Currently nsIThreadManager::spinEventLoopUntil doesn't monitor the shutting
down. Firefox shutting down can be blocked by a 'broken' use of
nsIThreadManager::spinEventLoopUntil.
nsIThreadManager::spinEventLoopUntilOrShutdown should be used instead.
Defining get() in the declaration of nsThreadManager implicitly sticks
an "inline" on the function, which is not what we want: inlining it
spreads around a lot of static initialization code. Providing an
out-of-line definition is much better in terms of code size.
This patch refactors the nsThread event queue to clean it up and to make it easier to restructure. The fundamental concepts are as follows:
Each nsThread will have a pointer to a refcounted SynchronizedEventQueue. A SynchronizedEQ takes care of doing the locking and condition variable work when posting and popping events. For the actual storage of events, it delegates to an AbstractEventQueue data structure. It keeps a UniquePtr to the AbstractEventQueue that it uses for storage.
Both SynchronizedEQ and AbstractEventQueue are abstract classes. There is only one concrete implementation of SynchronizedEQ in this patch, which is called ThreadEventQueue. ThreadEventQueue uses locks and condition variables to post and pop events the same way nsThread does. It also encapsulates the functionality that DOM workers need to implement their special event loops (PushEventQueue and PopEventQueue). In later Quantum DOM work, I plan to have another SynchronizedEQ implementation for the main thread, called SchedulerEventQueue. It will have special code for the cooperatively scheduling threads in Quantum DOM.
There are two concrete implementations of AbstractEventQueue in this patch: EventQueue and PrioritizedEventQueue. EventQueue replaces the old nsEventQueue. The other AbstractEventQueue implementation is PrioritizedEventQueue, which uses multiple queues for different event priorities.
The final major piece here is ThreadEventTarget, which splits some of the code for posting events out of nsThread. Eventually, my plan is for multiple cooperatively scheduled nsThreads to be able to share a ThreadEventTarget. In this patch, though, each nsThread has its own ThreadEventTarget. The class's purpose is just to collect some related code together.
One final note: I tried to avoid virtual dispatch overhead as much as possible. Calls to SynchronizedEQ methods do use virtual dispatch, since I plan to use different implementations for different threads with Quantum DOM. But all the calls to EventQueue methods should be non-virtual. Although the methods are declared virtual, all the classes used are final and the concrete classes involved should all be known through templatization.
MozReview-Commit-ID: 9Evtr9oIJvx
The bulk of this commit was generated with a script, executed at the top
level of a typical source code checkout. The only non-machine-generated
part was modifying MFBT's moz.build to reflect the new naming.
CLOSED TREE makes big refactorings like this a piece of cake.
# The main substitution.
find . -name '*.cpp' -o -name '*.cc' -o -name '*.h' -o -name '*.mm' -o -name '*.idl'| \
xargs perl -p -i -e '
s/nsRefPtr\.h/RefPtr\.h/g; # handle includes
s/nsRefPtr ?</RefPtr</g; # handle declarations and variables
'
# Handle a special friend declaration in gfx/layers/AtomicRefCountedWithFinalize.h.
perl -p -i -e 's/::nsRefPtr;/::RefPtr;/' gfx/layers/AtomicRefCountedWithFinalize.h
# Handle nsRefPtr.h itself, a couple places that define constructors
# from nsRefPtr, and code generators specially. We do this here, rather
# than indiscriminantly s/nsRefPtr/RefPtr/, because that would rename
# things like nsRefPtrHashtable.
perl -p -i -e 's/nsRefPtr/RefPtr/g' \
mfbt/nsRefPtr.h \
xpcom/glue/nsCOMPtr.h \
xpcom/base/OwningNonNull.h \
ipc/ipdl/ipdl/lower.py \
ipc/ipdl/ipdl/builtin.py \
dom/bindings/Codegen.py \
python/lldbutils/lldbutils/utils.py
# In our indiscriminate substitution above, we renamed
# nsRefPtrGetterAddRefs, the class behind getter_AddRefs. Fix that up.
find . -name '*.cpp' -o -name '*.h' -o -name '*.idl' | \
xargs perl -p -i -e 's/nsRefPtrGetterAddRefs/RefPtrGetterAddRefs/g'
if [ -d .git ]; then
git mv mfbt/nsRefPtr.h mfbt/RefPtr.h
else
hg mv mfbt/nsRefPtr.h mfbt/RefPtr.h
fi
Bug 645263, part 0: Count sync primitive ctor/dtors. r=dbaron
Bug 645263, part 1: Migrate content/media to mozilla:: sync primitives. r=doublec
Bug 645263, part 2: Migrate modules/plugin to mozilla:: sync primitives. sr=bsmedberg
Bug 645263, part 3: Migrate nsComponentManagerImpl to mozilla:: sync primitives. sr=bsmedberg
Bug 645263, part 4: Migrate everything else to mozilla:: sync primitives. r=dbaron
Bug 645263, part 5: Remove nsAutoLock.*. sr=bsmedberg
Bug 645263, part 6: Make editor test be nicer to deadlock detector. r=ehsan
Bug 645263, part 7: Disable tracemalloc backtraces for xpcshell tests. r=dbaron
Bug 646259: Fix nsCacheService to use a CondVar for notifying. r=cjones
Bug 645263, part 0: Count sync primitive ctor/dtors. r=dbaron
Bug 645263, part 1: Migrate content/media to mozilla:: sync primitives. r=doublec
Bug 645263, part 2: Migrate modules/plugin to mozilla:: sync primitives. sr=bsmedberg
Bug 645263, part 3: Migrate nsComponentManagerImpl to mozilla:: sync primitives. sr=bsmedberg
Bug 645263, part 4: Migrate everything else to mozilla:: sync primitives. r=dbaron
Bug 645263, part 5: Remove nsAutoLock.*. sr=bsmedberg
Bug 645263, part 6: Make editor test be nicer to deadlock detector. r=ehsan
Bug 645263, part 7: Disable tracemalloc backtraces for xpcshell tests. r=dbaron
Bug 646259: Fix nsCacheService to use a CondVar for notifying. r=cjones
