Files
bullet3/src/LinearMath/btPoolAllocator.h
Lunkhound 1c3686ca51 MultiThreaded Demo:
- fixing various race conditions throughout (usage of static vars, etc)
 - addition of a few lightweight mutexes (which are compiled out by default)
 - slight code rearrangement in discreteDynamicsWorld to facilitate multithreading
 - PoolAllocator::allocate() can now be called when pool is full without
     crashing (null pointer returned)
 - PoolAllocator allocate and freeMemory, are OPTIONALLY threadsafe
     (default is un-threadsafe)
 - CollisionDispatcher no longer checks if the pool allocator is full
     before calling allocate(), instead it just calls allocate() and
     checks if the return is null -- this avoids a race condition
 - SequentialImpulseConstraintSolver OPTIONALLY uses different logic in
     getOrInitSolverBody() to avoid a race condition with kinematic bodies
 - addition of 2 classes which together allow simulation islands to be run
   in parallel:
    - btSimulationIslandManagerMt
    - btDiscreteDynamicsWorldMt
 - MultiThreadedDemo example in the example browser demonstrating use of
   OpenMP, Microsoft PPL, and Intel TBB
 - use multithreading for other demos
 - benchmark demo: add parallel raycasting
2016-10-30 12:47:27 -07:00

131 lines
3.2 KiB
C++

/*
Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans http://continuousphysics.com/Bullet/
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 _BT_POOL_ALLOCATOR_H
#define _BT_POOL_ALLOCATOR_H
#include "btScalar.h"
#include "btAlignedAllocator.h"
#include "btThreads.h"
///The btPoolAllocator class allows to efficiently allocate a large pool of objects, instead of dynamically allocating them separately.
class btPoolAllocator
{
int m_elemSize;
int m_maxElements;
int m_freeCount;
void* m_firstFree;
unsigned char* m_pool;
btSpinMutex m_mutex; // only used if BT_THREADSAFE
public:
btPoolAllocator(int elemSize, int maxElements)
:m_elemSize(elemSize),
m_maxElements(maxElements)
{
m_pool = (unsigned char*) btAlignedAlloc( static_cast<unsigned int>(m_elemSize*m_maxElements),16);
unsigned char* p = m_pool;
m_firstFree = p;
m_freeCount = m_maxElements;
int count = m_maxElements;
while (--count) {
*(void**)p = (p + m_elemSize);
p += m_elemSize;
}
*(void**)p = 0;
}
~btPoolAllocator()
{
btAlignedFree( m_pool);
}
int getFreeCount() const
{
return m_freeCount;
}
int getUsedCount() const
{
return m_maxElements - m_freeCount;
}
int getMaxCount() const
{
return m_maxElements;
}
void* allocate(int size)
{
// release mode fix
(void)size;
btMutexLock(&m_mutex);
btAssert(!size || size<=m_elemSize);
//btAssert(m_freeCount>0); // should return null if all full
void* result = m_firstFree;
if (NULL != m_firstFree)
{
m_firstFree = *(void**)m_firstFree;
--m_freeCount;
}
btMutexUnlock(&m_mutex);
return result;
}
bool validPtr(void* ptr)
{
if (ptr) {
if (((unsigned char*)ptr >= m_pool && (unsigned char*)ptr < m_pool + m_maxElements * m_elemSize))
{
return true;
}
}
return false;
}
void freeMemory(void* ptr)
{
if (ptr) {
btAssert((unsigned char*)ptr >= m_pool && (unsigned char*)ptr < m_pool + m_maxElements * m_elemSize);
btMutexLock(&m_mutex);
*(void**)ptr = m_firstFree;
m_firstFree = ptr;
++m_freeCount;
btMutexUnlock(&m_mutex);
}
}
int getElementSize() const
{
return m_elemSize;
}
unsigned char* getPoolAddress()
{
return m_pool;
}
const unsigned char* getPoolAddress() const
{
return m_pool;
}
};
#endif //_BT_POOL_ALLOCATOR_H