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 */ |