bool blockUntilIdle(Deadline Timeout) const;
std::shared_ptr<const PreambleData> getPossiblyStalePreamble() const;
+ /// Wait for the first build of preamble to finish. Preamble itself can be
+ /// accessed via getPossibleStalePreamble(). Note that this function will
+ /// return after an unsuccessful build of the preamble too, i.e. result of
+ /// getPossiblyStalePreamble() can be null even after this function returns.
+ void waitForFirstPreamble() const;
+
std::size_t getUsedBytes() const;
bool isASTCached() const;
/// Guards members used by both TUScheduler and the worker thread.
mutable std::mutex Mutex;
std::shared_ptr<const PreambleData> LastBuiltPreamble; /* GUARDED_BY(Mutex) */
+ /// Becomes ready when the first preamble build finishes.
+ Notification PreambleWasBuilt;
/// Set to true to signal run() to finish processing.
bool Done; /* GUARDED_BY(Mutex) */
std::deque<Request> Requests; /* GUARDED_BY(Mutex) */
buildCompilerInvocation(Inputs);
if (!Invocation) {
log("Could not build CompilerInvocation for file " + FileName);
+ // Make sure anyone waiting for the preamble gets notified it could not
+ // be built.
+ PreambleWasBuilt.notify();
return;
}
if (NewPreamble)
LastBuiltPreamble = NewPreamble;
}
+ PreambleWasBuilt.notify();
+
// Build the AST for diagnostics.
llvm::Optional<ParsedAST> AST =
buildAST(FileName, std::move(Invocation), Inputs, NewPreamble, PCHs);
return LastBuiltPreamble;
}
+void ASTWorker::waitForFirstPreamble() const {
+ PreambleWasBuilt.wait();
+}
+
std::size_t ASTWorker::getUsedBytes() const {
// Note that we don't report the size of ASTs currently used for processing
// the in-flight requests. We used this information for debugging purposes
std::string Contents,
tooling::CompileCommand Command, Context Ctx,
decltype(Action) Action) mutable {
+ // We don't want to be running preamble actions before the preamble was
+ // built for the first time. This avoids extra work of processing the
+ // preamble headers in parallel multiple times.
+ Worker->waitForFirstPreamble();
+
std::lock_guard<Semaphore> BarrierLock(Barrier);
WithContext Guard(std::move(Ctx));
trace::Span Tracer(Name);
/// - validate that the preamble is still valid, and only use it in this case
/// - accept that preamble contents may be outdated, and try to avoid reading
/// source code from headers.
+ /// If there's no preamble yet (because the file was just opened), we'll wait
+ /// for it to build. The preamble may still be null if it fails to build or is
+ /// empty.
/// If an error occurs during processing, it is forwarded to the \p Action
/// callback.
void runWithPreamble(llvm::StringRef Name, PathRef File,
namespace clangd {
using ::testing::_;
+using ::testing::Each;
using ::testing::AnyOf;
using ::testing::Pair;
using ::testing::Pointee;
UnorderedElementsAre(Foo, AnyOf(Bar, Baz)));
}
+TEST_F(TUSchedulerTests, RunWaitsForPreamble) {
+ // Testing strategy: we update the file and schedule a few preamble reads at
+ // the same time. All reads should get the same non-null preamble.
+ TUScheduler S(
+ /*AsyncThreadsCount=*/4, /*StorePreambleInMemory=*/true,
+ PreambleParsedCallback(),
+ /*UpdateDebounce=*/std::chrono::steady_clock::duration::zero(),
+ ASTRetentionPolicy());
+ auto Foo = testPath("foo.cpp");
+ auto NonEmptyPreamble = R"cpp(
+ #define FOO 1
+ #define BAR 2
+
+ int main() {}
+ )cpp";
+ constexpr int ReadsToSchedule = 10;
+ std::mutex PreamblesMut;
+ std::vector<const void *> Preambles(ReadsToSchedule, nullptr);
+ S.update(Foo, getInputs(Foo, NonEmptyPreamble), WantDiagnostics::Auto,
+ [](std::vector<Diag>) {});
+ for (int I = 0; I < ReadsToSchedule; ++I) {
+ S.runWithPreamble(
+ "test", Foo,
+ [I, &PreamblesMut, &Preambles](llvm::Expected<InputsAndPreamble> IP) {
+ std::lock_guard<std::mutex> Lock(PreamblesMut);
+ Preambles[I] = cantFail(std::move(IP)).Preamble;
+ });
+ }
+ ASSERT_TRUE(S.blockUntilIdle(timeoutSeconds(10)));
+ // Check all actions got the same non-null preamble.
+ std::lock_guard<std::mutex> Lock(PreamblesMut);
+ ASSERT_NE(Preambles[0], nullptr);
+ ASSERT_THAT(Preambles, Each(Preambles[0]));
+}
+
} // namespace clangd
} // namespace clang