From ef93f1b1e8bc4294e01ffe402417e93bfbc05a7c Mon Sep 17 00:00:00 2001
From: Pavel Kirienko <pavel.kirienko@gmail.com>
Date: Thu, 15 Oct 2015 10:50:42 +0300
Subject: [PATCH] Heap based pool allocator - configurable getNumBlocks()

---
 .../uavcan/helpers/heap_based_pool_allocator.hpp      | 11 ++++++++---
 libuavcan/test/helpers/heap_based_pool_allocator.cpp  |  8 ++++++--
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/libuavcan/include/uavcan/helpers/heap_based_pool_allocator.hpp b/libuavcan/include/uavcan/helpers/heap_based_pool_allocator.hpp
index a012ee2c9a..566e21f2d3 100644
--- a/libuavcan/include/uavcan/helpers/heap_based_pool_allocator.hpp
+++ b/libuavcan/include/uavcan/helpers/heap_based_pool_allocator.hpp
@@ -49,6 +49,7 @@ class UAVCAN_EXPORT HeapBasedPoolAllocator : public IPoolAllocator, Noncopyable
     };
 
     Node* volatile cache_;
+    uint16_t reported_num_blocks_;
 
     Node* popCache()
     {
@@ -73,7 +74,10 @@ public:
     /**
      * The allocator initializes with empty cache, so first allocations will be served from heap.
      */
-    HeapBasedPoolAllocator() : cache_(NULL) { }
+    HeapBasedPoolAllocator(uint16_t reported_num_blocks) :
+        cache_(NULL),
+        reported_num_blocks_(reported_num_blocks)
+    { }
 
     /**
      * The destructor de-allocates all blocks that are currently in the cache.
@@ -121,9 +125,10 @@ public:
     }
 
     /**
-     * Heap-based pool is virutally infinite in size, so this method just returns maximum possible number of blocks.
+     * Heap-based pool is virutally infinite in size, so this method just returns some pre-defined value.
      */
-    virtual uint16_t getNumBlocks() const { return NumericTraits<uint16_t>::max(); }
+    virtual uint16_t getNumBlocks() const { return reported_num_blocks_; }
+    void setReportedNumBlocks(uint16_t x) { reported_num_blocks_ = x; }
 
     /**
      * Frees all blocks that are not in use at the moment.
diff --git a/libuavcan/test/helpers/heap_based_pool_allocator.cpp b/libuavcan/test/helpers/heap_based_pool_allocator.cpp
index 61daf378d8..ae250be287 100644
--- a/libuavcan/test/helpers/heap_based_pool_allocator.cpp
+++ b/libuavcan/test/helpers/heap_based_pool_allocator.cpp
@@ -16,10 +16,14 @@ TEST(HeapBasedPoolAllocator, Basic)
     std::cout << ">>> HEAP BEFORE:" << std::endl;
     malloc_stats();
 
-    uavcan::HeapBasedPoolAllocator<uavcan::MemPoolBlockSize, atomicCompareAndSwap> al;
+    uavcan::HeapBasedPoolAllocator<uavcan::MemPoolBlockSize, atomicCompareAndSwap> al(64);
 
     ASSERT_EQ(0, al.getNumCachedBlocks());
 
+    ASSERT_EQ(64, al.getNumBlocks());
+    al.setReportedNumBlocks(123);
+    ASSERT_EQ(123, al.getNumBlocks());
+
     void* a = al.allocate(10);
     void* b = al.allocate(10);
     void* c = al.allocate(10);
@@ -77,7 +81,7 @@ TEST(HeapBasedPoolAllocator, Concurrency)
     std::cout << ">>> HEAP BEFORE:" << std::endl;
     malloc_stats();
 
-    uavcan::HeapBasedPoolAllocator<uavcan::MemPoolBlockSize, atomicCompareAndSwapWithRescheduling> al;
+    uavcan::HeapBasedPoolAllocator<uavcan::MemPoolBlockSize, atomicCompareAndSwapWithRescheduling> al(1);
 
     volatile bool terminate = false;