Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 1906 insertions, 0 deletions

diff --git a/nsprpub/pr/src/malloc/Makefile.in b/nsprpub/pr/src/malloc/Makefile.in
new file mode 100644
index 0000000000..51f2a5a52a
--- /dev/null
+++ b/nsprpub/pr/src/malloc/Makefile.in
@@ -0,0 +1,28 @@
+# 
+# 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/.
+
+#! gmake
+
+MOD_DEPTH	= ../../..
+topsrcdir	= @top_srcdir@
+srcdir		= @srcdir@
+VPATH		= @srcdir@
+
+include $(MOD_DEPTH)/config/autoconf.mk
+
+include $(topsrcdir)/config/config.mk
+
+TARGETS	= $(OBJS)
+
+INCLUDES = -I$(dist_includedir) -I$(topsrcdir)/pr/include -I$(topsrcdir)/pr/include/private
+
+DEFINES += -D_NSPR_BUILD_
+
+CSRCS = prmalloc.c prmem.c
+
+include $(topsrcdir)/config/rules.mk
+
+export:: $(TARGETS)
+
diff --git a/nsprpub/pr/src/malloc/prmalloc.c b/nsprpub/pr/src/malloc/prmalloc.c
new file mode 100644
index 0000000000..c03b7d11e5
--- /dev/null
+++ b/nsprpub/pr/src/malloc/prmalloc.c
@@ -0,0 +1,1200 @@
+/* -*- 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 */
diff --git a/nsprpub/pr/src/malloc/prmem.c b/nsprpub/pr/src/malloc/prmem.c
new file mode 100644
index 0000000000..08a700f7a9
--- /dev/null
+++ b/nsprpub/pr/src/malloc/prmem.c
@@ -0,0 +1,678 @@
+/* -*- 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/. */
+
+/*
+** Thread safe versions of malloc, free, realloc, calloc and cfree.
+*/
+
+#include "primpl.h"
+
+#ifdef _PR_ZONE_ALLOCATOR
+
+/*
+** The zone allocator code must use native mutexes and cannot
+** use PRLocks because PR_NewLock calls PR_Calloc, resulting
+** in cyclic dependency of initialization.
+*/
+
+#include <string.h>
+
+union memBlkHdrUn;
+
+typedef struct MemoryZoneStr {
+    union memBlkHdrUn    *head;         /* free list */
+    pthread_mutex_t       lock;
+    size_t                blockSize;    /* size of blocks on this free list */
+    PRUint32              locked;       /* current state of lock */
+    PRUint32              contention;   /* counter: had to wait for lock */
+    PRUint32              hits;         /* allocated from free list */
+    PRUint32              misses;       /* had to call malloc */
+    PRUint32              elements;     /* on free list */
+} MemoryZone;
+
+typedef union memBlkHdrUn {
+    unsigned char filler[48];  /* fix the size of this beast */
+    struct memBlkHdrStr {
+        union memBlkHdrUn    *next;
+        MemoryZone           *zone;
+        size_t                blockSize;
+        size_t                requestedSize;
+        PRUint32              magic;
+    } s;
+} MemBlockHdr;
+
+#define MEM_ZONES     7
+#define THREAD_POOLS 11  /* prime number for modulus */
+#define ZONE_MAGIC  0x0BADC0DE
+
+static MemoryZone zones[MEM_ZONES][THREAD_POOLS];
+
+static PRBool use_zone_allocator = PR_FALSE;
+
+static void pr_ZoneFree(void *ptr);
+
+void
+_PR_DestroyZones(void)
+{
+    int i, j;
+
+    if (!use_zone_allocator) {
+        return;
+    }
+
+    for (j = 0; j < THREAD_POOLS; j++) {
+        for (i = 0; i < MEM_ZONES; i++) {
+            MemoryZone *mz = &zones[i][j];
+            pthread_mutex_destroy(&mz->lock);
+            while (mz->head) {
+                MemBlockHdr *hdr = mz->head;
+                mz->head = hdr->s.next;  /* unlink it */
+                free(hdr);
+                mz->elements--;
+            }
+        }
+    }
+    use_zone_allocator = PR_FALSE;
+}
+
+/*
+** pr_FindSymbolInProg
+**
+** Find the specified data symbol in the program and return
+** its address.
+*/
+
+#ifdef HAVE_DLL
+
+#if defined(USE_DLFCN) && !defined(NO_DLOPEN_NULL)
+
+#include <dlfcn.h>
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+    void *h;
+    void *sym;
+
+    h = dlopen(0, RTLD_LAZY);
+    if (h == NULL) {
+        return NULL;
+    }
+    sym = dlsym(h, name);
+    (void)dlclose(h);
+    return sym;
+}
+
+#elif defined(USE_HPSHL)
+
+#include <dl.h>
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+    shl_t h = NULL;
+    void *sym;
+
+    if (shl_findsym(&h, name, TYPE_DATA, &sym) == -1) {
+        return NULL;
+    }
+    return sym;
+}
+
+#elif defined(USE_MACH_DYLD) || defined(NO_DLOPEN_NULL)
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+    /* FIXME: not implemented */
+    return NULL;
+}
+
+#else
+
+#error "The zone allocator is not supported on this platform"
+
+#endif
+
+#else /* !defined(HAVE_DLL) */
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+    /* can't be implemented */
+    return NULL;
+}
+
+#endif /* HAVE_DLL */
+
+void
+_PR_InitZones(void)
+{
+    int i, j;
+    char *envp;
+    PRBool *sym;
+
+    if ((sym = (PRBool *)pr_FindSymbolInProg("nspr_use_zone_allocator")) != NULL) {
+        use_zone_allocator = *sym;
+    } else if ((envp = getenv("NSPR_USE_ZONE_ALLOCATOR")) != NULL) {
+        use_zone_allocator = (atoi(envp) == 1);
+    }
+
+    if (!use_zone_allocator) {
+        return;
+    }
+
+    for (j = 0; j < THREAD_POOLS; j++) {
+        for (i = 0; i < MEM_ZONES; i++) {
+            MemoryZone *mz = &zones[i][j];
+            int rv = pthread_mutex_init(&mz->lock, NULL);
+            PR_ASSERT(0 == rv);
+            if (rv != 0) {
+                goto loser;
+            }
+            mz->blockSize = 16 << ( 2 * i);
+        }
+    }
+    return;
+
+loser:
+    _PR_DestroyZones();
+    return;
+}
+
+PR_IMPLEMENT(void)
+PR_FPrintZoneStats(PRFileDesc *debug_out)
+{
+    int i, j;
+
+    for (j = 0; j < THREAD_POOLS; j++) {
+        for (i = 0; i < MEM_ZONES; i++) {
+            MemoryZone   *mz   = &zones[i][j];
+            MemoryZone    zone = *mz;
+            if (zone.elements || zone.misses || zone.hits) {
+                PR_fprintf(debug_out,
+                           "pool: %d, zone: %d, size: %d, free: %d, hit: %d, miss: %d, contend: %d\n",
+                           j, i, zone.blockSize, zone.elements,
+                           zone.hits, zone.misses, zone.contention);
+            }
+        }
+    }
+}
+
+static void *
+pr_ZoneMalloc(PRUint32 size)
+{
+    void         *rv;
+    unsigned int  zone;
+    size_t        blockSize;
+    MemBlockHdr  *mb, *mt;
+    MemoryZone   *mz;
+
+    /* Always allocate a non-zero amount of bytes */
+    if (size < 1) {
+        size = 1;
+    }
+    for (zone = 0, blockSize = 16; zone < MEM_ZONES; ++zone, blockSize <<= 2) {
+        if (size <= blockSize) {
+            break;
+        }
+    }
+    if (zone < MEM_ZONES) {
+        pthread_t me = pthread_self();
+        unsigned int pool = (PRUptrdiff)me % THREAD_POOLS;
+        PRUint32     wasLocked;
+        mz = &zones[zone][pool];
+        wasLocked = mz->locked;
+        pthread_mutex_lock(&mz->lock);
+        mz->locked = 1;
+        if (wasLocked) {
+            mz->contention++;
+        }
+        if (mz->head) {
+            mb = mz->head;
+            PR_ASSERT(mb->s.magic == ZONE_MAGIC);
+            PR_ASSERT(mb->s.zone  == mz);
+            PR_ASSERT(mb->s.blockSize == blockSize);
+            PR_ASSERT(mz->blockSize == blockSize);
+
+            mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+            PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+            PR_ASSERT(mt->s.zone  == mz);
+            PR_ASSERT(mt->s.blockSize == blockSize);
+
+            mz->hits++;
+            mz->elements--;
+            mz->head = mb->s.next;    /* take off free list */
+            mz->locked = 0;
+            pthread_mutex_unlock(&mz->lock);
+
+            mt->s.next          = mb->s.next          = NULL;
+            mt->s.requestedSize = mb->s.requestedSize = size;
+
+            rv = (void *)(mb + 1);
+            return rv;
+        }
+
+        mz->misses++;
+        mz->locked = 0;
+        pthread_mutex_unlock(&mz->lock);
+
+        mb = (MemBlockHdr *)malloc(blockSize + 2 * (sizeof *mb));
+        if (!mb) {
+            PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+            return NULL;
+        }
+        mb->s.next          = NULL;
+        mb->s.zone          = mz;
+        mb->s.magic         = ZONE_MAGIC;
+        mb->s.blockSize     = blockSize;
+        mb->s.requestedSize = size;
+
+        mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+        memcpy(mt, mb, sizeof *mb);
+
+        rv = (void *)(mb + 1);
+        return rv;
+    }
+
+    /* size was too big.  Create a block with no zone */
+    blockSize = (size & 15) ? size + 16 - (size & 15) : size;
+    mb = (MemBlockHdr *)malloc(blockSize + 2 * (sizeof *mb));
+    if (!mb) {
+        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+        return NULL;
+    }
+    mb->s.next          = NULL;
+    mb->s.zone          = NULL;
+    mb->s.magic         = ZONE_MAGIC;
+    mb->s.blockSize     = blockSize;
+    mb->s.requestedSize = size;
+
+    mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+    memcpy(mt, mb, sizeof *mb);
+
+    rv = (void *)(mb + 1);
+    return rv;
+}
+
+
+static void *
+pr_ZoneCalloc(PRUint32 nelem, PRUint32 elsize)
+{
+    PRUint32 size = nelem * elsize;
+    void *p = pr_ZoneMalloc(size);
+    if (p) {
+        memset(p, 0, size);
+    }
+    return p;
+}
+
+static void *
+pr_ZoneRealloc(void *oldptr, PRUint32 bytes)
+{
+    void         *rv;
+    MemBlockHdr  *mb;
+    int           ours;
+    MemBlockHdr   phony;
+
+    if (!oldptr) {
+        return pr_ZoneMalloc(bytes);
+    }
+    mb = (MemBlockHdr *)((char *)oldptr - (sizeof *mb));
+    if (mb->s.magic != ZONE_MAGIC) {
+        /* Maybe this just came from ordinary malloc */
+#ifdef DEBUG
+        fprintf(stderr,
+                "Warning: reallocing memory block %p from ordinary malloc\n",
+                oldptr);
+#endif
+        /*
+         * We are going to realloc oldptr.  If realloc succeeds, the
+         * original value of oldptr will point to freed memory.  So this
+         * function must not fail after a successfull realloc call.  We
+         * must perform any operation that may fail before the realloc
+         * call.
+         */
+        rv = pr_ZoneMalloc(bytes);  /* this may fail */
+        if (!rv) {
+            return rv;
+        }
+
+        /* We don't know how big it is.  But we can fix that. */
+        oldptr = realloc(oldptr, bytes);
+        /*
+         * If realloc returns NULL, this function loses the original
+         * value of oldptr.  This isn't a leak because the caller of
+         * this function still has the original value of oldptr.
+         */
+        if (!oldptr) {
+            if (bytes) {
+                PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+                pr_ZoneFree(rv);
+                return oldptr;
+            }
+        }
+        phony.s.requestedSize = bytes;
+        mb = &phony;
+        ours = 0;
+    } else {
+        size_t blockSize = mb->s.blockSize;
+        MemBlockHdr *mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+
+        PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+        PR_ASSERT(mt->s.zone  == mb->s.zone);
+        PR_ASSERT(mt->s.blockSize == blockSize);
+
+        if (bytes <= blockSize) {
+            /* The block is already big enough. */
+            mt->s.requestedSize = mb->s.requestedSize = bytes;
+            return oldptr;
+        }
+        ours = 1;
+        rv = pr_ZoneMalloc(bytes);
+        if (!rv) {
+            return rv;
+        }
+    }
+
+    if (oldptr && mb->s.requestedSize) {
+        memcpy(rv, oldptr, mb->s.requestedSize);
+    }
+    if (ours) {
+        pr_ZoneFree(oldptr);
+    }
+    else if (oldptr) {
+        free(oldptr);
+    }
+    return rv;
+}
+
+static void
+pr_ZoneFree(void *ptr)
+{
+    MemBlockHdr  *mb, *mt;
+    MemoryZone   *mz;
+    size_t        blockSize;
+    PRUint32      wasLocked;
+
+    if (!ptr) {
+        return;
+    }
+
+    mb = (MemBlockHdr *)((char *)ptr - (sizeof *mb));
+
+    if (mb->s.magic != ZONE_MAGIC) {
+        /* maybe this came from ordinary malloc */
+#ifdef DEBUG
+        fprintf(stderr,
+                "Warning: freeing memory block %p from ordinary malloc\n", ptr);
+#endif
+        free(ptr);
+        return;
+    }
+
+    blockSize = mb->s.blockSize;
+    mz        = mb->s.zone;
+    mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+    PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+    PR_ASSERT(mt->s.zone  == mz);
+    PR_ASSERT(mt->s.blockSize == blockSize);
+    if (!mz) {
+        PR_ASSERT(blockSize > 65536);
+        /* This block was not in any zone.  Just free it. */
+        free(mb);
+        return;
+    }
+    PR_ASSERT(mz->blockSize == blockSize);
+    wasLocked = mz->locked;
+    pthread_mutex_lock(&mz->lock);
+    mz->locked = 1;
+    if (wasLocked) {
+        mz->contention++;
+    }
+    mt->s.next = mb->s.next = mz->head;        /* put on head of list */
+    mz->head = mb;
+    mz->elements++;
+    mz->locked = 0;
+    pthread_mutex_unlock(&mz->lock);
+}
+
+PR_IMPLEMENT(void *) PR_Malloc(PRUint32 size)
+{
+    if (!_pr_initialized) {
+        _PR_ImplicitInitialization();
+    }
+
+    return use_zone_allocator ? pr_ZoneMalloc(size) : malloc(size);
+}
+
+PR_IMPLEMENT(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize)
+{
+    if (!_pr_initialized) {
+        _PR_ImplicitInitialization();
+    }
+
+    return use_zone_allocator ?
+           pr_ZoneCalloc(nelem, elsize) : calloc(nelem, elsize);
+}
+
+PR_IMPLEMENT(void *) PR_Realloc(void *ptr, PRUint32 size)
+{
+    if (!_pr_initialized) {
+        _PR_ImplicitInitialization();
+    }
+
+    return use_zone_allocator ? pr_ZoneRealloc(ptr, size) : realloc(ptr, size);
+}
+
+PR_IMPLEMENT(void) PR_Free(void *ptr)
+{
+    if (use_zone_allocator) {
+        pr_ZoneFree(ptr);
+    }
+    else {
+        free(ptr);
+    }
+}
+
+#else /* !defined(_PR_ZONE_ALLOCATOR) */
+
+/*
+** The PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free functions simply
+** call their libc equivalents now.  This may seem redundant, but it
+** ensures that we are calling into the same runtime library.  On
+** Win32, it is possible to have multiple runtime libraries (e.g.,
+** objects compiled with /MD and /MDd) in the same process, and
+** they maintain separate heaps, which cannot be mixed.
+*/
+PR_IMPLEMENT(void *) PR_Malloc(PRUint32 size)
+{
+#if defined (WIN16)
+    return PR_MD_malloc( (size_t) size);
+#else
+    return malloc(size);
+#endif
+}
+
+PR_IMPLEMENT(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize)
+{
+#if defined (WIN16)
+    return PR_MD_calloc( (size_t)nelem, (size_t)elsize );
+
+#else
+    return calloc(nelem, elsize);
+#endif
+}
+
+PR_IMPLEMENT(void *) PR_Realloc(void *ptr, PRUint32 size)
+{
+#if defined (WIN16)
+    return PR_MD_realloc( ptr, (size_t) size);
+#else
+    return realloc(ptr, size);
+#endif
+}
+
+PR_IMPLEMENT(void) PR_Free(void *ptr)
+{
+#if defined (WIN16)
+    PR_MD_free( ptr );
+#else
+    free(ptr);
+#endif
+}
+
+#endif /* _PR_ZONE_ALLOCATOR */
+
+/*
+** Complexity alert!
+**
+** If malloc/calloc/free (etc.) were implemented to use pr lock's then
+** the entry points could block when called if some other thread had the
+** lock.
+**
+** Most of the time this isn't a problem. However, in the case that we
+** are using the thread safe malloc code after PR_Init but before
+** PR_AttachThread has been called (on a native thread that nspr has yet
+** to be told about) we could get royally screwed if the lock was busy
+** and we tried to context switch the thread away. In this scenario
+**  PR_CURRENT_THREAD() == NULL
+**
+** To avoid this unfortunate case, we use the low level locking
+** facilities for malloc protection instead of the slightly higher level
+** locking. This makes malloc somewhat faster so maybe it's a good thing
+** anyway.
+*/
+#ifdef _PR_OVERRIDE_MALLOC
+
+/* Imports */
+extern void *_PR_UnlockedMalloc(size_t size);
+extern void *_PR_UnlockedMemalign(size_t alignment, size_t size);
+extern void _PR_UnlockedFree(void *ptr);
+extern void *_PR_UnlockedRealloc(void *ptr, size_t size);
+extern void *_PR_UnlockedCalloc(size_t n, size_t elsize);
+
+static PRBool _PR_malloc_initialised = PR_FALSE;
+
+#ifdef _PR_PTHREADS
+static pthread_mutex_t _PR_MD_malloc_crustylock;
+
+#define _PR_Lock_Malloc() {                     \
+                    if(PR_TRUE == _PR_malloc_initialised) { \
+                    PRStatus rv;            \
+                    rv = pthread_mutex_lock(&_PR_MD_malloc_crustylock); \
+                    PR_ASSERT(0 == rv);     \
+                }
+
+#define _PR_Unlock_Malloc()     if(PR_TRUE == _PR_malloc_initialised) { \
+                    PRStatus rv;            \
+                    rv = pthread_mutex_unlock(&_PR_MD_malloc_crustylock); \
+                    PR_ASSERT(0 == rv);     \
+                }                   \
+              }
+#else /* _PR_PTHREADS */
+static _MDLock _PR_MD_malloc_crustylock;
+
+#define _PR_Lock_Malloc() {                     \
+               PRIntn _is;                  \
+                    if(PR_TRUE == _PR_malloc_initialised) { \
+                if (_PR_MD_CURRENT_THREAD() &&      \
+                    !_PR_IS_NATIVE_THREAD(      \
+                    _PR_MD_CURRENT_THREAD()))   \
+                        _PR_INTSOFF(_is);   \
+                    _PR_MD_LOCK(&_PR_MD_malloc_crustylock); \
+                }
+
+#define _PR_Unlock_Malloc()     if(PR_TRUE == _PR_malloc_initialised) { \
+                    _PR_MD_UNLOCK(&_PR_MD_malloc_crustylock); \
+                if (_PR_MD_CURRENT_THREAD() &&      \
+                    !_PR_IS_NATIVE_THREAD(      \
+                    _PR_MD_CURRENT_THREAD()))   \
+                        _PR_INTSON(_is);    \
+                }                   \
+              }
+#endif /* _PR_PTHREADS */
+
+PR_IMPLEMENT(PRStatus) _PR_MallocInit(void)
+{
+    PRStatus rv = PR_SUCCESS;
+
+    if( PR_TRUE == _PR_malloc_initialised ) {
+        return PR_SUCCESS;
+    }
+
+#ifdef _PR_PTHREADS
+    {
+        int status;
+        pthread_mutexattr_t mattr;
+
+        status = _PT_PTHREAD_MUTEXATTR_INIT(&mattr);
+        PR_ASSERT(0 == status);
+        status = _PT_PTHREAD_MUTEX_INIT(_PR_MD_malloc_crustylock, mattr);
+        PR_ASSERT(0 == status);
+        status = _PT_PTHREAD_MUTEXATTR_DESTROY(&mattr);
+        PR_ASSERT(0 == status);
+    }
+#else /* _PR_PTHREADS */
+    _MD_NEW_LOCK(&_PR_MD_malloc_crustylock);
+#endif /* _PR_PTHREADS */
+
+    if( PR_SUCCESS == rv )
+    {
+        _PR_malloc_initialised = PR_TRUE;
+    }
+
+    return rv;
+}
+
+void *malloc(size_t size)
+{
+    void *p;
+    _PR_Lock_Malloc();
+    p = _PR_UnlockedMalloc(size);
+    _PR_Unlock_Malloc();
+    return p;
+}
+
+void free(void *ptr)
+{
+    _PR_Lock_Malloc();
+    _PR_UnlockedFree(ptr);
+    _PR_Unlock_Malloc();
+}
+
+void *realloc(void *ptr, size_t size)
+{
+    void *p;
+    _PR_Lock_Malloc();
+    p = _PR_UnlockedRealloc(ptr, size);
+    _PR_Unlock_Malloc();
+    return p;
+}
+
+void *calloc(size_t n, size_t elsize)
+{
+    void *p;
+    _PR_Lock_Malloc();
+    p = _PR_UnlockedCalloc(n, elsize);
+    _PR_Unlock_Malloc();
+    return p;
+}
+
+void cfree(void *p)
+{
+    _PR_Lock_Malloc();
+    _PR_UnlockedFree(p);
+    _PR_Unlock_Malloc();
+}
+
+void _PR_InitMem(void)
+{
+    PRStatus rv;
+    rv = _PR_MallocInit();
+    PR_ASSERT(PR_SUCCESS == rv);
+}
+
+#endif /* _PR_OVERRIDE_MALLOC */