| Index: mozilla/nsprpub/lib/ds/plarena.c
|
| ===================================================================
|
| --- mozilla/nsprpub/lib/ds/plarena.c (revision 191424)
|
| +++ mozilla/nsprpub/lib/ds/plarena.c (working copy)
|
| @@ -1,418 +0,0 @@
|
| -/* -*- 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/. */
|
| -
|
| -/*
|
| - * Lifetime-based fast allocation, inspired by much prior art, including
|
| - * "Fast Allocation and Deallocation of Memory Based on Object Lifetimes"
|
| - * David R. Hanson, Software -- Practice and Experience, Vol. 20(1).
|
| - */
|
| -#include <stdlib.h>
|
| -#include <string.h>
|
| -#include "plarena.h"
|
| -#include "prmem.h"
|
| -#include "prbit.h"
|
| -#include "prlog.h"
|
| -#include "prlock.h"
|
| -#include "prinit.h"
|
| -
|
| -static PLArena *arena_freelist;
|
| -
|
| -#ifdef PL_ARENAMETER
|
| -static PLArenaStats *arena_stats_list;
|
| -
|
| -#define COUNT(pool,what) (pool)->stats.what++
|
| -#else
|
| -#define COUNT(pool,what) /* nothing */
|
| -#endif
|
| -
|
| -#define PL_ARENA_DEFAULT_ALIGN sizeof(double)
|
| -
|
| -static PRLock *arenaLock;
|
| -static PRCallOnceType once;
|
| -static const PRCallOnceType pristineCallOnce;
|
| -
|
| -/*
|
| -** InitializeArenas() -- Initialize arena operations.
|
| -**
|
| -** InitializeArenas() is called exactly once and only once from
|
| -** LockArena(). This function creates the arena protection
|
| -** lock: arenaLock.
|
| -**
|
| -** Note: If the arenaLock cannot be created, InitializeArenas()
|
| -** fails quietly, returning only PR_FAILURE. This percolates up
|
| -** to the application using the Arena API. He gets no arena
|
| -** from PL_ArenaAllocate(). It's up to him to fail gracefully
|
| -** or recover.
|
| -**
|
| -*/
|
| -static PRStatus InitializeArenas( void )
|
| -{
|
| - PR_ASSERT( arenaLock == NULL );
|
| - arenaLock = PR_NewLock();
|
| - if ( arenaLock == NULL )
|
| - return PR_FAILURE;
|
| - else
|
| - return PR_SUCCESS;
|
| -} /* end ArenaInitialize() */
|
| -
|
| -static PRStatus LockArena( void )
|
| -{
|
| - PRStatus rc = PR_CallOnce( &once, InitializeArenas );
|
| -
|
| - if ( PR_FAILURE != rc )
|
| - PR_Lock( arenaLock );
|
| - return(rc);
|
| -} /* end LockArena() */
|
| -
|
| -static void UnlockArena( void )
|
| -{
|
| - PR_Unlock( arenaLock );
|
| - return;
|
| -} /* end UnlockArena() */
|
| -
|
| -PR_IMPLEMENT(void) PL_InitArenaPool(
|
| - PLArenaPool *pool, const char *name, PRUint32 size, PRUint32 align)
|
| -{
|
| - /*
|
| - * Look-up table of PR_BITMASK(PR_CeilingLog2(align)) values for
|
| - * align = 1 to 32.
|
| - */
|
| - static const PRUint8 pmasks[33] = {
|
| - 0, /* not used */
|
| - 0, 1, 3, 3, 7, 7, 7, 7,15,15,15,15,15,15,15,15, /* 1 ... 16 */
|
| - 31,31,31,31,31,31,31,31,31,31,31,31,31,31,31,31}; /* 17 ... 32 */
|
| -
|
| - if (align == 0)
|
| - align = PL_ARENA_DEFAULT_ALIGN;
|
| -
|
| - if (align < sizeof(pmasks)/sizeof(pmasks[0]))
|
| - pool->mask = pmasks[align];
|
| - else
|
| - pool->mask = PR_BITMASK(PR_CeilingLog2(align));
|
| -
|
| - pool->first.next = NULL;
|
| - pool->first.base = pool->first.avail = pool->first.limit =
|
| - (PRUword)PL_ARENA_ALIGN(pool, &pool->first + 1);
|
| - pool->current = &pool->first;
|
| - /*
|
| - * Compute the net size so that each arena's gross size is |size|.
|
| - * sizeof(PLArena) + pool->mask is the header and alignment slop
|
| - * that PL_ArenaAllocate adds to the net size.
|
| - */
|
| - if (size > sizeof(PLArena) + pool->mask)
|
| - pool->arenasize = size - (sizeof(PLArena) + pool->mask);
|
| - else
|
| - pool->arenasize = size;
|
| -#ifdef PL_ARENAMETER
|
| - memset(&pool->stats, 0, sizeof pool->stats);
|
| - pool->stats.name = strdup(name);
|
| - pool->stats.next = arena_stats_list;
|
| - arena_stats_list = &pool->stats;
|
| -#endif
|
| -}
|
| -
|
| -
|
| -/*
|
| -** PL_ArenaAllocate() -- allocate space from an arena pool
|
| -**
|
| -** Description: PL_ArenaAllocate() allocates space from an arena
|
| -** pool.
|
| -**
|
| -** First, try to satisfy the request from arenas starting at
|
| -** pool->current.
|
| -**
|
| -** If there is not enough space in the arena pool->current, try
|
| -** to claim an arena, on a first fit basis, from the global
|
| -** freelist (arena_freelist).
|
| -**
|
| -** If no arena in arena_freelist is suitable, then try to
|
| -** allocate a new arena from the heap.
|
| -**
|
| -** Returns: pointer to allocated space or NULL
|
| -**
|
| -** Notes: The original implementation had some difficult to
|
| -** solve bugs; the code was difficult to read. Sometimes it's
|
| -** just easier to rewrite it. I did that. larryh.
|
| -**
|
| -** See also: bugzilla: 45343.
|
| -**
|
| -*/
|
| -
|
| -PR_IMPLEMENT(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb)
|
| -{
|
| - PLArena *a;
|
| - char *rp; /* returned pointer */
|
| -
|
| - PR_ASSERT((nb & pool->mask) == 0);
|
| -
|
| - nb = (PRUword)PL_ARENA_ALIGN(pool, nb); /* force alignment */
|
| -
|
| - /* attempt to allocate from arenas at pool->current */
|
| - {
|
| - a = pool->current;
|
| - do {
|
| - if ( a->avail +nb <= a->limit ) {
|
| - pool->current = a;
|
| - rp = (char *)a->avail;
|
| - a->avail += nb;
|
| - return rp;
|
| - }
|
| - } while( NULL != (a = a->next) );
|
| - }
|
| -
|
| - /* attempt to allocate from arena_freelist */
|
| - {
|
| - PLArena *p; /* previous pointer, for unlinking from freelist */
|
| -
|
| - /* lock the arena_freelist. Make access to the freelist MT-Safe */
|
| - if ( PR_FAILURE == LockArena())
|
| - return(0);
|
| -
|
| - for ( a = arena_freelist, p = NULL; a != NULL ; p = a, a = a->next ) {
|
| - if ( a->base +nb <= a->limit ) {
|
| - if ( p == NULL )
|
| - arena_freelist = a->next;
|
| - else
|
| - p->next = a->next;
|
| - UnlockArena();
|
| - a->avail = a->base;
|
| - rp = (char *)a->avail;
|
| - a->avail += nb;
|
| - /* the newly allocated arena is linked after pool->current
|
| - * and becomes pool->current */
|
| - a->next = pool->current->next;
|
| - pool->current->next = a;
|
| - pool->current = a;
|
| - if ( NULL == pool->first.next )
|
| - pool->first.next = a;
|
| - return(rp);
|
| - }
|
| - }
|
| - UnlockArena();
|
| - }
|
| -
|
| - /* attempt to allocate from the heap */
|
| - {
|
| - PRUint32 sz = PR_MAX(pool->arenasize, nb);
|
| - sz += sizeof *a + pool->mask; /* header and alignment slop */
|
| - a = (PLArena*)PR_MALLOC(sz);
|
| - if ( NULL != a ) {
|
| - a->limit = (PRUword)a + sz;
|
| - a->base = a->avail = (PRUword)PL_ARENA_ALIGN(pool, a + 1);
|
| - rp = (char *)a->avail;
|
| - a->avail += nb;
|
| - /* the newly allocated arena is linked after pool->current
|
| - * and becomes pool->current */
|
| - a->next = pool->current->next;
|
| - pool->current->next = a;
|
| - pool->current = a;
|
| - if ( NULL == pool->first.next )
|
| - pool->first.next = a;
|
| - PL_COUNT_ARENA(pool,++);
|
| - COUNT(pool, nmallocs);
|
| - return(rp);
|
| - }
|
| - }
|
| -
|
| - /* we got to here, and there's no memory to allocate */
|
| - return(NULL);
|
| -} /* --- end PL_ArenaAllocate() --- */
|
| -
|
| -PR_IMPLEMENT(void *) PL_ArenaGrow(
|
| - PLArenaPool *pool, void *p, PRUint32 size, PRUint32 incr)
|
| -{
|
| - void *newp;
|
| -
|
| - PL_ARENA_ALLOCATE(newp, pool, size + incr);
|
| - if (newp)
|
| - memcpy(newp, p, size);
|
| - return newp;
|
| -}
|
| -
|
| -static void ClearArenaList(PLArena *a, PRInt32 pattern)
|
| -{
|
| -
|
| - for (; a; a = a->next) {
|
| - PR_ASSERT(a->base <= a->avail && a->avail <= a->limit);
|
| - a->avail = a->base;
|
| - PL_CLEAR_UNUSED_PATTERN(a, pattern);
|
| - }
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ClearArenaPool(PLArenaPool *pool, PRInt32 pattern)
|
| -{
|
| - ClearArenaList(pool->first.next, pattern);
|
| -}
|
| -
|
| -/*
|
| - * Free tail arenas linked after head, which may not be the true list head.
|
| - * Reset pool->current to point to head in case it pointed at a tail arena.
|
| - */
|
| -static void FreeArenaList(PLArenaPool *pool, PLArena *head, PRBool reallyFree)
|
| -{
|
| - PLArena **ap, *a;
|
| -
|
| - ap = &head->next;
|
| - a = *ap;
|
| - if (!a)
|
| - return;
|
| -
|
| -#ifdef DEBUG
|
| - ClearArenaList(a, PL_FREE_PATTERN);
|
| -#endif
|
| -
|
| - if (reallyFree) {
|
| - do {
|
| - *ap = a->next;
|
| - PL_CLEAR_ARENA(a);
|
| - PL_COUNT_ARENA(pool,--);
|
| - PR_DELETE(a);
|
| - } while ((a = *ap) != 0);
|
| - } else {
|
| - /* Insert the whole arena chain at the front of the freelist. */
|
| - do {
|
| - ap = &(*ap)->next;
|
| - } while (*ap);
|
| - LockArena();
|
| - *ap = arena_freelist;
|
| - arena_freelist = a;
|
| - head->next = 0;
|
| - UnlockArena();
|
| - }
|
| -
|
| - pool->current = head;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaRelease(PLArenaPool *pool, char *mark)
|
| -{
|
| - PLArena *a;
|
| -
|
| - for (a = &pool->first; a; a = a->next) {
|
| - if (PR_UPTRDIFF(mark, a->base) <= PR_UPTRDIFF(a->avail, a->base)) {
|
| - a->avail = (PRUword)PL_ARENA_ALIGN(pool, mark);
|
| - FreeArenaList(pool, a, PR_FALSE);
|
| - return;
|
| - }
|
| - }
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_FreeArenaPool(PLArenaPool *pool)
|
| -{
|
| - FreeArenaList(pool, &pool->first, PR_FALSE);
|
| - COUNT(pool, ndeallocs);
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_FinishArenaPool(PLArenaPool *pool)
|
| -{
|
| - FreeArenaList(pool, &pool->first, PR_TRUE);
|
| -#ifdef PL_ARENAMETER
|
| - {
|
| - PLArenaStats *stats, **statsp;
|
| -
|
| - if (pool->stats.name)
|
| - PR_DELETE(pool->stats.name);
|
| - for (statsp = &arena_stats_list; (stats = *statsp) != 0;
|
| - statsp = &stats->next) {
|
| - if (stats == &pool->stats) {
|
| - *statsp = stats->next;
|
| - return;
|
| - }
|
| - }
|
| - }
|
| -#endif
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_CompactArenaPool(PLArenaPool *ap)
|
| -{
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaFinish(void)
|
| -{
|
| - PLArena *a, *next;
|
| -
|
| - for (a = arena_freelist; a; a = next) {
|
| - next = a->next;
|
| - PR_DELETE(a);
|
| - }
|
| - arena_freelist = NULL;
|
| -
|
| - if (arenaLock) {
|
| - PR_DestroyLock(arenaLock);
|
| - arenaLock = NULL;
|
| - }
|
| - once = pristineCallOnce;
|
| -}
|
| -
|
| -#ifdef PL_ARENAMETER
|
| -PR_IMPLEMENT(void) PL_ArenaCountAllocation(PLArenaPool *pool, PRUint32 nb)
|
| -{
|
| - pool->stats.nallocs++;
|
| - pool->stats.nbytes += nb;
|
| - if (nb > pool->stats.maxalloc)
|
| - pool->stats.maxalloc = nb;
|
| - pool->stats.variance += nb * nb;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaCountInplaceGrowth(
|
| - PLArenaPool *pool, PRUint32 size, PRUint32 incr)
|
| -{
|
| - pool->stats.ninplace++;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaCountGrowth(
|
| - PLArenaPool *pool, PRUint32 size, PRUint32 incr)
|
| -{
|
| - pool->stats.ngrows++;
|
| - pool->stats.nbytes += incr;
|
| - pool->stats.variance -= size * size;
|
| - size += incr;
|
| - if (size > pool->stats.maxalloc)
|
| - pool->stats.maxalloc = size;
|
| - pool->stats.variance += size * size;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaCountRelease(PLArenaPool *pool, char *mark)
|
| -{
|
| - pool->stats.nreleases++;
|
| -}
|
| -
|
| -PR_IMPLEMENT(void) PL_ArenaCountRetract(PLArenaPool *pool, char *mark)
|
| -{
|
| - pool->stats.nfastrels++;
|
| -}
|
| -
|
| -#include <math.h>
|
| -#include <stdio.h>
|
| -
|
| -PR_IMPLEMENT(void) PL_DumpArenaStats(FILE *fp)
|
| -{
|
| - PLArenaStats *stats;
|
| - double mean, variance;
|
| -
|
| - for (stats = arena_stats_list; stats; stats = stats->next) {
|
| - if (stats->nallocs != 0) {
|
| - mean = (double)stats->nbytes / stats->nallocs;
|
| - variance = fabs(stats->variance / stats->nallocs - mean * mean);
|
| - } else {
|
| - mean = variance = 0;
|
| - }
|
| -
|
| - fprintf(fp, "\n%s allocation statistics:\n", stats->name);
|
| - fprintf(fp, " number of arenas: %u\n", stats->narenas);
|
| - fprintf(fp, " number of allocations: %u\n", stats->nallocs);
|
| - fprintf(fp, " number of free arena reclaims: %u\n", stats->nreclaims);
|
| - fprintf(fp, " number of malloc calls: %u\n", stats->nmallocs);
|
| - fprintf(fp, " number of deallocations: %u\n", stats->ndeallocs);
|
| - fprintf(fp, " number of allocation growths: %u\n", stats->ngrows);
|
| - fprintf(fp, " number of in-place growths: %u\n", stats->ninplace);
|
| - fprintf(fp, "number of released allocations: %u\n", stats->nreleases);
|
| - fprintf(fp, " number of fast releases: %u\n", stats->nfastrels);
|
| - fprintf(fp, " total bytes allocated: %u\n", stats->nbytes);
|
| - fprintf(fp, " mean allocation size: %g\n", mean);
|
| - fprintf(fp, " standard deviation: %g\n", sqrt(variance));
|
| - fprintf(fp, " maximum allocation size: %u\n", stats->maxalloc);
|
| - }
|
| -}
|
| -#endif /* PL_ARENAMETER */
|
|
|