summaryrefslogtreecommitdiff
path: root/lib/sanitizer_common/sanitizer_allocator_local_cache.h
diff options
context:
space:
mode:
Diffstat (limited to 'lib/sanitizer_common/sanitizer_allocator_local_cache.h')
-rw-r--r--lib/sanitizer_common/sanitizer_allocator_local_cache.h249
1 files changed, 249 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_allocator_local_cache.h b/lib/sanitizer_common/sanitizer_allocator_local_cache.h
new file mode 100644
index 0000000000000..e1172e0c2820b
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_allocator_local_cache.h
@@ -0,0 +1,249 @@
+//===-- sanitizer_allocator_local_cache.h -----------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Part of the Sanitizer Allocator.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_ALLOCATOR_H
+#error This file must be included inside sanitizer_allocator.h
+#endif
+
+// Objects of this type should be used as local caches for SizeClassAllocator64
+// or SizeClassAllocator32. Since the typical use of this class is to have one
+// object per thread in TLS, is has to be POD.
+template<class SizeClassAllocator>
+struct SizeClassAllocatorLocalCache
+ : SizeClassAllocator::AllocatorCache {
+};
+
+// Cache used by SizeClassAllocator64.
+template <class SizeClassAllocator>
+struct SizeClassAllocator64LocalCache {
+ typedef SizeClassAllocator Allocator;
+ static const uptr kNumClasses = SizeClassAllocator::kNumClasses;
+ typedef typename Allocator::SizeClassMapT SizeClassMap;
+ typedef typename Allocator::CompactPtrT CompactPtrT;
+
+ void Init(AllocatorGlobalStats *s) {
+ stats_.Init();
+ if (s)
+ s->Register(&stats_);
+ }
+
+ void Destroy(SizeClassAllocator *allocator, AllocatorGlobalStats *s) {
+ Drain(allocator);
+ if (s)
+ s->Unregister(&stats_);
+ }
+
+ void *Allocate(SizeClassAllocator *allocator, uptr class_id) {
+ CHECK_NE(class_id, 0UL);
+ CHECK_LT(class_id, kNumClasses);
+ stats_.Add(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
+ PerClass *c = &per_class_[class_id];
+ if (UNLIKELY(c->count == 0))
+ Refill(c, allocator, class_id);
+ CHECK_GT(c->count, 0);
+ CompactPtrT chunk = c->chunks[--c->count];
+ void *res = reinterpret_cast<void *>(allocator->CompactPtrToPointer(
+ allocator->GetRegionBeginBySizeClass(class_id), chunk));
+ return res;
+ }
+
+ void Deallocate(SizeClassAllocator *allocator, uptr class_id, void *p) {
+ CHECK_NE(class_id, 0UL);
+ CHECK_LT(class_id, kNumClasses);
+ // If the first allocator call on a new thread is a deallocation, then
+ // max_count will be zero, leading to check failure.
+ InitCache();
+ stats_.Sub(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
+ PerClass *c = &per_class_[class_id];
+ CHECK_NE(c->max_count, 0UL);
+ if (UNLIKELY(c->count == c->max_count))
+ Drain(c, allocator, class_id, c->max_count / 2);
+ CompactPtrT chunk = allocator->PointerToCompactPtr(
+ allocator->GetRegionBeginBySizeClass(class_id),
+ reinterpret_cast<uptr>(p));
+ c->chunks[c->count++] = chunk;
+ }
+
+ void Drain(SizeClassAllocator *allocator) {
+ for (uptr class_id = 0; class_id < kNumClasses; class_id++) {
+ PerClass *c = &per_class_[class_id];
+ while (c->count > 0)
+ Drain(c, allocator, class_id, c->count);
+ }
+ }
+
+ // private:
+ struct PerClass {
+ u32 count;
+ u32 max_count;
+ CompactPtrT chunks[2 * SizeClassMap::kMaxNumCachedHint];
+ };
+ PerClass per_class_[kNumClasses];
+ AllocatorStats stats_;
+
+ void InitCache() {
+ if (per_class_[1].max_count)
+ return;
+ for (uptr i = 0; i < kNumClasses; i++) {
+ PerClass *c = &per_class_[i];
+ c->max_count = 2 * SizeClassMap::MaxCachedHint(i);
+ }
+ }
+
+ NOINLINE void Refill(PerClass *c, SizeClassAllocator *allocator,
+ uptr class_id) {
+ InitCache();
+ uptr num_requested_chunks = SizeClassMap::MaxCachedHint(class_id);
+ allocator->GetFromAllocator(&stats_, class_id, c->chunks,
+ num_requested_chunks);
+ c->count = num_requested_chunks;
+ }
+
+ NOINLINE void Drain(PerClass *c, SizeClassAllocator *allocator, uptr class_id,
+ uptr count) {
+ InitCache();
+ CHECK_GE(c->count, count);
+ uptr first_idx_to_drain = c->count - count;
+ c->count -= count;
+ allocator->ReturnToAllocator(&stats_, class_id,
+ &c->chunks[first_idx_to_drain], count);
+ }
+};
+
+// Cache used by SizeClassAllocator32.
+template <class SizeClassAllocator>
+struct SizeClassAllocator32LocalCache {
+ typedef SizeClassAllocator Allocator;
+ typedef typename Allocator::TransferBatch TransferBatch;
+ static const uptr kNumClasses = SizeClassAllocator::kNumClasses;
+
+ void Init(AllocatorGlobalStats *s) {
+ stats_.Init();
+ if (s)
+ s->Register(&stats_);
+ }
+
+ void Destroy(SizeClassAllocator *allocator, AllocatorGlobalStats *s) {
+ Drain(allocator);
+ if (s)
+ s->Unregister(&stats_);
+ }
+
+ void *Allocate(SizeClassAllocator *allocator, uptr class_id) {
+ CHECK_NE(class_id, 0UL);
+ CHECK_LT(class_id, kNumClasses);
+ stats_.Add(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
+ PerClass *c = &per_class_[class_id];
+ if (UNLIKELY(c->count == 0))
+ Refill(allocator, class_id);
+ void *res = c->batch[--c->count];
+ PREFETCH(c->batch[c->count - 1]);
+ return res;
+ }
+
+ void Deallocate(SizeClassAllocator *allocator, uptr class_id, void *p) {
+ CHECK_NE(class_id, 0UL);
+ CHECK_LT(class_id, kNumClasses);
+ // If the first allocator call on a new thread is a deallocation, then
+ // max_count will be zero, leading to check failure.
+ InitCache();
+ stats_.Sub(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
+ PerClass *c = &per_class_[class_id];
+ CHECK_NE(c->max_count, 0UL);
+ if (UNLIKELY(c->count == c->max_count))
+ Drain(allocator, class_id);
+ c->batch[c->count++] = p;
+ }
+
+ void Drain(SizeClassAllocator *allocator) {
+ for (uptr class_id = 0; class_id < kNumClasses; class_id++) {
+ PerClass *c = &per_class_[class_id];
+ while (c->count > 0)
+ Drain(allocator, class_id);
+ }
+ }
+
+ // private:
+ typedef typename SizeClassAllocator::SizeClassMapT SizeClassMap;
+ struct PerClass {
+ uptr count;
+ uptr max_count;
+ void *batch[2 * TransferBatch::kMaxNumCached];
+ };
+ PerClass per_class_[kNumClasses];
+ AllocatorStats stats_;
+
+ void InitCache() {
+ if (per_class_[1].max_count)
+ return;
+ for (uptr i = 0; i < kNumClasses; i++) {
+ PerClass *c = &per_class_[i];
+ c->max_count = 2 * TransferBatch::MaxCached(i);
+ }
+ }
+
+ // TransferBatch class is declared in SizeClassAllocator.
+ // We transfer chunks between central and thread-local free lists in batches.
+ // For small size classes we allocate batches separately.
+ // For large size classes we may use one of the chunks to store the batch.
+ // sizeof(TransferBatch) must be a power of 2 for more efficient allocation.
+ static uptr SizeClassForTransferBatch(uptr class_id) {
+ if (Allocator::ClassIdToSize(class_id) <
+ TransferBatch::AllocationSizeRequiredForNElements(
+ TransferBatch::MaxCached(class_id)))
+ return SizeClassMap::ClassID(sizeof(TransferBatch));
+ return 0;
+ }
+
+ // Returns a TransferBatch suitable for class_id.
+ // For small size classes allocates the batch from the allocator.
+ // For large size classes simply returns b.
+ TransferBatch *CreateBatch(uptr class_id, SizeClassAllocator *allocator,
+ TransferBatch *b) {
+ if (uptr batch_class_id = SizeClassForTransferBatch(class_id))
+ return (TransferBatch*)Allocate(allocator, batch_class_id);
+ return b;
+ }
+
+ // Destroys TransferBatch b.
+ // For small size classes deallocates b to the allocator.
+ // Does notthing for large size classes.
+ void DestroyBatch(uptr class_id, SizeClassAllocator *allocator,
+ TransferBatch *b) {
+ if (uptr batch_class_id = SizeClassForTransferBatch(class_id))
+ Deallocate(allocator, batch_class_id, b);
+ }
+
+ NOINLINE void Refill(SizeClassAllocator *allocator, uptr class_id) {
+ InitCache();
+ PerClass *c = &per_class_[class_id];
+ TransferBatch *b = allocator->AllocateBatch(&stats_, this, class_id);
+ CHECK_GT(b->Count(), 0);
+ b->CopyToArray(c->batch);
+ c->count = b->Count();
+ DestroyBatch(class_id, allocator, b);
+ }
+
+ NOINLINE void Drain(SizeClassAllocator *allocator, uptr class_id) {
+ InitCache();
+ PerClass *c = &per_class_[class_id];
+ uptr cnt = Min(c->max_count / 2, c->count);
+ uptr first_idx_to_drain = c->count - cnt;
+ TransferBatch *b = CreateBatch(
+ class_id, allocator, (TransferBatch *)c->batch[first_idx_to_drain]);
+ b->SetFromArray(allocator->GetRegionBeginBySizeClass(class_id),
+ &c->batch[first_idx_to_drain], cnt);
+ c->count -= cnt;
+ allocator->DeallocateBatch(&stats_, class_id, b);
+ }
+};
+
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-25 17:35:43 +0000