diff options
Diffstat (limited to 'indra')
| -rw-r--r-- | indra/llcommon/llsingleton.cpp | 6 | ||||
| -rw-r--r-- | indra/llcommon/llsingleton.h | 44 |
2 files changed, 26 insertions, 24 deletions
diff --git a/indra/llcommon/llsingleton.cpp b/indra/llcommon/llsingleton.cpp index bf594f122c..4c76206d8d 100644 --- a/indra/llcommon/llsingleton.cpp +++ b/indra/llcommon/llsingleton.cpp @@ -384,7 +384,7 @@ LLSingletonBase::vec_t LLSingletonBase::dep_sort() SingletonDeps sdeps; // Lock while traversing the master list MasterList::LockedMaster master; - BOOST_FOREACH(LLSingletonBase* sp, master.get()) + for (LLSingletonBase* sp : master.get()) { // Build the SingletonDeps structure by adding, for each // LLSingletonBase* sp in the master list, sp itself. It has no @@ -401,14 +401,14 @@ LLSingletonBase::vec_t LLSingletonBase::dep_sort() // extracts just the first (key) element from each sorted_iterator, then // uses vec_t's range constructor... but frankly this is more // straightforward, as long as we remember the above reserve() call! - BOOST_FOREACH(SingletonDeps::sorted_iterator::value_type pair, sdeps.sort()) + for (const SingletonDeps::sorted_iterator::value_type& pair : sdeps.sort()) { ret.push_back(pair.first); } // The master list is not itself pushed onto the master list. Add it as // the very last entry -- it is the LLSingleton on which ALL others // depend! -- so our caller will process it. - ret.push_back(MasterList::getInstance()); + ret.push_back(&master.Lock::get()); return ret; } diff --git a/indra/llcommon/llsingleton.h b/indra/llcommon/llsingleton.h index 0c11e54910..5ee40a658a 100644 --- a/indra/llcommon/llsingleton.h +++ b/indra/llcommon/llsingleton.h @@ -428,6 +428,21 @@ protected: LLSingleton_manage_master<DERIVED_TYPE>().add(this); } +protected: + virtual ~LLSingleton() + { + // This phase of cleanup is performed in the destructor rather than in + // deleteSingleton() to defend against manual deletion. When we moved + // cleanup to deleteSingleton(), we hit crashes due to dangling + // pointers in the MasterList. + LockStatic lk; + lk->mInstance = nullptr; + lk->mInitState = DELETED; + + // Remove this instance from the master list. + LLSingleton_manage_master<DERIVED_TYPE>().remove(this); + } + public: /** * @brief Immediately delete the singleton. @@ -452,29 +467,16 @@ public: */ static void deleteSingleton() { - DERIVED_TYPE* lameduck; - { - LockStatic lk; - // Capture the instance and clear SingletonData. This sequence - // guards against the chance that the destructor throws, somebody - // catches it and there's a subsequent call to getInstance(). - lameduck = lk->mInstance; - lk->mInstance = nullptr; - lk->mInitState = DELETED; - // At this point we can safely unlock SingletonData during the - // remaining cleanup. If another thread calls deleteSingleton() (or - // getInstance(), or whatever) it won't find our instance, now - // referenced only as 'lameduck'. - } + // Hold the lock while we call cleanupSingleton() and the destructor. + // Our destructor also instantiates LockStatic, requiring a recursive + // mutex. + LockStatic lk; // of course, only cleanup and delete if there's something there - if (lameduck) + if (lk->mInstance) { - // remove this instance from the master list BEFORE attempting - // cleanup so possible destructor exception won't leave the master - // list confused - LLSingleton_manage_master<DERIVED_TYPE>().remove(lameduck); - lameduck->cleanup_(); - delete lameduck; + lk->mInstance->cleanup_(); + delete lk->mInstance; + // destructor clears mInstance (and mInitState) } } |