From be47aea0c8655e32a43455ede4eb0447535951fb Mon Sep 17 00:00:00 2001
From: Matthew Parkinson <mattpark@microsoft.com>
Date: Wed, 26 Feb 2020 21:24:02 +0000
Subject: [PATCH] Tidying

---
 src/mem/largealloc.h                          | 35 ++++++++++++++-----
 .../thread_alloc_external.cc                  |  8 +----
 2 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/src/mem/largealloc.h b/src/mem/largealloc.h
index 7e3de6a..5c1437b 100644
--- a/src/mem/largealloc.h
+++ b/src/mem/largealloc.h
@@ -57,19 +57,44 @@ namespace snmalloc
   template<class PAL>
   class MemoryProviderStateMixin : public PAL
   {
+    /**
+     * Flag to protect the bump allocator
+     **/
     std::atomic_flag lock = ATOMIC_FLAG_INIT;
+
+    /**
+     * Pointer to block being bump allocated
+     **/
     void* bump = nullptr;
+
+    /**
+     * Space remaining in this block being bump allocated
+     **/
     size_t remaining = 0;
 
+    /**
+     * The last time we saw a low memory notification.
+     */
+    std::atomic<uint64_t> last_low_memory_epoch = 0;
+
+    /**
+     * Simple flag for checking if another instance of lazy-decommit is
+     * running
+     **/
+    std::atomic_flag lazy_decommit_guard = {};
+
   public:
     /**
      * Stack of large allocations that have been returned for reuse.
      */
     ModArray<NUM_LARGE_CLASSES, MPMCStack<Largeslab, RequiresInit>> large_stack;
 
+    /**
+     * Make a new memory provide for this PAL.
+     **/
     static MemoryProviderStateMixin<PAL>* make() noexcept
     {
-      // Temporary storage to start the allocator in.
+      // Temporary stack-based storage to start the allocator in.
       MemoryProviderStateMixin<PAL> local;
 
       // Allocate permanent storage for the allocator usung temporary allocator
@@ -84,12 +109,6 @@ namespace snmalloc
     }
 
   private:
-    /**
-     * The last time we saw a low memory notification.
-     */
-    std::atomic<uint64_t> last_low_memory_epoch = 0;
-    std::atomic_flag lazy_decommit_guard = {};
-
     void new_block()
     {
       // Reserve the smallest large_class which is SUPERSLAB_SIZE
@@ -290,8 +309,6 @@ namespace snmalloc
           }
         }
 
-        // printf("Alloc %zx (size = %zx)\n", start, size);
-
         void* result = pointer_cast<void>(start);
         if (committed)
           PAL::template notify_using<NoZero>(result, size);
diff --git a/src/test/func/thread_alloc_external/thread_alloc_external.cc b/src/test/func/thread_alloc_external/thread_alloc_external.cc
index 5439248..f542759 100644
--- a/src/test/func/thread_alloc_external/thread_alloc_external.cc
+++ b/src/test/func/thread_alloc_external/thread_alloc_external.cc
@@ -26,17 +26,11 @@ int main()
 {
   setup();
 
-  MemoryProviderStateMixin<DefaultPal> mp;
-
-  // 28 is large enough to produce a nested allocator.
-  // It is also large enough for the example to run in.
-  // For 1MiB superslabs, SUPERSLAB_BITS + 4 is not big enough for the example.
-
   auto a = ThreadAlloc::get();
 
   for (size_t i = 0; i < 1000; i++)
   {
-    auto r1 = a->alloc(100);
+    auto r1 = a->alloc(i);
 
     a->dealloc(r1);
   }