open_toontown_panda3d/dtool/src/dtoolbase/memoryHook.I

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// Filename: memoryHook.I
// Created by: drose (28Jun07)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) Carnegie Mellon University. All rights reserved.
//
// All use of this software is subject to the terms of the revised BSD
// license. You should have received a copy of this license along
// with this source code in a file named "LICENSE."
//
////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::inc_heap
// Access: Public
// Description: Called by our alternative malloc implementations
// (dlmalloc and ptmalloc2) to indicate they have
// requested size bytes from the system for the heap.
////////////////////////////////////////////////////////////////////
INLINE void MemoryHook::
inc_heap(size_t size) {
#ifdef DO_MEMORY_USAGE
AtomicAdjust::add(_requested_heap_size, (AtomicAdjust::Integer)size);
#endif // DO_MEMORY_USAGE
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::dec_heap
// Access: Public
// Description: Called by our alternative malloc implementations
// (dlmalloc and ptmalloc2) to indicate they have
// returned size bytes to the system from the heap.
////////////////////////////////////////////////////////////////////
INLINE void MemoryHook::
dec_heap(size_t size) {
#ifdef DO_MEMORY_USAGE
//assert((int)size <= _requested_heap_size);
AtomicAdjust::add(_requested_heap_size, -(AtomicAdjust::Integer)size);
#endif // DO_MEMORY_USAGE
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::get_memory_alignment
// Access: Public, Static
// Description: Returns the global memory alignment. This is the
// number of bytes at which each allocated memory
// pointer will be aligned.
////////////////////////////////////////////////////////////////////
INLINE size_t MemoryHook::
get_memory_alignment() {
#ifdef LINMATH_ALIGN
// We require 16-byte alignment of certain structures, to support
// SSE2. We don't strictly have to align *everything*, but it's just
// easier to do so.
const size_t alignment_size = 16;
#else
// Otherwise, use word alignment.
const size_t alignment_size = sizeof(void *);
#endif
return alignment_size;
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::get_header_reserved_bytes
// Access: Public, Static
// Description: Returns the number of additional bytes that are
// reserved at the beginning of every allocated block to
// store a size_t.
////////////////////////////////////////////////////////////////////
INLINE size_t MemoryHook::
get_header_reserved_bytes() {
// We need to figure out the minimum amount of additional space we
// need in order to place a single word at the start of each
// allocated block, to store the size of the block.
#ifdef LINMATH_ALIGN
// If we're doing SSE2 alignment, we must reserve a full 16-byte
// block, since anything less than that will spoil the alignment.
static const size_t header_reserved_bytes = 16;
#elif defined(MEMORY_HOOK_DO_ALIGN)
// If we're just aligning to words, we reserve a block as big as two
// words, to allow us wiggle room to align the word precisely within
// that block.
static const size_t header_reserved_bytes = sizeof(size_t) + sizeof(size_t);
#else
// If we're not aligning, we just need space for the word itself.
static const size_t header_reserved_bytes = sizeof(size_t);
#endif
return header_reserved_bytes;
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::get_page_size
// Access: Public
// Description: Returns the operating system page size. This is the
// minimum granularity required for calls to
// mmap_alloc(). Also see round_up_to_page_size().
////////////////////////////////////////////////////////////////////
INLINE size_t MemoryHook::
get_page_size() const {
return _page_size;
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::round_up_to_page_size
// Access: Public
// Description: Rounds the indicated size request up to the next
// larger multiple of page_size, to qualify it for a
// call to mmap_alloc().
////////////////////////////////////////////////////////////////////
INLINE size_t MemoryHook::
round_up_to_page_size(size_t size) const {
return ((size + _page_size - 1) / _page_size) * _page_size;
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::inflate_size
// Access: Private, Static
// Description: Increments the amount of requested size as necessary
// to accommodate the extra data we might piggyback on
// each allocated block.
////////////////////////////////////////////////////////////////////
INLINE size_t MemoryHook::
inflate_size(size_t size) {
#if defined(MEMORY_HOOK_DO_ALIGN)
// If we're aligning, we need to request the header size, plus extra
// bytes to give us wiggle room to adjust the pointer.
return size + get_header_reserved_bytes() + get_memory_alignment() - 1;
#elif defined(DO_MEMORY_USAGE)
// If we're not aligning, but we're tracking memory allocations, we
// just need the header size extra (this gives us a place to store
// the size of the allocated block).
return size + get_header_reserved_bytes();
#else
// If we're not doing any of that, we can just allocate the precise
// requested amount.
return size;
#endif // DO_MEMORY_USAGE
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::alloc_to_ptr
// Access: Private, Static
// Description: Converts an allocated pointer to a pointer returnable
// to the application. Stuffs size in the first n bytes
// of the allocated space.
////////////////////////////////////////////////////////////////////
INLINE void *MemoryHook::
alloc_to_ptr(void *alloc, size_t size) {
#if defined(MEMORY_HOOK_DO_ALIGN)
size_t alignment = get_memory_alignment();
// Move the allocated pointer up to the next even alignment.
size_t *root = (size_t *)((((size_t)alloc + alignment - 1) / alignment) * alignment);
assert(alloc <= root && (size_t)((char *)root - (char *)alloc) < alignment);
root[0] = size;
root[1] = (size_t)alloc; // Save the pointer we originally allocated.
return (void *)((char *)root + get_header_reserved_bytes());
#elif defined(DO_MEMORY_USAGE)
size_t *root = (size_t *)alloc;
root[0] = size;
return (void *)((char *)root + get_header_reserved_bytes());
#else
return alloc;
#endif // DO_MEMORY_USAGE
}
////////////////////////////////////////////////////////////////////
// Function: MemoryHook::ptr_to_alloc
// Access: Private, Static
// Description: Converts an application pointer back to the original
// allocated pointer. Extracts size from the first n
// bytes of the allocated space.
////////////////////////////////////////////////////////////////////
INLINE void *MemoryHook::
ptr_to_alloc(void *ptr, size_t &size) {
#if defined(MEMORY_HOOK_DO_ALIGN)
size_t *root = (size_t *)((char *)ptr - get_header_reserved_bytes());
size = root[0];
void *alloc = (void *)root[1]; // Get the pointer we originally allocated.
assert(alloc <= root && (size_t)((char *)root - (char *)alloc) < get_memory_alignment());
return alloc;
#elif defined(DO_MEMORY_USAGE)
size_t *root = (size_t *)((char *)ptr - get_header_reserved_bytes());
size = root[0];
return (void *)root;
#else
return ptr;
#endif // DO_MEMORY_USAGE
}