diff options
Diffstat (limited to 'indra/llcommon/llthread.h')
| -rw-r--r-- | indra/llcommon/llthread.h | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h index 0d22bc863d..f51d985b5f 100644 --- a/indra/llcommon/llthread.h +++ b/indra/llcommon/llthread.h @@ -30,6 +30,7 @@ #include "llapp.h" #include "llapr.h" #include "apr_thread_cond.h" +#include "boost/intrusive_ptr.hpp" class LLThread; class LLMutex; @@ -250,26 +251,19 @@ public: mRef++; } - S32 unref() + void unref() { - llassert(mRef >= 1); - bool time_to_die = (mRef == 1); - if (time_to_die) - { - if (sMutex) sMutex->lock(); - // Looks redundant, but is very much not - // We need to check again once we've acquired the lock - // so that two threads who get into the if in parallel - // don't both attempt to the delete. - // - mRef--; - if (mRef == 0) - delete this; - if (sMutex) sMutex->unlock(); - return 0; + llassert(mRef >= 1); + if ((--mRef) == 0) // See note in llapr.h on atomic decrement operator return value. + { + // If we hit zero, the caller should be the only smart pointer owning the object and we can delete it. + // It is technically possible for a vanilla pointer to mess this up, or another thread to + // jump in, find this object, create another smart pointer and end up dangling, but if + // the code is that bad and not thread-safe, it's trouble already. + delete this; } - return --mRef; } + S32 getNumRefs() const { const S32 currentVal = mRef.CurrentValue(); @@ -280,6 +274,23 @@ private: LLAtomic32< S32 > mRef; }; + +/** + * intrusive pointer support for LLThreadSafeRefCount + * this allows you to use boost::intrusive_ptr with any LLThreadSafeRefCount-derived type + */ +namespace boost +{ + inline void intrusive_ptr_add_ref(LLThreadSafeRefCount* p) + { + p->ref(); + } + + inline void intrusive_ptr_release(LLThreadSafeRefCount* p) + { + p->unref(); + } +}; //============================================================================ // Simple responder for self destructing callbacks @@ -294,4 +305,6 @@ public: //============================================================================ +extern LL_COMMON_API void assert_main_thread(); + #endif // LL_LLTHREAD_H |