/* * :ts=4 * * Portable ISO 'C' (1994) runtime library for the Amiga computer * Copyright (c) 2002-2015 by Olaf Barthel * 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. */ /*#define DEBUG*/ #ifndef _STDLIB_HEADERS_H #include "stdlib_headers.h" #endif /* _STDLIB_HEADERS_H */ /****************************************************************************/ #ifndef _STDLIB_MEMORY_H #include "stdlib_memory.h" #endif /* _STDLIB_MEMORY_H */ /****************************************************************************/ struct SlabData NOCOMMON __slab_data; /****************************************************************************/ struct SlabChunk { struct SlabNode * sc_Parent; }; /****************************************************************************/ void * __slab_allocate(size_t allocation_size) { struct SlabChunk * chunk; void * allocation = NULL; size_t allocation_size_with_chunk_header; D(("allocating %lu bytes of memory",allocation_size)); assert( __slab_data.sd_StandardSlabSize > 0 ); /* Check for integer overflow. */ allocation_size_with_chunk_header = sizeof(*chunk) + allocation_size; if(allocation_size_with_chunk_header < allocation_size) return(NULL); /* Number of bytes to allocate exceeds the slab size? * If so, allocate this memory chunk separately and * keep track of it. */ if(allocation_size_with_chunk_header > __slab_data.sd_StandardSlabSize) { struct SlabSingleAllocation * ssa; ULONG total_single_allocation_size = sizeof(*ssa) + allocation_size; D(("allocation size is > %ld; this will be stored separately",__slab_data.sd_StandardSlabSize)); D(("allocating %ld (MinNode+Size) + %ld = %ld bytes",sizeof(*ssa),allocation_size,total_single_allocation_size)); /* No integer overflow? */ if(allocation_size < total_single_allocation_size) { PROFILE_OFF(); #if defined(__amigaos4__) { ssa = AllocMem(total_single_allocation_size,MEMF_PRIVATE); } #else { ssa = AllocMem(total_single_allocation_size,MEMF_ANY); } #endif /* __amigaos4__ */ PROFILE_ON(); } /* Integer overflow has occured. */ else { ssa = NULL; } if(ssa != NULL) { ssa->ssa_Size = total_single_allocation_size; allocation = &ssa[1]; D(("single allocation = 0x%08lx",allocation)); AddTail((struct List *)&__slab_data.sd_SingleAllocations,(struct Node *)ssa); __slab_data.sd_NumSingleAllocations++; __slab_data.sd_TotalSingleAllocationSize += total_single_allocation_size; D(("single allocation succeeded at 0x%08lx (number of single allocations = %lu)", allocation, __slab_data.sd_NumSingleAllocations)); } else { D(("single allocation failed")); } } /* Otherwise allocate a chunk from a slab. */ else { struct MinList * slab_list = NULL; BOOL slab_reused = FALSE; ULONG entry_size; ULONG chunk_size; int slab_index; D(("allocation size is <= %ld; this will be allocated from a slab",__slab_data.sd_StandardSlabSize)); /* Add room for a pointer back to the slab which * the chunk belongs to. */ entry_size = sizeof(*chunk) + allocation_size; /* 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. */ if(entry_size < sizeof(struct MinNode)) entry_size = sizeof(struct MinNode); D(("final entry size prior to picking slab size = %ld bytes",entry_size)); /* 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 = 2, chunk_size = (1UL << slab_index) ; slab_index < (int)NUM_ENTRIES(__slab_data.sd_Slabs) ; slab_index++, chunk_size += chunk_size) { if(entry_size <= chunk_size) { D(("using slab #%ld (%lu bytes per chunk)", slab_index, chunk_size)); assert( (chunk_size % sizeof(LONG)) == 0 ); slab_list = &__slab_data.sd_Slabs[slab_index]; break; } } if(slab_list != NULL) { struct SlabNode * sn; SHOWVALUE(chunk_size); /* The slab list is organized in such a way that the first * entry always has a free chunk ready for allocation. If * there is no such free chunk, it means that no other * slab nodes in this list have any free chunks. */ sn = (struct SlabNode *)slab_list->mlh_Head; /* Make sure that the slab list is not empty. */ if(sn->sn_MinNode.mln_Succ != NULL) { D(("slab = 0x%08lx, chunk size = %ld", sn, sn->sn_ChunkSize)); assert( sn->sn_ChunkSize == chunk_size ); chunk = (struct SlabChunk *)RemHead((struct List *)&sn->sn_FreeList); if(chunk != NULL) { /* Keep track of this chunk's parent slab. */ chunk->sc_Parent = sn; allocation = &chunk[1]; D(("allocation succeeded at 0x%08lx in slab 0x%08lx (slab use count = %lu)",allocation,sn,sn->sn_UseCount)); /* Was this slab empty before we began using it again? */ if(sn->sn_UseCount == 0) { D(("slab is no longer empty")); /* Pull it out of the list of slabs available for reuse. */ Remove((struct Node *)&sn->sn_EmptyLink); sn->sn_EmptyDecay = 0; sn->sn_NumReused++; } 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) { D(("slab is full")); Remove((struct Node *)sn); AddTail((struct List *)slab_list, (struct Node *)sn); } } } /* There is no slab with a free chunk? Then we might have to * allocate a new one. */ if(allocation == NULL) { struct MinNode * free_node; struct MinNode * free_node_next; struct SlabNode * new_sn = NULL; BOOL purge = FALSE; D(("no slab is available which still has free room")); /* 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); /* If the chunk size of the reused slab matches * exactly what we need then we won't have to * completely reinitialize it again. */ if(sn->sn_ChunkSize == chunk_size) { slab_reused = TRUE; } else { /* Unlink from list of slabs which keep chunks * of the same size. It will be added there * again, at a different position. */ Remove((struct Node *)sn); } D(("reusing a slab")); sn->sn_NumReused++; 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) { D(("no slab is available for reuse; allocating a new slab (%lu bytes)",sizeof(*new_sn) + __slab_data.sd_StandardSlabSize)); PROFILE_OFF(); #if defined(__amigaos4__) { new_sn = (struct SlabNode *)AllocVec(sizeof(*new_sn) + __slab_data.sd_StandardSlabSize,MEMF_PRIVATE); } #else { new_sn = (struct SlabNode *)AllocVec(sizeof(*new_sn) + __slab_data.sd_StandardSlabSize,MEMF_ANY); } #endif /* __amigaos4__ */ PROFILE_ON(); if(new_sn == NULL) D(("slab allocation failed")); /* If this allocation went well, try to free all currently unused * slabs which are ready for purging. This is done so that we don't * keep allocating new memory all the time without cutting back on * unused slabs. */ purge = TRUE; } if(new_sn != NULL) { D(("setting up slab 0x%08lx", new_sn)); assert( chunk_size <= __slab_data.sd_StandardSlabSize ); /* Do we have to completely initialize this slab from scratch? */ if(NOT slab_reused) { struct SlabChunk * free_chunk; ULONG num_free_chunks = 0; BYTE * first_byte; BYTE * last_byte; memset(new_sn,0,sizeof(*new_sn)); NewList((struct List *)&new_sn->sn_FreeList); /* This slab has room for new allocations, so make sure that * it goes to the front of the slab list. It will be used * by the next allocation request of this size. */ AddHead((struct List *)slab_list,(struct Node *)new_sn); /* 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_StandardSlabSize - chunk_size]; for(free_chunk = (struct SlabChunk *)first_byte ; free_chunk <= (struct SlabChunk *)last_byte; free_chunk = (struct SlabChunk *)(((BYTE *)free_chunk) + chunk_size)) { AddTail((struct List *)&new_sn->sn_FreeList, (struct Node *)free_chunk); num_free_chunks++; } new_sn->sn_Count = num_free_chunks; new_sn->sn_ChunkSize = chunk_size; D(("new slab contains %lu chunks, %lu bytes each",num_free_chunks,chunk_size)); } /* This slab was reused and need not be reinitialized from scratch. */ else { assert( new_sn->sn_FreeList.mlh_Head != NULL ); assert( new_sn->sn_ChunkSize == chunk_size ); assert( new_sn->sn_Count == 0 ); } /* Grab the first free chunk (there has to be one). */ chunk = (struct SlabChunk *)RemHead((struct List *)&new_sn->sn_FreeList); /* Keep track of this chunk's parent slab. */ chunk->sc_Parent = new_sn; assert( chunk != NULL ); assert( chunk->sc_Parent == new_sn ); allocation = &chunk[1]; /* This slab is now in use. */ new_sn->sn_UseCount = 1; D(("allocation succeeded at 0x%08lx in slab 0x%08lx (slab use count = %lu)",allocation,new_sn,new_sn->sn_UseCount)); } /* Mark unused slabs for purging, and purge those which * are ready to be purged. */ if(purge) { size_t total_purged = 0; D(("purging empty slabs")); 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) { D(("freeing empty slab")); /* Unlink from list of empty slabs. */ Remove((struct Node *)free_node); /* Unlink from list of slabs of the same size. */ Remove((struct Node *)sn); PROFILE_OFF(); FreeVec(sn); PROFILE_ON(); total_purged += sizeof(*sn) + __slab_data.sd_StandardSlabSize; /* Stop releasing memory if we reach the threshold. If no * threshold has been set, we will free as much memory * as possible. */ if(__slab_purge_threshold > 0 && total_purged >= __slab_purge_threshold) break; } /* Give it another chance. */ else { sn->sn_EmptyDecay--; /* Is this slab ready for reuse now? */ if(sn->sn_EmptyDecay == 0) { /* Move it to the front of the list, so that * it will be collected as soon as possible. */ if(free_node != (struct MinNode *)__slab_data.sd_EmptySlabs.mlh_Head) { Remove((struct Node *)free_node); AddHead((struct List *)&__slab_data.sd_EmptySlabs,(struct Node *)free_node); } } } } } } } else { D(("no matching slab found")); } } return(allocation); } /****************************************************************************/ void __slab_free(void * address,size_t allocation_size) { struct SlabChunk * chunk; D(("freeing allocation at 0x%08lx, %lu bytes",address,allocation_size)); assert( __slab_data.sd_StandardSlabSize > 0 ); /* Number of bytes allocated exceeds the slab size? * Then the chunk was allocated separately. */ if(sizeof(*chunk) + allocation_size > __slab_data.sd_StandardSlabSize) { struct SlabSingleAllocation * ssa = address; ULONG size; D(("allocation size is > %ld; this was stored separately",__slab_data.sd_StandardSlabSize)); assert( __slab_data.sd_NumSingleAllocations > 0 ); /* Management information (MinNode linkage, size in bytes) precedes * the address returned by malloc(), etc. */ ssa--; /* Verify that the allocation is really on the list we * will remove it from. */ #if DEBUG { struct MinNode * mln; BOOL found_allocation_in_list = FALSE; for(mln = __slab_data.sd_SingleAllocations.mlh_Head ; mln->mln_Succ != NULL ; mln = mln->mln_Succ) { if(mln == (struct MinNode *)ssa) { found_allocation_in_list = TRUE; break; } } assert( found_allocation_in_list ); } #endif /* DEBUG */ size = ssa->ssa_Size; assert( size > 0 ); assert( sizeof(*ssa) + allocation_size == size ); assert( size <= __slab_data.sd_TotalSingleAllocationSize ); Remove((struct Node *)ssa); PROFILE_OFF(); FreeMem(ssa, size); PROFILE_ON(); __slab_data.sd_NumSingleAllocations--; __slab_data.sd_TotalSingleAllocationSize -= size; D(("number of single allocations = %ld", __slab_data.sd_NumSingleAllocations)); } /* Otherwise the allocation should have come from a slab. */ else { struct MinList * slab_list = NULL; size_t entry_size; ULONG chunk_size; int slab_index; D(("allocation size is <= %ld; this was allocated from a slab",__slab_data.sd_StandardSlabSize)); /* Add room for a pointer back to the slab which * the chunk belongs to. */ entry_size = sizeof(*chunk) + allocation_size; /* 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. */ 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 * released. We end up picking the smallest chunk * size that still works. */ for(slab_index = 2, chunk_size = (1UL << slab_index) ; slab_index < (int)NUM_ENTRIES(__slab_data.sd_Slabs) ; slab_index++, chunk_size += chunk_size) { if(entry_size <= chunk_size) { D(("using slab #%ld (%ld bytes per chunk)", slab_index, chunk_size)); assert( (chunk_size % sizeof(LONG)) == 0 ); slab_list = &__slab_data.sd_Slabs[slab_index]; break; } } /* Pick the slab which contains the memory chunk. */ if(slab_list != NULL) { struct SlabNode * sn; assert( chunk_size <= __slab_data.sd_StandardSlabSize ); /* The pointer back to the slab which this chunk belongs * to precedes the address which __slab_allocate() * returned. */ chunk = address; chunk--; sn = chunk->sc_Parent; #if DEBUG { struct SlabNode * other_sn; BOOL slab_found = FALSE; BOOL chunk_found = FALSE; for(other_sn = (struct SlabNode *)slab_list->mlh_Head ; other_sn->sn_MinNode.mln_Succ != NULL ; other_sn = (struct SlabNode *)other_sn->sn_MinNode.mln_Succ) { if(other_sn == sn) { slab_found = TRUE; break; } } assert( slab_found ); if(slab_found) { struct MinNode * free_chunk; BYTE * first_byte; BYTE * last_byte; first_byte = (BYTE *)&sn[1]; last_byte = &first_byte[__slab_data.sd_StandardSlabSize - chunk_size]; for(free_chunk = (struct MinNode *)first_byte ; free_chunk <= (struct MinNode *)last_byte; free_chunk = (struct MinNode *)(((BYTE *)free_chunk) + chunk_size)) { if(free_chunk == (struct MinNode *)chunk) { chunk_found = TRUE; break; } } } assert( chunk_found ); } #endif /* DEBUG */ SHOWVALUE(sn->sn_ChunkSize); assert( sn->sn_ChunkSize != 0 ); assert( sn->sn_ChunkSize == chunk_size ); D(("allocation is part of slab 0x%08lx (slab use count = %ld)",sn,sn->sn_UseCount)); #if DEBUG { struct MinNode * mln; BOOL chunk_already_free = FALSE; for(mln = sn->sn_FreeList.mlh_Head ; mln->mln_Succ != NULL ; mln = mln->mln_Succ) { if(mln == (struct MinNode *)chunk) { chunk_already_free = TRUE; break; } } assert( NOT chunk_already_free ); } #endif /* DEBUG */ AddHead((struct List *)&sn->sn_FreeList, (struct Node *)chunk); assert( sn->sn_UseCount > 0 ); sn->sn_UseCount--; /* If this slab is empty, mark it as unused and * allow it to be purged. */ if(sn->sn_UseCount == 0) { D(("slab is now empty")); AddTail((struct List *)&__slab_data.sd_EmptySlabs,(struct Node *)&sn->sn_EmptyLink); sn->sn_EmptyDecay = 1; } /* This slab now has room. Move it to front of the list * so that searching for a free chunk will pick it * first. */ if(sn != (struct SlabNode *)slab_list->mlh_Head) { D(("moving slab to the head of the list")); Remove((struct Node *)sn); AddHead((struct List *)slab_list, (struct Node *)sn); } } else { D(("no matching slab found")); } } } /****************************************************************************/ void __slab_init(size_t slab_size) { const size_t max_slab_size = (1UL << (NUM_ENTRIES(__slab_data.sd_Slabs))); size_t size; SETDEBUGLEVEL(2); D(("slab_size = %ld",slab_size)); /* Do not allow for a slab size that is larger than * what we support. */ if(slab_size > max_slab_size) slab_size = max_slab_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 2^17, 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_size && (size & 0x80000000) == 0) size += size; D(("size = %lu",size)); /* If the slab size looks sound, enable the slab memory allocator. */ if((size & 0x80000000) == 0) { int i; D(("activating slab allocator")); memset(&__slab_data,0,sizeof(__slab_data)); assert( size <= slab_size ); /* Start with an empty list of slabs for each chunk size. */ for(i = 0 ; i < (int)NUM_ENTRIES(__slab_data.sd_Slabs) ; 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_StandardSlabSize = size; __slab_data.sd_InUse = TRUE; } } /****************************************************************************/ #if DEBUG static int print_json(void * ignore,const char * buffer,size_t len) { extern void kputs(const char * str); kputs(buffer); return(0); } #endif /* DEBUG */ /****************************************************************************/ void __slab_exit(void) { ENTER(); if(__slab_data.sd_InUse) { struct SlabSingleAllocation * ssa; struct SlabNode * sn; struct SlabNode * sn_next; struct MinNode * mn; struct MinNode * mn_next; size_t slab_count = 0, total_slab_size = 0; size_t single_allocation_count = 0, total_single_allocation_size = 0; int i, j; #if DEBUG { kprintf("---BEGIN JSON DATA ---\n"); __get_slab_stats(NULL, print_json); kprintf("---END JSON DATA ---\n\n"); } #endif /* DEBUG */ D(("freeing slabs")); /* Free the memory allocated for each slab. */ for(i = 0 ; i < (int)NUM_ENTRIES(__slab_data.sd_Slabs) ; i++) { if(__slab_data.sd_Slabs[i].mlh_Head->mln_Succ != NULL) D(("freeing slab slot #%ld (%lu bytes per chunk)", i, (1UL << i))); for(sn = (struct SlabNode *)__slab_data.sd_Slabs[i].mlh_Head, j = 0 ; sn->sn_MinNode.mln_Succ != NULL ; sn = sn_next) { sn_next = (struct SlabNode *)sn->sn_MinNode.mln_Succ; D((" slab #%ld.%ld at 0x%08lx",i, ++j, sn)); D((" fragmentation = %ld%%",100 * (__slab_data.sd_StandardSlabSize - sn->sn_Count * sn->sn_ChunkSize) / __slab_data.sd_StandardSlabSize)); D((" total space used = %ld (%ld%%)",sn->sn_UseCount * sn->sn_ChunkSize, 100 * sn->sn_UseCount / sn->sn_Count)); D((" number of chunks total = %ld",sn->sn_Count)); D((" number of chunks used = %ld%s",sn->sn_UseCount,sn->sn_UseCount == 0 ? " (empty)" : (sn->sn_UseCount == sn->sn_Count) ? " (full)" : "")); D((" how often reused = %ld",sn->sn_NumReused)); total_slab_size += sizeof(*sn) + __slab_data.sd_StandardSlabSize; slab_count++; PROFILE_OFF(); FreeVec(sn); PROFILE_ON(); } } if(slab_count > 0) D(("number of slabs = %ld, total slab size = %ld bytes",slab_count, total_slab_size)); if(__slab_data.sd_SingleAllocations.mlh_Head->mln_Succ != NULL) D(("freeing single allocations")); /* Free the memory allocated for each allocation which did not * go into a slab. */ for(mn = __slab_data.sd_SingleAllocations.mlh_Head, j = 0 ; mn->mln_Succ != NULL ; mn = mn_next) { mn_next = mn->mln_Succ; ssa = (struct SlabSingleAllocation *)mn; D((" allocation #%ld at 0x%08lx, %lu bytes", ++j, ssa, ssa->ssa_Size)); total_single_allocation_size += ssa->ssa_Size; single_allocation_count++; PROFILE_OFF(); FreeMem(ssa, ssa->ssa_Size); PROFILE_ON(); } if(single_allocation_count > 0) D(("number of single allocations = %ld, total single allocation size = %ld", single_allocation_count, total_single_allocation_size)); __slab_data.sd_InUse = FALSE; } LEAVE(); }