pw_allocator: Add dlmalloc-style allocator

In order to allow for dlmalloc-style deferral of deallocation, some changes to buckets were needed. Additionally, the TLSF allocator has been refactored slightly in order to make it and this allocator structurally similar. Change-Id: I37cd38c8412efd6002224bf4b1306105d3ffa35e Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/234717 Presubmit-Verified: CQ Bot Account <[email protected]> Lint: Lint 🤖 <[email protected]> Reviewed-by: Alexei Frolov <[email protected]> Reviewed-by: Wyatt Hepler <[email protected]> Commit-Queue: Aaron Green <[email protected]>
google · Feb 22, 2025 · 7eb28ce · 7eb28ce
1 parent b1a5820
commit 7eb28ce
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Showing 20 changed files with 775 additions and 104 deletions.
diff --git a/docs/BUILD.gn b/docs/BUILD.gn
@@ -194,6 +194,7 @@ _doxygen_input_files = [  # keep-sorted: start
   "$dir_pw_allocator/public/pw_allocator/chunk_pool.h",
   "$dir_pw_allocator/public/pw_allocator/config.h",
   "$dir_pw_allocator/public/pw_allocator/deallocator.h",
+  "$dir_pw_allocator/public/pw_allocator/dl_allocator.h",
   "$dir_pw_allocator/public/pw_allocator/fallback_allocator.h",
   "$dir_pw_allocator/public/pw_allocator/first_fit.h",
   "$dir_pw_allocator/public/pw_allocator/fragmentation.h",

diff --git a/pw_allocator/BUILD.bazel b/pw_allocator/BUILD.bazel
@@ -239,6 +239,20 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "dl_allocator",
+    hdrs = ["public/pw_allocator/dl_allocator.h"],
+    strip_include_prefix = "public",
+    deps = [
+        ":block_allocator",
+        ":config",
+        "//pw_allocator/block:detailed_block",
+        "//pw_allocator/bucket:fast_sorted",
+        "//pw_allocator/bucket:unordered",
+        "//third_party/fuchsia:stdcompat",
+    ],
+)
+
 # TODO(b/376730645): Remove deprecated interfaces.
 cc_library(
     name = "dual_first_fit_block_allocator",
@@ -606,6 +620,16 @@ pw_cc_test(
     ],
 )
 
+pw_cc_test(
+    name = "dl_allocator_test",
+    srcs = ["dl_allocator_test.cc"],
+    deps = [
+        ":block_allocator_testing",
+        ":dl_allocator",
+        "//pw_unit_test",
+    ],
+)
+
 pw_cc_test(
     name = "fallback_allocator_test",
     srcs = ["fallback_allocator_test.cc"],
@@ -793,6 +817,7 @@ filegroup(
         "public/pw_allocator/chunk_pool.h",
         "public/pw_allocator/config.h",
         "public/pw_allocator/deallocator.h",
+        "public/pw_allocator/dl_allocator.h",
         "public/pw_allocator/fallback_allocator.h",
         "public/pw_allocator/first_fit.h",
         "public/pw_allocator/fragmentation.h",
@@ -845,6 +870,13 @@ pw_size_diff(
     target = "//pw_allocator/size_report:bucket_allocator",
 )
 
+pw_size_diff(
+    name = "dl_allocator_size_report",
+    base = "//pw_allocator/size_report:detailed_block",
+    label = "DlAllocator",
+    target = "//pw_allocator/size_report:dl_allocator",
+)
+
 pw_size_diff(
     name = "first_fit_size_report",
     base = "//pw_allocator/size_report:detailed_block",
@@ -871,6 +903,7 @@ pw_size_table(
     reports = [
         ":best_fit_size_report",
         ":bucket_allocator_size_report",
+        ":dl_allocator_size_report",
         ":first_fit_size_report",
         ":tlsf_allocator_size_report",
         ":worst_fit_size_report",

diff --git a/pw_allocator/BUILD.gn b/pw_allocator/BUILD.gn
@@ -232,6 +232,19 @@ pw_source_set("deallocator") {
   ]
 }
 
+pw_source_set("dl_allocator") {
+  public_configs = [ ":public_include_path" ]
+  public = [ "public/pw_allocator/dl_allocator.h" ]
+  public_deps = [
+    ":block_allocator",
+    ":config",
+    "$dir_pw_third_party/fuchsia:stdcompat",
+    "block:detailed_block",
+    "bucket:fast_sorted",
+    "bucket:unordered",
+  ]
+}
+
 # TODO(b/376730645): Remove deprecated interfaces.
 pw_source_set("dual_first_fit_block_allocator") {
   public_configs = [ ":public_include_path" ]
@@ -559,6 +572,14 @@ pw_test("chunk_pool_test") {
   sources = [ "chunk_pool_test.cc" ]
 }
 
+pw_test("dl_allocator_test") {
+  deps = [
+    ":block_allocator_testing",
+    ":dl_allocator",
+  ]
+  sources = [ "dl_allocator_test.cc" ]
+}
+
 pw_test("fallback_allocator_test") {
   deps = [
     ":fallback_allocator",
@@ -721,6 +742,7 @@ pw_test_group("tests") {
     ":buffer_test",
     ":bump_allocator_test",
     ":chunk_pool_test",
+    ":dl_allocator_test",
     ":fallback_allocator_test",
     ":first_fit_test",
     ":fragmentation_test",
@@ -844,6 +866,11 @@ pw_size_diff("block_allocators_size_report") {
       base = "size_report:detailed_block"
       label = "BucketAllocator"
     },
+    {
+      target = "size_report:dl_allocator"
+      base = "size_report:detailed_block"
+      label = "DlAllocator"
+    },
     {
       target = "size_report:first_fit"
       base = "size_report:detailed_block"

diff --git a/pw_allocator/CMakeLists.txt b/pw_allocator/CMakeLists.txt
@@ -219,7 +219,21 @@ pw_add_library(pw_allocator.deallocator STATIC
     pw_status
 )
 
-# TODO(b/376730645): Remove deprecated interfaces.
+pw_add_library(pw_allocator.dl_allocator INTERFACE
+  HEADERS
+    public/pw_allocator/dl_allocator.h
+  PUBLIC_INCLUDES
+    public
+  PUBLIC_DEPS
+    pw_allocator.block_allocator
+    pw_allocator.block.detailed_block
+    pw_allocator.bucket.fast_sorted
+    pw_allocator.bucket.unordered
+    pw_allocator.config
+    pw_third_party.fuchsia.stdcompat
+)
+
+  # TODO(b/376730645): Remove deprecated interfaces.
 pw_add_library(pw_allocator.dual_first_fit_block_allocator INTERFACE
   HEADERS
     public/pw_allocator/dual_first_fit_block_allocator.h
@@ -616,6 +630,17 @@ pw_add_test(pw_allocator.chunk_pool_test
     pw_allocator
 )
 
+pw_add_test(pw_allocator.dl_allocator_test
+  SOURCES
+    dl_allocator_test.cc
+  PRIVATE_DEPS
+    pw_allocator.block_allocator_testing
+    pw_allocator.dl_allocator
+  GROUPS
+    modules
+    pw_allocator
+)
+
 pw_add_test(pw_allocator.fallback_allocator_test
   PRIVATE_DEPS
     pw_allocator.testing
@@ -753,7 +778,7 @@ pw_add_test(pw_allocator.synchronized_allocator_test
 
 pw_add_test(pw_allocator.tlsf_allocator_test
   SOURCES
-  tlsf_allocator_test.cc
+    tlsf_allocator_test.cc
   PRIVATE_DEPS
     pw_allocator.block_allocator_testing
     pw_allocator.tlsf_allocator

diff --git a/pw_allocator/api.rst b/pw_allocator/api.rst
@@ -145,6 +145,13 @@ BucketAllocator
 .. doxygenclass:: pw::allocator::BucketAllocator
    :members:
 
+.. _module-pw_allocator-api-dl_allocator:
+
+DlAllocator
+-------------
+.. doxygenclass:: pw::allocator::DlAllocator
+   :members:
+
 .. _module-pw_allocator-api-first_fit_allocator:
 
 FirstFitAllocator

diff --git a/pw_allocator/block/public/pw_allocator/block/testing.h b/pw_allocator/block/public/pw_allocator/block/testing.h
@@ -94,7 +94,7 @@ struct Preallocation {
   static constexpr size_t kSizeRemaining = std::numeric_limits<size_t>::max();
 };
 
-template <typename BlockType>
+template <typename BlockType, size_t kBufferSize = kDefaultCapacity>
 class BlockTestUtilities {
  public:
   BlockTestUtilities() : buffer_(), bytes_(buffer_.as_span()) {}
@@ -131,35 +131,35 @@ class BlockTestUtilities {
   size_t GetFirstAlignedOffset(Layout layout);
 
  private:
-  AlignedBuffer<kDefaultCapacity, BlockType::kAlignment> buffer_;
+  BlockAlignedBuffer<BlockType, kBufferSize> buffer_;
   ByteSpan bytes_;
 };
 
 //  Template method implementations.
 
-template <typename BlockType>
-constexpr void BlockTestUtilities<BlockType>::TrimBytes(size_t offset,
-                                                        size_t length) {
+template <typename BlockType, size_t kBufferSize>
+constexpr void BlockTestUtilities<BlockType, kBufferSize>::TrimBytes(
+    size_t offset, size_t length) {
   bytes_ = bytes_.subspan(offset, length);
 }
 
-template <typename BlockType>
-void BlockTestUtilities<BlockType>::TrimAligned(size_t extra) {
+template <typename BlockType, size_t kBufferSize>
+void BlockTestUtilities<BlockType, kBufferSize>::TrimAligned(size_t extra) {
   size_t offset =
       GetAlignedOffsetAfter(bytes_.data(), kAlign, BlockType::kBlockOverhead) +
       extra;
   bytes_ = bytes_.subspan(offset);
 }
 
-template <typename BlockType>
-constexpr size_t BlockTestUtilities<BlockType>::GetOuterSize(
+template <typename BlockType, size_t kBufferSize>
+constexpr size_t BlockTestUtilities<BlockType, kBufferSize>::GetOuterSize(
     size_t min_inner_size) {
   return BlockType::kBlockOverhead +
          AlignUp(min_inner_size, BlockType::kAlignment);
 }
 
-template <typename BlockType>
-BlockType* BlockTestUtilities<BlockType>::Preallocate(
+template <typename BlockType, size_t kBufferSize>
+BlockType* BlockTestUtilities<BlockType, kBufferSize>::Preallocate(
     std::initializer_list<Preallocation> preallocs) {
   static_assert(is_allocatable_v<BlockType>);
 
@@ -218,8 +218,9 @@ BlockType* BlockTestUtilities<BlockType>::Preallocate(
   return next;
 }
 
-template <typename BlockType>
-size_t BlockTestUtilities<BlockType>::GetFirstAlignedOffset(Layout layout) {
+template <typename BlockType, size_t kBufferSize>
+size_t BlockTestUtilities<BlockType, kBufferSize>::GetFirstAlignedOffset(
+    Layout layout) {
   size_t min_block = BlockType::kBlockOverhead + 1;
   size_t offset = GetAlignedOffsetAfter(bytes().data(),
                                         layout.alignment(),

diff --git a/pw_allocator/block_allocator_testing.cc b/pw_allocator/block_allocator_testing.cc
@@ -49,11 +49,11 @@ void BlockAllocatorTestBase::UseMemory(void* ptr, size_t size) {
 
 // Unit tests.
 
-void BlockAllocatorTestBase::GetCapacity() {
+void BlockAllocatorTestBase::GetCapacity(size_t expected) {
   Allocator& allocator = GetGenericAllocator();
   StatusWithSize capacity = allocator.GetCapacity();
   EXPECT_EQ(capacity.status(), OkStatus());
-  EXPECT_EQ(capacity.size(), kCapacity);
+  EXPECT_EQ(capacity.size(), expected);
 }
 
 void BlockAllocatorTestBase::AllocateLarge() {

diff --git a/pw_allocator/bucket/public/pw_allocator/bucket/base.h b/pw_allocator/bucket/public/pw_allocator/bucket/base.h
@@ -98,7 +98,7 @@ class BucketBase {
   /// null. Exactly which block is returned depends on the specific bucket
   /// implementation.
   [[nodiscard]] BlockType* RemoveAny() {
-    return derived()->DoRemoveCompatible(Layout(1, 1));
+    return empty() ? nullptr : derived()->DoRemoveAny();
   }
 
   /// If the given `block` is in this bucket, removes it and returns true;

diff --git a/pw_allocator/bucket/public/pw_allocator/bucket/fast_sorted.h b/pw_allocator/bucket/public/pw_allocator/bucket/fast_sorted.h
@@ -87,6 +87,14 @@ class FastSortedBucket
     items_.insert(*item);
   }
 
+  /// @copydoc `BucketBase::RemoveAny`
+  BlockType* DoRemoveAny() {
+    auto iter = items_.begin();
+    FastSortedItem<BlockType>& item = *iter;
+    items_.erase(iter);
+    return BlockType::FromUsableSpace(&item);
+  }
+
   /// @copydoc `BucketBase::Remove`
   bool DoRemove(BlockType& block) {
     FastSortedItem<BlockType>& item_to_remove = Base::GetItemFrom(block);
@@ -146,6 +154,14 @@ class ReverseFastSortedBucket
   /// @copydoc `BucketBase::Add`
   void DoAdd(BlockType& block) { impl_.DoAdd(block); }
 
+  /// @copydoc `BucketBase::RemoveAny`
+  BlockType* DoRemoveAny() {
+    auto iter = items_.begin();
+    FastSortedItem<BlockType>& item = *iter;
+    items_.erase(iter);
+    return BlockType::FromUsableSpace(&item);
+  }
+
   /// @copydoc `BucketBase::Remove`
   bool DoRemove(BlockType& block) { return impl_.DoRemove(block); }
 

diff --git a/pw_allocator/bucket/public/pw_allocator/bucket/sequenced.h b/pw_allocator/bucket/public/pw_allocator/bucket/sequenced.h
@@ -87,6 +87,13 @@ class SequencedBucket : public internal::BucketBase<SequencedBucket<BlockType>,
     items_.insert(iter, *item_to_add);
   }
 
+  /// @copydoc `BucketBase::RemoveAny`
+  BlockType* DoRemoveAny() {
+    SequencedItem& item = items_.front();
+    items_.pop_front();
+    return BlockType::FromUsableSpace(&item);
+  }
+
   /// @copydoc `BucketBase::Remove`
   bool DoRemove(BlockType& block) {
     SequencedItem& item_to_remove = Base::GetItemFrom(block);

diff --git a/pw_allocator/bucket/public/pw_allocator/bucket/sorted.h b/pw_allocator/bucket/public/pw_allocator/bucket/sorted.h
@@ -61,6 +61,13 @@ class SortedBucketBase : public BucketBase<Derived, BlockType, SortedItem> {
     items_.insert_after(prev, *item_to_add);
   }
 
+  /// @copydoc `BucketBase::RemoveAny`
+  BlockType* DoRemoveAny() {
+    SortedItem& item = items_.front();
+    items_.pop_front();
+    return BlockType::FromUsableSpace(&item);
+  }
+
   /// @copydoc `BucketBase::Remove`
   bool DoRemove(BlockType& block) {
     return items_.remove(Base::GetItemFrom(block));

diff --git a/pw_allocator/bucket/public/pw_allocator/bucket/unordered.h b/pw_allocator/bucket/public/pw_allocator/bucket/unordered.h
@@ -55,6 +55,13 @@ class UnorderedBucket : public internal::BucketBase<UnorderedBucket<BlockType>,
     items_.push_front(*item);
   }
 
+  /// @copydoc `BucketBase::RemoveAny`
+  BlockType* DoRemoveAny() {
+    UnorderedItem& item = items_.front();
+    items_.pop_front();
+    return BlockType::FromUsableSpace(&item);
+  }
+
   /// @copydoc `BucketBase::Remove`
   bool DoRemove(BlockType& block) {
     return items_.remove(Base::GetItemFrom(block));