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amiga-clib2/library/stdlib_malloc.c
Olaf Barthel 025b183b5a Unused slabs are getting purged after adding a new slab
If a new slab is allocated, or an empty slab is reused, the list of empty slabs is now purged, if possible. Empty slabs which cannot be immediately purged "decay" and will be collected the next time a new slab is allocated or an empty slab is reused.

If a chunk is allocated and the slab which the chunk came from is fully utilized, the slab is moved to the end of its list. This should avoid searching this slab for free space before all other slabs of the same chunk size have been tested first. Slabs with free space are always placed closer to the head of the list.
2016-11-17 13:14:13 +01:00

789 lines
20 KiB
C

/*
* $Id: stdlib_malloc.c,v 1.20 2008-09-30 14:09:00 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _STDLIB_HEADERS_H
#include "stdlib_headers.h"
#endif /* _STDLIB_HEADERS_H */
/****************************************************************************/
#ifndef _STDLIB_MEMORY_H
#include "stdlib_memory.h"
#endif /* _STDLIB_MEMORY_H */
/****************************************************************************/
#ifndef _STDLIB_CONSTRUCTOR_H
#include "stdlib_constructor.h"
#endif /* _STDLIB_CONSTRUCTOR_H */
/****************************************************************************/
#undef malloc
#undef __malloc
/****************************************************************************/
unsigned long NOCOMMON __maximum_memory_allocated;
unsigned long NOCOMMON __current_memory_allocated;
unsigned long NOCOMMON __maximum_num_memory_chunks_allocated;
unsigned long NOCOMMON __current_num_memory_chunks_allocated;
/****************************************************************************/
#if defined(__MEM_DEBUG) && defined(__USE_MEM_TREES)
struct MemoryTree NOCOMMON __memory_tree;
#endif /* __MEM_DEBUG && __USE_MEM_TREES */
/****************************************************************************/
APTR NOCOMMON __memory_pool;
struct MinList NOCOMMON __memory_list;
/****************************************************************************/
struct SlabData NOCOMMON __slab_data;
/****************************************************************************/
/* Free all currently unused slabs, regardless of whether they
* are ready to be purged (SlabNode.sn_EmptyDecay == 0).
*/
void
__free_unused_slabs(void)
{
struct MinNode * free_node;
struct MinNode * free_node_next;
struct SlabNode * sn;
__memory_lock();
for(free_node = (struct MinNode *)__slab_data.sd_EmptySlabs.mlh_Head ;
free_node->mln_Succ != NULL ;
free_node = free_node_next)
{
free_node_next = (struct MinNode *)free_node->mln_Succ;
/* free_node points to SlabNode.sn_EmptyLink, which
* directly follows the SlabNode.sn_MinNode.
*/
sn = (struct SlabNode *)&free_node[-1];
/* Unlink from list of empty slabs. */
Remove((struct Node *)free_node);
/* Unlink from list of slabs of the same size. */
Remove((struct Node *)sn);
FreeVec(sn);
}
__memory_unlock();
}
/****************************************************************************/
size_t
__get_allocation_size(size_t size)
{
#ifndef __MEM_DEBUG
{
size_t total_allocation_size;
total_allocation_size = sizeof(struct MemoryNode) + size;
/* Round up the allocation size to the physical allocation granularity. */
size += ((total_allocation_size + MEM_BLOCKMASK) & ~((ULONG)MEM_BLOCKMASK)) - total_allocation_size;
}
#endif /* __MEM_DEBUG */
return(size);
}
/****************************************************************************/
void *
__allocate_memory(size_t size,BOOL never_free,const char * UNUSED unused_file,int UNUSED unused_line)
{
struct MemoryNode * mn;
size_t allocation_size;
void * result = NULL;
size_t original_size;
#if defined(UNIX_PATH_SEMANTICS)
{
original_size = size;
/* The libunix.a flavour accepts zero length memory allocations
and quietly turns them into a pointer sized allocations. */
if(size == 0)
size = sizeof(char *);
}
#endif /* UNIX_PATH_SEMANTICS */
__memory_lock();
/* Zero length allocations are by default rejected. */
if(size == 0)
{
__set_errno(EINVAL);
goto out;
}
if(__free_memory_threshold > 0 && AvailMem(MEMF_ANY|MEMF_LARGEST) < __free_memory_threshold)
{
SHOWMSG("not enough free memory available to safely proceed with allocation");
goto out;
}
#ifdef __MEM_DEBUG
{
assert( MALLOC_HEAD_SIZE > 0 && (MALLOC_HEAD_SIZE % 4) == 0 );
assert( MALLOC_TAIL_SIZE > 0 && (MALLOC_TAIL_SIZE % 4) == 0 );
assert( (sizeof(*mn) % 4) == 0 );
allocation_size = sizeof(*mn) + MALLOC_HEAD_SIZE + size + MALLOC_TAIL_SIZE;
}
#else
{
/* Round up the allocation size to the physical allocation granularity. */
size = __get_allocation_size(size);
allocation_size = sizeof(*mn) + size;
}
#endif /* __MEM_DEBUG */
/* Are we using the slab allocator? */
if (__slab_data.sd_InUse)
{
mn = NULL;
assert( __slab_data.sd_MaxSlabSize > 0 );
/* Number of bytes to allocate exceeds the slab size?
* If so, allocate this memory chunk separately and
* keep track of it.
*/
if(allocation_size > __slab_data.sd_MaxSlabSize)
{
struct MinNode * single_allocation;
#if defined(__amigaos4__)
{
single_allocation = AllocVec(sizeof(*single_allocation) + allocation_size,MEMF_PRIVATE);
}
#else
{
single_allocation = AllocVec(sizeof(*single_allocation) + allocation_size,MEMF_ANY);
}
#endif /* __amigaos4__ */
if(single_allocation != NULL)
{
AddTail((struct List *)&__slab_data.sd_SingleAllocations,(struct Node *)single_allocation);
__slab_data.sd_NumSingleAllocations++;
mn = (struct MemoryNode *)&single_allocation[1];
}
}
/* Otherwise allocate a chunk from a slab. */
else
{
struct MinList * slab_list = NULL;
ULONG entry_size;
ULONG chunk_size;
int slab_index;
/* Chunks must be at least as small as a MinNode, because
* that's what we use for keeping track of the chunks which
* are available for allocation within each slab.
*/
entry_size = allocation_size;
if(entry_size < sizeof(struct MinNode))
entry_size = sizeof(struct MinNode);
/* Find a slab which keeps track of chunks that are no
* larger than the amount of memory which needs to be
* allocated. We end up picking the smallest chunk
* size that still works.
*/
for(slab_index = 0, chunk_size = (1UL << slab_index) ;
slab_index < 31 ;
slab_index++, chunk_size += chunk_size)
{
assert( (chunk_size % sizeof(LONG)) == 0);
if(entry_size <= chunk_size)
{
slab_list = &__slab_data.sd_Slabs[slab_index];
break;
}
}
if(slab_list != NULL)
{
struct SlabNode * sn;
/* Find the first slab which has a free chunk and use it. */
for(sn = (struct SlabNode *)slab_list->mlh_Head ;
sn->sn_MinNode.mln_Succ != NULL ;
sn = (struct SlabNode *)sn->sn_MinNode.mln_Succ)
{
assert( sn->sn_ChunkSize == chunk_size );
mn = (struct MemoryNode *)RemHead((struct List *)&sn->sn_FreeList);
if(mn != NULL)
{
/* Was this slab empty before we began using it again? */
if(sn->sn_UseCount == 0)
{
/* Mark it as no longer empty. */
Remove((struct Node *)&sn->sn_EmptyLink);
sn->sn_EmptyDecay = 0;
}
sn->sn_UseCount++;
/* Is this slab now fully utilized? Move it to the
* end of the queue so that it will not be checked
* before other slabs of the same size have been
* tested. Those at the front of the queue should
* still have room left.
*/
if(sn->sn_UseCount == sn->sn_Count && sn != (struct SlabNode *)slab_list->mlh_TailPred)
{
Remove((struct Node *)sn);
AddTail((struct List *)slab_list, (struct Node *)sn);
}
break;
}
}
/* There is no slab with a free chunk? Then we might have to
* allocate a new one.
*/
if(mn == NULL)
{
struct MinNode * free_node;
struct MinNode * free_node_next;
struct SlabNode * new_sn = NULL;
/* Try to recycle an empty (unused) slab, if possible. */
for(free_node = (struct MinNode *)__slab_data.sd_EmptySlabs.mlh_Head ;
free_node->mln_Succ != NULL ;
free_node = free_node_next)
{
free_node_next = (struct MinNode *)free_node->mln_Succ;
/* free_node points to SlabNode.sn_EmptyLink, which
* directly follows the SlabNode.sn_MinNode.
*/
sn = (struct SlabNode *)&free_node[-1];
/* Is this empty slab ready to be reused? */
if(sn->sn_EmptyDecay == 0)
{
/* Unlink from list of empty slabs. */
Remove((struct Node *)free_node);
/* Unlink from list of slabs which keep chunks
* of the same size.
*/
Remove((struct Node *)sn);
new_sn = sn;
break;
}
}
/* We couldn't reuse an empty slab? Then we'll have to allocate
* memory for another one.
*/
if(new_sn == NULL)
{
#if defined(__amigaos4__)
{
new_sn = (struct SlabNode *)AllocVec(sizeof(*sn) + __slab_data.sd_MaxSlabSize,MEMF_PRIVATE);
}
#else
{
new_sn = (struct SlabNode *)AllocVec(sizeof(*sn) + __slab_data.sd_MaxSlabSize,MEMF_ANY);
}
#endif /* __amigaos4__ */
}
if(new_sn != NULL)
{
struct MinNode * free_chunk;
ULONG num_free_chunks = 0;
BYTE * first_byte;
BYTE * last_byte;
/* Split up the slab memory into individual chunks
* of the same size and keep track of them
* in the free list. The memory managed by
* this slab immediately follows the
* SlabNode header.
*/
first_byte = (BYTE *)&new_sn[1];
last_byte = &first_byte[__slab_data.sd_MaxSlabSize - chunk_size];
for(free_chunk = (struct MinNode *)first_byte ;
free_chunk <= (struct MinNode *)last_byte;
free_chunk = (struct MinNode *)(((BYTE *)free_chunk) + chunk_size))
{
AddTail((struct List *)&new_sn->sn_FreeList, (struct Node *)free_chunk);
num_free_chunks++;
}
/* Grab the first free chunk (there has to be one). */
mn = (struct MemoryNode *)RemHead((struct List *)&new_sn->sn_FreeList);
assert( mn != NULL );
/* Set up the new slab and put it where it belongs. */
new_sn->sn_EmptyDecay = 0;
new_sn->sn_UseCount = 1;
new_sn->sn_Count = num_free_chunks;
new_sn->sn_ChunkSize = chunk_size;
AddHead((struct List *)slab_list,(struct Node *)&new_sn);
}
/* Mark unused slabs for purging, and purge those which
* are ready to be purged.
*/
for(free_node = (struct MinNode *)__slab_data.sd_EmptySlabs.mlh_Head ;
free_node->mln_Succ != NULL ;
free_node = free_node_next)
{
free_node_next = (struct MinNode *)free_node->mln_Succ;
/* free_node points to SlabNode.sn_EmptyLink, which
* directly follows the SlabNode.sn_MinNode.
*/
sn = (struct SlabNode *)&free_node[-1];
/* Is this empty slab ready to be purged? */
if(sn->sn_EmptyDecay == 0)
{
/* Unlink from list of empty slabs. */
Remove((struct Node *)free_node);
/* Unlink from list of slabs of the same size. */
Remove((struct Node *)sn);
FreeVec(sn);
}
/* Give it another chance. */
else
{
sn->sn_EmptyDecay--;
}
}
}
}
}
}
else if (__memory_pool != NULL)
{
mn = AllocPooled(__memory_pool,allocation_size);
}
else
{
#if defined(__amigaos4__)
{
mn = AllocMem(allocation_size,MEMF_PRIVATE);
}
#else
{
mn = AllocMem(allocation_size,MEMF_ANY);
}
#endif /* __amigaos4__ */
}
if(mn == NULL)
{
SHOWMSG("not enough memory");
goto out;
}
mn->mn_Size = size;
mn->mn_NeverFree = never_free;
AddTail((struct List *)&__memory_list,(struct Node *)mn);
__current_memory_allocated += allocation_size;
if(__maximum_memory_allocated < __current_memory_allocated)
__maximum_memory_allocated = __current_memory_allocated;
__current_num_memory_chunks_allocated++;
if(__maximum_num_memory_chunks_allocated < __current_num_memory_chunks_allocated)
__maximum_num_memory_chunks_allocated = __current_num_memory_chunks_allocated;
#ifdef __MEM_DEBUG
{
char * head = (char *)(mn + 1);
char * body = head + MALLOC_HEAD_SIZE;
char * tail = body + size;
mn->mn_AlreadyFree = FALSE;
mn->mn_Allocation = body;
mn->mn_AllocationSize = allocation_size;
mn->mn_File = (char *)file;
mn->mn_Line = line;
mn->mn_FreeFile = NULL;
mn->mn_FreeLine = 0;
memset(head,MALLOC_HEAD_FILL,MALLOC_HEAD_SIZE);
memset(body,MALLOC_NEW_FILL,size);
memset(tail,MALLOC_TAIL_FILL,MALLOC_TAIL_SIZE);
#ifdef __MEM_DEBUG_LOG
{
kprintf("[%s] + %10ld 0x%08lx [",__program_name,size,body);
kprintf("allocated at %s:%ld]\n",file,line);
}
#endif /* __MEM_DEBUG_LOG */
#ifdef __USE_MEM_TREES
{
__red_black_tree_insert(&__memory_tree,mn);
}
#endif /* __USE_MEM_TREES */
result = mn->mn_Allocation;
}
#else
{
result = &mn[1];
}
#endif /* __MEM_DEBUG */
#if defined(UNIX_PATH_SEMANTICS)
{
/* Set the zero length allocation contents to NULL. */
if(original_size == 0)
*(char **)result = NULL;
}
#endif /* UNIX_PATH_SEMANTICS */
assert( (((ULONG)result) & 3) == 0 );
out:
#ifdef __MEM_DEBUG_LOG
{
if(result == NULL)
{
kprintf("[%s] + %10ld 0x%08lx [",__program_name,size,NULL);
kprintf("FAILED: allocated at %s:%ld]\n",file,line);
}
}
#endif /* __MEM_DEBUG_LOG */
__memory_unlock();
return(result);
}
/****************************************************************************/
__static void *
__malloc(size_t size,const char * file,int line)
{
void * result = NULL;
__memory_lock();
/* Try to get rid of now unused memory. */
if(__alloca_cleanup != NULL)
(*__alloca_cleanup)(file,line);
__memory_unlock();
#ifdef __MEM_DEBUG
{
/*if((rand() % 16) == 0)
__check_memory_allocations(file,line);*/
}
#endif /* __MEM_DEBUG */
/* Allocate memory which can be put through realloc() and free(). */
result = __allocate_memory(size,FALSE,file,line);
return(result);
}
/****************************************************************************/
void *
malloc(size_t size)
{
void * result;
result = __malloc(size,NULL,0);
return(result);
}
/****************************************************************************/
#if defined(__THREAD_SAFE)
/****************************************************************************/
static struct SignalSemaphore * memory_semaphore;
/****************************************************************************/
void
__memory_lock(void)
{
if(memory_semaphore != NULL)
ObtainSemaphore(memory_semaphore);
}
/****************************************************************************/
void
__memory_unlock(void)
{
if(memory_semaphore != NULL)
ReleaseSemaphore(memory_semaphore);
}
/****************************************************************************/
#endif /* __THREAD_SAFE */
/****************************************************************************/
STDLIB_DESTRUCTOR(stdlib_memory_exit)
{
ENTER();
#ifdef __MEM_DEBUG
{
kprintf("[%s] %ld bytes still allocated upon exit, maximum of %ld bytes allocated at a time.\n",
__program_name,__current_memory_allocated,__maximum_memory_allocated);
kprintf("[%s] %ld chunks of memory still allocated upon exit, maximum of %ld chunks allocated at a time.\n",
__program_name,__current_num_memory_chunks_allocated,__maximum_num_memory_chunks_allocated);
__check_memory_allocations(__FILE__,__LINE__);
__never_free = FALSE;
if(__memory_list.mlh_Head != NULL)
{
while(NOT IsListEmpty((struct List *)&__memory_list))
{
((struct MemoryNode *)__memory_list.mlh_Head)->mn_AlreadyFree = FALSE;
__free_memory_node((struct MemoryNode *)__memory_list.mlh_Head,__FILE__,__LINE__);
}
}
#if defined(__USE_MEM_TREES)
{
__initialize_red_black_tree(&__memory_tree);
}
#endif /* __USE_MEM_TREES */
}
#endif /* __MEM_DEBUG */
/* Is the slab memory allocator enabled? */
if (__slab_data.sd_InUse)
{
struct SlabNode * sn;
struct SlabNode * sn_next;
struct MinNode * mn;
struct MinNode * mn_next;
int i;
/* Free the memory allocated for each slab. */
for(i = 0 ; i < 31 ; i++)
{
for(sn = (struct SlabNode *)__slab_data.sd_Slabs[i].mlh_Head ;
sn->sn_MinNode.mln_Succ != NULL ;
sn = sn_next)
{
sn_next = (struct SlabNode *)sn->sn_MinNode.mln_Succ;
FreeVec(sn);
}
NewList((struct List *)&__slab_data.sd_Slabs[i]);
}
/* Free the memory allocated for each allocation which did not
* go into a slab.
*/
for(mn = __slab_data.sd_SingleAllocations.mlh_Head ; mn->mln_Succ != NULL ; mn = mn_next)
{
mn_next = mn->mln_Succ;
FreeVec(mn);
}
NewList((struct List *)&__slab_data.sd_SingleAllocations);
NewList((struct List *)&__slab_data.sd_EmptySlabs);
__slab_data.sd_InUse = FALSE;
}
else if (__memory_pool != NULL)
{
NewList((struct List *)&__memory_list);
DeletePool(__memory_pool);
__memory_pool = NULL;
}
else if (__memory_list.mlh_Head != NULL)
{
#ifdef __MEM_DEBUG
{
while(NOT IsListEmpty((struct List *)&__memory_list))
__free_memory_node((struct MemoryNode *)__memory_list.mlh_Head,__FILE__,__LINE__);
}
#else
{
while(NOT IsListEmpty((struct List *)&__memory_list))
__free_memory_node((struct MemoryNode *)__memory_list.mlh_Head,NULL,0);
}
#endif /* __MEM_DEBUG */
}
#if defined(__THREAD_SAFE)
{
__delete_semaphore(memory_semaphore);
memory_semaphore = NULL;
}
#endif /* __THREAD_SAFE */
LEAVE();
}
/****************************************************************************/
STDLIB_CONSTRUCTOR(stdlib_memory_init)
{
BOOL success = FALSE;
ENTER();
#if defined(__THREAD_SAFE)
{
memory_semaphore = __create_semaphore();
if(memory_semaphore == NULL)
goto out;
}
#endif /* __THREAD_SAFE */
#if defined(__USE_MEM_TREES) && defined(__MEM_DEBUG)
{
__initialize_red_black_tree(&__memory_tree);
}
#endif /* __USE_MEM_TREES && __MEM_DEBUG */
NewList((struct List *)&__memory_list);
/* Enable the slab memory allocator? */
if(__slab_max_size > 0)
{
size_t size;
/* If the maximum allocation size to be made from the slab
* is not already a power of 2, round it up. We do not
* support allocations larger than 2^31, and the maximum
* allocation size should be much smaller.
*
* Note that the maximum allocation size also defines the
* amount of memory which each slab manages.
*/
size = sizeof(struct MinNode);
while(size < __slab_max_size && (size & 0x80000000) == 0)
size += size;
/* If the slab size looks sound, enable the slab memory allocator. */
if((size & 0x80000000) == 0)
{
int i;
assert( size <= __slab_max_size );
/* Start with an empty slab list. */
for(i = 0 ; i < 31 ; i++)
NewList((struct List *)&__slab_data.sd_Slabs[i]);
NewList((struct List *)&__slab_data.sd_SingleAllocations);
NewList((struct List *)&__slab_data.sd_EmptySlabs);
__slab_data.sd_MaxSlabSize = size;
__slab_data.sd_InUse = TRUE;
}
}
else
{
#if defined(__amigaos4__)
{
__memory_pool = CreatePool(MEMF_PRIVATE,(ULONG)__default_pool_size,(ULONG)__default_puddle_size);
}
#else
{
/* There is no support for memory pools in the operating system
* prior to Kickstart 3.0 (V39).
*/
if(((struct Library *)SysBase)->lib_Version >= 39)
__memory_pool = CreatePool(MEMF_ANY,(ULONG)__default_pool_size,(ULONG)__default_puddle_size);
}
#endif /* __amigaos4__ */
}
success = TRUE;
out:
SHOWVALUE(success);
LEAVE();
if(success)
CONSTRUCTOR_SUCCEED();
else
CONSTRUCTOR_FAIL();
}