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Diffstat (limited to 'tcl8.6/generic/tclAlloc.c')
| -rw-r--r-- | tcl8.6/generic/tclAlloc.c | 759 |
1 files changed, 0 insertions, 759 deletions
diff --git a/tcl8.6/generic/tclAlloc.c b/tcl8.6/generic/tclAlloc.c deleted file mode 100644 index cda1f38..0000000 --- a/tcl8.6/generic/tclAlloc.c +++ /dev/null @@ -1,759 +0,0 @@ -/* - * tclAlloc.c -- - * - * This is a very fast storage allocator. It allocates blocks of a small - * number of different sizes, and keeps free lists of each size. Blocks - * that don't exactly fit are passed up to the next larger size. Blocks - * over a certain size are directly allocated from the system. - * - * Copyright (c) 1983 Regents of the University of California. - * Copyright (c) 1996-1997 Sun Microsystems, Inc. - * Copyright (c) 1998-1999 by Scriptics Corporation. - * - * Portions contributed by Chris Kingsley, Jack Jansen and Ray Johnson. - * - * See the file "license.terms" for information on usage and redistribution of - * this file, and for a DISCLAIMER OF ALL WARRANTIES. - */ - -/* - * Windows and Unix use an alternative allocator when building with threads - * that has significantly reduced lock contention. - */ - -#include "tclInt.h" -#if !defined(TCL_THREADS) || !defined(USE_THREAD_ALLOC) - -#if USE_TCLALLOC - -/* - * We should really make use of AC_CHECK_TYPE(caddr_t) here, but it can wait - * until Tcl uses config.h properly. - */ - -#if defined(_MSC_VER) || defined(__MSVCRT__) || defined(__BORLANDC__) -typedef unsigned long caddr_t; -#endif - -/* - * The overhead on a block is at least 8 bytes. When free, this space contains - * a pointer to the next free block, and the bottom two bits must be zero. - * When in use, the first byte is set to MAGIC, and the second byte is the - * size index. The remaining bytes are for alignment. If range checking is - * enabled then a second word holds the size of the requested block, less 1, - * rounded up to a multiple of sizeof(RMAGIC). The order of elements is - * critical: ov.magic must overlay the low order bits of ov.next, and ov.magic - * can not be a valid ov.next bit pattern. - */ - -union overhead { - union overhead *next; /* when free */ - unsigned char padding[TCL_ALLOCALIGN]; /* align struct to TCL_ALLOCALIGN bytes */ - struct { - unsigned char magic0; /* magic number */ - unsigned char index; /* bucket # */ - unsigned char unused; /* unused */ - unsigned char magic1; /* other magic number */ -#ifndef NDEBUG - unsigned short rmagic; /* range magic number */ - unsigned long size; /* actual block size */ - unsigned short unused2; /* padding to 8-byte align */ -#endif - } ovu; -#define overMagic0 ovu.magic0 -#define overMagic1 ovu.magic1 -#define bucketIndex ovu.index -#define rangeCheckMagic ovu.rmagic -#define realBlockSize ovu.size -}; - - -#define MAGIC 0xef /* magic # on accounting info */ -#define RMAGIC 0x5555 /* magic # on range info */ - -#ifndef NDEBUG -#define RSLOP sizeof(unsigned short) -#else -#define RSLOP 0 -#endif - -#define OVERHEAD (sizeof(union overhead) + RSLOP) - -/* - * Macro to make it easier to refer to the end-of-block guard magic. - */ - -#define BLOCK_END(overPtr) \ - (*(unsigned short *)((caddr_t)((overPtr) + 1) + (overPtr)->realBlockSize)) - -/* - * nextf[i] is the pointer to the next free block of size 2^(i+3). The - * smallest allocatable block is MINBLOCK bytes. The overhead information - * precedes the data area returned to the user. - */ - -#define MINBLOCK ((sizeof(union overhead) + (TCL_ALLOCALIGN-1)) & ~(TCL_ALLOCALIGN-1)) -#define NBUCKETS (13 - (MINBLOCK >> 4)) -#define MAXMALLOC (1<<(NBUCKETS+2)) -static union overhead *nextf[NBUCKETS]; - -/* - * The following structure is used to keep track of all system memory - * currently owned by Tcl. When finalizing, all this memory will be returned - * to the system. - */ - -struct block { - struct block *nextPtr; /* Linked list. */ - struct block *prevPtr; /* Linked list for big blocks, ensures 8-byte - * alignment for suballocated blocks. */ -}; - -static struct block *blockList; /* Tracks the suballocated blocks. */ -static struct block bigBlocks={ /* Big blocks aren't suballocated. */ - &bigBlocks, &bigBlocks -}; - -/* - * The allocator is protected by a special mutex that must be explicitly - * initialized. Futhermore, because Tcl_Alloc may be used before anything else - * in Tcl, we make this module self-initializing after all with the allocInit - * variable. - */ - -#ifdef TCL_THREADS -static Tcl_Mutex *allocMutexPtr; -#endif -static int allocInit = 0; - -#ifdef MSTATS - -/* - * numMallocs[i] is the difference between the number of mallocs and frees for - * a given block size. - */ - -static unsigned int numMallocs[NBUCKETS+1]; -#endif - -#if !defined(NDEBUG) -#define ASSERT(p) if (!(p)) Tcl_Panic(# p) -#define RANGE_ASSERT(p) if (!(p)) Tcl_Panic(# p) -#else -#define ASSERT(p) -#define RANGE_ASSERT(p) -#endif - -/* - * Prototypes for functions used only in this file. - */ - -static void MoreCore(int bucket); - -/* - *------------------------------------------------------------------------- - * - * TclInitAlloc -- - * - * Initialize the memory system. - * - * Results: - * None. - * - * Side effects: - * Initialize the mutex used to serialize allocations. - * - *------------------------------------------------------------------------- - */ - -void -TclInitAlloc(void) -{ - if (!allocInit) { - allocInit = 1; -#ifdef TCL_THREADS - allocMutexPtr = Tcl_GetAllocMutex(); -#endif - } -} - -/* - *------------------------------------------------------------------------- - * - * TclFinalizeAllocSubsystem -- - * - * Release all resources being used by this subsystem, including - * aggressively freeing all memory allocated by TclpAlloc() that has not - * yet been released with TclpFree(). - * - * After this function is called, all memory allocated with TclpAlloc() - * should be considered unusable. - * - * Results: - * None. - * - * Side effects: - * This subsystem is self-initializing, since memory can be allocated - * before Tcl is formally initialized. After this call, this subsystem - * has been reset to its initial state and is usable again. - * - *------------------------------------------------------------------------- - */ - -void -TclFinalizeAllocSubsystem(void) -{ - unsigned int i; - struct block *blockPtr, *nextPtr; - - Tcl_MutexLock(allocMutexPtr); - for (blockPtr = blockList; blockPtr != NULL; blockPtr = nextPtr) { - nextPtr = blockPtr->nextPtr; - TclpSysFree(blockPtr); - } - blockList = NULL; - - for (blockPtr = bigBlocks.nextPtr; blockPtr != &bigBlocks; ) { - nextPtr = blockPtr->nextPtr; - TclpSysFree(blockPtr); - blockPtr = nextPtr; - } - bigBlocks.nextPtr = &bigBlocks; - bigBlocks.prevPtr = &bigBlocks; - - for (i=0 ; i<NBUCKETS ; i++) { - nextf[i] = NULL; -#ifdef MSTATS - numMallocs[i] = 0; -#endif - } -#ifdef MSTATS - numMallocs[i] = 0; -#endif - Tcl_MutexUnlock(allocMutexPtr); -} - -/* - *---------------------------------------------------------------------- - * - * TclpAlloc -- - * - * Allocate more memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -char * -TclpAlloc( - unsigned int numBytes) /* Number of bytes to allocate. */ -{ - register union overhead *overPtr; - register long bucket; - register unsigned amount; - struct block *bigBlockPtr = NULL; - - if (!allocInit) { - /* - * We have to make the "self initializing" because Tcl_Alloc may be - * used before any other part of Tcl. E.g., see main() for tclsh! - */ - - TclInitAlloc(); - } - Tcl_MutexLock(allocMutexPtr); - - /* - * First the simple case: we simple allocate big blocks directly. - */ - - if (numBytes >= MAXMALLOC - OVERHEAD) { - if (numBytes <= UINT_MAX - OVERHEAD -sizeof(struct block)) { - bigBlockPtr = (struct block *) TclpSysAlloc((unsigned) - (sizeof(struct block) + OVERHEAD + numBytes), 0); - } - if (bigBlockPtr == NULL) { - Tcl_MutexUnlock(allocMutexPtr); - return NULL; - } - bigBlockPtr->nextPtr = bigBlocks.nextPtr; - bigBlocks.nextPtr = bigBlockPtr; - bigBlockPtr->prevPtr = &bigBlocks; - bigBlockPtr->nextPtr->prevPtr = bigBlockPtr; - - overPtr = (union overhead *) (bigBlockPtr + 1); - overPtr->overMagic0 = overPtr->overMagic1 = MAGIC; - overPtr->bucketIndex = 0xff; -#ifdef MSTATS - numMallocs[NBUCKETS]++; -#endif - -#ifndef NDEBUG - /* - * Record allocated size of block and bound space with magic numbers. - */ - - overPtr->realBlockSize = (numBytes + RSLOP - 1) & ~(RSLOP - 1); - overPtr->rangeCheckMagic = RMAGIC; - BLOCK_END(overPtr) = RMAGIC; -#endif - - Tcl_MutexUnlock(allocMutexPtr); - return (void *)(overPtr+1); - } - - /* - * Convert amount of memory requested into closest block size stored in - * hash buckets which satisfies request. Account for space used per block - * for accounting. - */ - - amount = MINBLOCK; /* size of first bucket */ - bucket = MINBLOCK >> 4; - - while (numBytes + OVERHEAD > amount) { - amount <<= 1; - if (amount == 0) { - Tcl_MutexUnlock(allocMutexPtr); - return NULL; - } - bucket++; - } - ASSERT(bucket < NBUCKETS); - - /* - * If nothing in hash bucket right now, request more memory from the - * system. - */ - - if ((overPtr = nextf[bucket]) == NULL) { - MoreCore(bucket); - if ((overPtr = nextf[bucket]) == NULL) { - Tcl_MutexUnlock(allocMutexPtr); - return NULL; - } - } - - /* - * Remove from linked list - */ - - nextf[bucket] = overPtr->next; - overPtr->overMagic0 = overPtr->overMagic1 = MAGIC; - overPtr->bucketIndex = (unsigned char) bucket; - -#ifdef MSTATS - numMallocs[bucket]++; -#endif - -#ifndef NDEBUG - /* - * Record allocated size of block and bound space with magic numbers. - */ - - overPtr->realBlockSize = (numBytes + RSLOP - 1) & ~(RSLOP - 1); - overPtr->rangeCheckMagic = RMAGIC; - BLOCK_END(overPtr) = RMAGIC; -#endif - - Tcl_MutexUnlock(allocMutexPtr); - return ((char *)(overPtr + 1)); -} - -/* - *---------------------------------------------------------------------- - * - * MoreCore -- - * - * Allocate more memory to the indicated bucket. - * - * Assumes Mutex is already held. - * - * Results: - * None. - * - * Side effects: - * Attempts to get more memory from the system. - * - *---------------------------------------------------------------------- - */ - -static void -MoreCore( - int bucket) /* What bucket to allocat to. */ -{ - register union overhead *overPtr; - register long size; /* size of desired block */ - long amount; /* amount to allocate */ - int numBlocks; /* how many blocks we get */ - struct block *blockPtr; - - /* - * sbrk_size <= 0 only for big, FLUFFY, requests (about 2^30 bytes on a - * VAX, I think) or for a negative arg. - */ - - size = 1 << (bucket + 3); - ASSERT(size > 0); - - amount = MAXMALLOC; - numBlocks = amount / size; - ASSERT(numBlocks*size == amount); - - blockPtr = (struct block *) TclpSysAlloc((unsigned) - (sizeof(struct block) + amount), 1); - /* no more room! */ - if (blockPtr == NULL) { - return; - } - blockPtr->nextPtr = blockList; - blockList = blockPtr; - - overPtr = (union overhead *) (blockPtr + 1); - - /* - * Add new memory allocated to that on free list for this hash bucket. - */ - - nextf[bucket] = overPtr; - while (--numBlocks > 0) { - overPtr->next = (union overhead *)((caddr_t)overPtr + size); - overPtr = (union overhead *)((caddr_t)overPtr + size); - } - overPtr->next = NULL; -} - -/* - *---------------------------------------------------------------------- - * - * TclpFree -- - * - * Free memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -void -TclpFree( - char *oldPtr) /* Pointer to memory to free. */ -{ - register long size; - register union overhead *overPtr; - struct block *bigBlockPtr; - - if (oldPtr == NULL) { - return; - } - - Tcl_MutexLock(allocMutexPtr); - overPtr = (union overhead *)((caddr_t)oldPtr - sizeof(union overhead)); - - ASSERT(overPtr->overMagic0 == MAGIC); /* make sure it was in use */ - ASSERT(overPtr->overMagic1 == MAGIC); - if (overPtr->overMagic0 != MAGIC || overPtr->overMagic1 != MAGIC) { - Tcl_MutexUnlock(allocMutexPtr); - return; - } - - RANGE_ASSERT(overPtr->rangeCheckMagic == RMAGIC); - RANGE_ASSERT(BLOCK_END(overPtr) == RMAGIC); - size = overPtr->bucketIndex; - if (size == 0xff) { -#ifdef MSTATS - numMallocs[NBUCKETS]--; -#endif - - bigBlockPtr = (struct block *) overPtr - 1; - bigBlockPtr->prevPtr->nextPtr = bigBlockPtr->nextPtr; - bigBlockPtr->nextPtr->prevPtr = bigBlockPtr->prevPtr; - TclpSysFree(bigBlockPtr); - - Tcl_MutexUnlock(allocMutexPtr); - return; - } - ASSERT(size < NBUCKETS); - overPtr->next = nextf[size]; /* also clobbers overMagic */ - nextf[size] = overPtr; - -#ifdef MSTATS - numMallocs[size]--; -#endif - - Tcl_MutexUnlock(allocMutexPtr); -} - -/* - *---------------------------------------------------------------------- - * - * TclpRealloc -- - * - * Reallocate memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -char * -TclpRealloc( - char *oldPtr, /* Pointer to alloced block. */ - unsigned int numBytes) /* New size of memory. */ -{ - int i; - union overhead *overPtr; - struct block *bigBlockPtr; - int expensive; - unsigned long maxSize; - - if (oldPtr == NULL) { - return TclpAlloc(numBytes); - } - - Tcl_MutexLock(allocMutexPtr); - - overPtr = (union overhead *)((caddr_t)oldPtr - sizeof(union overhead)); - - ASSERT(overPtr->overMagic0 == MAGIC); /* make sure it was in use */ - ASSERT(overPtr->overMagic1 == MAGIC); - if (overPtr->overMagic0 != MAGIC || overPtr->overMagic1 != MAGIC) { - Tcl_MutexUnlock(allocMutexPtr); - return NULL; - } - - RANGE_ASSERT(overPtr->rangeCheckMagic == RMAGIC); - RANGE_ASSERT(BLOCK_END(overPtr) == RMAGIC); - i = overPtr->bucketIndex; - - /* - * If the block isn't in a bin, just realloc it. - */ - - if (i == 0xff) { - struct block *prevPtr, *nextPtr; - bigBlockPtr = (struct block *) overPtr - 1; - prevPtr = bigBlockPtr->prevPtr; - nextPtr = bigBlockPtr->nextPtr; - bigBlockPtr = (struct block *) TclpSysRealloc(bigBlockPtr, - sizeof(struct block) + OVERHEAD + numBytes); - if (bigBlockPtr == NULL) { - Tcl_MutexUnlock(allocMutexPtr); - return NULL; - } - - if (prevPtr->nextPtr != bigBlockPtr) { - /* - * If the block has moved, splice the new block into the list - * where the old block used to be. - */ - - prevPtr->nextPtr = bigBlockPtr; - nextPtr->prevPtr = bigBlockPtr; - } - - overPtr = (union overhead *) (bigBlockPtr + 1); - -#ifdef MSTATS - numMallocs[NBUCKETS]++; -#endif - -#ifndef NDEBUG - /* - * Record allocated size of block and update magic number bounds. - */ - - overPtr->realBlockSize = (numBytes + RSLOP - 1) & ~(RSLOP - 1); - BLOCK_END(overPtr) = RMAGIC; -#endif - - Tcl_MutexUnlock(allocMutexPtr); - return (char *)(overPtr+1); - } - maxSize = 1 << (i+3); - expensive = 0; - if (numBytes+OVERHEAD > maxSize) { - expensive = 1; - } else if (i>0 && numBytes+OVERHEAD < maxSize/2) { - expensive = 1; - } - - if (expensive) { - void *newPtr; - - Tcl_MutexUnlock(allocMutexPtr); - - newPtr = TclpAlloc(numBytes); - if (newPtr == NULL) { - return NULL; - } - maxSize -= OVERHEAD; - if (maxSize < numBytes) { - numBytes = maxSize; - } - memcpy(newPtr, oldPtr, (size_t) numBytes); - TclpFree(oldPtr); - return newPtr; - } - - /* - * Ok, we don't have to copy, it fits as-is - */ - -#ifndef NDEBUG - overPtr->realBlockSize = (numBytes + RSLOP - 1) & ~(RSLOP - 1); - BLOCK_END(overPtr) = RMAGIC; -#endif - - Tcl_MutexUnlock(allocMutexPtr); - return(oldPtr); -} - -/* - *---------------------------------------------------------------------- - * - * mstats -- - * - * Prints two lines of numbers, one showing the length of the free list - * for each size category, the second showing the number of mallocs - - * frees for each size category. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -#ifdef MSTATS -void -mstats( - char *s) /* Where to write info. */ -{ - register int i, j; - register union overhead *overPtr; - int totalFree = 0, totalUsed = 0; - - Tcl_MutexLock(allocMutexPtr); - - fprintf(stderr, "Memory allocation statistics %s\nTclpFree:\t", s); - for (i = 0; i < NBUCKETS; i++) { - for (j=0, overPtr=nextf[i]; overPtr; overPtr=overPtr->next, j++) { - fprintf(stderr, " %d", j); - } - totalFree += j * (1 << (i + 3)); - } - - fprintf(stderr, "\nused:\t"); - for (i = 0; i < NBUCKETS; i++) { - fprintf(stderr, " %d", numMallocs[i]); - totalUsed += numMallocs[i] * (1 << (i + 3)); - } - - fprintf(stderr, "\n\tTotal small in use: %d, total free: %d\n", - totalUsed, totalFree); - fprintf(stderr, "\n\tNumber of big (>%d) blocks in use: %d\n", - MAXMALLOC, numMallocs[NBUCKETS]); - - Tcl_MutexUnlock(allocMutexPtr); -} -#endif - -#else /* !USE_TCLALLOC */ - -/* - *---------------------------------------------------------------------- - * - * TclpAlloc -- - * - * Allocate more memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -char * -TclpAlloc( - unsigned int numBytes) /* Number of bytes to allocate. */ -{ - return (char *) malloc(numBytes); -} - -/* - *---------------------------------------------------------------------- - * - * TclpFree -- - * - * Free memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -void -TclpFree( - char *oldPtr) /* Pointer to memory to free. */ -{ - free(oldPtr); - return; -} - -/* - *---------------------------------------------------------------------- - * - * TclpRealloc -- - * - * Reallocate memory. - * - * Results: - * None. - * - * Side effects: - * None. - * - *---------------------------------------------------------------------- - */ - -char * -TclpRealloc( - char *oldPtr, /* Pointer to alloced block. */ - unsigned int numBytes) /* New size of memory. */ -{ - return (char *) realloc(oldPtr, numBytes); -} - -#endif /* !USE_TCLALLOC */ -#endif /* !TCL_THREADS */ - -/* - * Local Variables: - * mode: c - * c-basic-offset: 4 - * fill-column: 78 - * End: - */ |