NFC: MPMCStack: prepare for pointer wrappers

src/ds/aba.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "bits.h"
+#include "ptrwrap.h"
 
 /**
  * This file contains an abstraction of ABA protection. This API should be
@@ -23,19 +24,23 @@ namespace snmalloc
   // fall back to locked implementation.
 #if defined(PLATFORM_IS_X86) && \
   !(defined(GCC_NOT_CLANG) && defined(OPEN_ENCLAVE))
-  template<typename T, Construction c = RequiresInit>
+  template<
+    typename T,
+    Construction c = RequiresInit,
+    template<typename> typename Ptr = Pointer,
+    template<typename> typename AtomicPtr = AtomicPointer>
   class ABA
   {
   public:
     struct alignas(2 * sizeof(std::size_t)) Linked
     {
-      T* ptr;
+      Ptr<T> ptr;
       uintptr_t aba;
     };
 
     struct Independent
     {
-      std::atomic<T*> ptr;
+      AtomicPtr<T> ptr;
       std::atomic<uintptr_t> aba;
     };
 
@@ -60,7 +65,7 @@ namespace snmalloc
         init(nullptr);
     }
 
-    void init(T* x)
+    void init(Ptr<T> x)
     {
       independent.ptr.store(x, std::memory_order_relaxed);
       independent.aba.store(0, std::memory_order_relaxed);
@@ -92,18 +97,18 @@ namespace snmalloc
        */
       Cmp(Linked old, ABA* parent) : old(old), parent(parent) {}
 
-      T* ptr()
+      Ptr<T> ptr()
       {
         return old.ptr;
       }
 
-      bool store_conditional(T* value)
+      bool store_conditional(Ptr<T> value)
       {
 #  if defined(_MSC_VER) && defined(SNMALLOC_VA_BITS_64)
         auto result = _InterlockedCompareExchange128(
           (volatile __int64*)parent,
           (__int64)(old.aba + (uintptr_t)1),
-          (__int64)value,
+          (__int64)address_cast(value),
           (__int64*)&old);
 #  else
 #    if defined(__GNUC__) && defined(SNMALLOC_VA_BITS_64) && \
@@ -132,7 +137,7 @@ namespace snmalloc
     };
 
     // This method is used in Verona
-    T* peek()
+    Ptr<T> peek()
     {
       return independent.ptr.load(std::memory_order_relaxed);
     }
@@ -141,10 +146,14 @@ namespace snmalloc
   /**
    * Naive implementation of ABA protection using a spin lock.
    */
-  template<typename T, Construction c = RequiresInit>
+  template<
+    typename T,
+    Construction c = RequiresInit,
+    template<typename> typename Ptr = Pointer,
+    template<typename> typename AtomicPtr = AtomicPointer>
   class ABA
   {
-    std::atomic<T*> ptr = nullptr;
+    AtomicPtr<T> ptr = nullptr;
     std::atomic_flag lock = ATOMIC_FLAG_INIT;
 
   public:
@@ -169,12 +178,12 @@ namespace snmalloc
       ABA* parent;
 
     public:
-      T* ptr()
+      Ptr<T> ptr()
       {
         return parent->ptr;
       }
 
-      bool store_conditional(T* t)
+      bool store_conditional(Ptr<T> t)
       {
         parent->ptr = t;
         return true;
@@ -190,7 +199,7 @@ namespace snmalloc
     };
 
     // This method is used in Verona
-    T* peek()
+    Ptr<T> peek()
     {
       return ptr.load(std::memory_order_relaxed);
     }

src/ds/mpmcstack.h

@@ -4,43 +4,47 @@
 
 namespace snmalloc
 {
-  template<class T, Construction c = RequiresInit>
+  template<
+    class T,
+    Construction c = RequiresInit,
+    template<typename> typename Ptr = Pointer,
+    template<typename> typename AtomicPtr = AtomicPointer>
   class MPMCStack
   {
-    using ABAT = ABA<T, c>;
+    using ABAT = ABA<T, c, Ptr, AtomicPtr>;
 
   private:
     static_assert(
-      std::is_same<decltype(T::next), std::atomic<T*>>::value,
-      "T->next must be a std::atomic<T*>");
+      std::is_same<decltype(T::next), AtomicPtr<T>>::value,
+      "T->next must be an AtomicPtr<T>");
 
     ABAT stack;
 
   public:
-    void push(T* item)
+    void push(Ptr<T> item)
     {
       return push(item, item);
     }
 
-    void push(T* first, T* last)
+    void push(Ptr<T> first, Ptr<T> last)
     {
       // Pushes an item on the stack.
       auto cmp = stack.read();
 
       do
       {
-        T* top = cmp.ptr();
+        Ptr<T> top = cmp.ptr();
         last->next.store(top, std::memory_order_release);
       } while (!cmp.store_conditional(first));
     }
 
-    T* pop()
+    Ptr<T> pop()
     {
       // Returns the next item. If the returned value is decommitted, it is
       // possible for the read of top->next to segfault.
       auto cmp = stack.read();
-      T* top;
-      T* next;
+      Ptr<T> top;
+      Ptr<T> next;
 
       do
       {
@@ -55,11 +59,11 @@ namespace snmalloc
       return top;
     }
 
-    T* pop_all()
+    Ptr<T> pop_all()
     {
       // Returns all items as a linked list, leaving an empty stack.
       auto cmp = stack.read();
-      T* top;
+      Ptr<T> top;
 
       do
       {

src/mem/largealloc.h

@@ -22,7 +22,13 @@ namespace snmalloc
     // This is the view of a contiguous memory area when it is being kept
     // in the global size-classed caches of available contiguous memory areas.
   private:
-    template<class a, Construction c>
+    template<
+      class a,
+      Construction c,
+      template<typename>
+      typename P,
+      template<typename>
+      typename AP>
     friend class MPMCStack;
     template<SNMALLOC_CONCEPT(ConceptPAL) PAL>
     friend class MemoryProviderStateMixin;

src/mem/pooled.h

@@ -10,7 +10,13 @@ namespace snmalloc
   private:
     template<class TT, class MemoryProvider>
     friend class Pool;
-    template<class TT, Construction c>
+    template<
+      class a,
+      Construction c,
+      template<typename>
+      typename P,
+      template<typename>
+      typename AP>
     friend class MPMCStack;
 
     /// Used by the pool for chaining together entries when not in use.