[clangd] Avoid emitting Queued status when we are able to acquire the Barrier.
Reviewers: ilya-biryukov
Subscribers: javed.absar, ioeric, MaskRay, jkorous, arphaman, kadircet, cfe-commits
Differential Revision: https://reviews.llvm.org/D55359
git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@349032 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clangd/TUScheduler.cpp b/clangd/TUScheduler.cpp
index b53fe3f..764bc26 100644
--- a/clangd/TUScheduler.cpp
+++ b/clangd/TUScheduler.cpp
@@ -634,9 +634,11 @@
} // unlock Mutex
{
- // FIXME: only emit this status when the Barrier couldn't be acquired.
- emitTUStatus({TUAction::Queued, Req.Name});
- std::lock_guard<Semaphore> BarrierLock(Barrier);
+ std::unique_lock<Semaphore> Lock(Barrier, std::try_to_lock);
+ if (!Lock.owns_lock()) {
+ emitTUStatus({TUAction::Queued, Req.Name});
+ Lock.lock();
+ }
WithContext Guard(std::move(Req.Ctx));
trace::Span Tracer(Req.Name);
emitTUStatus({TUAction::RunningAction, Req.Name});
diff --git a/clangd/Threading.cpp b/clangd/Threading.cpp
index b427ce3..cfb5e02 100644
--- a/clangd/Threading.cpp
+++ b/clangd/Threading.cpp
@@ -28,6 +28,15 @@
Semaphore::Semaphore(std::size_t MaxLocks) : FreeSlots(MaxLocks) {}
+bool Semaphore::try_lock() {
+ std::unique_lock<std::mutex> Lock(Mutex);
+ if (FreeSlots > 0) {
+ --FreeSlots;
+ return true;
+ }
+ return false;
+}
+
void Semaphore::lock() {
trace::Span Span("WaitForFreeSemaphoreSlot");
// trace::Span can also acquire locks in ctor and dtor, we make sure it
diff --git a/clangd/Threading.h b/clangd/Threading.h
index 1b34831..628dd55 100644
--- a/clangd/Threading.h
+++ b/clangd/Threading.h
@@ -42,6 +42,7 @@
public:
Semaphore(std::size_t MaxLocks);
+ bool try_lock();
void lock();
void unlock();
diff --git a/unittests/clangd/TUSchedulerTests.cpp b/unittests/clangd/TUSchedulerTests.cpp
index 674ab19..b26a7dd 100644
--- a/unittests/clangd/TUSchedulerTests.cpp
+++ b/unittests/clangd/TUSchedulerTests.cpp
@@ -698,13 +698,11 @@
EXPECT_THAT(CaptureTUStatus.AllStatus,
ElementsAre(
// Statuses of "Update" action.
- TUState(TUAction::Queued, "Update"),
TUState(TUAction::RunningAction, "Update"),
TUState(TUAction::BuildingPreamble, "Update"),
TUState(TUAction::BuildingFile, "Update"),
// Statuses of "Definitions" action
- TUState(TUAction::Queued, "Definitions"),
TUState(TUAction::RunningAction, "Definitions"),
TUState(TUAction::Idle, /*No action*/ "")));
}