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Diffstat (limited to 'distrho/src/CoreAudio106/AudioUnits/AUPublic/AUInstrumentBase/LockFreeFIFO.h')
| -rwxr-xr-x | distrho/src/CoreAudio106/AudioUnits/AUPublic/AUInstrumentBase/LockFreeFIFO.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/distrho/src/CoreAudio106/AudioUnits/AUPublic/AUInstrumentBase/LockFreeFIFO.h b/distrho/src/CoreAudio106/AudioUnits/AUPublic/AUInstrumentBase/LockFreeFIFO.h new file mode 100755 index 00000000..50f97771 --- /dev/null +++ b/distrho/src/CoreAudio106/AudioUnits/AUPublic/AUInstrumentBase/LockFreeFIFO.h @@ -0,0 +1,167 @@ +/* Copyright © 2007 Apple Inc. All Rights Reserved. + + Disclaimer: IMPORTANT: This Apple software is supplied to you by + Apple Inc. ("Apple") in consideration of your agreement to the + following terms, and your use, installation, modification or + redistribution of this Apple software constitutes acceptance of these + terms. If you do not agree with these terms, please do not use, + install, modify or redistribute this Apple software. + + In consideration of your agreement to abide by the following terms, and + subject to these terms, Apple grants you a personal, non-exclusive + license, under Apple's copyrights in this original Apple software (the + "Apple Software"), to use, reproduce, modify and redistribute the Apple + Software, with or without modifications, in source and/or binary forms; + provided that if you redistribute the Apple Software in its entirety and + without modifications, you must retain this notice and the following + text and disclaimers in all such redistributions of the Apple Software. + Neither the name, trademarks, service marks or logos of Apple Inc. + may be used to endorse or promote products derived from the Apple + Software without specific prior written permission from Apple. Except + as expressly stated in this notice, no other rights or licenses, express + or implied, are granted by Apple herein, including but not limited to + any patent rights that may be infringed by your derivative works or by + other works in which the Apple Software may be incorporated. + + The Apple Software is provided by Apple on an "AS IS" basis. APPLE + MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION + THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS + FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND + OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS. + + IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL + OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, + MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED + AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE), + STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. +*/ +#include <Carbon/Carbon.h> + + +template <class ITEM> +class LockFreeFIFOWithFree +{ + LockFreeFIFOWithFree(); // private, unimplemented. +public: + LockFreeFIFOWithFree(UInt32 inMaxSize) + : mReadIndex(0), mWriteIndex(0), mFreeIndex(0) + { + //assert(IsPowerOfTwo(inMaxSize)); + mItems = new ITEM[inMaxSize]; + mMask = inMaxSize - 1; + } + + ~LockFreeFIFOWithFree() + { + delete [] mItems; + } + + + void Reset() + { + FreeItems(); + mReadIndex = 0; + mWriteIndex = 0; + mFreeIndex = 0; + } + + ITEM* WriteItem() + { + //printf("WriteItem %d %d\n", mReadIndex, mWriteIndex); + FreeItems(); // free items on the write thread. + UInt32 nextWriteIndex = (mWriteIndex + 1) & mMask; + if (nextWriteIndex == mFreeIndex) return NULL; + return &mItems[mWriteIndex]; + } + + ITEM* ReadItem() + { + //printf("ReadItem %d %d\n", mReadIndex, mWriteIndex); + if (mReadIndex == mWriteIndex) return NULL; + return &mItems[mReadIndex]; + } + + // the CompareAndSwap will always succeed. We use CompareAndSwap because it calls the PowerPC sync instruction, + // plus any processor bug workarounds for various CPUs. + void AdvanceWritePtr() { CompareAndSwap(mWriteIndex, (mWriteIndex + 1) & mMask, (UInt32*)&mWriteIndex); } + void AdvanceReadPtr() { CompareAndSwap(mReadIndex, (mReadIndex + 1) & mMask, (UInt32*)&mReadIndex); } + +private: + ITEM* FreeItem() + { + if (mFreeIndex == mReadIndex) return NULL; + return &mItems[mFreeIndex]; + } + void AdvanceFreePtr() { CompareAndSwap(mFreeIndex, (mFreeIndex + 1) & mMask, (UInt32*)&mFreeIndex); } + + void FreeItems() + { + ITEM* item; + while ((item = FreeItem()) != NULL) + { + item->Free(); + AdvanceFreePtr(); + } + } + + volatile UInt32 mReadIndex, mWriteIndex, mFreeIndex; + UInt32 mMask; + ITEM *mItems; +}; + + + +// Same as above but no free. + +template <class ITEM> +class LockFreeFIFO +{ + LockFreeFIFO(); // private, unimplemented. +public: + LockFreeFIFO(UInt32 inMaxSize) + : mReadIndex(0), mWriteIndex(0) + { + //assert(IsPowerOfTwo(inMaxSize)); + mItems = new ITEM[inMaxSize]; + mMask = inMaxSize - 1; + } + + ~LockFreeFIFO() + { + delete [] mItems; + } + + void Reset() + { + mReadIndex = 0; + mWriteIndex = 0; + } + + ITEM* WriteItem() + { + UInt32 nextWriteIndex = (mWriteIndex + 1) & mMask; + if (nextWriteIndex == mReadIndex) return NULL; + return &mItems[mWriteIndex]; + } + + ITEM* ReadItem() + { + if (mReadIndex == mWriteIndex) return NULL; + return &mItems[mReadIndex]; + } + + // the CompareAndSwap will always succeed. We use CompareAndSwap because it calls the PowerPC sync instruction, + // plus any processor bug workarounds for various CPUs. + void AdvanceWritePtr() { CompareAndSwap(mWriteIndex, (mWriteIndex + 1) & mMask, (UInt32*)&mWriteIndex); } + void AdvanceReadPtr() { CompareAndSwap(mReadIndex, (mReadIndex + 1) & mMask, (UInt32*)&mReadIndex); } + +private: + + volatile UInt32 mReadIndex, mWriteIndex; + UInt32 mMask; + ITEM *mItems; +}; + |