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Diffstat (limited to 'indra/llcorehttp/tests/test_allocator.cpp')
| -rw-r--r-- | indra/llcorehttp/tests/test_allocator.cpp | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/indra/llcorehttp/tests/test_allocator.cpp b/indra/llcorehttp/tests/test_allocator.cpp new file mode 100644 index 0000000000..ea12dc58eb --- /dev/null +++ b/indra/llcorehttp/tests/test_allocator.cpp @@ -0,0 +1,184 @@ +/** + * @file test_allocator.cpp + * @brief quick and dirty allocator for tracking memory allocations + * + * $LicenseInfo:firstyear=2012&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2012, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#include "test_allocator.h" + +#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1050 +#include <libkern/OSAtomic.h> +#elif defined(_MSC_VER) +#include <Windows.h> +#elif (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ ) > 40100 +// atomic extensions are built into GCC on posix platforms +#endif + +#include <cassert> +#include <cstdlib> +#include <cstring> +#include <vector> +#include <iostream> +#include <new> + +#include <boost/thread.hpp> + + +#if defined(WIN32) +#define THROW_BAD_ALLOC() _THROW1(std::bad_alloc) +#define THROW_NOTHING() _THROW0() +#else +#define THROW_BAD_ALLOC() throw(std::bad_alloc) +#define THROW_NOTHING() throw() +#endif + + +struct BlockHeader +{ + struct Block * next; + std::size_t size; + bool in_use; +}; + +struct Block +{ + BlockHeader hdr; + unsigned char data[1]; +}; + +#define TRACE_MSG(val) std::cout << __FUNCTION__ << "(" << val << ") [" << __FILE__ << ":" << __LINE__ << "]" << std::endl; + +static unsigned char MemBuf[ 4096 * 1024 ]; +Block * pNext = static_cast<Block *>(static_cast<void *>(MemBuf)); +volatile std::size_t MemTotal = 0; + +// cross-platform compare and swap operation +static bool CAS(void * volatile * ptr, void * expected, void * new_value) +{ +#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1050 + return OSAtomicCompareAndSwapPtr( expected, new_value, ptr ); +#elif defined(_MSC_VER) + return expected == InterlockedCompareExchangePointer( ptr, new_value, expected ); +#elif (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__ ) > 40100 + return __sync_bool_compare_and_swap( ptr, expected, new_value ); +#endif +} + +static void * GetMem(std::size_t size) +{ + // TRACE_MSG(size); + volatile Block * pBlock = NULL; + volatile Block * pNewNext = NULL; + + // do a lock-free update of the global next pointer + do + { + pBlock = pNext; + pNewNext = (volatile Block *)(pBlock->data + size); + + } while(! CAS((void * volatile *) &pNext, (void *) pBlock, (void *) pNewNext)); + + // if we get here, we safely carved out a block of memory in the + // memory pool... + + // initialize our block + pBlock->hdr.next = (Block *)(pBlock->data + size); + pBlock->hdr.size = size; + pBlock->hdr.in_use = true; + memset((void *) pBlock->data, 0, pBlock->hdr.size); + + // do a lock-free update of the global memory total + volatile size_t total = 0; + volatile size_t new_total = 0; + do + { + total = MemTotal; + new_total = total + size; + + } while (! CAS((void * volatile *) &MemTotal, (void *) total, (void *) new_total)); + + return (void *) pBlock->data; +} + + +static void FreeMem(void * p) +{ + // get the pointer to the block record + Block * pBlock = (Block *)((unsigned char *) p - sizeof(BlockHeader)); + + // TRACE_MSG(pBlock->hdr.size); + bool * cur_in_use = &(pBlock->hdr.in_use); + volatile bool in_use = false; + bool new_in_use = false; + do + { + in_use = pBlock->hdr.in_use; + } while (! CAS((void * volatile *) cur_in_use, (void *) in_use, (void *) new_in_use)); + + // do a lock-free update of the global memory total + volatile size_t total = 0; + volatile size_t new_total = 0; + do + { + total = MemTotal; + new_total = total - pBlock->hdr.size; + } while (! CAS((void * volatile *)&MemTotal, (void *) total, (void *) new_total)); +} + + +std::size_t GetMemTotal() +{ + return MemTotal; +} + + +void * operator new(std::size_t size) THROW_BAD_ALLOC() +{ + return GetMem( size ); +} + + +void * operator new[](std::size_t size) THROW_BAD_ALLOC() +{ + return GetMem( size ); +} + + +void operator delete(void * p) THROW_NOTHING() +{ + if (p) + { + FreeMem( p ); + } +} + + +void operator delete[](void * p) THROW_NOTHING() +{ + if (p) + { + FreeMem( p ); + } +} + + |