diff options
Diffstat (limited to 'indra/llcommon')
| -rw-r--r-- | indra/llcommon/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | indra/llcommon/llhandle.h | 217 | ||||
| -rw-r--r-- | indra/llcommon/llstat.cpp | 19 | ||||
| -rw-r--r-- | indra/llcommon/llstat.h | 6 |
4 files changed, 233 insertions, 10 deletions
diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt index dd7b8c6eb8..36a8319189 100644 --- a/indra/llcommon/CMakeLists.txt +++ b/indra/llcommon/CMakeLists.txt @@ -174,6 +174,7 @@ set(llcommon_HEADER_FILES llfoldertype.h llformat.h llframetimer.h + llhandle.h llhash.h llheartbeat.h llhttpstatuscodes.h diff --git a/indra/llcommon/llhandle.h b/indra/llcommon/llhandle.h new file mode 100644 index 0000000000..6af5e198d6 --- /dev/null +++ b/indra/llcommon/llhandle.h @@ -0,0 +1,217 @@ +/** +* @file llhandle.h +* @brief "Handle" to an object (usually a floater) whose lifetime you don't +* control. +* +* $LicenseInfo:firstyear=2001&license=viewerlgpl$ +* Second Life Viewer Source Code +* Copyright (C) 2010, 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 +* License as published by the Free Software Foundation; +* version 2.1 of the License only. +* +* This library is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +* Lesser General Public License for more details. +* +* You should have received a copy of the GNU Lesser General Public +* License along with this library; if not, write to the Free Software +* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA +* +* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA +* $/LicenseInfo$ +*/ +#ifndef LLHANDLE_H +#define LLHANDLE_H + +#include "llpointer.h" +#include <boost/type_traits/is_convertible.hpp> +#include <boost/utility/enable_if.hpp> + +/** + * Helper object for LLHandle. Don't instantiate these directly, used + * exclusively by LLHandle. + */ +class LLTombStone : public LLRefCount +{ +public: + LLTombStone(void* target = NULL) : mTarget(target) {} + + void setTarget(void* target) { mTarget = target; } + void* getTarget() const { return mTarget; } +private: + mutable void* mTarget; +}; + +/** + * LLHandles are used to refer to objects whose lifetime you do not control or influence. + * Calling get() on a handle will return a pointer to the referenced object or NULL, + * if the object no longer exists. Note that during the lifetime of the returned pointer, + * you are assuming that the object will not be deleted by any action you perform, + * or any other thread, as normal when using pointers, so avoid using that pointer outside of + * the local code block. + * + * https://wiki.lindenlab.com/mediawiki/index.php?title=LLHandle&oldid=79669 + * + * The implementation is like some "weak pointer" implementations. When we + * can't control the lifespan of the referenced object of interest, we can + * still instantiate a proxy object whose lifespan we DO control, and store in + * the proxy object a dumb pointer to the actual target. Then we just have to + * ensure that on destruction of the target object, the proxy's dumb pointer + * is set NULL. + * + * LLTombStone is our proxy object. LLHandle contains an LLPointer to the + * LLTombStone, so every copy of an LLHandle increments the LLTombStone's ref + * count as usual. + * + * One copy of the LLHandle, specifically the LLRootHandle, must be stored in + * the referenced object. Destroying the LLRootHandle is what NULLs the + * proxy's target pointer. + * + * Minor optimization: we want LLHandle's mTombStone to always be a valid + * LLPointer, saving some conditionals in dereferencing. That's the + * getDefaultTombStone() mechanism. The default LLTombStone object's target + * pointer is always NULL, so it's semantically identical to allowing + * mTombStone to be invalid. + */ +template <typename T> +class LLHandle +{ + template <typename U> friend class LLHandle; + template <typename U> friend class LLHandleProvider; +public: + LLHandle() : mTombStone(getDefaultTombStone()) {} + + template<typename U> + LLHandle(const LLHandle<U>& other, typename boost::enable_if< typename boost::is_convertible<U*, T*> >::type* dummy = 0) + : mTombStone(other.mTombStone) + {} + + bool isDead() const + { + return mTombStone->getTarget() == NULL; + } + + void markDead() + { + mTombStone = getDefaultTombStone(); + } + + T* get() const + { + return reinterpret_cast<T*>(mTombStone->getTarget()); + } + + friend bool operator== (const LLHandle<T>& lhs, const LLHandle<T>& rhs) + { + return lhs.mTombStone == rhs.mTombStone; + } + friend bool operator!= (const LLHandle<T>& lhs, const LLHandle<T>& rhs) + { + return !(lhs == rhs); + } + friend bool operator< (const LLHandle<T>& lhs, const LLHandle<T>& rhs) + { + return lhs.mTombStone < rhs.mTombStone; + } + friend bool operator> (const LLHandle<T>& lhs, const LLHandle<T>& rhs) + { + return lhs.mTombStone > rhs.mTombStone; + } + +protected: + LLPointer<LLTombStone> mTombStone; + +private: + typedef T* pointer_t; + static LLPointer<LLTombStone>& getDefaultTombStone() + { + static LLPointer<LLTombStone> sDefaultTombStone = new LLTombStone; + return sDefaultTombStone; + } +}; + +/** + * LLRootHandle isa LLHandle which must be stored in the referenced object. + * You can either store it directly and explicitly bind(this), or derive from + * LLHandleProvider (q.v.) which automates that for you. The essential point + * is that destroying the LLRootHandle (as a consequence of destroying the + * referenced object) calls unbind(), setting the LLTombStone's target pointer + * NULL. + */ +template <typename T> +class LLRootHandle : public LLHandle<T> +{ +public: + typedef LLRootHandle<T> self_t; + typedef LLHandle<T> base_t; + + LLRootHandle(T* object) { bind(object); } + LLRootHandle() {}; + ~LLRootHandle() { unbind(); } + + // this is redundant, since an LLRootHandle *is* an LLHandle + //LLHandle<T> getHandle() { return LLHandle<T>(*this); } + + void bind(T* object) + { + // unbind existing tombstone + if (LLHandle<T>::mTombStone.notNull()) + { + if (LLHandle<T>::mTombStone->getTarget() == (void*)object) return; + LLHandle<T>::mTombStone->setTarget(NULL); + } + // tombstone reference counted, so no paired delete + LLHandle<T>::mTombStone = new LLTombStone((void*)object); + } + + void unbind() + { + LLHandle<T>::mTombStone->setTarget(NULL); + } + + //don't allow copying of root handles, since there should only be one +private: + LLRootHandle(const LLRootHandle& other) {}; +}; + +/** + * Use this as a mixin for simple classes that need handles and when you don't + * want handles at multiple points of the inheritance hierarchy + */ +template <typename T> +class LLHandleProvider +{ +public: + LLHandle<T> getHandle() const + { + // perform lazy binding to avoid small tombstone allocations for handle + // providers whose handles are never referenced + mHandle.bind(static_cast<T*>(const_cast<LLHandleProvider<T>* >(this))); + return mHandle; + } + +protected: + typedef LLHandle<T> handle_type_t; + LLHandleProvider() + { + // provided here to enforce T deriving from LLHandleProvider<T> + } + + template <typename U> + LLHandle<U> getDerivedHandle(typename boost::enable_if< typename boost::is_convertible<U*, T*> >::type* dummy = 0) const + { + LLHandle<U> downcast_handle; + downcast_handle.mTombStone = getHandle().mTombStone; + return downcast_handle; + } + + +private: + mutable LLRootHandle<T> mHandle; +}; + +#endif diff --git a/indra/llcommon/llstat.cpp b/indra/llcommon/llstat.cpp index 057257057f..b82d52797e 100644 --- a/indra/llcommon/llstat.cpp +++ b/indra/llcommon/llstat.cpp @@ -40,7 +40,6 @@ S32 LLPerfBlock::sStatsFlags = LLPerfBlock::LLSTATS_NO_OPTIONAL_STATS; // Control what is being recorded LLPerfBlock::stat_map_t LLPerfBlock::sStatMap; // Map full path string to LLStatTime objects, tracks all active objects std::string LLPerfBlock::sCurrentStatPath = ""; // Something like "/total_time/physics/physics step" -LLStat::stat_map_t LLStat::sStatList; //------------------------------------------------------------------------ // Live config file to trigger stats logging @@ -771,13 +770,19 @@ void LLStat::init() if (!mName.empty()) { - stat_map_t::iterator iter = sStatList.find(mName); - if (iter != sStatList.end()) + stat_map_t::iterator iter = getStatList().find(mName); + if (iter != getStatList().end()) llwarns << "LLStat with duplicate name: " << mName << llendl; - sStatList.insert(std::make_pair(mName, this)); + getStatList().insert(std::make_pair(mName, this)); } } +LLStat::stat_map_t& LLStat::getStatList() +{ + static LLStat::stat_map_t stat_list; + return stat_list; +} + LLStat::LLStat(const U32 num_bins, const BOOL use_frame_timer) : mUseFrameTimer(use_frame_timer), mNumBins(num_bins) @@ -803,10 +808,10 @@ LLStat::~LLStat() if (!mName.empty()) { // handle multiple entries with the same name - stat_map_t::iterator iter = sStatList.find(mName); - while (iter != sStatList.end() && iter->second != this) + stat_map_t::iterator iter = getStatList().find(mName); + while (iter != getStatList().end() && iter->second != this) ++iter; - sStatList.erase(iter); + getStatList().erase(iter); } } diff --git a/indra/llcommon/llstat.h b/indra/llcommon/llstat.h index b877432e86..1a8404cc07 100644 --- a/indra/llcommon/llstat.h +++ b/indra/llcommon/llstat.h @@ -263,9 +263,9 @@ class LL_COMMON_API LLStat { private: typedef std::multimap<std::string, LLStat*> stat_map_t; - static stat_map_t sStatList; void init(); + static stat_map_t& getStatList(); public: LLStat(U32 num_bins = 32, BOOL use_frame_timer = FALSE); @@ -342,8 +342,8 @@ public: static LLStat* getStat(const std::string& name) { // return the first stat that matches 'name' - stat_map_t::iterator iter = sStatList.find(name); - if (iter != sStatList.end()) + stat_map_t::iterator iter = getStatList().find(name); + if (iter != getStatList().end()) return iter->second; else return NULL; |