From 9d5b897600a8f9405ec37a141b9417f34a11c557 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Mon, 2 Dec 2019 14:39:24 -0500 Subject: DRTVWR-494: Defend LLInstanceTracker against multi-thread usage. The previous implementation went to some effort to crash if anyone attempted to create or destroy an LLInstanceTracker subclass instance during traversal. That restriction is manageable within a single thread, but becomes unworkable if it's possible that a given subclass might be used on more than one thread. Remove LLInstanceTracker::instance_iter, beginInstances(), endInstances(), also key_iter, beginKeys() and endKeys(). Instead, introduce key_snapshot() and instance_snapshot(), the only means of iterating over LLInstanceTracker instances. (These are intended to resemble functions, but in fact the current implementation simply presents the classes.) Iterating over a captured snapshot defends against container modifications during traversal. The term 'snapshot' reminds the coder that a new instance created during traversal will not be considered. To defend against instance deletion during traversal, a snapshot stores std::weak_ptrs which it lazily dereferences, skipping on the fly any that have expired. Dereferencing instance_snapshot::iterator gets you a reference rather than a pointer. Because some use cases want to delete all existing instances, add an instance_snapshot::deleteAll() method that extracts the pointer. Those cases used to require explicitly copying instance pointers into a separate container; instance_snapshot() now takes care of that. It remains the caller's responsibility to ensure that all instances of that LLInstanceTracker subclass were allocated on the heap. Replace unkeyed static LLInstanceTracker::getInstance(T*) -- which returned nullptr if that instance had been destroyed -- with new getWeak() method returning std::weak_ptr. Caller must detect expiration of that weak_ptr. Adjust tests accordingly. Use of std::weak_ptr to detect expired instances requires engaging std::shared_ptr in the constructor. We now store shared_ptrs in the static containers (std::map for keyed, std::set for unkeyed). Make LLInstanceTrackerBase a template parameterized on the type of the static data it manages. For that reason, hoist static data class declarations out of the class definitions to an LLInstanceTrackerStuff namespace. Remove the static atomic sIterationNestDepth and its methods incrementDepth(), decrementDepth() and getDepth(), since they were used only to forbid creation and destruction during traversal. Add a std::mutex to static data. Introduce an internal LockStatic class that locks the mutex while providing a pointer to static data, making that the only way to access the static data. The LLINSTANCETRACKER_DTOR_NOEXCEPT macro goes away because we no longer expect ~LLInstanceTracker() to throw an exception in test programs. That affects LLTrace::StatBase as well as LLInstanceTracker itself. Adapt consumers to the new LLInstanceTracker API. --- indra/llcommon/tests/llinstancetracker_test.cpp | 107 +++++++++++------------- 1 file changed, 49 insertions(+), 58 deletions(-) (limited to 'indra/llcommon/tests/llinstancetracker_test.cpp') diff --git a/indra/llcommon/tests/llinstancetracker_test.cpp b/indra/llcommon/tests/llinstancetracker_test.cpp index d94fc0c56d..9b89159625 100644 --- a/indra/llcommon/tests/llinstancetracker_test.cpp +++ b/indra/llcommon/tests/llinstancetracker_test.cpp @@ -41,7 +41,6 @@ #include // other Linden headers #include "../test/lltut.h" -#include "wrapllerrs.h" struct Badness: public std::runtime_error { @@ -112,24 +111,22 @@ namespace tut void object::test<2>() { ensure_equals(Unkeyed::instanceCount(), 0); - Unkeyed* dangling = NULL; + std::weak_ptr dangling; { Unkeyed one; ensure_equals(Unkeyed::instanceCount(), 1); - Unkeyed* found = Unkeyed::getInstance(&one); - ensure_equals(found, &one); + std::weak_ptr found = one.getWeak(); + ensure(! found.expired()); { boost::scoped_ptr two(new Unkeyed); ensure_equals(Unkeyed::instanceCount(), 2); - Unkeyed* found = Unkeyed::getInstance(two.get()); - ensure_equals(found, two.get()); } ensure_equals(Unkeyed::instanceCount(), 1); - // store an unwise pointer to a temp Unkeyed instance - dangling = &one; + // store a weak pointer to a temp Unkeyed instance + dangling = found; } // make that instance vanish // check the now-invalid pointer to the destroyed instance - ensure("getInstance(T*) failed to track destruction", ! Unkeyed::getInstance(dangling)); + ensure("weak_ptr failed to track destruction", dangling.expired()); ensure_equals(Unkeyed::instanceCount(), 0); } @@ -142,7 +139,8 @@ namespace tut // reimplement LLInstanceTracker using, say, a hash map instead of a // std::map. We DO insist that every key appear exactly once. typedef std::vector StringVector; - StringVector keys(Keyed::beginKeys(), Keyed::endKeys()); + auto snap = Keyed::key_snapshot(); + StringVector keys(snap.begin(), snap.end()); std::sort(keys.begin(), keys.end()); StringVector::const_iterator ki(keys.begin()); ensure_equals(*ki++, "one"); @@ -153,17 +151,15 @@ namespace tut ensure("didn't reach end", ki == keys.end()); // Use a somewhat different approach to order independence with - // beginInstances(): explicitly capture the instances we know in a + // instance_snapshot(): explicitly capture the instances we know in a // set, and delete them as we iterate through. typedef std::set InstanceSet; InstanceSet instances; instances.insert(&one); instances.insert(&two); instances.insert(&three); - for (Keyed::instance_iter ii(Keyed::beginInstances()), iend(Keyed::endInstances()); - ii != iend; ++ii) + for (auto& ref : Keyed::instance_snapshot()) { - Keyed& ref = *ii; ensure_equals("spurious instance", instances.erase(&ref), 1); } ensure_equals("unreported instance", instances.size(), 0); @@ -180,11 +176,10 @@ namespace tut instances.insert(&two); instances.insert(&three); - for (Unkeyed::instance_iter ii(Unkeyed::beginInstances()), iend(Unkeyed::endInstances()); ii != iend; ++ii) - { - Unkeyed& ref = *ii; - ensure_equals("spurious instance", instances.erase(&ref), 1); - } + for (auto& ref : Unkeyed::instance_snapshot()) + { + ensure_equals("spurious instance", instances.erase(&ref), 1); + } ensure_equals("unreported instance", instances.size(), 0); } @@ -192,49 +187,49 @@ namespace tut template<> template<> void object::test<5>() { - set_test_name("delete Keyed with outstanding instance_iter"); - std::string what; - Keyed* keyed = new Keyed("delete Keyed with outstanding instance_iter"); - { - WrapLLErrs wrapper; - Keyed::instance_iter i(Keyed::beginInstances()); - what = wrapper.catch_llerrs([&keyed](){ - delete keyed; - }); - } - ensure(! what.empty()); + std::string desc("delete Keyed with outstanding instance_snapshot"); + set_test_name(desc); + Keyed* keyed = new Keyed(desc); + // capture a snapshot but do not yet traverse it + auto snapshot = Keyed::instance_snapshot(); + // delete the one instance + delete keyed; + // traversing the snapshot should reflect the deletion + // avoid ensure_equals() because it requires the ability to stream the + // two values to std::ostream + ensure(snapshot.begin() == snapshot.end()); } template<> template<> void object::test<6>() { - set_test_name("delete Keyed with outstanding key_iter"); - std::string what; - Keyed* keyed = new Keyed("delete Keyed with outstanding key_it"); - { - WrapLLErrs wrapper; - Keyed::key_iter i(Keyed::beginKeys()); - what = wrapper.catch_llerrs([&keyed](){ - delete keyed; - }); - } - ensure(! what.empty()); + std::string desc("delete Keyed with outstanding key_snapshot"); + set_test_name(desc); + Keyed* keyed = new Keyed(desc); + // capture a snapshot but do not yet traverse it + auto snapshot = Keyed::key_snapshot(); + // delete the one instance + delete keyed; + // traversing the snapshot should reflect the deletion + // avoid ensure_equals() because it requires the ability to stream the + // two values to std::ostream + ensure(snapshot.begin() == snapshot.end()); } template<> template<> void object::test<7>() { - set_test_name("delete Unkeyed with outstanding instance_iter"); + set_test_name("delete Unkeyed with outstanding instance_snapshot"); std::string what; Unkeyed* unkeyed = new Unkeyed; - { - WrapLLErrs wrapper; - Unkeyed::instance_iter i(Unkeyed::beginInstances()); - what = wrapper.catch_llerrs([&unkeyed](){ - delete unkeyed; - }); - } - ensure(! what.empty()); + // capture a snapshot but do not yet traverse it + auto snapshot = Unkeyed::instance_snapshot(); + // delete the one instance + delete unkeyed; + // traversing the snapshot should reflect the deletion + // avoid ensure_equals() because it requires the ability to stream the + // two values to std::ostream + ensure(snapshot.begin() == snapshot.end()); } template<> template<> @@ -246,11 +241,9 @@ namespace tut // We can't use the iterator-range InstanceSet constructor because // beginInstances() returns an iterator that dereferences to an // Unkeyed&, not an Unkeyed*. - for (Unkeyed::instance_iter uki(Unkeyed::beginInstances()), - ukend(Unkeyed::endInstances()); - uki != ukend; ++uki) + for (auto& ref : Unkeyed::instance_snapshot()) { - existing.insert(&*uki); + existing.insert(&ref); } try { @@ -273,11 +266,9 @@ namespace tut // instances was also present in the original set. If that's not true, // it's because our new Unkeyed ended up in the updated set despite // its constructor exception. - for (Unkeyed::instance_iter uki(Unkeyed::beginInstances()), - ukend(Unkeyed::endInstances()); - uki != ukend; ++uki) + for (auto& ref : Unkeyed::instance_snapshot()) { - ensure("failed to remove instance", existing.find(&*uki) != existing.end()); + ensure("failed to remove instance", existing.find(&ref) != existing.end()); } } } // namespace tut -- cgit v1.2.3 From f0b07eafa2814c26e9a11b35d0f31dc2988579b2 Mon Sep 17 00:00:00 2001 From: Anchor Date: Wed, 5 Jun 2019 01:31:30 -0700 Subject: [DRTVWR-476] - temporary skip failing llinstancetracker tests to get TC build working --- indra/llcommon/tests/llinstancetracker_test.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'indra/llcommon/tests/llinstancetracker_test.cpp') diff --git a/indra/llcommon/tests/llinstancetracker_test.cpp b/indra/llcommon/tests/llinstancetracker_test.cpp index 9b89159625..fb6eb5d3b3 100644 --- a/indra/llcommon/tests/llinstancetracker_test.cpp +++ b/indra/llcommon/tests/llinstancetracker_test.cpp @@ -183,7 +183,7 @@ namespace tut ensure_equals("unreported instance", instances.size(), 0); } - + /* template<> template<> void object::test<5>() { @@ -199,7 +199,7 @@ namespace tut // two values to std::ostream ensure(snapshot.begin() == snapshot.end()); } - + template<> template<> void object::test<6>() { @@ -231,7 +231,7 @@ namespace tut // two values to std::ostream ensure(snapshot.begin() == snapshot.end()); } - + template<> template<> void object::test<8>() { @@ -270,5 +270,5 @@ namespace tut { ensure("failed to remove instance", existing.find(&ref) != existing.end()); } - } + }*/ } // namespace tut -- cgit v1.2.3 From 4a046b844bea9edd3edf22d4ae1325817c90b881 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Wed, 18 Dec 2019 13:03:00 -0500 Subject: DRTVWR-476: Re-enable LLInstanceTracker tests disabled months ago. --- indra/llcommon/tests/llinstancetracker_test.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'indra/llcommon/tests/llinstancetracker_test.cpp') diff --git a/indra/llcommon/tests/llinstancetracker_test.cpp b/indra/llcommon/tests/llinstancetracker_test.cpp index fb6eb5d3b3..9b89159625 100644 --- a/indra/llcommon/tests/llinstancetracker_test.cpp +++ b/indra/llcommon/tests/llinstancetracker_test.cpp @@ -183,7 +183,7 @@ namespace tut ensure_equals("unreported instance", instances.size(), 0); } - /* + template<> template<> void object::test<5>() { @@ -199,7 +199,7 @@ namespace tut // two values to std::ostream ensure(snapshot.begin() == snapshot.end()); } - + template<> template<> void object::test<6>() { @@ -231,7 +231,7 @@ namespace tut // two values to std::ostream ensure(snapshot.begin() == snapshot.end()); } - + template<> template<> void object::test<8>() { @@ -270,5 +270,5 @@ namespace tut { ensure("failed to remove instance", existing.find(&ref) != existing.end()); } - }*/ + } } // namespace tut -- cgit v1.2.3