Author: Sam McCall Date: 2020-06-25T00:18:53+02:00 New Revision: 3c5745cb1f3c501e551a8fa63b8f1d564c35016d
URL: https://github.com/llvm/llvm-project/commit/3c5745cb1f3c501e551a8fa63b8f1d564c35016d DIFF: https://github.com/llvm/llvm-project/commit/3c5745cb1f3c501e551a8fa63b8f1d564c35016d.diff LOG: [clangd] Make background index thread count calculation clearer Summary: This confusion was inadvertently introduced in a change to the heavyweight_hardware_concurrency API: 8404aeb56a73ab24f9b295111de3b37a37f0b841 - don't indirect through the rebuilder policy when building the thread pool - document that rebuilder thresholds are exposed for testing only - don't use 0 as a sentinel value for "all threads", as we use it as a sentinel value for "synchronous" (though unsupported for BackgroundIndex) - rather than pick some new sentinel value, just always use 4 threads for tests Reviewers: kadircet, aganea Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, usaxena95, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D82352 Added: Modified: clang-tools-extra/clangd/index/Background.cpp clang-tools-extra/clangd/index/Background.h clang-tools-extra/clangd/index/BackgroundRebuild.h Removed: ################################################################################ diff --git a/clang-tools-extra/clangd/index/Background.cpp b/clang-tools-extra/clangd/index/Background.cpp index 3e68d9e9c62a..5aae49345b65 100644 --- a/clang-tools-extra/clangd/index/Background.cpp +++ b/clang-tools-extra/clangd/index/Background.cpp @@ -103,10 +103,9 @@ BackgroundIndex::BackgroundIndex( CDB.watch([&](const std::vector<std::string> &ChangedFiles) { enqueue(ChangedFiles); })) { - assert(Rebuilder.TUsBeforeFirstBuild > 0 && - "Thread pool size can't be zero."); + assert(ThreadPoolSize > 0 && "Thread pool size can't be zero."); assert(this->IndexStorageFactory && "Storage factory can not be null!"); - for (unsigned I = 0; I < Rebuilder.TUsBeforeFirstBuild; ++I) { + for (unsigned I = 0; I < ThreadPoolSize; ++I) { ThreadPool.runAsync("background-worker-" + llvm::Twine(I + 1), [this] { WithContext Ctx(this->BackgroundContext.clone()); Queue.work([&] { Rebuilder.idle(); }); diff --git a/clang-tools-extra/clangd/index/Background.h b/clang-tools-extra/clangd/index/Background.h index 9ae63828cc6b..9e6b9724af24 100644 --- a/clang-tools-extra/clangd/index/Background.h +++ b/clang-tools-extra/clangd/index/Background.h @@ -135,7 +135,9 @@ class BackgroundIndex : public SwapIndex { Context BackgroundContext, const ThreadsafeFS &, const GlobalCompilationDatabase &CDB, BackgroundIndexStorage::Factory IndexStorageFactory, - size_t ThreadPoolSize = 0, // 0 = use all hardware threads + // Arbitrary value to ensure some concurrency in tests. + // In production an explicit value is passed. + size_t ThreadPoolSize = 4, std::function<void(BackgroundQueue::Stats)> OnProgress = nullptr); ~BackgroundIndex(); // Blocks while the current task finishes. diff --git a/clang-tools-extra/clangd/index/BackgroundRebuild.h b/clang-tools-extra/clangd/index/BackgroundRebuild.h index 295f705c98e8..bc68536c847f 100644 --- a/clang-tools-extra/clangd/index/BackgroundRebuild.h +++ b/clang-tools-extra/clangd/index/BackgroundRebuild.h @@ -49,9 +49,7 @@ class BackgroundIndexRebuilder { public: BackgroundIndexRebuilder(SwapIndex *Target, FileSymbols *Source, unsigned Threads) - : TUsBeforeFirstBuild(llvm::heavyweight_hardware_concurrency(Threads) - .compute_thread_count()), - Target(Target), Source(Source) {} + : TUsBeforeFirstBuild(Threads), Target(Target), Source(Source) {} // Called to indicate a TU has been indexed. // May rebuild, if enough TUs have been indexed. @@ -72,7 +70,7 @@ class BackgroundIndexRebuilder { // Ensures we won't start any more rebuilds. void shutdown(); - // Thresholds for rebuilding as TUs get indexed. + // Thresholds for rebuilding as TUs get indexed. Exposed for testing. const unsigned TUsBeforeFirstBuild; // Typically one per worker thread. const unsigned TUsBeforeRebuild = 100; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
