1 files changed, 69 insertions, 0 deletions
diff --git a/src/common/allocator.h b/src/common/allocator.h
new file mode 100644
index 000000000..b28572faa
--- /dev/null
+++ b/src/common/allocator.h
@@ -0,0 +1,69 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_COMMON_ALLOCATOR_H
+#define CEPH_COMMON_ALLOCATOR_H
+
+#include "acconfig.h"
+
+#ifdef LIBTCMALLOC_MISSING_ALIGNED_ALLOC
+#include <malloc.h>
+#include <new>
+#endif
+#include <memory>
+
+namespace ceph {
+
+#ifdef LIBTCMALLOC_MISSING_ALIGNED_ALLOC
+
+// If libtcmalloc is missing 'aligned_alloc', provide a new allocator class that
+// uses memalign which is what newer versions of tcmalloc do internally. C++17
+// will automatically use 'operator new(size_t, align_val_t)' for aligned
+// structures, which will invoke the missing 'aligned_alloc' tcmalloc function.
+// This method was added to tcmalloc (gperftools) in commit d406f228 after
+// the 2.6.1 release was tagged.
+template <typename T>
+struct allocator : public std::allocator<T> {
+  using pointer = typename std::allocator<T>::pointer;
+  using size_type = typename std::allocator<T>::size_type;
+
+  template<class U>
+  struct rebind {
+    typedef allocator<U> other;
+  };
+
+  allocator() noexcept {
+  }
+
+  allocator(const allocator& other) noexcept : std::allocator<T>(other) {
+  }
+
+  template <class U>
+  allocator(const allocator<U>& other) noexcept : std::allocator<T>(other) {
+  }
+
+  pointer allocate(size_type n, const void* hint = nullptr) {
+    if (n > this->max_size()) {
+      throw std::bad_alloc();
+    }
+
+    if (alignof(T) > __STDCPP_DEFAULT_NEW_ALIGNMENT__) {
+      return static_cast<T*>(memalign(alignof(T), n * sizeof(T)));
+    }
+    return std::allocator<T>::allocate(n, hint);
+  }
+};
+
+#else  // LIBTCMALLOC_MISSING_ALIGNED_ALLOC
+
+// re-use the full std::allocator implementation if tcmalloc is functional
+
+template <typename T>
+using allocator = std::allocator<T>;
+
+#endif // LIBTCMALLOC_MISSING_ALIGNED_ALLOC
+
+} // namespace ceph
+
+#endif // CEPH_COMMON_ALLOCATOR_H
+