diff options
Diffstat (limited to 'indra/llcommon')
| -rwxr-xr-x | indra/llcommon/llthread.cpp | 32 | ||||
| -rwxr-xr-x | indra/llcommon/llthread.h | 46 |
2 files changed, 75 insertions, 3 deletions
diff --git a/indra/llcommon/llthread.cpp b/indra/llcommon/llthread.cpp index 1d56a52c32..7563975959 100755 --- a/indra/llcommon/llthread.cpp +++ b/indra/llcommon/llthread.cpp @@ -3,7 +3,7 @@ * * $LicenseInfo:firstyear=2004&license=viewerlgpl$ * Second Life Viewer Source Code - * Copyright (C) 2010, Linden Research, Inc. + * Copyright (C) 2010-2013, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -372,6 +372,36 @@ void LLMutex::lock() #endif } +bool LLMutex::trylock() +{ + if(isSelfLocked()) + { //redundant lock + mCount++; + return true; + } + + apr_status_t status(apr_thread_mutex_trylock(mAPRMutexp)); + if (APR_STATUS_IS_EBUSY(status)) + { + return false; + } + +#if MUTEX_DEBUG + // Have to have the lock before we can access the debug info + U32 id = LLThread::currentID(); + if (mIsLocked[id] != FALSE) + llerrs << "Already locked in Thread: " << id << llendl; + mIsLocked[id] = TRUE; +#endif + +#if LL_DARWIN + mLockingThread = LLThread::currentID(); +#else + mLockingThread = sThreadID; +#endif + return true; +} + void LLMutex::unlock() { if (mCount > 0) diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h index 0fb89c5613..376df398d7 100755 --- a/indra/llcommon/llthread.h +++ b/indra/llcommon/llthread.h @@ -4,7 +4,7 @@ * * $LicenseInfo:firstyear=2004&license=viewerlgpl$ * Second Life Viewer Source Code - * Copyright (C) 2010, Linden Research, Inc. + * Copyright (C) 2010-2013, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -156,7 +156,8 @@ public: virtual ~LLMutex(); void lock(); // blocks - void unlock(); + bool trylock(); // non-blocking, returns true if lock held. + void unlock(); // undefined behavior when called on mutex not being held bool isLocked(); // non-blocking, but does do a lock/unlock so not free bool isSelfLocked(); //return true if locked in a same thread U32 lockingThread() const; //get ID of locking thread @@ -174,6 +175,8 @@ protected: #endif }; +//============================================================================ + // Actually a condition/mutex pair (since each condition needs to be associated with a mutex). class LL_COMMON_API LLCondition : public LLMutex { @@ -189,6 +192,8 @@ protected: apr_thread_cond_t *mAPRCondp; }; +//============================================================================ + class LLMutexLock { public: @@ -210,6 +215,43 @@ private: //============================================================================ +// Scoped locking class similar in function to LLMutexLock but uses +// the trylock() method to conditionally acquire lock without +// blocking. Caller resolves the resulting condition by calling +// the isLocked() method and either punts or continues as indicated. +// +// Mostly of interest to callers needing to avoid stalls who can +// guarantee another attempt at a later time. + +class LLMutexTrylock +{ +public: + LLMutexTrylock(LLMutex* mutex) + : mMutex(mutex), + mLocked(false) + { + if (mMutex) + mLocked = mMutex->trylock(); + } + + ~LLMutexTrylock() + { + if (mMutex && mLocked) + mMutex->unlock(); + } + + bool isLocked() const + { + return mLocked; + } + +private: + LLMutex* mMutex; + bool mLocked; +}; + +//============================================================================ + void LLThread::lockData() { mDataLock->lock(); |