2159 lines
62 KiB
C
2159 lines
62 KiB
C
|
||
#include <malloc.h>
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#include <config.h>
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#include <stdio.h>
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#include <module.h>
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/*
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Emulation of sbrk for WIN32
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All code within the ifdef WIN32 is untested by me.
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Thanks to Martin Fong and others for supplying this.
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*/
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#ifdef WIN32
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#define AlignPage(add) (((add) + (malloc_getpagesize-1)) & \
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~(malloc_getpagesize-1))
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#define AlignPage64K(add) (((add) + (0x10000 - 1)) & ~(0x10000 - 1))
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/* resrve 64MB to insure large contiguous space */
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#define RESERVED_SIZE (1024*1024*64)
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#define NEXT_SIZE (2048*1024)
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#define TOP_MEMORY ((unsigned long)2*1024*1024*1024)
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struct GmListElement;
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typedef struct GmListElement GmListElement;
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struct GmListElement
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{
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GmListElement* next;
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void* base;
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};
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static GmListElement* head = 0;
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static unsigned int gNextAddress = 0;
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static unsigned int gAddressBase = 0;
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static unsigned int gAllocatedSize = 0;
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static
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GmListElement* makeGmListElement (void* bas)
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{
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GmListElement* this;
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this = (GmListElement*)(void*)LocalAlloc (0, sizeof (GmListElement));
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assert (this);
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if (this)
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{
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this->base = bas;
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this->next = head;
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head = this;
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}
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return this;
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}
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void gcleanup ()
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{
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BOOL rval;
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assert ( (head == NULL) || (head->base == (void*)gAddressBase));
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if (gAddressBase && (gNextAddress - gAddressBase))
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{
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rval = VirtualFree ((void*)gAddressBase,
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gNextAddress - gAddressBase,
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MEM_DECOMMIT);
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assert (rval);
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}
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while (head)
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{
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GmListElement* next = head->next;
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rval = VirtualFree (head->base, 0, MEM_RELEASE);
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assert (rval);
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LocalFree (head);
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head = next;
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}
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}
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static
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void* findRegion (void* start_address, unsigned long size)
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{
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MEMORY_BASIC_INFORMATION info;
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if (size >= TOP_MEMORY) return NULL;
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while ((unsigned long)start_address + size < TOP_MEMORY)
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{
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VirtualQuery (start_address, &info, sizeof (info));
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if ((info.State == MEM_FREE) && (info.RegionSize >= size))
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return start_address;
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else
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{
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/* Requested region is not available so see if the */
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/* next region is available. Set 'start_address' */
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/* to the next region and call 'VirtualQuery()' */
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/* again. */
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start_address = (char*)info.BaseAddress + info.RegionSize;
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/* Make sure we start looking for the next region */
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/* on the *next* 64K boundary. Otherwise, even if */
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/* the new region is free according to */
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/* 'VirtualQuery()', the subsequent call to */
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/* 'VirtualAlloc()' (which follows the call to */
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/* this routine in 'wsbrk()') will round *down* */
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/* the requested address to a 64K boundary which */
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/* we already know is an address in the */
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/* unavailable region. Thus, the subsequent call */
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/* to 'VirtualAlloc()' will fail and bring us back */
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/* here, causing us to go into an infinite loop. */
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start_address =
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(void *) AlignPage64K((unsigned long) start_address);
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}
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}
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return NULL;
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}
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void* wsbrk (long size)
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{
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void* tmp;
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if (size > 0)
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{
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if (gAddressBase == 0)
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{
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gAllocatedSize = max (RESERVED_SIZE, AlignPage (size));
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gNextAddress = gAddressBase =
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(unsigned int)VirtualAlloc (NULL, gAllocatedSize,
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MEM_RESERVE, PAGE_NOACCESS);
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} else if (AlignPage (gNextAddress + size) > (gAddressBase +
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gAllocatedSize))
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{
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long new_size = max (NEXT_SIZE, AlignPage (size));
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void* new_address = (void*)(gAddressBase+gAllocatedSize);
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do
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{
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new_address = findRegion (new_address, new_size);
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if (new_address == 0)
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return (void*)-1;
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gAddressBase = gNextAddress =
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(unsigned int)VirtualAlloc (new_address, new_size,
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MEM_RESERVE, PAGE_NOACCESS);
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/* repeat in case of race condition */
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/* The region that we found has been snagged */
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/* by another thread */
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}
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while (gAddressBase == 0);
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assert (new_address == (void*)gAddressBase);
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gAllocatedSize = new_size;
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if (!makeGmListElement ((void*)gAddressBase))
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return (void*)-1;
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}
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if ((size + gNextAddress) > AlignPage (gNextAddress))
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{
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void* res;
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res = VirtualAlloc ((void*)AlignPage (gNextAddress),
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(size + gNextAddress -
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AlignPage (gNextAddress)),
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MEM_COMMIT, PAGE_READWRITE);
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if (res == 0)
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return (void*)-1;
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}
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tmp = (void*)gNextAddress;
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gNextAddress = (unsigned int)tmp + size;
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return tmp;
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}
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else if (size < 0)
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{
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unsigned int alignedGoal = AlignPage (gNextAddress + size);
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/* Trim by releasing the virtual memory */
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if (alignedGoal >= gAddressBase)
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{
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VirtualFree ((void*)alignedGoal, gNextAddress - alignedGoal,
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MEM_DECOMMIT);
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gNextAddress = gNextAddress + size;
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return (void*)gNextAddress;
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}
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else
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{
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VirtualFree ((void*)gAddressBase, gNextAddress - gAddressBase,
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MEM_DECOMMIT);
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gNextAddress = gAddressBase;
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return (void*)-1;
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}
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}
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else
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{
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return (void*)gNextAddress;
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}
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}
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#endif
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/*
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Type declarations
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*/
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struct malloc_chunk
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{
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INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
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INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */
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struct malloc_chunk* fd; /* double links -- used only if free. */
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struct malloc_chunk* bk;
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};
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typedef struct malloc_chunk* mchunkptr;
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/*
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malloc_chunk details:
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(The following includes lightly edited explanations by Colin Plumb.)
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Chunks of memory are maintained using a `boundary tag' method as
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described in e.g., Knuth or Standish. (See the paper by Paul
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Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
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survey of such techniques.) Sizes of free chunks are stored both
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in the front of each chunk and at the end. This makes
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consolidating fragmented chunks into bigger chunks very fast. The
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size fields also hold bits representing whether chunks are free or
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in use.
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An allocated chunk looks like this:
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chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Size of previous chunk, if allocated | |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Size of chunk, in bytes |P|
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mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| User data starts here... .
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. .
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. (malloc_usable_space() bytes) .
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. |
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nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Size of chunk |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Where "chunk" is the front of the chunk for the purpose of most of
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the malloc code, but "mem" is the pointer that is returned to the
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user. "Nextchunk" is the beginning of the next contiguous chunk.
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Chunks always begin on even word boundries, so the mem portion
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(which is returned to the user) is also on an even word boundary, and
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thus double-word aligned.
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Free chunks are stored in circular doubly-linked lists, and look like this:
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chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Size of previous chunk |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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`head:' | Size of chunk, in bytes |P|
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mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Forward pointer to next chunk in list |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Back pointer to previous chunk in list |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| Unused space (may be 0 bytes long) .
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. .
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. |
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nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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`foot:' | Size of chunk, in bytes |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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The P (PREV_INUSE) bit, stored in the unused low-order bit of the
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chunk size (which is always a multiple of two words), is an in-use
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bit for the *previous* chunk. If that bit is *clear*, then the
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word before the current chunk size contains the previous chunk
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size, and can be used to find the front of the previous chunk.
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(The very first chunk allocated always has this bit set,
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preventing access to non-existent (or non-owned) memory.)
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Note that the `foot' of the current chunk is actually represented
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as the prev_size of the NEXT chunk. (This makes it easier to
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deal with alignments etc).
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The two exceptions to all this are
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1. The special chunk `top', which doesn't bother using the
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trailing size field since there is no
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next contiguous chunk that would have to index off it. (After
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initialization, `top' is forced to always exist. If it would
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become less than MINSIZE bytes long, it is replenished via
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malloc_extend_top.)
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2. Chunks allocated via mmap, which have the second-lowest-order
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bit (IS_MMAPPED) set in their size fields. Because they are
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never merged or traversed from any other chunk, they have no
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foot size or inuse information.
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Available chunks are kept in any of several places (all declared below):
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* `av': An array of chunks serving as bin headers for consolidated
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chunks. Each bin is doubly linked. The bins are approximately
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proportionally (log) spaced. There are a lot of these bins
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(128). This may look excessive, but works very well in
|
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practice. All procedures maintain the invariant that no
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consolidated chunk physically borders another one. Chunks in
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bins are kept in size order, with ties going to the
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approximately least recently used chunk.
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The chunks in each bin are maintained in decreasing sorted order by
|
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size. This is irrelevant for the small bins, which all contain
|
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the same-sized chunks, but facilitates best-fit allocation for
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larger chunks. (These lists are just sequential. Keeping them in
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order almost never requires enough traversal to warrant using
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fancier ordered data structures.) Chunks of the same size are
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linked with the most recently freed at the front, and allocations
|
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are taken from the back. This results in LRU or FIFO allocation
|
||
order, which tends to give each chunk an equal opportunity to be
|
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consolidated with adjacent freed chunks, resulting in larger free
|
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chunks and less fragmentation.
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||
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* `top': The top-most available chunk (i.e., the one bordering the
|
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end of available memory) is treated specially. It is never
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included in any bin, is used only if no other chunk is
|
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available, and is released back to the system if it is very
|
||
large (see M_TRIM_THRESHOLD).
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||
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* `last_remainder': A bin holding only the remainder of the
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||
most recently split (non-top) chunk. This bin is checked
|
||
before other non-fitting chunks, so as to provide better
|
||
locality for runs of sequentially allocated chunks.
|
||
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||
* Implicitly, through the host system's memory mapping tables.
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||
If supported, requests greater than a threshold are usually
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serviced via calls to mmap, and then later released via munmap.
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||
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||
*/
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||
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/* sizes, alignments */
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||
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#define SIZE_SZ (sizeof(INTERNAL_SIZE_T))
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#define MALLOC_ALIGNMENT (SIZE_SZ + SIZE_SZ)
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||
#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
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#define MINSIZE (sizeof(struct malloc_chunk))
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||
|
||
/* conversion from malloc headers to user pointers, and back */
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||
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||
#define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ))
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||
#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
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||
|
||
/* pad request bytes into a usable size */
|
||
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||
#define request2size(req) \
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(((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \
|
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(long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \
|
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(((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK)))
|
||
|
||
/* Check if m has acceptable alignment */
|
||
|
||
#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
|
||
|
||
|
||
|
||
|
||
/*
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||
Physical chunk operations
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||
*/
|
||
|
||
|
||
/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
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||
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||
#define PREV_INUSE 0x1
|
||
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||
/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
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||
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||
#define IS_MMAPPED 0x2
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||
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||
/* Bits to mask off when extracting size */
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||
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||
#define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
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||
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||
|
||
/* Ptr to next physical malloc_chunk. */
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||
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||
#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
|
||
|
||
/* Ptr to previous physical malloc_chunk */
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||
|
||
#define prev_chunk(p)\
|
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((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
|
||
|
||
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||
/* Treat space at ptr + offset as a chunk */
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||
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||
#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s)))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with use bits
|
||
*/
|
||
|
||
/* extract p's inuse bit */
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||
|
||
#define inuse(p)\
|
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((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
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||
|
||
/* extract inuse bit of previous chunk */
|
||
|
||
#define prev_inuse(p) ((p)->size & PREV_INUSE)
|
||
|
||
/* check for mmap()'ed chunk */
|
||
|
||
#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
|
||
|
||
/* set/clear chunk as in use without otherwise disturbing */
|
||
|
||
#define set_inuse(p)\
|
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((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
|
||
|
||
#define clear_inuse(p)\
|
||
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
|
||
|
||
/* check/set/clear inuse bits in known places */
|
||
|
||
#define inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
|
||
|
||
#define set_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
|
||
|
||
#define clear_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with size fields
|
||
*/
|
||
|
||
/* Get size, ignoring use bits */
|
||
|
||
#define chunksize(p) ((p)->size & ~(SIZE_BITS))
|
||
|
||
/* Set size at head, without disturbing its use bit */
|
||
|
||
#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s)))
|
||
|
||
/* Set size/use ignoring previous bits in header */
|
||
|
||
#define set_head(p, s) ((p)->size = (s))
|
||
|
||
/* Set size at footer (only when chunk is not in use) */
|
||
|
||
#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
Bins
|
||
|
||
The bins, `av_' are an array of pairs of pointers serving as the
|
||
heads of (initially empty) doubly-linked lists of chunks, laid out
|
||
in a way so that each pair can be treated as if it were in a
|
||
malloc_chunk. (This way, the fd/bk offsets for linking bin heads
|
||
and chunks are the same).
|
||
|
||
Bins for sizes < 512 bytes contain chunks of all the same size, spaced
|
||
8 bytes apart. Larger bins are approximately logarithmically
|
||
spaced. (See the table below.) The `av_' array is never mentioned
|
||
directly in the code, but instead via bin access macros.
|
||
|
||
Bin layout:
|
||
|
||
64 bins of size 8
|
||
32 bins of size 64
|
||
16 bins of size 512
|
||
8 bins of size 4096
|
||
4 bins of size 32768
|
||
2 bins of size 262144
|
||
1 bin of size what's left
|
||
|
||
There is actually a little bit of slop in the numbers in bin_index
|
||
for the sake of speed. This makes no difference elsewhere.
|
||
|
||
The special chunks `top' and `last_remainder' get their own bins,
|
||
(this is implemented via yet more trickery with the av_ array),
|
||
although `top' is never properly linked to its bin since it is
|
||
always handled specially.
|
||
|
||
*/
|
||
|
||
#define NAV 128 /* number of bins */
|
||
|
||
typedef struct malloc_chunk* mbinptr;
|
||
|
||
/* access macros */
|
||
|
||
#define bin_at(i) ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ))
|
||
#define next_bin(b) ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr)))
|
||
#define prev_bin(b) ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr)))
|
||
|
||
/*
|
||
The first 2 bins are never indexed. The corresponding av_ cells are instead
|
||
used for bookkeeping. This is not to save space, but to simplify
|
||
indexing, maintain locality, and avoid some initialization tests.
|
||
*/
|
||
|
||
#define top (bin_at(0)->fd) /* The topmost chunk */
|
||
#define last_remainder (bin_at(1)) /* remainder from last split */
|
||
|
||
|
||
/*
|
||
Because top initially points to its own bin with initial
|
||
zero size, thus forcing extension on the first malloc request,
|
||
we avoid having any special code in malloc to check whether
|
||
it even exists yet. But we still need to in malloc_extend_top.
|
||
*/
|
||
|
||
#define initial_top ((mchunkptr)(bin_at(0)))
|
||
|
||
/* Helper macro to initialize bins */
|
||
|
||
#define IAV(i) bin_at(i), bin_at(i)
|
||
|
||
static mbinptr av_[NAV * 2 + 2] = {
|
||
0, 0,
|
||
IAV(0), IAV(1), IAV(2), IAV(3), IAV(4), IAV(5), IAV(6), IAV(7),
|
||
IAV(8), IAV(9), IAV(10), IAV(11), IAV(12), IAV(13), IAV(14), IAV(15),
|
||
IAV(16), IAV(17), IAV(18), IAV(19), IAV(20), IAV(21), IAV(22), IAV(23),
|
||
IAV(24), IAV(25), IAV(26), IAV(27), IAV(28), IAV(29), IAV(30), IAV(31),
|
||
IAV(32), IAV(33), IAV(34), IAV(35), IAV(36), IAV(37), IAV(38), IAV(39),
|
||
IAV(40), IAV(41), IAV(42), IAV(43), IAV(44), IAV(45), IAV(46), IAV(47),
|
||
IAV(48), IAV(49), IAV(50), IAV(51), IAV(52), IAV(53), IAV(54), IAV(55),
|
||
IAV(56), IAV(57), IAV(58), IAV(59), IAV(60), IAV(61), IAV(62), IAV(63),
|
||
IAV(64), IAV(65), IAV(66), IAV(67), IAV(68), IAV(69), IAV(70), IAV(71),
|
||
IAV(72), IAV(73), IAV(74), IAV(75), IAV(76), IAV(77), IAV(78), IAV(79),
|
||
IAV(80), IAV(81), IAV(82), IAV(83), IAV(84), IAV(85), IAV(86), IAV(87),
|
||
IAV(88), IAV(89), IAV(90), IAV(91), IAV(92), IAV(93), IAV(94), IAV(95),
|
||
IAV(96), IAV(97), IAV(98), IAV(99), IAV(100), IAV(101), IAV(102), IAV(103),
|
||
IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111),
|
||
IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119),
|
||
IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127)
|
||
};
|
||
|
||
/* field-extraction macros */
|
||
|
||
#define first(b) ((b)->fd)
|
||
#define last(b) ((b)->bk)
|
||
|
||
/*
|
||
Indexing into bins
|
||
*/
|
||
|
||
#define bin_index(sz) \
|
||
(((((unsigned long)(sz)) >> 9) == 0) ? (((unsigned long)(sz)) >> 3): \
|
||
((((unsigned long)(sz)) >> 9) <= 4) ? 56 + (((unsigned long)(sz)) >> 6): \
|
||
((((unsigned long)(sz)) >> 9) <= 20) ? 91 + (((unsigned long)(sz)) >> 9): \
|
||
((((unsigned long)(sz)) >> 9) <= 84) ? 110 + (((unsigned long)(sz)) >> 12): \
|
||
((((unsigned long)(sz)) >> 9) <= 340) ? 119 + (((unsigned long)(sz)) >> 15): \
|
||
((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \
|
||
126)
|
||
/*
|
||
bins for chunks < 512 are all spaced 8 bytes apart, and hold
|
||
identically sized chunks. This is exploited in malloc.
|
||
*/
|
||
|
||
#define MAX_SMALLBIN 63
|
||
#define MAX_SMALLBIN_SIZE 512
|
||
#define SMALLBIN_WIDTH 8
|
||
|
||
#define smallbin_index(sz) (((unsigned long)(sz)) >> 3)
|
||
|
||
/*
|
||
Requests are `small' if both the corresponding and the next bin are small
|
||
*/
|
||
|
||
#define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH)
|
||
|
||
|
||
|
||
/*
|
||
To help compensate for the large number of bins, a one-level index
|
||
structure is used for bin-by-bin searching. `binblocks' is a
|
||
one-word bitvector recording whether groups of BINBLOCKWIDTH bins
|
||
have any (possibly) non-empty bins, so they can be skipped over
|
||
all at once during during traversals. The bits are NOT always
|
||
cleared as soon as all bins in a block are empty, but instead only
|
||
when all are noticed to be empty during traversal in malloc.
|
||
*/
|
||
|
||
#define BINBLOCKWIDTH 4 /* bins per block */
|
||
|
||
#define binblocks (bin_at(0)->size) /* bitvector of nonempty blocks */
|
||
|
||
/* bin<->block macros */
|
||
|
||
#define idx2binblock(ix) ((unsigned)1 << (ix / BINBLOCKWIDTH))
|
||
#define mark_binblock(ii) (binblocks |= idx2binblock(ii))
|
||
#define clear_binblock(ii) (binblocks &= ~(idx2binblock(ii)))
|
||
|
||
|
||
|
||
|
||
|
||
/* Other static bookkeeping data */
|
||
|
||
/* variables holding tunable values */
|
||
#ifndef __U_BOOT__
|
||
static unsigned long trim_threshold = DEFAULT_TRIM_THRESHOLD;
|
||
static unsigned int n_mmaps_max = DEFAULT_MMAP_MAX;
|
||
static unsigned long mmap_threshold = DEFAULT_MMAP_THRESHOLD;
|
||
#endif
|
||
static unsigned long top_pad = DEFAULT_TOP_PAD;
|
||
|
||
/* The first value returned from sbrk */
|
||
static char* sbrk_base = (char*)(-1);
|
||
|
||
/* The maximum memory obtained from system via sbrk */
|
||
static unsigned long max_sbrked_mem = 0;
|
||
|
||
/* The maximum via either sbrk or mmap */
|
||
static unsigned long max_total_mem = 0;
|
||
|
||
/* internal working copy of mallinfo */
|
||
static struct mallinfo current_mallinfo = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
|
||
|
||
/* The total memory obtained from system via sbrk */
|
||
#define sbrked_mem (current_mallinfo.arena)
|
||
|
||
/* Tracking mmaps */
|
||
|
||
static unsigned long mmapped_mem = 0;
|
||
|
||
|
||
|
||
/*
|
||
Debugging support
|
||
*/
|
||
|
||
#ifdef DEBUG
|
||
|
||
|
||
/*
|
||
These routines make a number of assertions about the states
|
||
of data structures that should be true at all times. If any
|
||
are not true, it's very likely that a user program has somehow
|
||
trashed memory. (It's also possible that there is a coding error
|
||
in malloc. In which case, please report it!)
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void do_check_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
|
||
/* No checkable chunk is mmapped */
|
||
assert(!chunk_is_mmapped(p));
|
||
|
||
/* Check for legal address ... */
|
||
assert((char*)p >= sbrk_base);
|
||
if (p != top)
|
||
assert((char*)p + sz <= (char*)top);
|
||
else
|
||
assert((char*)p + sz <= sbrk_base + sbrked_mem);
|
||
|
||
}
|
||
|
||
|
||
#if __STD_C
|
||
static void do_check_free_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_free_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
|
||
do_check_chunk(p);
|
||
|
||
/* Check whether it claims to be free ... */
|
||
assert(!inuse(p));
|
||
|
||
/* Unless a special marker, must have OK fields */
|
||
if ((long)sz >= (long)MINSIZE)
|
||
{
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
/* ... matching footer field */
|
||
assert(next->prev_size == sz);
|
||
/* ... and is fully consolidated */
|
||
assert(prev_inuse(p));
|
||
assert (next == top || inuse(next));
|
||
|
||
/* ... and has minimally sane links */
|
||
assert(p->fd->bk == p);
|
||
assert(p->bk->fd == p);
|
||
}
|
||
else /* markers are always of size SIZE_SZ */
|
||
assert(sz == SIZE_SZ);
|
||
}
|
||
|
||
#if __STD_C
|
||
static void do_check_inuse_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_inuse_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
mchunkptr next = next_chunk(p);
|
||
do_check_chunk(p);
|
||
|
||
/* Check whether it claims to be in use ... */
|
||
assert(inuse(p));
|
||
|
||
/* ... and is surrounded by OK chunks.
|
||
Since more things can be checked with free chunks than inuse ones,
|
||
if an inuse chunk borders them and debug is on, it's worth doing them.
|
||
*/
|
||
if (!prev_inuse(p))
|
||
{
|
||
mchunkptr prv = prev_chunk(p);
|
||
assert(next_chunk(prv) == p);
|
||
do_check_free_chunk(prv);
|
||
}
|
||
if (next == top)
|
||
{
|
||
assert(prev_inuse(next));
|
||
assert(chunksize(next) >= MINSIZE);
|
||
}
|
||
else if (!inuse(next))
|
||
do_check_free_chunk(next);
|
||
|
||
}
|
||
|
||
#if __STD_C
|
||
static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
|
||
#else
|
||
static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
|
||
#endif
|
||
{
|
||
|
||
do_check_inuse_chunk(p);
|
||
|
||
/* Legal size ... */
|
||
assert((long)sz >= (long)MINSIZE);
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert(room >= 0);
|
||
assert(room < (long)MINSIZE);
|
||
|
||
/* ... and alignment */
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
|
||
|
||
/* ... and was allocated at front of an available chunk */
|
||
assert(prev_inuse(p));
|
||
|
||
}
|
||
|
||
|
||
#define check_free_chunk(P) do_check_free_chunk(P)
|
||
#define check_inuse_chunk(P) do_check_inuse_chunk(P)
|
||
#define check_chunk(P) do_check_chunk(P)
|
||
#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N)
|
||
#else
|
||
#define check_free_chunk(P)
|
||
#define check_inuse_chunk(P)
|
||
#define check_chunk(P)
|
||
#define check_malloced_chunk(P,N)
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
Macro-based internal utilities
|
||
*/
|
||
|
||
|
||
/*
|
||
Linking chunks in bin lists.
|
||
Call these only with variables, not arbitrary expressions, as arguments.
|
||
*/
|
||
|
||
/*
|
||
Place chunk p of size s in its bin, in size order,
|
||
putting it ahead of others of same size.
|
||
*/
|
||
|
||
|
||
#define frontlink(P, S, IDX, BK, FD) \
|
||
{ \
|
||
if (S < MAX_SMALLBIN_SIZE) \
|
||
{ \
|
||
IDX = smallbin_index(S); \
|
||
mark_binblock(IDX); \
|
||
BK = bin_at(IDX); \
|
||
FD = BK->fd; \
|
||
P->bk = BK; \
|
||
P->fd = FD; \
|
||
FD->bk = BK->fd = P; \
|
||
} \
|
||
else \
|
||
{ \
|
||
IDX = bin_index(S); \
|
||
BK = bin_at(IDX); \
|
||
FD = BK->fd; \
|
||
if (FD == BK) mark_binblock(IDX); \
|
||
else \
|
||
{ \
|
||
while (FD != BK && S < chunksize(FD)) FD = FD->fd; \
|
||
BK = FD->bk; \
|
||
} \
|
||
P->bk = BK; \
|
||
P->fd = FD; \
|
||
FD->bk = BK->fd = P; \
|
||
} \
|
||
}
|
||
|
||
|
||
/* take a chunk off a list */
|
||
|
||
#define unlink(P, BK, FD) \
|
||
{ \
|
||
BK = P->bk; \
|
||
FD = P->fd; \
|
||
FD->bk = BK; \
|
||
BK->fd = FD; \
|
||
} \
|
||
|
||
/* Place p as the last remainder */
|
||
|
||
#define link_last_remainder(P) \
|
||
{ \
|
||
last_remainder->fd = last_remainder->bk = P; \
|
||
P->fd = P->bk = last_remainder; \
|
||
}
|
||
|
||
/* Clear the last_remainder bin */
|
||
|
||
#define clear_last_remainder \
|
||
(last_remainder->fd = last_remainder->bk = last_remainder)
|
||
|
||
|
||
|
||
|
||
|
||
/* Routines dealing with mmap(). */
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
Extend the top-most chunk by obtaining memory from system.
|
||
Main interface to sbrk (but see also malloc_trim).
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void malloc_extend_top(INTERNAL_SIZE_T nb)
|
||
#else
|
||
static void malloc_extend_top(nb) INTERNAL_SIZE_T nb;
|
||
#endif
|
||
{
|
||
char* brk; /* return value from sbrk */
|
||
INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */
|
||
INTERNAL_SIZE_T correction; /* bytes for 2nd sbrk call */
|
||
char* new_brk; /* return of 2nd sbrk call */
|
||
INTERNAL_SIZE_T top_size; /* new size of top chunk */
|
||
|
||
mchunkptr old_top = top; /* Record state of old top */
|
||
INTERNAL_SIZE_T old_top_size = chunksize(old_top);
|
||
char* old_end = (char*)(chunk_at_offset(old_top, old_top_size));
|
||
|
||
/* Pad request with top_pad plus minimal overhead */
|
||
|
||
INTERNAL_SIZE_T sbrk_size = nb + top_pad + MINSIZE;
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
|
||
/* If not the first time through, round to preserve page boundary */
|
||
/* Otherwise, we need to correct to a page size below anyway. */
|
||
/* (We also correct below if an intervening foreign sbrk call.) */
|
||
|
||
if (sbrk_base != (char*)(-1))
|
||
sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1);
|
||
|
||
brk = (char*)(MORECORE (sbrk_size));
|
||
|
||
/* Fail if sbrk failed or if a foreign sbrk call killed our space */
|
||
if (brk == (char*)(MORECORE_FAILURE) ||
|
||
(brk < old_end && old_top != initial_top))
|
||
return;
|
||
|
||
sbrked_mem += sbrk_size;
|
||
|
||
if (brk == old_end) /* can just add bytes to current top */
|
||
{
|
||
top_size = sbrk_size + old_top_size;
|
||
set_head(top, top_size | PREV_INUSE);
|
||
}
|
||
else
|
||
{
|
||
if (sbrk_base == (char*)(-1)) /* First time through. Record base */
|
||
sbrk_base = brk;
|
||
else /* Someone else called sbrk(). Count those bytes as sbrked_mem. */
|
||
sbrked_mem += brk - (char*)old_end;
|
||
|
||
/* Guarantee alignment of first new chunk made from this space */
|
||
front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
|
||
if (front_misalign > 0)
|
||
{
|
||
correction = (MALLOC_ALIGNMENT) - front_misalign;
|
||
brk += correction;
|
||
}
|
||
else
|
||
correction = 0;
|
||
|
||
/* Guarantee the next brk will be at a page boundary */
|
||
|
||
correction += ((((unsigned long)(brk + sbrk_size))+(pagesz-1)) &
|
||
~(pagesz - 1)) - ((unsigned long)(brk + sbrk_size));
|
||
|
||
/* Allocate correction */
|
||
new_brk = (char*)(MORECORE (correction));
|
||
if (new_brk == (char*)(MORECORE_FAILURE)) return;
|
||
|
||
sbrked_mem += correction;
|
||
|
||
top = (mchunkptr)brk;
|
||
top_size = new_brk - brk + correction;
|
||
set_head(top, top_size | PREV_INUSE);
|
||
|
||
if (old_top != initial_top)
|
||
{
|
||
|
||
/* There must have been an intervening foreign sbrk call. */
|
||
/* A double fencepost is necessary to prevent consolidation */
|
||
|
||
/* If not enough space to do this, then user did something very wrong */
|
||
if (old_top_size < MINSIZE)
|
||
{
|
||
set_head(top, PREV_INUSE); /* will force null return from malloc */
|
||
return;
|
||
}
|
||
|
||
/* Also keep size a multiple of MALLOC_ALIGNMENT */
|
||
old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK;
|
||
set_head_size(old_top, old_top_size);
|
||
chunk_at_offset(old_top, old_top_size )->size =
|
||
SIZE_SZ|PREV_INUSE;
|
||
chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size =
|
||
SIZE_SZ|PREV_INUSE;
|
||
/* If possible, release the rest. */
|
||
if (old_top_size >= MINSIZE)
|
||
fREe(chunk2mem(old_top));
|
||
}
|
||
}
|
||
|
||
if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem)
|
||
max_sbrked_mem = sbrked_mem;
|
||
if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
|
||
max_total_mem = mmapped_mem + sbrked_mem;
|
||
|
||
/* We always land on a page boundary */
|
||
assert(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0);
|
||
}
|
||
|
||
|
||
|
||
|
||
/* Main public routines */
|
||
|
||
|
||
/*
|
||
Malloc Algorthim:
|
||
|
||
The requested size is first converted into a usable form, `nb'.
|
||
This currently means to add 4 bytes overhead plus possibly more to
|
||
obtain 8-byte alignment and/or to obtain a size of at least
|
||
MINSIZE (currently 16 bytes), the smallest allocatable size.
|
||
(All fits are considered `exact' if they are within MINSIZE bytes.)
|
||
|
||
From there, the first successful of the following steps is taken:
|
||
|
||
1. The bin corresponding to the request size is scanned, and if
|
||
a chunk of exactly the right size is found, it is taken.
|
||
|
||
2. The most recently remaindered chunk is used if it is big
|
||
enough. This is a form of (roving) first fit, used only in
|
||
the absence of exact fits. Runs of consecutive requests use
|
||
the remainder of the chunk used for the previous such request
|
||
whenever possible. This limited use of a first-fit style
|
||
allocation strategy tends to give contiguous chunks
|
||
coextensive lifetimes, which improves locality and can reduce
|
||
fragmentation in the long run.
|
||
|
||
3. Other bins are scanned in increasing size order, using a
|
||
chunk big enough to fulfill the request, and splitting off
|
||
any remainder. This search is strictly by best-fit; i.e.,
|
||
the smallest (with ties going to approximately the least
|
||
recently used) chunk that fits is selected.
|
||
|
||
4. If large enough, the chunk bordering the end of memory
|
||
(`top') is split off. (This use of `top' is in accord with
|
||
the best-fit search rule. In effect, `top' is treated as
|
||
larger (and thus less well fitting) than any other available
|
||
chunk since it can be extended to be as large as necessary
|
||
(up to system limitations).
|
||
|
||
5. If the request size meets the mmap threshold and the
|
||
system supports mmap, and there are few enough currently
|
||
allocated mmapped regions, and a call to mmap succeeds,
|
||
the request is allocated via direct memory mapping.
|
||
|
||
6. Otherwise, the top of memory is extended by
|
||
obtaining more space from the system (normally using sbrk,
|
||
but definable to anything else via the MORECORE macro).
|
||
Memory is gathered from the system (in system page-sized
|
||
units) in a way that allows chunks obtained across different
|
||
sbrk calls to be consolidated, but does not require
|
||
contiguous memory. Thus, it should be safe to intersperse
|
||
mallocs with other sbrk calls.
|
||
|
||
|
||
All allocations are made from the the `lowest' part of any found
|
||
chunk. (The implementation invariant is that prev_inuse is
|
||
always true of any allocated chunk; i.e., that each allocated
|
||
chunk borders either a previously allocated and still in-use chunk,
|
||
or the base of its memory arena.)
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* mALLOc(size_t bytes)
|
||
#else
|
||
Void_t* mALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
mchunkptr victim; /* inspected/selected chunk */
|
||
INTERNAL_SIZE_T victim_size; /* its size */
|
||
int idx; /* index for bin traversal */
|
||
mbinptr bin; /* associated bin */
|
||
mchunkptr remainder; /* remainder from a split */
|
||
long remainder_size; /* its size */
|
||
int remainder_index; /* its bin index */
|
||
unsigned long block; /* block traverser bit */
|
||
int startidx; /* first bin of a traversed block */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mbinptr q; /* misc temp */
|
||
|
||
INTERNAL_SIZE_T nb;
|
||
|
||
if ((long)bytes < 0) return 0;
|
||
|
||
nb = request2size(bytes); /* padded request size; */
|
||
|
||
/* Check for exact match in a bin */
|
||
|
||
if (is_small_request(nb)) /* Faster version for small requests */
|
||
{
|
||
idx = smallbin_index(nb);
|
||
|
||
/* No traversal or size check necessary for small bins. */
|
||
|
||
q = bin_at(idx);
|
||
victim = last(q);
|
||
|
||
/* Also scan the next one, since it would have a remainder < MINSIZE */
|
||
if (victim == q)
|
||
{
|
||
q = next_bin(q);
|
||
victim = last(q);
|
||
}
|
||
if (victim != q)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
unlink(victim, bck, fwd);
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */
|
||
|
||
}
|
||
else
|
||
{
|
||
idx = bin_index(nb);
|
||
bin = bin_at(idx);
|
||
|
||
for (victim = last(bin); victim != bin; victim = victim->bk)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* too big */
|
||
{
|
||
--idx; /* adjust to rescan below after checking last remainder */
|
||
break;
|
||
}
|
||
|
||
else if (remainder_size >= 0) /* exact fit */
|
||
{
|
||
unlink(victim, bck, fwd);
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
}
|
||
|
||
++idx;
|
||
|
||
}
|
||
|
||
/* Try to use the last split-off remainder */
|
||
|
||
if ( (victim = last_remainder->fd) != last_remainder)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* re-split */
|
||
{
|
||
remainder = chunk_at_offset(victim, nb);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
link_last_remainder(remainder);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
clear_last_remainder;
|
||
|
||
if (remainder_size >= 0) /* exhaust */
|
||
{
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
/* Else place in bin */
|
||
|
||
frontlink(victim, victim_size, remainder_index, bck, fwd);
|
||
}
|
||
|
||
/*
|
||
If there are any possibly nonempty big-enough blocks,
|
||
search for best fitting chunk by scanning bins in blockwidth units.
|
||
*/
|
||
|
||
if ( (block = idx2binblock(idx)) <= binblocks)
|
||
{
|
||
|
||
/* Get to the first marked block */
|
||
|
||
if ( (block & binblocks) == 0)
|
||
{
|
||
/* force to an even block boundary */
|
||
idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
while ((block & binblocks) == 0)
|
||
{
|
||
idx += BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
}
|
||
}
|
||
|
||
/* For each possibly nonempty block ... */
|
||
for (;;)
|
||
{
|
||
startidx = idx; /* (track incomplete blocks) */
|
||
q = bin = bin_at(idx);
|
||
|
||
/* For each bin in this block ... */
|
||
do
|
||
{
|
||
/* Find and use first big enough chunk ... */
|
||
|
||
for (victim = last(bin); victim != bin; victim = victim->bk)
|
||
{
|
||
victim_size = chunksize(victim);
|
||
remainder_size = victim_size - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) /* split */
|
||
{
|
||
remainder = chunk_at_offset(victim, nb);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
unlink(victim, bck, fwd);
|
||
link_last_remainder(remainder);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
else if (remainder_size >= 0) /* take */
|
||
{
|
||
set_inuse_bit_at_offset(victim, victim_size);
|
||
unlink(victim, bck, fwd);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
}
|
||
|
||
bin = next_bin(bin);
|
||
|
||
} while ((++idx & (BINBLOCKWIDTH - 1)) != 0);
|
||
|
||
/* Clear out the block bit. */
|
||
|
||
do /* Possibly backtrack to try to clear a partial block */
|
||
{
|
||
if ((startidx & (BINBLOCKWIDTH - 1)) == 0)
|
||
{
|
||
binblocks &= ~block;
|
||
break;
|
||
}
|
||
--startidx;
|
||
q = prev_bin(q);
|
||
} while (first(q) == q);
|
||
|
||
/* Get to the next possibly nonempty block */
|
||
|
||
if ( (block <<= 1) <= binblocks && (block != 0) )
|
||
{
|
||
while ((block & binblocks) == 0)
|
||
{
|
||
idx += BINBLOCKWIDTH;
|
||
block <<= 1;
|
||
}
|
||
}
|
||
else
|
||
break;
|
||
}
|
||
}
|
||
|
||
|
||
/* Try to use top chunk */
|
||
|
||
/* Require that there be a remainder, ensuring top always exists */
|
||
if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
|
||
{
|
||
|
||
|
||
/* Try to extend */
|
||
malloc_extend_top(nb);
|
||
if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
|
||
return 0; /* propagate failure */
|
||
}
|
||
|
||
victim = top;
|
||
set_head(victim, nb | PREV_INUSE);
|
||
top = chunk_at_offset(victim, nb);
|
||
set_head(top, remainder_size | PREV_INUSE);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
free() algorithm :
|
||
|
||
cases:
|
||
|
||
1. free(0) has no effect.
|
||
|
||
2. If the chunk was allocated via mmap, it is release via munmap().
|
||
|
||
3. If a returned chunk borders the current high end of memory,
|
||
it is consolidated into the top, and if the total unused
|
||
topmost memory exceeds the trim threshold, malloc_trim is
|
||
called.
|
||
|
||
4. Other chunks are consolidated as they arrive, and
|
||
placed in corresponding bins. (This includes the case of
|
||
consolidating with the current `last_remainder').
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
void fREe(Void_t* mem)
|
||
#else
|
||
void fREe(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mchunkptr p; /* chunk corresponding to mem */
|
||
INTERNAL_SIZE_T hd; /* its head field */
|
||
INTERNAL_SIZE_T sz; /* its size */
|
||
int idx; /* its bin index */
|
||
mchunkptr next; /* next contiguous chunk */
|
||
INTERNAL_SIZE_T nextsz; /* its size */
|
||
INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
int islr; /* track whether merging with last_remainder */
|
||
|
||
if (mem == 0) /* free(0) has no effect */
|
||
return;
|
||
|
||
p = mem2chunk(mem);
|
||
hd = p->size;
|
||
|
||
|
||
check_inuse_chunk(p);
|
||
|
||
sz = hd & ~PREV_INUSE;
|
||
next = chunk_at_offset(p, sz);
|
||
nextsz = chunksize(next);
|
||
|
||
if (next == top) /* merge with top */
|
||
{
|
||
sz += nextsz;
|
||
|
||
if (!(hd & PREV_INUSE)) /* consolidate backward */
|
||
{
|
||
prevsz = p->prev_size;
|
||
p = chunk_at_offset(p, -((long) prevsz));
|
||
sz += prevsz;
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
set_head(p, sz | PREV_INUSE);
|
||
top = p;
|
||
#ifdef USE_MALLOC_TRIM
|
||
if ((unsigned long)(sz) >= (unsigned long)trim_threshold)
|
||
malloc_trim(top_pad);
|
||
#endif
|
||
return;
|
||
}
|
||
|
||
set_head(next, nextsz); /* clear inuse bit */
|
||
|
||
islr = 0;
|
||
|
||
if (!(hd & PREV_INUSE)) /* consolidate backward */
|
||
{
|
||
prevsz = p->prev_size;
|
||
p = chunk_at_offset(p, -((long) prevsz));
|
||
sz += prevsz;
|
||
|
||
if (p->fd == last_remainder) /* keep as last_remainder */
|
||
islr = 1;
|
||
else
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
if (!(inuse_bit_at_offset(next, nextsz))) /* consolidate forward */
|
||
{
|
||
sz += nextsz;
|
||
|
||
if (!islr && next->fd == last_remainder) /* re-insert last_remainder */
|
||
{
|
||
islr = 1;
|
||
link_last_remainder(p);
|
||
}
|
||
else
|
||
unlink(next, bck, fwd);
|
||
}
|
||
|
||
|
||
set_head(p, sz | PREV_INUSE);
|
||
set_foot(p, sz);
|
||
if (!islr)
|
||
frontlink(p, sz, idx, bck, fwd);
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
Realloc algorithm:
|
||
|
||
Chunks that were obtained via mmap cannot be extended or shrunk
|
||
unless HAVE_MREMAP is defined, in which case mremap is used.
|
||
Otherwise, if their reallocation is for additional space, they are
|
||
copied. If for less, they are just left alone.
|
||
|
||
Otherwise, if the reallocation is for additional space, and the
|
||
chunk can be extended, it is, else a malloc-copy-free sequence is
|
||
taken. There are several different ways that a chunk could be
|
||
extended. All are tried:
|
||
|
||
* Extending forward into following adjacent free chunk.
|
||
* Shifting backwards, joining preceding adjacent space
|
||
* Both shifting backwards and extending forward.
|
||
* Extending into newly sbrked space
|
||
|
||
Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a
|
||
size argument of zero (re)allocates a minimum-sized chunk.
|
||
|
||
If the reallocation is for less space, and the new request is for
|
||
a `small' (<512 bytes) size, then the newly unused space is lopped
|
||
off and freed.
|
||
|
||
The old unix realloc convention of allowing the last-free'd chunk
|
||
to be used as an argument to realloc is no longer supported.
|
||
I don't know of any programs still relying on this feature,
|
||
and allowing it would also allow too many other incorrect
|
||
usages of realloc to be sensible.
|
||
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* rEALLOc(Void_t* oldmem, size_t bytes)
|
||
#else
|
||
Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
|
||
mchunkptr oldp; /* chunk corresponding to oldmem */
|
||
INTERNAL_SIZE_T oldsize; /* its size */
|
||
|
||
mchunkptr newp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize; /* its size */
|
||
Void_t* newmem; /* corresponding user mem */
|
||
|
||
mchunkptr next; /* next contiguous chunk after oldp */
|
||
INTERNAL_SIZE_T nextsize; /* its size */
|
||
|
||
mchunkptr prev; /* previous contiguous chunk before oldp */
|
||
INTERNAL_SIZE_T prevsize; /* its size */
|
||
|
||
mchunkptr remainder; /* holds split off extra space from newp */
|
||
INTERNAL_SIZE_T remainder_size; /* its size */
|
||
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
|
||
#ifdef REALLOC_ZERO_BYTES_FREES
|
||
if (bytes == 0) { fREe(oldmem); return 0; }
|
||
#endif
|
||
|
||
if ((long)bytes < 0) return 0;
|
||
|
||
/* realloc of null is supposed to be same as malloc */
|
||
if (oldmem == 0) return mALLOc(bytes);
|
||
|
||
newp = oldp = mem2chunk(oldmem);
|
||
newsize = oldsize = chunksize(oldp);
|
||
|
||
|
||
nb = request2size(bytes);
|
||
|
||
|
||
check_inuse_chunk(oldp);
|
||
|
||
if ((long)(oldsize) < (long)(nb))
|
||
{
|
||
|
||
/* Try expanding forward */
|
||
|
||
next = chunk_at_offset(oldp, oldsize);
|
||
if (next == top || !inuse(next))
|
||
{
|
||
nextsize = chunksize(next);
|
||
|
||
/* Forward into top only if a remainder */
|
||
if (next == top)
|
||
{
|
||
if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE))
|
||
{
|
||
newsize += nextsize;
|
||
top = chunk_at_offset(oldp, nb);
|
||
set_head(top, (newsize - nb) | PREV_INUSE);
|
||
set_head_size(oldp, nb);
|
||
return chunk2mem(oldp);
|
||
}
|
||
}
|
||
|
||
/* Forward into next chunk */
|
||
else if (((long)(nextsize + newsize) >= (long)(nb)))
|
||
{
|
||
unlink(next, bck, fwd);
|
||
newsize += nextsize;
|
||
goto split;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
next = 0;
|
||
nextsize = 0;
|
||
}
|
||
|
||
/* Try shifting backwards. */
|
||
|
||
if (!prev_inuse(oldp))
|
||
{
|
||
prev = prev_chunk(oldp);
|
||
prevsize = chunksize(prev);
|
||
|
||
/* try forward + backward first to save a later consolidation */
|
||
|
||
if (next != 0)
|
||
{
|
||
/* into top */
|
||
if (next == top)
|
||
{
|
||
if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE))
|
||
{
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += prevsize + nextsize;
|
||
newmem = chunk2mem(newp);
|
||
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
|
||
top = chunk_at_offset(newp, nb);
|
||
set_head(top, (newsize - nb) | PREV_INUSE);
|
||
set_head_size(newp, nb);
|
||
return newmem;
|
||
}
|
||
}
|
||
|
||
/* into next chunk */
|
||
else if (((long)(nextsize + prevsize + newsize) >= (long)(nb)))
|
||
{
|
||
unlink(next, bck, fwd);
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += nextsize + prevsize;
|
||
newmem = chunk2mem(newp);
|
||
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
|
||
goto split;
|
||
}
|
||
}
|
||
|
||
/* backward only */
|
||
if (prev != 0 && (long)(prevsize + newsize) >= (long)nb)
|
||
{
|
||
unlink(prev, bck, fwd);
|
||
newp = prev;
|
||
newsize += prevsize;
|
||
newmem = chunk2mem(newp);
|
||
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
|
||
goto split;
|
||
}
|
||
}
|
||
|
||
/* Must allocate */
|
||
|
||
newmem = mALLOc (bytes);
|
||
|
||
if (newmem == 0) /* propagate failure */
|
||
return 0;
|
||
|
||
/* Avoid copy if newp is next chunk after oldp. */
|
||
/* (This can only happen when new chunk is sbrk'ed.) */
|
||
|
||
if ( (newp = mem2chunk(newmem)) == next_chunk(oldp))
|
||
{
|
||
newsize += chunksize(newp);
|
||
newp = oldp;
|
||
goto split;
|
||
}
|
||
|
||
/* Otherwise copy, free, and exit */
|
||
MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
|
||
fREe(oldmem);
|
||
return newmem;
|
||
}
|
||
|
||
|
||
split: /* split off extra room in old or expanded chunk */
|
||
|
||
if (newsize - nb >= MINSIZE) /* split off remainder */
|
||
{
|
||
remainder = chunk_at_offset(newp, nb);
|
||
remainder_size = newsize - nb;
|
||
set_head_size(newp, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_inuse_bit_at_offset(remainder, remainder_size);
|
||
fREe(chunk2mem(remainder)); /* let free() deal with it */
|
||
}
|
||
else
|
||
{
|
||
set_head_size(newp, newsize);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
}
|
||
|
||
check_inuse_chunk(newp);
|
||
return chunk2mem(newp);
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
|
||
memalign algorithm:
|
||
|
||
memalign requests more than enough space from malloc, finds a spot
|
||
within that chunk that meets the alignment request, and then
|
||
possibly frees the leading and trailing space.
|
||
|
||
The alignment argument must be a power of two. This property is not
|
||
checked by memalign, so misuse may result in random runtime errors.
|
||
|
||
8-byte alignment is guaranteed by normal malloc calls, so don't
|
||
bother calling memalign with an argument of 8 or less.
|
||
|
||
Overreliance on memalign is a sure way to fragment space.
|
||
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* mEMALIGn(size_t alignment, size_t bytes)
|
||
#else
|
||
Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
char* m; /* memory returned by malloc call */
|
||
mchunkptr p; /* corresponding chunk */
|
||
char* brk; /* alignment point within p */
|
||
mchunkptr newp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize; /* its size */
|
||
INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */
|
||
mchunkptr remainder; /* spare room at end to split off */
|
||
long remainder_size; /* its size */
|
||
|
||
if ((long)bytes < 0) return 0;
|
||
|
||
/* If need less alignment than we give anyway, just relay to malloc */
|
||
|
||
if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes);
|
||
|
||
/* Otherwise, ensure that it is at least a minimum chunk size */
|
||
|
||
if (alignment < MINSIZE) alignment = MINSIZE;
|
||
|
||
/* Call malloc with worst case padding to hit alignment. */
|
||
|
||
nb = request2size(bytes);
|
||
m = (char*)(mALLOc(nb + alignment + MINSIZE));
|
||
|
||
if (m == 0) return 0; /* propagate failure */
|
||
|
||
p = mem2chunk(m);
|
||
|
||
if ((((unsigned long)(m)) % alignment) == 0) /* aligned */
|
||
{
|
||
}
|
||
else /* misaligned */
|
||
{
|
||
/*
|
||
Find an aligned spot inside chunk.
|
||
Since we need to give back leading space in a chunk of at
|
||
least MINSIZE, if the first calculation places us at
|
||
a spot with less than MINSIZE leader, we can move to the
|
||
next aligned spot -- we've allocated enough total room so that
|
||
this is always possible.
|
||
*/
|
||
|
||
brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -((signed) alignment));
|
||
if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment;
|
||
|
||
newp = (mchunkptr)brk;
|
||
leadsize = brk - (char*)(p);
|
||
newsize = chunksize(p) - leadsize;
|
||
|
||
|
||
/* give back leader, use the rest */
|
||
|
||
set_head(newp, newsize | PREV_INUSE);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
set_head_size(p, leadsize);
|
||
fREe(chunk2mem(p));
|
||
p = newp;
|
||
|
||
assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
|
||
}
|
||
|
||
/* Also give back spare room at the end */
|
||
|
||
remainder_size = chunksize(p) - nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE)
|
||
{
|
||
remainder = chunk_at_offset(p, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_head_size(p, nb);
|
||
fREe(chunk2mem(remainder));
|
||
}
|
||
|
||
check_inuse_chunk(p);
|
||
return chunk2mem(p);
|
||
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
valloc just invokes memalign with alignment argument equal
|
||
to the page size of the system (or as near to this as can
|
||
be figured out from all the includes/defines above.)
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* vALLOc(size_t bytes)
|
||
#else
|
||
Void_t* vALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
return mEMALIGn (malloc_getpagesize, bytes);
|
||
}
|
||
|
||
/*
|
||
pvalloc just invokes valloc for the nearest pagesize
|
||
that will accommodate request
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* pvALLOc(size_t bytes)
|
||
#else
|
||
Void_t* pvALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
size_t pagesize = malloc_getpagesize;
|
||
return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
|
||
}
|
||
|
||
/*
|
||
|
||
calloc calls malloc, then zeroes out the allocated chunk.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* cALLOc(size_t n, size_t elem_size)
|
||
#else
|
||
Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
INTERNAL_SIZE_T csz;
|
||
|
||
INTERNAL_SIZE_T sz = n * elem_size;
|
||
|
||
|
||
/* check if expand_top called, in which case don't need to clear */
|
||
#if MORECORE_CLEARS
|
||
mchunkptr oldtop = top;
|
||
INTERNAL_SIZE_T oldtopsize = chunksize(top);
|
||
#endif
|
||
Void_t* mem = mALLOc (sz);
|
||
|
||
if ((long)n < 0) return 0;
|
||
|
||
if (mem == 0)
|
||
return 0;
|
||
else
|
||
{
|
||
p = mem2chunk(mem);
|
||
|
||
/* Two optional cases in which clearing not necessary */
|
||
|
||
|
||
|
||
csz = chunksize(p);
|
||
|
||
#if MORECORE_CLEARS
|
||
if (p == oldtop && csz > oldtopsize)
|
||
{
|
||
/* clear only the bytes from non-freshly-sbrked memory */
|
||
csz = oldtopsize;
|
||
}
|
||
#endif
|
||
|
||
MALLOC_ZERO(mem, csz - SIZE_SZ);
|
||
return mem;
|
||
}
|
||
}
|
||
|
||
/*
|
||
|
||
cfree just calls free. It is needed/defined on some systems
|
||
that pair it with calloc, presumably for odd historical reasons.
|
||
|
||
*/
|
||
|
||
#if !defined(INTERNAL_LINUX_C_LIB) || !defined(__ELF__)
|
||
#if __STD_C
|
||
void cfree(Void_t *mem)
|
||
#else
|
||
void cfree(mem) Void_t *mem;
|
||
#endif
|
||
{
|
||
fREe(mem);
|
||
}
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
|
||
Malloc_trim gives memory back to the system (via negative
|
||
arguments to sbrk) if there is unused memory at the `high' end of
|
||
the malloc pool. You can call this after freeing large blocks of
|
||
memory to potentially reduce the system-level memory requirements
|
||
of a program. However, it cannot guarantee to reduce memory. Under
|
||
some allocation patterns, some large free blocks of memory will be
|
||
locked between two used chunks, so they cannot be given back to
|
||
the system.
|
||
|
||
The `pad' argument to malloc_trim represents the amount of free
|
||
trailing space to leave untrimmed. If this argument is zero,
|
||
only the minimum amount of memory to maintain internal data
|
||
structures will be left (one page or less). Non-zero arguments
|
||
can be supplied to maintain enough trailing space to service
|
||
future expected allocations without having to re-obtain memory
|
||
from the system.
|
||
|
||
Malloc_trim returns 1 if it actually released any memory, else 0.
|
||
|
||
*/
|
||
#ifdef USE_MALLOC_TRIM
|
||
#if __STD_C
|
||
int malloc_trim(size_t pad)
|
||
#else
|
||
int malloc_trim(pad) size_t pad;
|
||
#endif
|
||
{
|
||
long top_size; /* Amount of top-most memory */
|
||
long extra; /* Amount to release */
|
||
char* current_brk; /* address returned by pre-check sbrk call */
|
||
char* new_brk; /* address returned by negative sbrk call */
|
||
|
||
unsigned long pagesz = malloc_getpagesize;
|
||
|
||
top_size = chunksize(top);
|
||
extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
|
||
|
||
if (extra < (long)pagesz) /* Not enough memory to release */
|
||
return 0;
|
||
|
||
else
|
||
{
|
||
/* Test to make sure no one else called sbrk */
|
||
current_brk = (char*)(MORECORE (0));
|
||
if (current_brk != (char*)(top) + top_size)
|
||
return 0; /* Apparently we don't own memory; must fail */
|
||
|
||
else
|
||
{
|
||
new_brk = (char*)(MORECORE (-extra));
|
||
|
||
if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */
|
||
{
|
||
/* Try to figure out what we have */
|
||
current_brk = (char*)(MORECORE (0));
|
||
top_size = current_brk - (char*)top;
|
||
if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */
|
||
{
|
||
sbrked_mem = current_brk - sbrk_base;
|
||
set_head(top, top_size | PREV_INUSE);
|
||
}
|
||
check_chunk(top);
|
||
return 0;
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Success. Adjust top accordingly. */
|
||
set_head(top, (top_size - extra) | PREV_INUSE);
|
||
sbrked_mem -= extra;
|
||
check_chunk(top);
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
#endif
|
||
|
||
|
||
/*
|
||
malloc_usable_size:
|
||
|
||
This routine tells you how many bytes you can actually use in an
|
||
allocated chunk, which may be more than you requested (although
|
||
often not). You can use this many bytes without worrying about
|
||
overwriting other allocated objects. Not a particularly great
|
||
programming practice, but still sometimes useful.
|
||
|
||
*/
|
||
|
||
#if __STD_C
|
||
size_t malloc_usable_size(Void_t* mem)
|
||
#else
|
||
size_t malloc_usable_size(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
if (mem == 0)
|
||
return 0;
|
||
else
|
||
{
|
||
p = mem2chunk(mem);
|
||
if(!chunk_is_mmapped(p))
|
||
{
|
||
if (!inuse(p)) return 0;
|
||
check_inuse_chunk(p);
|
||
return chunksize(p) - SIZE_SZ;
|
||
}
|
||
return chunksize(p) - 2*SIZE_SZ;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
/* Utility to update current_mallinfo for malloc_stats and mallinfo() */
|
||
|
||
#ifdef CONFIG_CMD_MEMINFO
|
||
static void malloc_update_mallinfo(void)
|
||
{
|
||
int i;
|
||
mbinptr b;
|
||
mchunkptr p;
|
||
#ifdef DEBUG
|
||
mchunkptr q;
|
||
#endif
|
||
|
||
INTERNAL_SIZE_T avail = chunksize(top);
|
||
int navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0;
|
||
|
||
for (i = 1; i < NAV; ++i)
|
||
{
|
||
b = bin_at(i);
|
||
for (p = last(b); p != b; p = p->bk)
|
||
{
|
||
#ifdef DEBUG
|
||
check_free_chunk(p);
|
||
for (q = next_chunk(p);
|
||
q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE;
|
||
q = next_chunk(q))
|
||
check_inuse_chunk(q);
|
||
#endif
|
||
avail += chunksize(p);
|
||
navail++;
|
||
}
|
||
}
|
||
|
||
current_mallinfo.ordblks = navail;
|
||
current_mallinfo.uordblks = sbrked_mem - avail;
|
||
current_mallinfo.fordblks = avail;
|
||
#if HAVE_MMAP
|
||
current_mallinfo.hblks = n_mmaps;
|
||
#endif
|
||
current_mallinfo.hblkhd = mmapped_mem;
|
||
current_mallinfo.keepcost = chunksize(top);
|
||
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
|
||
malloc_stats:
|
||
|
||
Prints on the amount of space obtain from the system (both
|
||
via sbrk and mmap), the maximum amount (which may be more than
|
||
current if malloc_trim and/or munmap got called), the maximum
|
||
number of simultaneous mmap regions used, and the current number
|
||
of bytes allocated via malloc (or realloc, etc) but not yet
|
||
freed. (Note that this is the number of bytes allocated, not the
|
||
number requested. It will be larger than the number requested
|
||
because of alignment and bookkeeping overhead.)
|
||
|
||
*/
|
||
|
||
|
||
/*
|
||
mallinfo returns a copy of updated current mallinfo.
|
||
*/
|
||
|
||
void malloc_stats()
|
||
{
|
||
malloc_update_mallinfo();
|
||
printf("max system bytes = %10u\n",
|
||
(unsigned int)(max_total_mem));
|
||
printf("system bytes = %10u\n",
|
||
(unsigned int)(sbrked_mem + mmapped_mem));
|
||
printf("in use bytes = %10u\n",
|
||
(unsigned int)(current_mallinfo.uordblks + mmapped_mem));
|
||
#if HAVE_MMAP
|
||
fprintf(stderr, "max mmap regions = %10u\n",
|
||
(unsigned int)max_n_mmaps);
|
||
#endif
|
||
}
|
||
|
||
#endif /* CONFIG_CMD_MEMINFO */
|
||
|
||
|
||
|
||
/*
|
||
mallopt:
|
||
|
||
mallopt is the general SVID/XPG interface to tunable parameters.
|
||
The format is to provide a (parameter-number, parameter-value) pair.
|
||
mallopt then sets the corresponding parameter to the argument
|
||
value if it can (i.e., so long as the value is meaningful),
|
||
and returns 1 if successful else 0.
|
||
|
||
See descriptions of tunable parameters above.
|
||
|
||
*/
|
||
#ifndef __U_BOOT__
|
||
#if __STD_C
|
||
int mALLOPt(int param_number, int value)
|
||
#else
|
||
int mALLOPt(param_number, value) int param_number; int value;
|
||
#endif
|
||
{
|
||
switch(param_number)
|
||
{
|
||
case M_TRIM_THRESHOLD:
|
||
trim_threshold = value; return 1;
|
||
case M_TOP_PAD:
|
||
top_pad = value; return 1;
|
||
case M_MMAP_THRESHOLD:
|
||
mmap_threshold = value; return 1;
|
||
case M_MMAP_MAX:
|
||
if (value != 0) return 0; else n_mmaps_max = value; return 1;
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
#endif
|
||
/*
|
||
|
||
History:
|
||
|
||
V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee)
|
||
* return null for negative arguments
|
||
* Added Several WIN32 cleanups from Martin C. Fong <mcfong@yahoo.com>
|
||
* Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h'
|
||
(e.g. WIN32 platforms)
|
||
* Cleanup up header file inclusion for WIN32 platforms
|
||
* Cleanup code to avoid Microsoft Visual C++ compiler complaints
|
||
* Add 'USE_DL_PREFIX' to quickly allow co-existence with existing
|
||
memory allocation routines
|
||
* Set 'malloc_getpagesize' for WIN32 platforms (needs more work)
|
||
* Use 'assert' rather than 'ASSERT' in WIN32 code to conform to
|
||
usage of 'assert' in non-WIN32 code
|
||
* Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to
|
||
avoid infinite loop
|
||
* Always call 'fREe()' rather than 'free()'
|
||
|
||
V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee)
|
||
* Fixed ordering problem with boundary-stamping
|
||
|
||
V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee)
|
||
* Added pvalloc, as recommended by H.J. Liu
|
||
* Added 64bit pointer support mainly from Wolfram Gloger
|
||
* Added anonymously donated WIN32 sbrk emulation
|
||
* Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
|
||
* malloc_extend_top: fix mask error that caused wastage after
|
||
foreign sbrks
|
||
* Add linux mremap support code from HJ Liu
|
||
|
||
V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee)
|
||
* Integrated most documentation with the code.
|
||
* Add support for mmap, with help from
|
||
Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Use last_remainder in more cases.
|
||
* Pack bins using idea from colin@nyx10.cs.du.edu
|
||
* Use ordered bins instead of best-fit threshhold
|
||
* Eliminate block-local decls to simplify tracing and debugging.
|
||
* Support another case of realloc via move into top
|
||
* Fix error occuring when initial sbrk_base not word-aligned.
|
||
* Rely on page size for units instead of SBRK_UNIT to
|
||
avoid surprises about sbrk alignment conventions.
|
||
* Add mallinfo, mallopt. Thanks to Raymond Nijssen
|
||
(raymond@es.ele.tue.nl) for the suggestion.
|
||
* Add `pad' argument to malloc_trim and top_pad mallopt parameter.
|
||
* More precautions for cases where other routines call sbrk,
|
||
courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Added macros etc., allowing use in linux libc from
|
||
H.J. Lu (hjl@gnu.ai.mit.edu)
|
||
* Inverted this history list
|
||
|
||
V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee)
|
||
* Re-tuned and fixed to behave more nicely with V2.6.0 changes.
|
||
* Removed all preallocation code since under current scheme
|
||
the work required to undo bad preallocations exceeds
|
||
the work saved in good cases for most test programs.
|
||
* No longer use return list or unconsolidated bins since
|
||
no scheme using them consistently outperforms those that don't
|
||
given above changes.
|
||
* Use best fit for very large chunks to prevent some worst-cases.
|
||
* Added some support for debugging
|
||
|
||
V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee)
|
||
* Removed footers when chunks are in use. Thanks to
|
||
Paul Wilson (wilson@cs.texas.edu) for the suggestion.
|
||
|
||
V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee)
|
||
* Added malloc_trim, with help from Wolfram Gloger
|
||
(wmglo@Dent.MED.Uni-Muenchen.DE).
|
||
|
||
V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g)
|
||
|
||
V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g)
|
||
* realloc: try to expand in both directions
|
||
* malloc: swap order of clean-bin strategy;
|
||
* realloc: only conditionally expand backwards
|
||
* Try not to scavenge used bins
|
||
* Use bin counts as a guide to preallocation
|
||
* Occasionally bin return list chunks in first scan
|
||
* Add a few optimizations from colin@nyx10.cs.du.edu
|
||
|
||
V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g)
|
||
* faster bin computation & slightly different binning
|
||
* merged all consolidations to one part of malloc proper
|
||
(eliminating old malloc_find_space & malloc_clean_bin)
|
||
* Scan 2 returns chunks (not just 1)
|
||
* Propagate failure in realloc if malloc returns 0
|
||
* Add stuff to allow compilation on non-ANSI compilers
|
||
from kpv@research.att.com
|
||
|
||
V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu)
|
||
* removed potential for odd address access in prev_chunk
|
||
* removed dependency on getpagesize.h
|
||
* misc cosmetics and a bit more internal documentation
|
||
* anticosmetics: mangled names in macros to evade debugger strangeness
|
||
* tested on sparc, hp-700, dec-mips, rs6000
|
||
with gcc & native cc (hp, dec only) allowing
|
||
Detlefs & Zorn comparison study (in SIGPLAN Notices.)
|
||
|
||
Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu)
|
||
* Based loosely on libg++-1.2X malloc. (It retains some of the overall
|
||
structure of old version, but most details differ.)
|
||
|
||
*/
|
||
|
||
EXPORT_SYMBOL(malloc);
|
||
EXPORT_SYMBOL(calloc);
|
||
EXPORT_SYMBOL(free);
|
||
EXPORT_SYMBOL(realloc);
|
||
|