From 687efd84eabc524e339e61458b0cbf53f9a38f8a Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Fri, 26 Jun 2015 13:03:59 -0400 Subject: MAINT-5232: Loosen LLSingleton circularity constraints slightly. LLSingleton explicitly supports circular dependencies: initialization performed during an LLSingleton subclass's initSingleton() method may recursively call that same subclass's getInstance() method. On the other hand, circularity from a subclass constructor cannot be permitted, else getInstance() would have to return a partially-constructed object. Our dependency tracking circularity check initially forbade both. Loosen it to permit references from within initSingleton(). --- indra/llcommon/llsingleton.cpp | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'indra/llcommon/llsingleton.cpp') diff --git a/indra/llcommon/llsingleton.cpp b/indra/llcommon/llsingleton.cpp index a3edf925ad..2813814ae1 100755 --- a/indra/llcommon/llsingleton.cpp +++ b/indra/llcommon/llsingleton.cpp @@ -123,7 +123,7 @@ void LLSingletonBase::pop_initializing() list.pop_back(); } -void LLSingletonBase::capture_dependency() +void LLSingletonBase::capture_dependency(EInitState initState) { // Did this getInstance() call come from another LLSingleton, or from // vanilla application code? Note that although this is a nontrivial @@ -150,11 +150,18 @@ void LLSingletonBase::capture_dependency() // is the actual LLSingletonBase instance. out << typeid(**found).name() << " -> "; } - // DEBUGGING: Initially, make this crump. We want to know how bad - // the problem is before we add it to the long, sad list of - // ominous warnings that everyone always ignores. - logerrs("LLSingleton circularity: ", out.str().c_str(), - typeid(*this).name()); + // We promise to capture dependencies from both the constructor + // and the initSingleton() method, so an LLSingleton's instance + // pointer is on the initializing list during both. Now that we've + // detected circularity, though, we must distinguish the two. If + // the recursive call is from the constructor, we CAN'T honor it: + // otherwise we'd be returning a pointer to a partially- + // constructed object! But from initSingleton() is okay: that + // method exists specifically to support circularity. + // Decide which log helper to call based on initState. They have + // identical signatures. + ((initState == CONSTRUCTING)? logerrs : logwarns) + ("LLSingleton circularity: ", out.str().c_str(), typeid(*this).name(), ""); } else { -- cgit v1.2.3