void
FileSystemTaskParentBase::Start()
{
AssertIsOnBackgroundThread();
mFileSystem->AssertIsOnOwningThread();
DebugOnly<nsresult> rv = DispatchToIOThread(this);
NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "DispatchToIOThread failed");
}
NS_IMETHODIMP
FileSystemTaskParentBase::Run()
{
// This method can run in 3 different threads. Here why:
// 1. if we are on the main-thread it's because the task must do something
// here. If no errors are returned we go the step 2.
// 2. We can be here directly if the task doesn't have nothing to do on the
// main-thread. We are are on the I/O thread and we call IOWork().
// 3. Both step 1 (in case of error) and step 2 end up here where return the
// value back to the PBackground thread.
if (NS_IsMainThread()) {
MOZ_ASSERT(NeedToGoToMainThread());
nsresult rv = MainThreadWork();
if (NS_WARN_IF(NS_FAILED(rv))) {
SetError(rv);
// Something when wrong. Let's go to the Background thread directly
// skipping the I/O thread step.
rv = mBackgroundEventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
}
// Next step must happen on the I/O thread.
rv = DispatchToIOThread(this);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
return NS_OK;
}
// Run I/O thread tasks
if (!IsOnBackgroundThread()) {
nsresult rv = IOWork();
if (NS_WARN_IF(NS_FAILED(rv))) {
SetError(rv);
}
// Let's go back to PBackground thread to finish the work.
rv = mBackgroundEventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
if (NS_WARN_IF(NS_FAILED(rv))) {
return rv;
}
return NS_OK;
}
// If we are here, it's because the I/O work has been done and we have to
// handle the result back via IPC.
AssertIsOnBackgroundThread();
HandleResult();
return NS_OK;
}
void
FileSystemTaskParentBase::Start()
{
AssertIsOnBackgroundThread();
mFileSystem->AssertIsOnOwningThread();
if (NeedToGoToMainThread()) {
nsresult rv = NS_DispatchToMainThread(this, NS_DISPATCH_NORMAL);
NS_WARN_IF(NS_FAILED(rv));
return;
}
nsresult rv = DispatchToIOThread(this);
NS_WARN_IF(NS_FAILED(rv));
}
