Author: Jacques Pienaar Date: 2024-05-24T07:45:37-07:00 New Revision: 50cb2160464ef916146c199ab8c9fe3ea9f054d6
URL: https://github.com/llvm/llvm-project/commit/50cb2160464ef916146c199ab8c9fe3ea9f054d6 DIFF: https://github.com/llvm/llvm-project/commit/50cb2160464ef916146c199ab8c9fe3ea9f054d6.diff LOG: Revert "[mlir] Optimize ThreadLocalCache by removing atomic bottleneck (#93270)" This reverts commit 1b803fe53dda11ca63f008f5ab8e206f3954ce48. Added: Modified: mlir/include/mlir/Support/ThreadLocalCache.h Removed: ################################################################################ diff --git a/mlir/include/mlir/Support/ThreadLocalCache.h b/mlir/include/mlir/Support/ThreadLocalCache.h index d19257bf6e25e..1be94ca14bcfa 100644 --- a/mlir/include/mlir/Support/ThreadLocalCache.h +++ b/mlir/include/mlir/Support/ThreadLocalCache.h @@ -58,12 +58,11 @@ class ThreadLocalCache { /// ValueT. We use a weak reference here so that the object can be destroyed /// without needing to lock access to the cache itself. struct CacheType - : public llvm::SmallDenseMap<PerInstanceState *, - std::pair<std::weak_ptr<ValueT>, ValueT *>> { + : public llvm::SmallDenseMap<PerInstanceState *, std::weak_ptr<ValueT>> { ~CacheType() { // Remove the values of this cache that haven't already expired. for (auto &it : *this) - if (std::shared_ptr<ValueT> value = it.second.first.lock()) + if (std::shared_ptr<ValueT> value = it.second.lock()) it.first->remove(value.get()); } @@ -72,7 +71,7 @@ class ThreadLocalCache { void clearExpiredEntries() { for (auto it = this->begin(), e = this->end(); it != e;) { auto curIt = it++; - if (curIt->second.first.expired()) + if (curIt->second.expired()) this->erase(curIt); } } @@ -89,27 +88,22 @@ class ThreadLocalCache { ValueT &get() { // Check for an already existing instance for this thread. CacheType &staticCache = getStaticCache(); - std::pair<std::weak_ptr<ValueT>, ValueT *> &threadInstance = - staticCache[perInstanceState.get()]; - if (ValueT *value = threadInstance.second) + std::weak_ptr<ValueT> &threadInstance = staticCache[perInstanceState.get()]; + if (std::shared_ptr<ValueT> value = threadInstance.lock()) return *value; // Otherwise, create a new instance for this thread. - { - llvm::sys::SmartScopedLock<true> threadInstanceLock( - perInstanceState->instanceMutex); - threadInstance.second = - perInstanceState->instances.emplace_back(std::make_unique<ValueT>()) - .get(); - } - threadInstance.first = - std::shared_ptr<ValueT>(perInstanceState, threadInstance.second); + llvm::sys::SmartScopedLock<true> threadInstanceLock( + perInstanceState->instanceMutex); + perInstanceState->instances.push_back(std::make_unique<ValueT>()); + ValueT *instance = perInstanceState->instances.back().get(); + threadInstance = std::shared_ptr<ValueT>(perInstanceState, instance); // Before returning the new instance, take the chance to clear out any used // entries in the static map. The cache is only cleared within the same // thread to remove the need to lock the cache itself. staticCache.clearExpiredEntries(); - return *threadInstance.second; + return *instance; } ValueT &operator*() { return get(); } ValueT *operator->() { return &get(); } _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
