ProcessThreadImpl - hold the lock while checking thread_ and calling ProcessThreadAttached().
This is needed since DeRegisterModule is currently being called on arbitrary threads.
BUG=4508
R=perkj@webrtc.org
Review URL: https://webrtc-codereview.appspot.com/48829004
Cr-Commit-Position: refs/heads/master@{#8924}
diff --git a/webrtc/modules/utility/source/process_thread_impl.cc b/webrtc/modules/utility/source/process_thread_impl.cc
index 6ebf4a2..ca319ad 100644
--- a/webrtc/modules/utility/source/process_thread_impl.cc
+++ b/webrtc/modules/utility/source/process_thread_impl.cc
@@ -94,21 +94,22 @@
wake_up_->Set();
CHECK(thread_->Stop());
- thread_.reset();
stop_ = false;
// TODO(tommi): Since DeRegisterModule is currently being called from
// different threads in some cases (ChannelOwner), we need to lock access to
// the modules_ collection even on the controller thread.
+ // Since DeRegisterModule also checks thread_, we also need to hold the
+ // lock for the .reset() operation.
// Once we've cleaned up those places, we can remove this lock.
rtc::CritScope lock(&lock_);
+ thread_.reset();
for (ModuleCallback& m : modules_)
m.module->ProcessThreadAttached(nullptr);
}
void ProcessThreadImpl::WakeUp(Module* module) {
// Allowed to be called on any thread.
- // TODO(tommi): Disallow this ^^^
{
rtc::CritScope lock(&lock_);
for (ModuleCallback& m : modules_) {
@@ -121,7 +122,6 @@
void ProcessThreadImpl::PostTask(rtc::scoped_ptr<ProcessTask> task) {
// Allowed to be called on any thread.
- // TODO(tommi): Disallow this ^^^
{
rtc::CritScope lock(&lock_);
queue_.push(task.release());
@@ -131,6 +131,7 @@
void ProcessThreadImpl::RegisterModule(Module* module) {
// Allowed to be called on any thread.
+ // TODO(tommi): Disallow this ^^^
DCHECK(module);
#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
@@ -161,17 +162,26 @@
void ProcessThreadImpl::DeRegisterModule(Module* module) {
// Allowed to be called on any thread.
+ // TODO(tommi): Disallow this ^^^
DCHECK(module);
+
{
rtc::CritScope lock(&lock_);
modules_.remove_if([&module](const ModuleCallback& m) {
return m.module == module;
});
- }
- // Notify the module that it's been detached, while not holding the lock.
- if (thread_.get())
- module->ProcessThreadAttached(nullptr);
+ // TODO(tommi): we currently need to hold the lock while calling out to
+ // ProcessThreadAttached. This is to make sure that the thread hasn't been
+ // destroyed while we attach the module. Once we can make sure
+ // DeRegisterModule isn't being called on arbitrary threads, we can move the
+ // |if (thread_.get())| check and ProcessThreadAttached() call outside the
+ // lock scope.
+
+ // Notify the module that it's been detached.
+ if (thread_.get())
+ module->ProcessThreadAttached(nullptr);
+ }
}
// static