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Diffstat (limited to 'nsprpub/pr/src/malloc/prmalloc.c')
| -rw-r--r-- | nsprpub/pr/src/malloc/prmalloc.c | 1142 |
1 files changed, 1142 insertions, 0 deletions
diff --git a/nsprpub/pr/src/malloc/prmalloc.c b/nsprpub/pr/src/malloc/prmalloc.c new file mode 100644 index 000000000..174d0daf7 --- /dev/null +++ b/nsprpub/pr/src/malloc/prmalloc.c @@ -0,0 +1,1142 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "primpl.h" + +/* +** We override malloc etc. on any platform which has preemption + +** nspr20 user level threads. When we're debugging, we can make our +** version of malloc fail occasionally. +*/ +#ifdef _PR_OVERRIDE_MALLOC + +/* +** Thread safe version of malloc, calloc, realloc, free +*/ +#include <stdarg.h> + +#ifdef DEBUG +#define SANITY +#define EXTRA_SANITY +#else +#undef SANITY +#undef EXTRA_SANITY +#endif + +/* Forward decls */ +void *_PR_UnlockedMalloc(size_t size); +void _PR_UnlockedFree(void *ptr); +void *_PR_UnlockedRealloc(void *ptr, size_t size); +void *_PR_UnlockedCalloc(size_t n, size_t elsize); + +/************************************************************************/ + +/* + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you + * can do whatever you want with this stuff. If we meet some day, and you think + * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + * + */ + +/* + * Defining SANITY will enable some checks which will tell you if the users + * program did botch something + */ + +/* + * Defining EXTRA_SANITY will enable some checks which are mostly related + * to internal conditions in malloc.c + */ + +/* + * Very verbose progress on stdout... + */ +#if 0 +# define TRACE(foo) printf foo +static int malloc_event; +#else +# define TRACE(foo) +#endif + +/* XXX Pick a number, any number */ +# define malloc_pagesize 4096UL +# define malloc_pageshift 12UL + +#ifdef XP_UNIX +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/mman.h> +#endif + +/* + * This structure describes a page's worth of chunks. + */ + +struct pginfo { + struct pginfo *next; /* next on the free list */ + char *page; /* Pointer to the page */ + u_short size; /* size of this page's chunks */ + u_short shift; /* How far to shift for this size chunks */ + u_short free; /* How many free chunks */ + u_short total; /* How many chunk */ + u_long bits[1]; /* Which chunks are free */ +}; + +struct pgfree { + struct pgfree *next; /* next run of free pages */ + struct pgfree *prev; /* prev run of free pages */ + char *page; /* pointer to free pages */ + char *end; /* pointer to end of free pages */ + u_long size; /* number of bytes free */ +}; + +/* + * How many bits per u_long in the bitmap. + * Change only if not 8 bits/byte + */ +#define MALLOC_BITS (8*sizeof(u_long)) + +/* + * Magic values to put in the page_directory + */ +#define MALLOC_NOT_MINE ((struct pginfo*) 0) +#define MALLOC_FREE ((struct pginfo*) 1) +#define MALLOC_FIRST ((struct pginfo*) 2) +#define MALLOC_FOLLOW ((struct pginfo*) 3) +#define MALLOC_MAGIC ((struct pginfo*) 4) + +/* + * Set to one when malloc_init has been called + */ +static unsigned initialized; + +/* + * The size of a page. + * Must be a integral multiplum of the granularity of mmap(2). + * Your toes will curl if it isn't a power of two + */ +#define malloc_pagemask ((malloc_pagesize)-1) + +/* + * The size of the largest chunk. + * Half a page. + */ +#define malloc_maxsize ((malloc_pagesize)>>1) + +/* + * malloc_pagesize == 1 << malloc_pageshift + */ +#ifndef malloc_pageshift +static unsigned malloc_pageshift; +#endif /* malloc_pageshift */ + +/* + * The smallest allocation we bother about. + * Must be power of two + */ +#ifndef malloc_minsize +static unsigned malloc_minsize; +#endif /* malloc_minsize */ + +/* + * The largest chunk we care about. + * Must be smaller than pagesize + * Must be power of two + */ +#ifndef malloc_maxsize +static unsigned malloc_maxsize; +#endif /* malloc_maxsize */ + +#ifndef malloc_cache +static unsigned malloc_cache; +#endif /* malloc_cache */ + +/* + * The offset from pagenumber to index into the page directory + */ +static u_long malloc_origo; + +/* + * The last index in the page directory we care about + */ +static u_long last_index; + +/* + * Pointer to page directory. + * Allocated "as if with" malloc + */ +static struct pginfo **page_dir; + +/* + * How many slots in the page directory + */ +static unsigned malloc_ninfo; + +/* + * Free pages line up here + */ +static struct pgfree free_list; + +/* + * Abort() if we fail to get VM ? + */ +static int malloc_abort; + +#ifdef SANITY +/* + * Are we trying to die ? + */ +static int suicide; +#endif + +/* + * dump statistics + */ +static int malloc_stats; + +/* + * always realloc ? + */ +static int malloc_realloc; + +/* + * my last break. + */ +static void *malloc_brk; + +/* + * one location cache for free-list holders + */ +static struct pgfree *px; + +static int set_pgdir(void *ptr, struct pginfo *info); +static int extend_page_directory(u_long index); + +#ifdef SANITY +void +malloc_dump(FILE *fd) +{ + struct pginfo **pd; + struct pgfree *pf; + int j; + + pd = page_dir; + + /* print out all the pages */ + for(j=0;j<=last_index;j++) { + fprintf(fd,"%08lx %5d ",(j+malloc_origo) << malloc_pageshift,j); + if (pd[j] == MALLOC_NOT_MINE) { + for(j++;j<=last_index && pd[j] == MALLOC_NOT_MINE;j++) + ; + j--; + fprintf(fd,".. %5d not mine\n", j); + } else if (pd[j] == MALLOC_FREE) { + for(j++;j<=last_index && pd[j] == MALLOC_FREE;j++) + ; + j--; + fprintf(fd,".. %5d free\n", j); + } else if (pd[j] == MALLOC_FIRST) { + for(j++;j<=last_index && pd[j] == MALLOC_FOLLOW;j++) + ; + j--; + fprintf(fd,".. %5d in use\n", j); + } else if (pd[j] < MALLOC_MAGIC) { + fprintf(fd,"(%p)\n", pd[j]); + } else { + fprintf(fd,"%p %d (of %d) x %d @ %p --> %p\n", + pd[j],pd[j]->free, pd[j]->total, + pd[j]->size, pd[j]->page, pd[j]->next); + } + } + + for(pf=free_list.next; pf; pf=pf->next) { + fprintf(fd,"Free: @%p [%p...%p[ %ld ->%p <-%p\n", + pf,pf->page,pf->end,pf->size,pf->prev,pf->next); + if (pf == pf->next) { + fprintf(fd,"Free_list loops.\n"); + break; + } + } + + /* print out various info */ + fprintf(fd,"Minsize\t%d\n",malloc_minsize); + fprintf(fd,"Maxsize\t%ld\n",malloc_maxsize); + fprintf(fd,"Pagesize\t%ld\n",malloc_pagesize); + fprintf(fd,"Pageshift\t%ld\n",malloc_pageshift); + fprintf(fd,"FirstPage\t%ld\n",malloc_origo); + fprintf(fd,"LastPage\t%ld %lx\n",last_index+malloc_pageshift, + (last_index + malloc_pageshift) << malloc_pageshift); + fprintf(fd,"Break\t%ld\n",(u_long)sbrk(0) >> malloc_pageshift); +} + +static void wrterror(char *fmt, ...) +{ + char *q = "malloc() error: "; + char buf[100]; + va_list ap; + + suicide = 1; + + va_start(ap, fmt); + PR_vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + fputs(q, stderr); + fputs(buf, stderr); + + malloc_dump(stderr); + PR_Abort(); +} + +static void wrtwarning(char *fmt, ...) +{ + char *q = "malloc() warning: "; + char buf[100]; + va_list ap; + + va_start(ap, fmt); + PR_vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + fputs(q, stderr); + fputs(buf, stderr); +} +#endif /* SANITY */ + + +/* + * Allocate a number of pages from the OS + */ +static caddr_t +map_pages(int pages, int update) +{ + caddr_t result,tail; + + result = ((caddr_t)sbrk(0)) + malloc_pagemask - 1; + result = (caddr_t) ((u_long)result & ~malloc_pagemask); + tail = result + (pages << malloc_pageshift); + if (!brk(tail)) { + last_index = ((u_long)tail >> malloc_pageshift) - malloc_origo -1; + malloc_brk = tail; + TRACE(("%6d S %p .. %p\n",malloc_event++, result, tail)); + if (!update || last_index < malloc_ninfo || + extend_page_directory(last_index)) + return result; + } + TRACE(("%6d s %d %p %d\n",malloc_event++,pages,sbrk(0),errno)); +#ifdef EXTRA_SANITY + wrterror("map_pages fails\n"); +#endif + return 0; +} + +#define set_bit(_pi,_bit) \ + (_pi)->bits[(_bit)/MALLOC_BITS] |= 1L<<((_bit)%MALLOC_BITS) + +#define clr_bit(_pi,_bit) \ + (_pi)->bits[(_bit)/MALLOC_BITS] &= ~(1L<<((_bit)%MALLOC_BITS)); + +#define tst_bit(_pi,_bit) \ + ((_pi)->bits[(_bit)/MALLOC_BITS] & (1L<<((_bit)%MALLOC_BITS))) + +/* + * Extend page directory + */ +static int +extend_page_directory(u_long index) +{ + struct pginfo **young, **old; + int i; + + TRACE(("%6d E %lu\n",malloc_event++,index)); + + /* Make it this many pages */ + i = index * sizeof *page_dir; + i /= malloc_pagesize; + i += 2; + + /* Get new pages, if you used this much mem you don't care :-) */ + young = (struct pginfo**) map_pages(i,0); + if (!young) + return 0; + + /* Copy the old stuff */ + memset(young, 0, i * malloc_pagesize); + memcpy(young, page_dir, + malloc_ninfo * sizeof *page_dir); + + /* register the new size */ + malloc_ninfo = i * malloc_pagesize / sizeof *page_dir; + + /* swap the pointers */ + old = page_dir; + page_dir = young; + + /* Mark the pages */ + index = ((u_long)young >> malloc_pageshift) - malloc_origo; + page_dir[index] = MALLOC_FIRST; + while (--i) { + page_dir[++index] = MALLOC_FOLLOW; + } + + /* Now free the old stuff */ + _PR_UnlockedFree(old); + return 1; +} + +/* + * Set entry in page directory. + * Extend page directory if need be. + */ +static int +set_pgdir(void *ptr, struct pginfo *info) +{ + u_long index = ((u_long)ptr >> malloc_pageshift) - malloc_origo; + + if (index >= malloc_ninfo && !extend_page_directory(index)) + return 0; + page_dir[index] = info; + return 1; +} + +/* + * Initialize the world + */ +static void +malloc_init (void) +{ + int i; + char *p; + + TRACE(("%6d I\n",malloc_event++)); +#ifdef DEBUG + for (p=getenv("MALLOC_OPTIONS"); p && *p; p++) { + switch (*p) { + case 'a': malloc_abort = 0; break; + case 'A': malloc_abort = 1; break; + case 'd': malloc_stats = 0; break; + case 'D': malloc_stats = 1; break; + case 'r': malloc_realloc = 0; break; + case 'R': malloc_realloc = 1; break; + default: + wrtwarning("Unknown chars in MALLOC_OPTIONS\n"); + break; + } + } +#endif + +#ifndef malloc_pagesize + /* determine our pagesize */ + malloc_pagesize = getpagesize(); +#endif /* malloc_pagesize */ + +#ifndef malloc_pageshift + /* determine how much we shift by to get there */ + for (i = malloc_pagesize; i > 1; i >>= 1) + malloc_pageshift++; +#endif /* malloc_pageshift */ + +#ifndef malloc_cache + malloc_cache = 50 << malloc_pageshift; +#endif /* malloc_cache */ + +#ifndef malloc_minsize + /* + * find the smallest size allocation we will bother about. + * this is determined as the smallest allocation that can hold + * it's own pginfo; + */ + i = 2; + for(;;) { + int j; + + /* Figure out the size of the bits */ + j = malloc_pagesize/i; + j /= 8; + if (j < sizeof(u_long)) + j = sizeof (u_long); + if (sizeof(struct pginfo) + j - sizeof (u_long) <= i) + break; + i += i; + } + malloc_minsize = i; +#endif /* malloc_minsize */ + + + /* Allocate one page for the page directory */ + page_dir = (struct pginfo **) map_pages(1,0); +#ifdef SANITY + if (!page_dir) + wrterror("fatal: my first mmap failed. (check limits ?)\n"); +#endif + + /* + * We need a maximum of malloc_pageshift buckets, steal these from the + * front of the page_directory; + */ + malloc_origo = (u_long) page_dir >> malloc_pageshift; + malloc_origo -= malloc_pageshift; + + /* Clear it */ + memset(page_dir,0,malloc_pagesize); + + /* Find out how much it tells us */ + malloc_ninfo = malloc_pagesize / sizeof *page_dir; + + /* Plug the page directory into itself */ + i = set_pgdir(page_dir,MALLOC_FIRST); +#ifdef SANITY + if (!i) + wrterror("fatal: couldn't set myself in the page directory\n"); +#endif + + /* Been here, done that */ + initialized++; +} + +/* + * Allocate a number of complete pages + */ +static void *malloc_pages(size_t size) +{ + void *p,*delay_free = 0; + int i; + struct pgfree *pf; + u_long index; + + /* How many pages ? */ + size += (malloc_pagesize-1); + size &= ~malloc_pagemask; + + p = 0; + /* Look for free pages before asking for more */ + for(pf = free_list.next; pf; pf = pf->next) { +#ifdef EXTRA_SANITY + if (pf->page == pf->end) + wrterror("zero entry on free_list\n"); + if (pf->page > pf->end) { + TRACE(("%6d !s %p %p %p <%d>\n",malloc_event++, + pf,pf->page,pf->end,__LINE__)); + wrterror("sick entry on free_list\n"); + } + if ((void*)pf->page >= (void*)sbrk(0)) + wrterror("entry on free_list past brk\n"); + if (page_dir[((u_long)pf->page >> malloc_pageshift) - malloc_origo] + != MALLOC_FREE) { + TRACE(("%6d !f %p %p %p <%d>\n",malloc_event++, + pf,pf->page,pf->end,__LINE__)); + wrterror("non-free first page on free-list\n"); + } + if (page_dir[((u_long)pf->end >> malloc_pageshift) - 1 - malloc_origo] + != MALLOC_FREE) + wrterror("non-free last page on free-list\n"); +#endif /* EXTRA_SANITY */ + if (pf->size < size) + continue; + else if (pf->size == size) { + p = pf->page; + if (pf->next) + pf->next->prev = pf->prev; + pf->prev->next = pf->next; + delay_free = pf; + break; + } else { + p = pf->page; + pf->page += size; + pf->size -= size; + break; + } + } +#ifdef EXTRA_SANITY + if (p && page_dir[((u_long)p >> malloc_pageshift) - malloc_origo] + != MALLOC_FREE) { + wrterror("allocated non-free page on free-list\n"); + } +#endif /* EXTRA_SANITY */ + + size >>= malloc_pageshift; + + /* Map new pages */ + if (!p) + p = map_pages(size,1); + + if (p) { + /* Mark the pages in the directory */ + index = ((u_long)p >> malloc_pageshift) - malloc_origo; + page_dir[index] = MALLOC_FIRST; + for (i=1;i<size;i++) + page_dir[index+i] = MALLOC_FOLLOW; + } + if (delay_free) { + if (!px) + px = (struct pgfree*)delay_free; + else + _PR_UnlockedFree(delay_free); + } + return p; +} + +/* + * Allocate a page of fragments + */ + +static int +malloc_make_chunks(int bits) +{ + struct pginfo *bp; + void *pp; + int i,k,l; + + /* Allocate a new bucket */ + pp = malloc_pages(malloc_pagesize); + if (!pp) + return 0; + l = sizeof *bp - sizeof(u_long); + l += sizeof(u_long) * + (((malloc_pagesize >> bits)+MALLOC_BITS-1) / MALLOC_BITS); + if ((1<<(bits)) <= l+l) { + bp = (struct pginfo *)pp; + } else { + bp = (struct pginfo *)_PR_UnlockedMalloc(l); + } + if (!bp) + return 0; + bp->size = (1<<bits); + bp->shift = bits; + bp->total = bp->free = malloc_pagesize >> bits; + bp->next = page_dir[bits]; + bp->page = (char*)pp; + i = set_pgdir(pp,bp); + if (!i) + return 0; + + /* We can safely assume that there is nobody in this chain */ + page_dir[bits] = bp; + + /* set all valid bits in the bits */ + k = bp->total; + i = 0; +/* + for(;k-i >= MALLOC_BITS; i += MALLOC_BITS) + bp->bits[i / MALLOC_BITS] = ~0; +*/ + for(; i < k; i++) + set_bit(bp,i); + + if (bp != pp) + return 1; + + /* We may have used the first ones already */ + for(i=0;l > 0;i++) { + clr_bit(bp,i); + bp->free--; + bp->total--; + l -= (1 << bits); + } + return 1; +} + +/* + * Allocate a fragment + */ +static void *malloc_bytes(size_t size) +{ + size_t s; + int j; + struct pginfo *bp; + int k; + u_long *lp, bf; + + /* Don't bother with anything less than this */ + if (size < malloc_minsize) { + size = malloc_minsize; + } + + /* Find the right bucket */ + j = 1; + s = size - 1; + while (s >>= 1) { + j++; + } + + /* If it's empty, make a page more of that size chunks */ + if (!page_dir[j] && !malloc_make_chunks(j)) + return 0; + + /* Find first word of bitmap which isn't empty */ + bp = page_dir[j]; + for (lp = bp->bits; !*lp; lp++) + ; + + /* Find that bit */ + bf = *lp; + k = 0; + while ((bf & 1) == 0) { + bf >>= 1; + k++; + } + + *lp ^= 1L<<k; /* clear it */ + bp->free--; + if (!bp->free) { + page_dir[j] = bp->next; + bp->next = 0; + } + k += (lp - bp->bits)*MALLOC_BITS; + return bp->page + (k << bp->shift); +} + +void *_PR_UnlockedMalloc(size_t size) +{ + void *result; + + /* Round up to a multiple of 8 bytes */ + if (size & 7) { + size = size + 8 - (size & 7); + } + + if (!initialized) + malloc_init(); + +#ifdef SANITY + if (suicide) + PR_Abort(); +#endif + + if (size <= malloc_maxsize) + result = malloc_bytes(size); + else + result = malloc_pages(size); +#ifdef SANITY + if (malloc_abort && !result) + wrterror("malloc() returns NULL\n"); +#endif + TRACE(("%6d M %p %d\n",malloc_event++,result,size)); + + return result; +} + +void *_PR_UnlockedMemalign(size_t alignment, size_t size) +{ + void *result; + + /* + * alignment has to be a power of 2 + */ + + if ((size <= alignment) && (alignment <= malloc_maxsize)) + size = alignment; + else + size += alignment - 1; + + /* Round up to a multiple of 8 bytes */ + if (size & 7) { + size = size + 8 - (size & 7); + } + + if (!initialized) + malloc_init(); + +#ifdef SANITY + if (suicide) + abort(); +#endif + + if (size <= malloc_maxsize) + result = malloc_bytes(size); + else + result = malloc_pages(size); +#ifdef SANITY + if (malloc_abort && !result) + wrterror("malloc() returns NULL\n"); +#endif + TRACE(("%6d A %p %d\n",malloc_event++,result,size)); + + if ((u_long)result & (alignment - 1)) + return ((void *)(((u_long)result + alignment) & ~(alignment - 1))); + else + return result; +} + +void *_PR_UnlockedCalloc(size_t n, size_t nelem) +{ + void *p; + + /* Compute total size and then round up to a double word amount */ + n *= nelem; + if (n & 7) { + n = n + 8 - (n & 7); + } + + /* Get the memory */ + p = _PR_UnlockedMalloc(n); + if (p) { + /* Zero it */ + memset(p, 0, n); + } + return p; +} + +/* + * Change an allocation's size + */ +void *_PR_UnlockedRealloc(void *ptr, size_t size) +{ + void *p; + u_long osize,page,index,tmp_index; + struct pginfo **mp; + + if (!initialized) + malloc_init(); + +#ifdef SANITY + if (suicide) + PR_Abort(); +#endif + + /* used as free() */ + TRACE(("%6d R %p %d\n",malloc_event++, ptr, size)); + if (ptr && !size) { + _PR_UnlockedFree(ptr); + return _PR_UnlockedMalloc (1); + } + + /* used as malloc() */ + if (!ptr) { + p = _PR_UnlockedMalloc(size); + return p; + } + + /* Find the page directory entry for the page in question */ + page = (u_long)ptr >> malloc_pageshift; + index = page - malloc_origo; + + /* + * check if memory was allocated by memalign + */ + tmp_index = index; + while (page_dir[tmp_index] == MALLOC_FOLLOW) + tmp_index--; + if (tmp_index != index) { + /* + * memalign-allocated memory + */ + index = tmp_index; + page = index + malloc_origo; + ptr = (void *) (page << malloc_pageshift); + } + TRACE(("%6d R2 %p %d\n",malloc_event++, ptr, size)); + + /* make sure it makes sense in some fashion */ + if (index < malloc_pageshift || index > last_index) { +#ifdef SANITY + wrtwarning("junk pointer passed to realloc()\n"); +#endif + return 0; + } + + /* find the size of that allocation, and see if we need to relocate */ + mp = &page_dir[index]; + if (*mp == MALLOC_FIRST) { + osize = malloc_pagesize; + while (mp[1] == MALLOC_FOLLOW) { + osize += malloc_pagesize; + mp++; + } + if (!malloc_realloc && + size < osize && + size > malloc_maxsize && + size > (osize - malloc_pagesize)) { + return ptr; + } + } else if (*mp >= MALLOC_MAGIC) { + osize = (*mp)->size; + if (!malloc_realloc && + size < osize && + (size > (*mp)->size/2 || (*mp)->size == malloc_minsize)) { + return ptr; + } + } else { +#ifdef SANITY + wrterror("realloc() of wrong page.\n"); +#endif + } + + /* try to reallocate */ + p = _PR_UnlockedMalloc(size); + + if (p) { + /* copy the lesser of the two sizes */ + if (osize < size) + memcpy(p,ptr,osize); + else + memcpy(p,ptr,size); + _PR_UnlockedFree(ptr); + } +#ifdef DEBUG + else if (malloc_abort) + wrterror("realloc() returns NULL\n"); +#endif + + return p; +} + +/* + * Free a sequence of pages + */ + +static void +free_pages(char *ptr, u_long page, int index, struct pginfo *info) +{ + int i; + struct pgfree *pf,*pt; + u_long l; + char *tail; + + TRACE(("%6d FP %p %d\n",malloc_event++, ptr, page)); + /* Is it free already ? */ + if (info == MALLOC_FREE) { +#ifdef SANITY + wrtwarning("freeing free page at %p.\n", ptr); +#endif + return; + } + +#ifdef SANITY + /* Is it not the right place to begin ? */ + if (info != MALLOC_FIRST) + wrterror("freeing wrong page.\n"); + + /* Is this really a pointer to a page ? */ + if ((u_long)ptr & malloc_pagemask) + wrterror("freeing messed up page pointer.\n"); +#endif + + /* Count how many pages it is anyway */ + page_dir[index] = MALLOC_FREE; + for (i = 1; page_dir[index+i] == MALLOC_FOLLOW; i++) + page_dir[index + i] = MALLOC_FREE; + + l = i << malloc_pageshift; + + tail = ptr+l; + + /* add to free-list */ + if (!px) + px = (struct pgfree*)_PR_UnlockedMalloc(sizeof *pt); + /* XXX check success */ + px->page = ptr; + px->end = tail; + px->size = l; + if (!free_list.next) { + px->next = free_list.next; + px->prev = &free_list; + free_list.next = px; + pf = px; + px = 0; + } else { + tail = ptr+l; + for(pf = free_list.next; pf->next && pf->end < ptr; pf = pf->next) + ; + for(; pf; pf = pf->next) { + if (pf->end == ptr ) { + /* append to entry */ + pf->end += l; + pf->size += l; + if (pf->next && pf->end == pf->next->page ) { + pt = pf->next; + pf->end = pt->end; + pf->size += pt->size; + pf->next = pt->next; + if (pf->next) + pf->next->prev = pf; + _PR_UnlockedFree(pt); + } + } else if (pf->page == tail) { + /* prepend to entry */ + pf->size += l; + pf->page = ptr; + } else if (pf->page > ptr) { + px->next = pf; + px->prev = pf->prev; + pf->prev = px; + px->prev->next = px; + pf = px; + px = 0; + } else if (!pf->next) { + px->next = 0; + px->prev = pf; + pf->next = px; + pf = px; + px = 0; + } else { + continue; + } + break; + } + } + if (!pf->next && + pf->size > malloc_cache && + pf->end == malloc_brk && + malloc_brk == (void*)sbrk(0)) { + pf->end = pf->page + malloc_cache; + pf->size = malloc_cache; + TRACE(("%6d U %p %d\n",malloc_event++,pf->end,pf->end - pf->page)); + brk(pf->end); + malloc_brk = pf->end; + /* Find the page directory entry for the page in question */ + page = (u_long)pf->end >> malloc_pageshift; + index = page - malloc_origo; + /* Now update the directory */ + for(i=index;i <= last_index;) + page_dir[i++] = MALLOC_NOT_MINE; + last_index = index - 1; + } +} + +/* + * Free a chunk, and possibly the page it's on, if the page becomes empty. + */ + +static void +free_bytes(void *ptr, u_long page, int index, struct pginfo *info) +{ + int i; + struct pginfo **mp; + void *vp; + + /* Make sure that pointer is multiplum of chunk-size */ +#ifdef SANITY + if ((u_long)ptr & (info->size - 1)) + wrterror("freeing messed up chunk pointer\n"); +#endif + + /* Find the chunk number on the page */ + i = ((u_long)ptr & malloc_pagemask) >> info->shift; + + /* See if it's free already */ + if (tst_bit(info,i)) { +#ifdef SANITY + wrtwarning("freeing free chunk at %p\n", ptr); +#endif + return; + } + + /* Mark it free */ + set_bit(info,i); + info->free++; + + /* If the page was full before, we need to put it on the queue now */ + if (info->free == 1) { + mp = page_dir + info->shift; + while (*mp && (*mp)->next && (*mp)->next->page < info->page) + mp = &(*mp)->next; + info->next = *mp; + *mp = info; + return; + } + + /* If this page isn't empty, don't do anything. */ + if (info->free != info->total) + return; + + /* We may want to keep at least one page of each size chunks around. */ + mp = page_dir + info->shift; + if (0 && (*mp == info) && !info->next) + return; + + /* Find & remove this page in the queue */ + while (*mp != info) { + mp = &((*mp)->next); +#ifdef EXTRA_SANITY + if (!*mp) { + TRACE(("%6d !q %p\n",malloc_event++,info)); + wrterror("Not on queue\n"); + } +#endif + } + *mp = info->next; + + /* Free the page & the info structure if need be */ + set_pgdir(info->page,MALLOC_FIRST); + if((void*)info->page == (void*)info) { + _PR_UnlockedFree(info->page); + } else { + vp = info->page; + _PR_UnlockedFree(info); + _PR_UnlockedFree(vp); + } +} + +void _PR_UnlockedFree(void *ptr) +{ + u_long page; + struct pginfo *info; + int index, tmp_index; + + TRACE(("%6d F %p\n",malloc_event++,ptr)); + /* This is legal */ + if (!ptr) + return; + +#ifdef SANITY + /* There wouldn't be anything to free */ + if (!initialized) { + wrtwarning("free() called before malloc() ever got called\n"); + return; + } +#endif + +#ifdef SANITY + if (suicide) + PR_Abort(); +#endif + + /* Find the page directory entry for the page in question */ + page = (u_long)ptr >> malloc_pageshift; + index = page - malloc_origo; + + /* + * check if memory was allocated by memalign + */ + tmp_index = index; + while (page_dir[tmp_index] == MALLOC_FOLLOW) + tmp_index--; + if (tmp_index != index) { + /* + * memalign-allocated memory + */ + index = tmp_index; + page = index + malloc_origo; + ptr = (void *) (page << malloc_pageshift); + } + /* make sure it makes sense in some fashion */ + if (index < malloc_pageshift) { +#ifdef SANITY + wrtwarning("junk pointer %p (low) passed to free()\n", ptr); +#endif + return; + } + if (index > last_index) { +#ifdef SANITY + wrtwarning("junk pointer %p (high) passed to free()\n", ptr); +#endif + return; + } + + /* handle as page-allocation or chunk allocation */ + info = page_dir[index]; + if (info < MALLOC_MAGIC) + free_pages((char*)ptr, page, index, info); + else + free_bytes(ptr,page,index,info); + return; +} +#endif /* _PR_OVERRIDE_MALLOC */ |