex()
+{
+ if (pthread_enabled)
+ {
+ pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+ assert(rwlock != 0);
+ pthread_rwlock_destroy(rwlock);
+ free(rwlock);
+ }
+}
+
+bool
+RWMutex::reader_acquire()
+{
+ if (pthread_enabled)
+ {
+ pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+ assert(rwlock != 0);
+
+ int errorcode = pthread_rwlock_rdlock(rwlock);
+ return errorcode == 0;
+ }
+ return false;
+}
+
+bool
+RWMutex::reader_release()
+{
+ if (pthread_enabled)
+ {
+ pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+ assert(rwlock != 0);
+
+ int errorcode = pthread_rwlock_unlock(rwlock);
+ return errorcode == 0;
+ }
+ return false;
+}
+
+bool
+RWMutex::writer_acquire()
+{
+ if (pthread_enabled)
+ {
+ pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+ assert(rwlock != 0);
+
+ int errorcode = pthread_rwlock_wrlock(rwlock);
+ return errorcode == 0;
+ }
+ return false;
+}
+
+bool
+RWMutex::writer_release()
+{
+ if (pthread_enabled)
+ {
+ pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+ assert(rwlock != 0);
+
+ int errorcode = pthread_rwlock_unlock(rwlock);
+ return errorcode == 0;
+ }
+ return false;
+}
+
+}
+
+#elif defined(LLVM_ON_UNIX)
+#include "Unix/RWMutex.inc"
+#elif defined( LLVM_ON_WIN32)
+#include "Win32/RWMutex.inc"
+#else
+#warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in System/Mutex.cpp
+#endif
+#endif
+
Added: llvm/trunk/lib/System/Unix/RWMutex.inc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/System/Unix/RWMutex.inc?rev=73545&view=auto
==============================================================================
--- llvm/trunk/lib/System/Unix/RWMutex.inc (added)
+++ llvm/trunk/lib/System/Unix/RWMutex.inc Tue Jun 16 15:19:28 2009
@@ -0,0 +1,43 @@
+//= llvm/System/Unix/RWMutex.inc - Unix Reader/Writer Mutual Exclusion Lock =//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Unix specific (non-pthread) RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic UNIX code that
+//=== is guaranteed to work on *all* UNIX variants.
+//===----------------------------------------------------------------------===//
+
+namespace llvm {
+
+using namespace sys;
+
+RWMutex::RWMutex() { }
+
+RWMutex::~RWMutex() { }
+
+bool RWMutex::reader_acquire() {
+ return true;
+}
+
+bool RWMutex::reader_release() {
+ return true;
+}
+
+bool RWMutex::writer_acquire() {
+ return true;
+}
+
+bool RWMutex::writer_release() {
+ return true;
+}
+
+}
Modified: llvm/trunk/lib/System/Win32/Mutex.inc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/System/Win32/Mutex.inc?rev=73545&r1=73544&r2=73545&view=diff
==============================================================================
--- llvm/trunk/lib/System/Win32/Mutex.inc (original)
+++ llvm/trunk/lib/System/Win32/Mutex.inc Tue Jun 16 15:19:28 2009
@@ -22,7 +22,7 @@
namespace llvm {
using namespace sys;
-Mutex::Mutex(bool /*recursive*/)
+Mutex::Mutex()
{
data_ = new CRITICAL_SECTION;
InitializeCriticalSection((LPCRITICAL_SECTION)data_);
Added: llvm/trunk/lib/System/Win32/RWMutex.inc
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/System/Win32/RWMutex.inc?rev=73545&view=auto
==============================================================================
--- llvm/trunk/lib/System/Win32/RWMutex.inc (added)
+++ llvm/trunk/lib/System/Win32/RWMutex.inc Tue Jun 16 15:19:28 2009
@@ -0,0 +1,55 @@
+//= llvm/System/Win32/Mutex.inc - Win32 Reader/Writer Mutual Exclusion Lock =//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Win32 specific (non-pthread) RWMutex class.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only generic Win32 code that
+//=== is guaranteed to work on *all* Win32 variants.
+//===----------------------------------------------------------------------===//
+
+#include "Win32.h"
+
+namespace llvm {
+using namespace sys;
+
+RWMutex::RWMutex() {
+ data_ = new PSRWLOCK;
+ InitializeSRWLock((PSRWLOCK*)data_);
+}
+
+RWMutex::~RWMutex() {
+ delete (PSRWLOCK*)data_;
+ data_ = 0;
+}
+
+bool RWMutex::reader_acquire() {
+ AcquireSRWLockShared((PSRWLOCK*)data_);
+ return true;
+}
+
+bool RWMutex::reader_release() {
+ ReleaseSRWLockShared((PSRWLOCK*)data_);
+ return true;
+}
+
+bool RWMutex::writer_acquire() {
+ AcquireSRWLockExclusive((PSRWLOCK*)data_);
+ return true;
+}
+
+bool RWMutex::writer_release() {
+ ReleaseSRWLockExclusive((PSRWLOCK*)data_);
+ return true;
+}
+
+
+}
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