diff options
Diffstat (limited to 'LibOVR/Src/OVR_ThreadCommandQueue.cpp')
-rw-r--r-- | LibOVR/Src/OVR_ThreadCommandQueue.cpp | 740 |
1 files changed, 370 insertions, 370 deletions
diff --git a/LibOVR/Src/OVR_ThreadCommandQueue.cpp b/LibOVR/Src/OVR_ThreadCommandQueue.cpp index d9dbab3..00a5a39 100644 --- a/LibOVR/Src/OVR_ThreadCommandQueue.cpp +++ b/LibOVR/Src/OVR_ThreadCommandQueue.cpp @@ -1,370 +1,370 @@ -/************************************************************************************
-
-PublicHeader: None
-Filename : OVR_ThreadCommandQueue.cpp
-Content : Command queue for operations executed on a thread
-Created : October 29, 2012
-
-Copyright : Copyright 2012 Oculus VR, Inc. All Rights reserved.
-
-Use of this software is subject to the terms of the Oculus license
-agreement provided at the time of installation or download, or which
-otherwise accompanies this software in either electronic or hard copy form.
-
-************************************************************************************/
-
-#include "OVR_ThreadCommandQueue.h"
-
-namespace OVR {
-
-
-//------------------------------------------------------------------------
-// ***** CircularBuffer
-
-// CircularBuffer is a FIFO buffer implemented in a single block of memory,
-// which allows writing and reading variable-size data chucks. Write fails
-// if buffer is full.
-
-class CircularBuffer
-{
- enum {
- AlignSize = 16,
- AlignMask = AlignSize - 1
- };
-
- UByte* pBuffer;
- UPInt Size;
- UPInt Tail; // Byte offset of next item to be popped.
- UPInt Head; // Byte offset of where next push will take place.
- UPInt End; // When Head < Tail, this is used instead of Size.
-
- inline UPInt roundUpSize(UPInt size)
- { return (size + AlignMask) & ~(UPInt)AlignMask; }
-
-public:
-
- CircularBuffer(UPInt size)
- : Size(size), Tail(0), Head(0), End(0)
- {
- pBuffer = (UByte*)OVR_ALLOC_ALIGNED(roundUpSize(size), AlignSize);
- }
- ~CircularBuffer()
- {
- // For ThreadCommands, we must consume everything before shutdown.
- OVR_ASSERT(IsEmpty());
- OVR_FREE_ALIGNED(pBuffer);
- }
-
- bool IsEmpty() const { return (Head == Tail); }
-
- // Allocates a state block of specified size and advances pointers,
- // returning 0 if buffer is full.
- UByte* Write(UPInt size);
-
- // Returns a pointer to next available data block; 0 if none available.
- UByte* ReadBegin()
- { return (Head != Tail) ? (pBuffer + Tail) : 0; }
- // Consumes data of specified size; this must match size passed to Write.
- void ReadEnd(UPInt size);
-};
-
-
-// Allocates a state block of specified size and advances pointers,
-// returning 0 if buffer is full.
-UByte* CircularBuffer::Write(UPInt size)
-{
- UByte* p = 0;
-
- size = roundUpSize(size);
- // Since this is circular buffer, always allow at least one item.
- OVR_ASSERT(size < Size/2);
-
- if (Head >= Tail)
- {
- OVR_ASSERT(End == 0);
-
- if (size <= (Size - Head))
- {
- p = pBuffer + Head;
- Head += size;
- }
- else if (size < Tail)
- {
- p = pBuffer;
- End = Head;
- Head = size;
- OVR_ASSERT(Head != Tail);
- }
- }
- else
- {
- OVR_ASSERT(End != 0);
-
- if ((Tail - Head) > size)
- {
- p = pBuffer + Head;
- Head += size;
- OVR_ASSERT(Head != Tail);
- }
- }
-
- return p;
-}
-
-void CircularBuffer::ReadEnd(UPInt size)
-{
- OVR_ASSERT(Head != Tail);
- size = roundUpSize(size);
-
- Tail += size;
- if (Tail == End)
- {
- Tail = End = 0;
- }
- else if (Tail == Head)
- {
- OVR_ASSERT(End == 0);
- Tail = Head = 0;
- }
-}
-
-
-//-------------------------------------------------------------------------------------
-// ***** ThreadCommand
-
-ThreadCommand::PopBuffer::~PopBuffer()
-{
- if (Size)
- Destruct<ThreadCommand>(toCommand());
-}
-
-void ThreadCommand::PopBuffer::InitFromBuffer(void* data)
-{
- ThreadCommand* cmd = (ThreadCommand*)data;
- OVR_ASSERT(cmd->Size <= MaxSize);
-
- if (Size)
- Destruct<ThreadCommand>(toCommand());
- Size = cmd->Size;
- memcpy(Buffer, (void*)cmd, Size);
-}
-
-void ThreadCommand::PopBuffer::Execute()
-{
- ThreadCommand* command = toCommand();
- OVR_ASSERT(command);
- command->Execute();
- if (NeedsWait())
- GetEvent()->PulseEvent();
-}
-
-//-------------------------------------------------------------------------------------
-
-class ThreadCommandQueueImpl : public NewOverrideBase
-{
- typedef ThreadCommand::NotifyEvent NotifyEvent;
- friend class ThreadCommandQueue;
-
-public:
-
- ThreadCommandQueueImpl(ThreadCommandQueue* queue)
- : pQueue(queue), CommandBuffer(2048),
- ExitEnqueued(false), ExitProcessed(false)
- {
- }
- ~ThreadCommandQueueImpl();
-
-
- bool PushCommand(const ThreadCommand& command);
- bool PopCommand(ThreadCommand::PopBuffer* popBuffer);
-
-
- // ExitCommand is used by notify us that Thread is shutting down.
- struct ExitCommand : public ThreadCommand
- {
- ThreadCommandQueueImpl* pImpl;
-
- ExitCommand(ThreadCommandQueueImpl* impl, bool wait)
- : ThreadCommand(sizeof(ExitCommand), wait, true), pImpl(impl) { }
-
- virtual void Execute() const
- {
- Lock::Locker lock(&pImpl->QueueLock);
- pImpl->ExitProcessed = true;
- }
- virtual ThreadCommand* CopyConstruct(void* p) const
- { return Construct<ExitCommand>(p, *this); }
- };
-
-
- NotifyEvent* AllocNotifyEvent_NTS()
- {
- NotifyEvent* p = AvailableEvents.GetFirst();
-
- if (!AvailableEvents.IsNull(p))
- p->RemoveNode();
- else
- p = new NotifyEvent;
- return p;
- }
-
- void FreeNotifyEvent_NTS(NotifyEvent* p)
- {
- AvailableEvents.PushBack(p);
- }
-
- void FreeNotifyEvents_NTS()
- {
- while(!AvailableEvents.IsEmpty())
- {
- NotifyEvent* p = AvailableEvents.GetFirst();
- p->RemoveNode();
- delete p;
- }
- }
-
- ThreadCommandQueue* pQueue;
- Lock QueueLock;
- volatile bool ExitEnqueued;
- volatile bool ExitProcessed;
- List<NotifyEvent> AvailableEvents;
- List<NotifyEvent> BlockedProducers;
- CircularBuffer CommandBuffer;
-};
-
-
-
-ThreadCommandQueueImpl::~ThreadCommandQueueImpl()
-{
- Lock::Locker lock(&QueueLock);
- OVR_ASSERT(BlockedProducers.IsEmpty());
- FreeNotifyEvents_NTS();
-}
-
-bool ThreadCommandQueueImpl::PushCommand(const ThreadCommand& command)
-{
- ThreadCommand::NotifyEvent* completeEvent = 0;
- ThreadCommand::NotifyEvent* queueAvailableEvent = 0;
-
- // Repeat writing command into buffer until it is available.
- do {
-
- { // Lock Scope
- Lock::Locker lock(&QueueLock);
-
- if (queueAvailableEvent)
- {
- FreeNotifyEvent_NTS(queueAvailableEvent);
- queueAvailableEvent = 0;
- }
-
- // Don't allow any commands after PushExitCommand() is called.
- if (ExitEnqueued && !command.ExitFlag)
- return false;
-
-
- bool bufferWasEmpty = CommandBuffer.IsEmpty();
- UByte* buffer = CommandBuffer.Write(command.GetSize());
- if (buffer)
- {
- ThreadCommand* c = command.CopyConstruct(buffer);
- if (c->NeedsWait())
- completeEvent = c->pEvent = AllocNotifyEvent_NTS();
- // Signal-waker consumer when we add data to buffer.
- if (bufferWasEmpty)
- pQueue->OnPushNonEmpty_Locked();
- break;
- }
-
- queueAvailableEvent = AllocNotifyEvent_NTS();
- BlockedProducers.PushBack(queueAvailableEvent);
- } // Lock Scope
-
- queueAvailableEvent->Wait();
-
- } while(1);
-
- // Command was enqueued, wait if necessary.
- if (completeEvent)
- {
- completeEvent->Wait();
- Lock::Locker lock(&QueueLock);
- FreeNotifyEvent_NTS(completeEvent);
- }
-
- return true;
-}
-
-
-// Pops the next command from the thread queue, if any is available.
-bool ThreadCommandQueueImpl::PopCommand(ThreadCommand::PopBuffer* popBuffer)
-{
- Lock::Locker lock(&QueueLock);
-
- UByte* buffer = CommandBuffer.ReadBegin();
- if (!buffer)
- {
- // Notify thread while in lock scope, enabling initialization of wait.
- pQueue->OnPopEmpty_Locked();
- return false;
- }
-
- popBuffer->InitFromBuffer(buffer);
- CommandBuffer.ReadEnd(popBuffer->GetSize());
-
- if (!BlockedProducers.IsEmpty())
- {
- ThreadCommand::NotifyEvent* queueAvailableEvent = BlockedProducers.GetFirst();
- queueAvailableEvent->RemoveNode();
- queueAvailableEvent->PulseEvent();
- // Event is freed later by waiter.
- }
- return true;
-}
-
-
-//-------------------------------------------------------------------------------------
-
-ThreadCommandQueue::ThreadCommandQueue()
-{
- pImpl = new ThreadCommandQueueImpl(this);
-}
-ThreadCommandQueue::~ThreadCommandQueue()
-{
- delete pImpl;
-}
-
-bool ThreadCommandQueue::PushCommand(const ThreadCommand& command)
-{
- return pImpl->PushCommand(command);
-}
-
-bool ThreadCommandQueue::PopCommand(ThreadCommand::PopBuffer* popBuffer)
-{
- return pImpl->PopCommand(popBuffer);
-}
-
-void ThreadCommandQueue::PushExitCommand(bool wait)
-{
- // Exit is processed in two stages:
- // - First, ExitEnqueued flag is set to block further commands from queuing up.
- // - Second, the actual exit call is processed on the consumer thread, flushing
- // any prior commands.
- // IsExiting() only returns true after exit has flushed.
- {
- Lock::Locker lock(&pImpl->QueueLock);
- if (pImpl->ExitEnqueued)
- return;
- pImpl->ExitEnqueued = true;
- }
-
- PushCommand(ThreadCommandQueueImpl::ExitCommand(pImpl, wait));
-}
-
-bool ThreadCommandQueue::IsExiting() const
-{
- return pImpl->ExitProcessed;
-}
-
-
-} // namespace OVR
+/************************************************************************************ + +PublicHeader: None +Filename : OVR_ThreadCommandQueue.cpp +Content : Command queue for operations executed on a thread +Created : October 29, 2012 + +Copyright : Copyright 2012 Oculus VR, Inc. All Rights reserved. + +Use of this software is subject to the terms of the Oculus license +agreement provided at the time of installation or download, or which +otherwise accompanies this software in either electronic or hard copy form. + +************************************************************************************/ + +#include "OVR_ThreadCommandQueue.h" + +namespace OVR { + + +//------------------------------------------------------------------------ +// ***** CircularBuffer + +// CircularBuffer is a FIFO buffer implemented in a single block of memory, +// which allows writing and reading variable-size data chucks. Write fails +// if buffer is full. + +class CircularBuffer +{ + enum { + AlignSize = 16, + AlignMask = AlignSize - 1 + }; + + UByte* pBuffer; + UPInt Size; + UPInt Tail; // Byte offset of next item to be popped. + UPInt Head; // Byte offset of where next push will take place. + UPInt End; // When Head < Tail, this is used instead of Size. + + inline UPInt roundUpSize(UPInt size) + { return (size + AlignMask) & ~(UPInt)AlignMask; } + +public: + + CircularBuffer(UPInt size) + : Size(size), Tail(0), Head(0), End(0) + { + pBuffer = (UByte*)OVR_ALLOC_ALIGNED(roundUpSize(size), AlignSize); + } + ~CircularBuffer() + { + // For ThreadCommands, we must consume everything before shutdown. + OVR_ASSERT(IsEmpty()); + OVR_FREE_ALIGNED(pBuffer); + } + + bool IsEmpty() const { return (Head == Tail); } + + // Allocates a state block of specified size and advances pointers, + // returning 0 if buffer is full. + UByte* Write(UPInt size); + + // Returns a pointer to next available data block; 0 if none available. + UByte* ReadBegin() + { return (Head != Tail) ? (pBuffer + Tail) : 0; } + // Consumes data of specified size; this must match size passed to Write. + void ReadEnd(UPInt size); +}; + + +// Allocates a state block of specified size and advances pointers, +// returning 0 if buffer is full. +UByte* CircularBuffer::Write(UPInt size) +{ + UByte* p = 0; + + size = roundUpSize(size); + // Since this is circular buffer, always allow at least one item. + OVR_ASSERT(size < Size/2); + + if (Head >= Tail) + { + OVR_ASSERT(End == 0); + + if (size <= (Size - Head)) + { + p = pBuffer + Head; + Head += size; + } + else if (size < Tail) + { + p = pBuffer; + End = Head; + Head = size; + OVR_ASSERT(Head != Tail); + } + } + else + { + OVR_ASSERT(End != 0); + + if ((Tail - Head) > size) + { + p = pBuffer + Head; + Head += size; + OVR_ASSERT(Head != Tail); + } + } + + return p; +} + +void CircularBuffer::ReadEnd(UPInt size) +{ + OVR_ASSERT(Head != Tail); + size = roundUpSize(size); + + Tail += size; + if (Tail == End) + { + Tail = End = 0; + } + else if (Tail == Head) + { + OVR_ASSERT(End == 0); + Tail = Head = 0; + } +} + + +//------------------------------------------------------------------------------------- +// ***** ThreadCommand + +ThreadCommand::PopBuffer::~PopBuffer() +{ + if (Size) + Destruct<ThreadCommand>(toCommand()); +} + +void ThreadCommand::PopBuffer::InitFromBuffer(void* data) +{ + ThreadCommand* cmd = (ThreadCommand*)data; + OVR_ASSERT(cmd->Size <= MaxSize); + + if (Size) + Destruct<ThreadCommand>(toCommand()); + Size = cmd->Size; + memcpy(Buffer, (void*)cmd, Size); +} + +void ThreadCommand::PopBuffer::Execute() +{ + ThreadCommand* command = toCommand(); + OVR_ASSERT(command); + command->Execute(); + if (NeedsWait()) + GetEvent()->PulseEvent(); +} + +//------------------------------------------------------------------------------------- + +class ThreadCommandQueueImpl : public NewOverrideBase +{ + typedef ThreadCommand::NotifyEvent NotifyEvent; + friend class ThreadCommandQueue; + +public: + + ThreadCommandQueueImpl(ThreadCommandQueue* queue) + : pQueue(queue), CommandBuffer(2048), + ExitEnqueued(false), ExitProcessed(false) + { + } + ~ThreadCommandQueueImpl(); + + + bool PushCommand(const ThreadCommand& command); + bool PopCommand(ThreadCommand::PopBuffer* popBuffer); + + + // ExitCommand is used by notify us that Thread is shutting down. + struct ExitCommand : public ThreadCommand + { + ThreadCommandQueueImpl* pImpl; + + ExitCommand(ThreadCommandQueueImpl* impl, bool wait) + : ThreadCommand(sizeof(ExitCommand), wait, true), pImpl(impl) { } + + virtual void Execute() const + { + Lock::Locker lock(&pImpl->QueueLock); + pImpl->ExitProcessed = true; + } + virtual ThreadCommand* CopyConstruct(void* p) const + { return Construct<ExitCommand>(p, *this); } + }; + + + NotifyEvent* AllocNotifyEvent_NTS() + { + NotifyEvent* p = AvailableEvents.GetFirst(); + + if (!AvailableEvents.IsNull(p)) + p->RemoveNode(); + else + p = new NotifyEvent; + return p; + } + + void FreeNotifyEvent_NTS(NotifyEvent* p) + { + AvailableEvents.PushBack(p); + } + + void FreeNotifyEvents_NTS() + { + while(!AvailableEvents.IsEmpty()) + { + NotifyEvent* p = AvailableEvents.GetFirst(); + p->RemoveNode(); + delete p; + } + } + + ThreadCommandQueue* pQueue; + Lock QueueLock; + volatile bool ExitEnqueued; + volatile bool ExitProcessed; + List<NotifyEvent> AvailableEvents; + List<NotifyEvent> BlockedProducers; + CircularBuffer CommandBuffer; +}; + + + +ThreadCommandQueueImpl::~ThreadCommandQueueImpl() +{ + Lock::Locker lock(&QueueLock); + OVR_ASSERT(BlockedProducers.IsEmpty()); + FreeNotifyEvents_NTS(); +} + +bool ThreadCommandQueueImpl::PushCommand(const ThreadCommand& command) +{ + ThreadCommand::NotifyEvent* completeEvent = 0; + ThreadCommand::NotifyEvent* queueAvailableEvent = 0; + + // Repeat writing command into buffer until it is available. + do { + + { // Lock Scope + Lock::Locker lock(&QueueLock); + + if (queueAvailableEvent) + { + FreeNotifyEvent_NTS(queueAvailableEvent); + queueAvailableEvent = 0; + } + + // Don't allow any commands after PushExitCommand() is called. + if (ExitEnqueued && !command.ExitFlag) + return false; + + + bool bufferWasEmpty = CommandBuffer.IsEmpty(); + UByte* buffer = CommandBuffer.Write(command.GetSize()); + if (buffer) + { + ThreadCommand* c = command.CopyConstruct(buffer); + if (c->NeedsWait()) + completeEvent = c->pEvent = AllocNotifyEvent_NTS(); + // Signal-waker consumer when we add data to buffer. + if (bufferWasEmpty) + pQueue->OnPushNonEmpty_Locked(); + break; + } + + queueAvailableEvent = AllocNotifyEvent_NTS(); + BlockedProducers.PushBack(queueAvailableEvent); + } // Lock Scope + + queueAvailableEvent->Wait(); + + } while(1); + + // Command was enqueued, wait if necessary. + if (completeEvent) + { + completeEvent->Wait(); + Lock::Locker lock(&QueueLock); + FreeNotifyEvent_NTS(completeEvent); + } + + return true; +} + + +// Pops the next command from the thread queue, if any is available. +bool ThreadCommandQueueImpl::PopCommand(ThreadCommand::PopBuffer* popBuffer) +{ + Lock::Locker lock(&QueueLock); + + UByte* buffer = CommandBuffer.ReadBegin(); + if (!buffer) + { + // Notify thread while in lock scope, enabling initialization of wait. + pQueue->OnPopEmpty_Locked(); + return false; + } + + popBuffer->InitFromBuffer(buffer); + CommandBuffer.ReadEnd(popBuffer->GetSize()); + + if (!BlockedProducers.IsEmpty()) + { + ThreadCommand::NotifyEvent* queueAvailableEvent = BlockedProducers.GetFirst(); + queueAvailableEvent->RemoveNode(); + queueAvailableEvent->PulseEvent(); + // Event is freed later by waiter. + } + return true; +} + + +//------------------------------------------------------------------------------------- + +ThreadCommandQueue::ThreadCommandQueue() +{ + pImpl = new ThreadCommandQueueImpl(this); +} +ThreadCommandQueue::~ThreadCommandQueue() +{ + delete pImpl; +} + +bool ThreadCommandQueue::PushCommand(const ThreadCommand& command) +{ + return pImpl->PushCommand(command); +} + +bool ThreadCommandQueue::PopCommand(ThreadCommand::PopBuffer* popBuffer) +{ + return pImpl->PopCommand(popBuffer); +} + +void ThreadCommandQueue::PushExitCommand(bool wait) +{ + // Exit is processed in two stages: + // - First, ExitEnqueued flag is set to block further commands from queuing up. + // - Second, the actual exit call is processed on the consumer thread, flushing + // any prior commands. + // IsExiting() only returns true after exit has flushed. + { + Lock::Locker lock(&pImpl->QueueLock); + if (pImpl->ExitEnqueued) + return; + pImpl->ExitEnqueued = true; + } + + PushCommand(ThreadCommandQueueImpl::ExitCommand(pImpl, wait)); +} + +bool ThreadCommandQueue::IsExiting() const +{ + return pImpl->ExitProcessed; +} + + +} // namespace OVR |