Refactor PoolAllocator and add SingleFrameAllocator

src/memory/PoolAllocator.cpp

@@ -24,19 +24,19 @@
 ********************************************************************************/
 
 // Libraries
-#include "MemoryAllocator.h"
+#include "PoolAllocator.h"
 #include <cstdlib>
 #include <cassert>
 
 using namespace reactphysics3d;
 
 // Initialization of static variables
-bool MemoryAllocator::isMapSizeToHeadIndexInitialized = false;
+bool PoolAllocator::isMapSizeToHeadIndexInitialized = false;
-size_t MemoryAllocator::mUnitSizes[NB_HEAPS];
+size_t PoolAllocator::mUnitSizes[NB_HEAPS];
-int MemoryAllocator::mMapSizeToHeapIndex[MAX_UNIT_SIZE + 1];
+int PoolAllocator::mMapSizeToHeapIndex[MAX_UNIT_SIZE + 1];
 
 // Constructor
-MemoryAllocator::MemoryAllocator() {
+PoolAllocator::PoolAllocator() {
 
     // Allocate some memory to manage the blocks
     mNbAllocatedMemoryBlocks = 64;
@@ -78,7 +78,7 @@ MemoryAllocator::MemoryAllocator() {
 }
 
 // Destructor
-MemoryAllocator::~MemoryAllocator() {
+PoolAllocator::~PoolAllocator() {
 
     // Release the memory allocated for each block
     for (uint i=0; i<mNbCurrentMemoryBlocks; i++) {
@@ -96,7 +96,7 @@ MemoryAllocator::~MemoryAllocator() {
 
 // Allocate memory of a given size (in bytes) and return a pointer to the
 // allocated memory.
-void* MemoryAllocator::allocate(size_t size) {
+void* PoolAllocator::allocate(size_t size) {
 
     // We cannot allocate zero bytes
     if (size == 0) return nullptr;
@@ -164,7 +164,7 @@ void* MemoryAllocator::allocate(size_t size) {
 }
 
 // Release previously allocated memory.
-void MemoryAllocator::release(void* pointer, size_t size) {
+void PoolAllocator::release(void* pointer, size_t size) {
 
     // Cannot release a 0-byte allocated memory
     if (size == 0) return;

src/memory/PoolAllocator.h

@@ -23,8 +23,8 @@
 *                                                                               *
 ********************************************************************************/
 
-#ifndef REACTPHYSICS3D_MEMORY_ALLOCATOR_H
+#ifndef REACTPHYSICS3D_POOL_ALLOCATOR_H
-#define REACTPHYSICS3D_MEMORY_ALLOCATOR_H
+#define REACTPHYSICS3D_POOL_ALLOCATOR_H
 
 // Libraries
 #include <cstring>
@@ -33,14 +33,14 @@
 /// ReactPhysics3D namespace
 namespace reactphysics3d {
 
-// Class MemoryAllocator
+// Class PoolAllocator
 /**
  * This class is used to efficiently allocate memory on the heap.
  * It allows us to allocate small blocks of memory (smaller or equal to 1024 bytes)
  * efficiently. This implementation is inspired by the small block allocator
  * described here : http://www.codeproject.com/useritems/Small_Block_Allocator.asp
  */
-class MemoryAllocator {
+class PoolAllocator {
 
     private :
 
@@ -126,10 +126,10 @@ class MemoryAllocator {
         // -------------------- Methods -------------------- //
 
         /// Constructor
-        MemoryAllocator();
+        PoolAllocator();
 
         /// Destructor
-        ~MemoryAllocator();
+        ~PoolAllocator();
 
         /// Allocate memory of a given size (in bytes) and return a pointer to the
         /// allocated memory.

src/memory/SingleFrameAllocator.cpp

@@ -0,0 +1,80 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://www.reactphysics3d.com                 *
+* Copyright (c) 2010-2016 Daniel Chappuis                                       *
+*********************************************************************************
+*                                                                               *
+* This software is provided 'as-is', without any express or implied warranty.   *
+* In no event will the authors be held liable for any damages arising from the  *
+* use of this software.                                                         *
+*                                                                               *
+* Permission is granted to anyone to use this software for any purpose,         *
+* including commercial applications, and to alter it and redistribute it        *
+* freely, subject to the following restrictions:                                *
+*                                                                               *
+* 1. The origin of this software must not be misrepresented; you must not claim *
+*    that you wrote the original software. If you use this software in a        *
+*    product, an acknowledgment in the product documentation would be           *
+*    appreciated but is not required.                                           *
+*                                                                               *
+* 2. Altered source versions must be plainly marked as such, and must not be    *
+*    misrepresented as being the original software.                             *
+*                                                                               *
+* 3. This notice may not be removed or altered from any source distribution.    *
+*                                                                               *
+********************************************************************************/
+
+// Libraries
+#include "SingleFrameAllocator.h"
+#include <cstdlib>
+#include <cassert>
+
+using namespace reactphysics3d;
+
+// Constructor
+SingleFrameAllocator::SingleFrameAllocator(size_t totalSizeBytes)
+    : mTotalSizeBytes(totalSizeBytes), mCurrentOffset(0) {
+
+    // Allocate a whole block of memory at the beginning
+    mMemoryBufferStart = static_cast<char*>(malloc(mTotalSizeBytes));
+    assert(mMemoryBufferStart != nullptr);
+}
+
+// Destructor
+SingleFrameAllocator::~SingleFrameAllocator() {
+
+    // Release the memory allocated at the beginning
+    free(mMemoryBufferStart);
+}
+
+
+// Allocate memory of a given size (in bytes) and return a pointer to the
+// allocated memory.
+void* SingleFrameAllocator::allocate(size_t size) {
+
+    // Check that there is enough remaining memory in the buffer
+    if (static_cast<size_t>(mCurrentOffset) + size > mTotalSizeBytes) {
+
+        // This should never occur. If it does, you must increase the initial
+        // size of memory of this allocator
+        assert(false);
+
+        // Return null
+        return nullptr;
+    }
+
+    // Next available memory location
+    void* nextAvailableMemory = mMemoryBufferStart + mCurrentOffset;
+
+    // Increment the offset
+    mCurrentOffset += size;
+
+    // Return the next available memory location
+    return nextAvailableMemory;
+}
+
+// Reset the marker of the current allocated memory
+void SingleFrameAllocator::reset() {
+
+    // Reset the current offset at the beginning of the block
+    mCurrentOffset = 0;
+}

src/memory/SingleFrameAllocator.h

@@ -0,0 +1,76 @@
+/********************************************************************************
+* ReactPhysics3D physics library, http://www.reactphysics3d.com                 *
+* Copyright (c) 2010-2016 Daniel Chappuis                                       *
+*********************************************************************************
+*                                                                               *
+* This software is provided 'as-is', without any express or implied warranty.   *
+* In no event will the authors be held liable for any damages arising from the  *
+* use of this software.                                                         *
+*                                                                               *
+* Permission is granted to anyone to use this software for any purpose,         *
+* including commercial applications, and to alter it and redistribute it        *
+* freely, subject to the following restrictions:                                *
+*                                                                               *
+* 1. The origin of this software must not be misrepresented; you must not claim *
+*    that you wrote the original software. If you use this software in a        *
+*    product, an acknowledgment in the product documentation would be           *
+*    appreciated but is not required.                                           *
+*                                                                               *
+* 2. Altered source versions must be plainly marked as such, and must not be    *
+*    misrepresented as being the original software.                             *
+*                                                                               *
+* 3. This notice may not be removed or altered from any source distribution.    *
+*                                                                               *
+********************************************************************************/
+
+#ifndef REACTPHYSICS3D_SINGLE_FRAME_ALLOCATOR_H
+#define REACTPHYSICS3D_SINGLE_FRAME_ALLOCATOR_H
+
+// Libraries
+#include <cstring>
+#include "configuration.h"
+
+/// ReactPhysics3D namespace
+namespace reactphysics3d {
+
+// Class SingleFrameAllocator
+/**
+ * This class represent a memory allocator used to efficiently allocate
+ * memory on the heap that is used during a single frame.
+ */
+class SingleFrameAllocator {
+
+    private :
+
+        // -------------------- Attributes -------------------- //
+
+        /// Total size (in bytes) of memory of the allocator
+        size_t mTotalSizeBytes;
+
+        /// Pointer to the beginning of the allocated memory block
+        char* mMemoryBufferStart;
+
+        /// Pointer to the next available memory location in the buffer
+        int mCurrentOffset;
+
+    public :
+
+        // -------------------- Methods -------------------- //
+
+        /// Constructor
+        SingleFrameAllocator(size_t totalSizeBytes);
+
+        /// Destructor
+        ~SingleFrameAllocator();
+
+        /// Allocate memory of a given size (in bytes)
+        void* allocate(size_t size);
+
+        /// Reset the marker of the current allocated memory
+        void reset();
+
+};
+
+}
+
+#endif