diff options
author | Sven Gothel <[email protected]> | 2015-03-28 01:43:35 +0100 |
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committer | Sven Gothel <[email protected]> | 2015-03-28 01:43:35 +0100 |
commit | 4207f9c279e832e3afcb3f5fc6cd8d84cb4cfe4c (patch) | |
tree | cf3671058d55b47ab6cb6f36f369928606137628 /LibOVRKernel/Src/Kernel/OVR_Atomic.cpp | |
parent | c29cd1a2fbff6282bab956ad61661ac9d48c4e6e (diff) |
Bump OculusVR RIFT SDK to 0.5.0.1vanilla_0.5.0.1
Diffstat (limited to 'LibOVRKernel/Src/Kernel/OVR_Atomic.cpp')
-rw-r--r-- | LibOVRKernel/Src/Kernel/OVR_Atomic.cpp | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/LibOVRKernel/Src/Kernel/OVR_Atomic.cpp b/LibOVRKernel/Src/Kernel/OVR_Atomic.cpp new file mode 100644 index 0000000..f7cf9a6 --- /dev/null +++ b/LibOVRKernel/Src/Kernel/OVR_Atomic.cpp @@ -0,0 +1,139 @@ +/************************************************************************************ + +Filename : OVR_Atomic.cpp +Content : Contains atomic operations and inline fastest locking + functionality. Will contain #ifdefs for OS efficiency. + Have non-thread-safe implementation if not available. +Created : September 19, 2012 +Notes : + +Copyright : Copyright 2014 Oculus VR, LLC All Rights reserved. + +Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); +you may not use the Oculus VR Rift SDK except in compliance with the License, +which is provided at the time of installation or download, or which +otherwise accompanies this software in either electronic or hard copy form. + +You may obtain a copy of the License at + +http://www.oculusvr.com/licenses/LICENSE-3.2 + +Unless required by applicable law or agreed to in writing, the Oculus VR SDK +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. + +************************************************************************************/ + +#include "OVR_Atomic.h" +#include "OVR_Allocator.h" + +#ifdef OVR_ENABLE_THREADS + +// Include Windows 8-Metro compatible Synchronization API +#if defined(OVR_OS_MS) && defined(NTDDI_WIN8) && (NTDDI_VERSION >= NTDDI_WIN8) +#include <synchapi.h> +#endif + + +namespace OVR { + +// ***** Windows Lock implementation + +#if defined(OVR_OS_MS) + +// ***** Standard Win32 Lock implementation + +// Constructors +Lock::Lock(unsigned spinCount) +{ + #if defined(NTDDI_WIN8) && (NTDDI_VERSION >= NTDDI_WIN8) + // On Windows 8 we use InitializeCriticalSectionEx due to Metro-Compatibility + InitializeCriticalSectionEx(&cs, (DWORD)spinCount, + OVR_DEBUG_SELECT(NULL, CRITICAL_SECTION_NO_DEBUG_INFO)); + #else + ::InitializeCriticalSectionAndSpinCount(&cs, (DWORD)spinCount); // This is available with WindowsXP+. + #endif +} + + +Lock::~Lock() +{ + DeleteCriticalSection(&cs); +} + + +#endif + + +//------------------------------------------------------------------------------------- +// ***** SharedLock + +// This is a general purpose globally shared Lock implementation that should probably be +// moved to Kernel. +// May in theory busy spin-wait if we hit contention on first lock creation, +// but this shouldn't matter in practice since Lock* should be cached. + + +enum { LockInitMarker = 0xFFFFFFFF }; + +Lock* SharedLock::GetLockAddRef() +{ + int oldUseCount; + + do { + oldUseCount = UseCount; + if (oldUseCount == (int)LockInitMarker) + continue; + + if (oldUseCount == 0) + { + // Initialize marker + if (AtomicOps<int>::CompareAndSet_Sync(&UseCount, 0, LockInitMarker)) + { + Construct<Lock>(Buffer); + do { } + while (!AtomicOps<int>::CompareAndSet_Sync(&UseCount, LockInitMarker, 1)); + return toLock(); + } + continue; + } + + } while (!AtomicOps<int>::CompareAndSet_NoSync(&UseCount, oldUseCount, oldUseCount + 1)); + + return toLock(); +} + +void SharedLock::ReleaseLock(Lock* plock) +{ + OVR_UNUSED(plock); + OVR_ASSERT(plock == toLock()); + + int oldUseCount; + + do { + oldUseCount = UseCount; + OVR_ASSERT(oldUseCount != (int)LockInitMarker); + + if (oldUseCount == 1) + { + // Initialize marker + if (AtomicOps<int>::CompareAndSet_Sync(&UseCount, 1, LockInitMarker)) + { + Destruct<Lock>(toLock()); + + do { } + while (!AtomicOps<int>::CompareAndSet_Sync(&UseCount, LockInitMarker, 0)); + + return; + } + continue; + } + + } while (!AtomicOps<int>::CompareAndSet_NoSync(&UseCount, oldUseCount, oldUseCount - 1)); +} + +} // OVR + +#endif // OVR_ENABLE_THREADS |