Core-local allocator

[folly.git] / folly / detail / CacheLocality.cpp

diff --git a/folly/detail/CacheLocality.cpp b/folly/detail/CacheLocality.cpp
index 09da2871592999375cfa38f3b29227347678da4e..d646ebe9783fb4a6cb97474fc026ff4f97b32263 100644 (file)
--- a/folly/detail/CacheLocality.cpp
+++ b/folly/detail/CacheLocality.cpp
@@ -238,5 +238,38 @@ template struct SequentialThreadId<std::atomic>;
 /////////////// AccessSpreader
 template struct AccessSpreader<std::atomic>;
 
+SimpleAllocator::SimpleAllocator(size_t allocSize, size_t sz)
+    : allocSize_{allocSize}, sz_(sz) {}
+
+SimpleAllocator::~SimpleAllocator() {
+  std::lock_guard<std::mutex> g(m_);
+  for (auto& block : blocks_) {
+    aligned_free(block);
+  }
+}
+
+void* SimpleAllocator::allocateHard() {
+  // Allocate a new slab.
+  mem_ = static_cast<uint8_t*>(aligned_malloc(allocSize_, allocSize_));
+  if (!mem_) {
+    std::__throw_bad_alloc();
+  }
+  end_ = mem_ + allocSize_;
+  blocks_.push_back(mem_);
+
+  // Install a pointer to ourselves as the allocator.
+  *reinterpret_cast<SimpleAllocator**>(mem_) = this;
+  static_assert(
+      alignof(std::max_align_t) >= sizeof(SimpleAllocator*),
+      "alignment too small");
+  mem_ += std::min(sz_, alignof(std::max_align_t));
+
+  // New allocation.
+  auto mem = mem_;
+  mem_ += sz_;
+  assert(intptr_t(mem) % 128 != 0);
+  return mem;
+}
+
 } // namespace detail
 } // namespace folly