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-rw-r--r--tcl8.6/generic/tclThreadAlloc.c1185
1 files changed, 1185 insertions, 0 deletions
diff --git a/tcl8.6/generic/tclThreadAlloc.c b/tcl8.6/generic/tclThreadAlloc.c
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--- /dev/null
+++ b/tcl8.6/generic/tclThreadAlloc.c
@@ -0,0 +1,1185 @@
+/*
+ * tclThreadAlloc.c --
+ *
+ * This is a very fast storage allocator for used with threads (designed
+ * avoid lock contention). The basic strategy is to allocate memory in
+ * fixed size blocks from block caches.
+ *
+ * The Initial Developer of the Original Code is America Online, Inc.
+ * Portions created by AOL are Copyright (C) 1999 America Online, Inc.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tclInt.h"
+#if defined(TCL_THREADS) && defined(USE_THREAD_ALLOC)
+
+/*
+ * If range checking is enabled, an additional byte will be allocated to store
+ * the magic number at the end of the requested memory.
+ */
+
+#ifndef RCHECK
+#ifdef NDEBUG
+#define RCHECK 0
+#else
+#define RCHECK 1
+#endif
+#endif
+
+/*
+ * The following define the number of Tcl_Obj's to allocate/move at a time and
+ * the high water mark to prune a per-thread cache. On a 32 bit system,
+ * sizeof(Tcl_Obj) = 24 so 800 * 24 = ~16k.
+ */
+
+#define NOBJALLOC 800
+
+/* Actual definition moved to tclInt.h */
+#define NOBJHIGH ALLOC_NOBJHIGH
+
+/*
+ * The following union stores accounting information for each block including
+ * two small magic numbers and a bucket number when in use or a next pointer
+ * when free. The original requested size (not including the Block overhead)
+ * is also maintained.
+ */
+
+typedef union Block {
+ struct {
+ union {
+ union Block *next; /* Next in free list. */
+ struct {
+ unsigned char magic1; /* First magic number. */
+ unsigned char bucket; /* Bucket block allocated from. */
+ unsigned char unused; /* Padding. */
+ unsigned char magic2; /* Second magic number. */
+ } s;
+ } u;
+ size_t reqSize; /* Requested allocation size. */
+ } b;
+ unsigned char padding[TCL_ALLOCALIGN];
+} Block;
+#define nextBlock b.u.next
+#define sourceBucket b.u.s.bucket
+#define magicNum1 b.u.s.magic1
+#define magicNum2 b.u.s.magic2
+#define MAGIC 0xEF
+#define blockReqSize b.reqSize
+
+/*
+ * The following defines the minimum and and maximum block sizes and the number
+ * of buckets in the bucket cache.
+ */
+
+#define MINALLOC ((sizeof(Block) + 8 + (TCL_ALLOCALIGN-1)) & ~(TCL_ALLOCALIGN-1))
+#define NBUCKETS (11 - (MINALLOC >> 5))
+#define MAXALLOC (MINALLOC << (NBUCKETS - 1))
+
+/*
+ * The following structure defines a bucket of blocks with various accounting
+ * and statistics information.
+ */
+
+typedef struct Bucket {
+ Block *firstPtr; /* First block available */
+ Block *lastPtr; /* End of block list */
+ long numFree; /* Number of blocks available */
+
+ /* All fields below for accounting only */
+
+ long numRemoves; /* Number of removes from bucket */
+ long numInserts; /* Number of inserts into bucket */
+ long numWaits; /* Number of waits to acquire a lock */
+ long numLocks; /* Number of locks acquired */
+ long totalAssigned; /* Total space assigned to bucket */
+} Bucket;
+
+/*
+ * The following structure defines a cache of buckets and objs, of which there
+ * will be (at most) one per thread. Any changes need to be reflected in the
+ * struct AllocCache defined in tclInt.h, possibly also in the initialisation
+ * code in Tcl_CreateInterp().
+ */
+
+typedef struct Cache {
+ struct Cache *nextPtr; /* Linked list of cache entries */
+ Tcl_ThreadId owner; /* Which thread's cache is this? */
+ Tcl_Obj *firstObjPtr; /* List of free objects for thread */
+ int numObjects; /* Number of objects for thread */
+ Tcl_Obj *lastPtr; /* Last object in this cache */
+ int totalAssigned; /* Total space assigned to thread */
+ Bucket buckets[NBUCKETS]; /* The buckets for this thread */
+} Cache;
+
+/*
+ * The following array specifies various per-bucket limits and locks. The
+ * values are statically initialized to avoid calculating them repeatedly.
+ */
+
+static struct {
+ size_t blockSize; /* Bucket blocksize. */
+ int maxBlocks; /* Max blocks before move to share. */
+ int numMove; /* Num blocks to move to share. */
+ Tcl_Mutex *lockPtr; /* Share bucket lock. */
+} bucketInfo[NBUCKETS];
+
+/*
+ * Static functions defined in this file.
+ */
+
+static Cache * GetCache(void);
+static void LockBucket(Cache *cachePtr, int bucket);
+static void UnlockBucket(Cache *cachePtr, int bucket);
+static void PutBlocks(Cache *cachePtr, int bucket, int numMove);
+static int GetBlocks(Cache *cachePtr, int bucket);
+static Block * Ptr2Block(char *ptr);
+static char * Block2Ptr(Block *blockPtr, int bucket, unsigned int reqSize);
+static void MoveObjs(Cache *fromPtr, Cache *toPtr, int numMove);
+static void PutObjs(Cache *fromPtr, int numMove);
+
+/*
+ * Local variables defined in this file and initialized at startup.
+ */
+
+static Tcl_Mutex *listLockPtr;
+static Tcl_Mutex *objLockPtr;
+static Cache sharedCache;
+static Cache *sharedPtr = &sharedCache;
+static Cache *firstCachePtr = &sharedCache;
+
+#if defined(HAVE_FAST_TSD)
+static __thread Cache *tcachePtr;
+
+# define GETCACHE(cachePtr) \
+ do { \
+ if (!tcachePtr) { \
+ tcachePtr = GetCache(); \
+ } \
+ (cachePtr) = tcachePtr; \
+ } while (0)
+#else
+# define GETCACHE(cachePtr) \
+ do { \
+ (cachePtr) = TclpGetAllocCache(); \
+ if ((cachePtr) == NULL) { \
+ (cachePtr) = GetCache(); \
+ } \
+ } while (0)
+#endif
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetCache ---
+ *
+ * Gets per-thread memory cache, allocating it if necessary.
+ *
+ * Results:
+ * Pointer to cache.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static Cache *
+GetCache(void)
+{
+ Cache *cachePtr;
+
+ /*
+ * Check for first-time initialization.
+ */
+
+ if (listLockPtr == NULL) {
+ Tcl_Mutex *initLockPtr;
+ unsigned int i;
+
+ initLockPtr = Tcl_GetAllocMutex();
+ Tcl_MutexLock(initLockPtr);
+ if (listLockPtr == NULL) {
+ listLockPtr = TclpNewAllocMutex();
+ objLockPtr = TclpNewAllocMutex();
+ for (i = 0; i < NBUCKETS; ++i) {
+ bucketInfo[i].blockSize = MINALLOC << i;
+ bucketInfo[i].maxBlocks = 1 << (NBUCKETS - 1 - i);
+ bucketInfo[i].numMove = i < NBUCKETS - 1 ?
+ 1 << (NBUCKETS - 2 - i) : 1;
+ bucketInfo[i].lockPtr = TclpNewAllocMutex();
+ }
+ }
+ Tcl_MutexUnlock(initLockPtr);
+ }
+
+ /*
+ * Get this thread's cache, allocating if necessary.
+ */
+
+ cachePtr = TclpGetAllocCache();
+ if (cachePtr == NULL) {
+ cachePtr = TclpSysAlloc(sizeof(Cache), 0);
+ if (cachePtr == NULL) {
+ Tcl_Panic("alloc: could not allocate new cache");
+ }
+ memset(cachePtr, 0, sizeof(Cache));
+ Tcl_MutexLock(listLockPtr);
+ cachePtr->nextPtr = firstCachePtr;
+ firstCachePtr = cachePtr;
+ Tcl_MutexUnlock(listLockPtr);
+ cachePtr->owner = Tcl_GetCurrentThread();
+ TclpSetAllocCache(cachePtr);
+ }
+ return cachePtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFreeAllocCache --
+ *
+ * Flush and delete a cache, removing from list of caches.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFreeAllocCache(
+ void *arg)
+{
+ Cache *cachePtr = arg;
+ Cache **nextPtrPtr;
+ register unsigned int bucket;
+
+ /*
+ * Flush blocks.
+ */
+
+ for (bucket = 0; bucket < NBUCKETS; ++bucket) {
+ if (cachePtr->buckets[bucket].numFree > 0) {
+ PutBlocks(cachePtr, bucket, cachePtr->buckets[bucket].numFree);
+ }
+ }
+
+ /*
+ * Flush objs.
+ */
+
+ if (cachePtr->numObjects > 0) {
+ PutObjs(cachePtr, cachePtr->numObjects);
+ }
+
+ /*
+ * Remove from pool list.
+ */
+
+ Tcl_MutexLock(listLockPtr);
+ nextPtrPtr = &firstCachePtr;
+ while (*nextPtrPtr != cachePtr) {
+ nextPtrPtr = &(*nextPtrPtr)->nextPtr;
+ }
+ *nextPtrPtr = cachePtr->nextPtr;
+ cachePtr->nextPtr = NULL;
+ Tcl_MutexUnlock(listLockPtr);
+ TclpSysFree(cachePtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclpAlloc --
+ *
+ * Allocate memory.
+ *
+ * Results:
+ * Pointer to memory just beyond Block pointer.
+ *
+ * Side effects:
+ * May allocate more blocks for a bucket.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+TclpAlloc(
+ unsigned int reqSize)
+{
+ Cache *cachePtr;
+ Block *blockPtr;
+ register int bucket;
+ size_t size;
+
+#ifndef __LP64__
+ if (sizeof(int) >= sizeof(size_t)) {
+ /* An unsigned int overflow can also be a size_t overflow */
+ const size_t zero = 0;
+ const size_t max = ~zero;
+
+ if (((size_t) reqSize) > max - sizeof(Block) - RCHECK) {
+ /* Requested allocation exceeds memory */
+ return NULL;
+ }
+ }
+#endif
+
+ GETCACHE(cachePtr);
+
+ /*
+ * Increment the requested size to include room for the Block structure.
+ * Call TclpSysAlloc() directly if the required amount is greater than the
+ * largest block, otherwise pop the smallest block large enough,
+ * allocating more blocks if necessary.
+ */
+
+ blockPtr = NULL;
+ size = reqSize + sizeof(Block);
+#if RCHECK
+ size++;
+#endif
+ if (size > MAXALLOC) {
+ bucket = NBUCKETS;
+ blockPtr = TclpSysAlloc(size, 0);
+ if (blockPtr != NULL) {
+ cachePtr->totalAssigned += reqSize;
+ }
+ } else {
+ bucket = 0;
+ while (bucketInfo[bucket].blockSize < size) {
+ bucket++;
+ }
+ if (cachePtr->buckets[bucket].numFree || GetBlocks(cachePtr, bucket)) {
+ blockPtr = cachePtr->buckets[bucket].firstPtr;
+ cachePtr->buckets[bucket].firstPtr = blockPtr->nextBlock;
+ cachePtr->buckets[bucket].numFree--;
+ cachePtr->buckets[bucket].numRemoves++;
+ cachePtr->buckets[bucket].totalAssigned += reqSize;
+ }
+ }
+ if (blockPtr == NULL) {
+ return NULL;
+ }
+ return Block2Ptr(blockPtr, bucket, reqSize);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclpFree --
+ *
+ * Return blocks to the thread block cache.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * May move blocks to shared cache.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclpFree(
+ char *ptr)
+{
+ Cache *cachePtr;
+ Block *blockPtr;
+ int bucket;
+
+ if (ptr == NULL) {
+ return;
+ }
+
+ GETCACHE(cachePtr);
+
+ /*
+ * Get the block back from the user pointer and call system free directly
+ * for large blocks. Otherwise, push the block back on the bucket and move
+ * blocks to the shared cache if there are now too many free.
+ */
+
+ blockPtr = Ptr2Block(ptr);
+ bucket = blockPtr->sourceBucket;
+ if (bucket == NBUCKETS) {
+ cachePtr->totalAssigned -= blockPtr->blockReqSize;
+ TclpSysFree(blockPtr);
+ return;
+ }
+
+ cachePtr->buckets[bucket].totalAssigned -= blockPtr->blockReqSize;
+ blockPtr->nextBlock = cachePtr->buckets[bucket].firstPtr;
+ cachePtr->buckets[bucket].firstPtr = blockPtr;
+ if (cachePtr->buckets[bucket].numFree == 0) {
+ cachePtr->buckets[bucket].lastPtr = blockPtr;
+ }
+ cachePtr->buckets[bucket].numFree++;
+ cachePtr->buckets[bucket].numInserts++;
+
+ if (cachePtr != sharedPtr &&
+ cachePtr->buckets[bucket].numFree > bucketInfo[bucket].maxBlocks) {
+ PutBlocks(cachePtr, bucket, bucketInfo[bucket].numMove);
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclpRealloc --
+ *
+ * Re-allocate memory to a larger or smaller size.
+ *
+ * Results:
+ * Pointer to memory just beyond Block pointer.
+ *
+ * Side effects:
+ * Previous memory, if any, may be freed.
+ *
+ *----------------------------------------------------------------------
+ */
+
+char *
+TclpRealloc(
+ char *ptr,
+ unsigned int reqSize)
+{
+ Cache *cachePtr;
+ Block *blockPtr;
+ void *newPtr;
+ size_t size, min;
+ int bucket;
+
+ if (ptr == NULL) {
+ return TclpAlloc(reqSize);
+ }
+
+#ifndef __LP64__
+ if (sizeof(int) >= sizeof(size_t)) {
+ /* An unsigned int overflow can also be a size_t overflow */
+ const size_t zero = 0;
+ const size_t max = ~zero;
+
+ if (((size_t) reqSize) > max - sizeof(Block) - RCHECK) {
+ /* Requested allocation exceeds memory */
+ return NULL;
+ }
+ }
+#endif
+
+ GETCACHE(cachePtr);
+
+ /*
+ * If the block is not a system block and fits in place, simply return the
+ * existing pointer. Otherwise, if the block is a system block and the new
+ * size would also require a system block, call TclpSysRealloc() directly.
+ */
+
+ blockPtr = Ptr2Block(ptr);
+ size = reqSize + sizeof(Block);
+#if RCHECK
+ size++;
+#endif
+ bucket = blockPtr->sourceBucket;
+ if (bucket != NBUCKETS) {
+ if (bucket > 0) {
+ min = bucketInfo[bucket-1].blockSize;
+ } else {
+ min = 0;
+ }
+ if (size > min && size <= bucketInfo[bucket].blockSize) {
+ cachePtr->buckets[bucket].totalAssigned -= blockPtr->blockReqSize;
+ cachePtr->buckets[bucket].totalAssigned += reqSize;
+ return Block2Ptr(blockPtr, bucket, reqSize);
+ }
+ } else if (size > MAXALLOC) {
+ cachePtr->totalAssigned -= blockPtr->blockReqSize;
+ cachePtr->totalAssigned += reqSize;
+ blockPtr = TclpSysRealloc(blockPtr, size);
+ if (blockPtr == NULL) {
+ return NULL;
+ }
+ return Block2Ptr(blockPtr, NBUCKETS, reqSize);
+ }
+
+ /*
+ * Finally, perform an expensive malloc/copy/free.
+ */
+
+ newPtr = TclpAlloc(reqSize);
+ if (newPtr != NULL) {
+ if (reqSize > blockPtr->blockReqSize) {
+ reqSize = blockPtr->blockReqSize;
+ }
+ memcpy(newPtr, ptr, reqSize);
+ TclpFree(ptr);
+ }
+ return newPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclThreadAllocObj --
+ *
+ * Allocate a Tcl_Obj from the per-thread cache.
+ *
+ * Results:
+ * Pointer to uninitialized Tcl_Obj.
+ *
+ * Side effects:
+ * May move Tcl_Obj's from shared cached or allocate new Tcl_Obj's if
+ * list is empty.
+ *
+ * Note:
+ * If this code is updated, the changes need to be reflected in the macro
+ * TclAllocObjStorageEx() defined in tclInt.h
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Obj *
+TclThreadAllocObj(void)
+{
+ register Cache *cachePtr;
+ register Tcl_Obj *objPtr;
+
+ GETCACHE(cachePtr);
+
+ /*
+ * Get this thread's obj list structure and move or allocate new objs if
+ * necessary.
+ */
+
+ if (cachePtr->numObjects == 0) {
+ register int numMove;
+
+ Tcl_MutexLock(objLockPtr);
+ numMove = sharedPtr->numObjects;
+ if (numMove > 0) {
+ if (numMove > NOBJALLOC) {
+ numMove = NOBJALLOC;
+ }
+ MoveObjs(sharedPtr, cachePtr, numMove);
+ }
+ Tcl_MutexUnlock(objLockPtr);
+ if (cachePtr->numObjects == 0) {
+ Tcl_Obj *newObjsPtr;
+
+ cachePtr->numObjects = numMove = NOBJALLOC;
+ newObjsPtr = TclpSysAlloc(sizeof(Tcl_Obj) * numMove, 0);
+ if (newObjsPtr == NULL) {
+ Tcl_Panic("alloc: could not allocate %d new objects", numMove);
+ }
+ cachePtr->lastPtr = newObjsPtr + numMove - 1;
+ objPtr = cachePtr->firstObjPtr; /* NULL */
+ while (--numMove >= 0) {
+ newObjsPtr[numMove].internalRep.twoPtrValue.ptr1 = objPtr;
+ objPtr = newObjsPtr + numMove;
+ }
+ cachePtr->firstObjPtr = newObjsPtr;
+ }
+ }
+
+ /*
+ * Pop the first object.
+ */
+
+ objPtr = cachePtr->firstObjPtr;
+ cachePtr->firstObjPtr = objPtr->internalRep.twoPtrValue.ptr1;
+ cachePtr->numObjects--;
+ return objPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclThreadFreeObj --
+ *
+ * Return a free Tcl_Obj to the per-thread cache.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * May move free Tcl_Obj's to shared list upon hitting high water mark.
+ *
+ * Note:
+ * If this code is updated, the changes need to be reflected in the macro
+ * TclAllocObjStorageEx() defined in tclInt.h
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclThreadFreeObj(
+ Tcl_Obj *objPtr)
+{
+ Cache *cachePtr;
+
+ GETCACHE(cachePtr);
+
+ /*
+ * Get this thread's list and push on the free Tcl_Obj.
+ */
+
+ objPtr->internalRep.twoPtrValue.ptr1 = cachePtr->firstObjPtr;
+ cachePtr->firstObjPtr = objPtr;
+ if (cachePtr->numObjects == 0) {
+ cachePtr->lastPtr = objPtr;
+ }
+ cachePtr->numObjects++;
+
+ /*
+ * If the number of free objects has exceeded the high water mark, move
+ * some blocks to the shared list.
+ */
+
+ if (cachePtr->numObjects > NOBJHIGH) {
+ PutObjs(cachePtr, NOBJALLOC);
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetMemoryInfo --
+ *
+ * Return a list-of-lists of memory stats.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * List appended to given dstring.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_GetMemoryInfo(
+ Tcl_DString *dsPtr)
+{
+ Cache *cachePtr;
+ char buf[200];
+ unsigned int n;
+
+ Tcl_MutexLock(listLockPtr);
+ cachePtr = firstCachePtr;
+ while (cachePtr != NULL) {
+ Tcl_DStringStartSublist(dsPtr);
+ if (cachePtr == sharedPtr) {
+ Tcl_DStringAppendElement(dsPtr, "shared");
+ } else {
+ sprintf(buf, "thread%p", cachePtr->owner);
+ Tcl_DStringAppendElement(dsPtr, buf);
+ }
+ for (n = 0; n < NBUCKETS; ++n) {
+ sprintf(buf, "%lu %ld %ld %ld %ld %ld %ld",
+ (unsigned long) bucketInfo[n].blockSize,
+ cachePtr->buckets[n].numFree,
+ cachePtr->buckets[n].numRemoves,
+ cachePtr->buckets[n].numInserts,
+ cachePtr->buckets[n].totalAssigned,
+ cachePtr->buckets[n].numLocks,
+ cachePtr->buckets[n].numWaits);
+ Tcl_DStringAppendElement(dsPtr, buf);
+ }
+ Tcl_DStringEndSublist(dsPtr);
+ cachePtr = cachePtr->nextPtr;
+ }
+ Tcl_MutexUnlock(listLockPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * MoveObjs --
+ *
+ * Move Tcl_Obj's between caches.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+MoveObjs(
+ Cache *fromPtr,
+ Cache *toPtr,
+ int numMove)
+{
+ register Tcl_Obj *objPtr = fromPtr->firstObjPtr;
+ Tcl_Obj *fromFirstObjPtr = objPtr;
+
+ toPtr->numObjects += numMove;
+ fromPtr->numObjects -= numMove;
+
+ /*
+ * Find the last object to be moved; set the next one (the first one not
+ * to be moved) as the first object in the 'from' cache.
+ */
+
+ while (--numMove) {
+ objPtr = objPtr->internalRep.twoPtrValue.ptr1;
+ }
+ fromPtr->firstObjPtr = objPtr->internalRep.twoPtrValue.ptr1;
+
+ /*
+ * Move all objects as a block - they are already linked to each other, we
+ * just have to update the first and last.
+ */
+
+ toPtr->lastPtr = objPtr;
+ objPtr->internalRep.twoPtrValue.ptr1 = toPtr->firstObjPtr; /* NULL */
+ toPtr->firstObjPtr = fromFirstObjPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * PutObjs --
+ *
+ * Move Tcl_Obj's from thread cache to shared cache.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+PutObjs(
+ Cache *fromPtr,
+ int numMove)
+{
+ int keep = fromPtr->numObjects - numMove;
+ Tcl_Obj *firstPtr, *lastPtr = NULL;
+
+ fromPtr->numObjects = keep;
+ firstPtr = fromPtr->firstObjPtr;
+ if (keep == 0) {
+ fromPtr->firstObjPtr = NULL;
+ } else {
+ do {
+ lastPtr = firstPtr;
+ firstPtr = firstPtr->internalRep.twoPtrValue.ptr1;
+ } while (--keep > 0);
+ lastPtr->internalRep.twoPtrValue.ptr1 = NULL;
+ }
+
+ /*
+ * Move all objects as a block - they are already linked to each other, we
+ * just have to update the first and last.
+ */
+
+ Tcl_MutexLock(objLockPtr);
+ fromPtr->lastPtr->internalRep.twoPtrValue.ptr1 = sharedPtr->firstObjPtr;
+ sharedPtr->firstObjPtr = firstPtr;
+ if (sharedPtr->numObjects == 0) {
+ sharedPtr->lastPtr = fromPtr->lastPtr;
+ }
+ sharedPtr->numObjects += numMove;
+ Tcl_MutexUnlock(objLockPtr);
+
+ fromPtr->lastPtr = lastPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Block2Ptr, Ptr2Block --
+ *
+ * Convert between internal blocks and user pointers.
+ *
+ * Results:
+ * User pointer or internal block.
+ *
+ * Side effects:
+ * Invalid blocks will abort the server.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static char *
+Block2Ptr(
+ Block *blockPtr,
+ int bucket,
+ unsigned int reqSize)
+{
+ register void *ptr;
+
+ blockPtr->magicNum1 = blockPtr->magicNum2 = MAGIC;
+ blockPtr->sourceBucket = bucket;
+ blockPtr->blockReqSize = reqSize;
+ ptr = ((void *) (blockPtr + 1));
+#if RCHECK
+ ((unsigned char *)(ptr))[reqSize] = MAGIC;
+#endif
+ return (char *) ptr;
+}
+
+static Block *
+Ptr2Block(
+ char *ptr)
+{
+ register Block *blockPtr;
+
+ blockPtr = (((Block *) ptr) - 1);
+ if (blockPtr->magicNum1 != MAGIC || blockPtr->magicNum2 != MAGIC) {
+ Tcl_Panic("alloc: invalid block: %p: %x %x",
+ blockPtr, blockPtr->magicNum1, blockPtr->magicNum2);
+ }
+#if RCHECK
+ if (((unsigned char *) ptr)[blockPtr->blockReqSize] != MAGIC) {
+ Tcl_Panic("alloc: invalid block: %p: %x %x %x",
+ blockPtr, blockPtr->magicNum1, blockPtr->magicNum2,
+ ((unsigned char *) ptr)[blockPtr->blockReqSize]);
+ }
+#endif
+ return blockPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * LockBucket, UnlockBucket --
+ *
+ * Set/unset the lock to access a bucket in the shared cache.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Lock activity and contention are monitored globally and on a per-cache
+ * basis.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+LockBucket(
+ Cache *cachePtr,
+ int bucket)
+{
+ Tcl_MutexLock(bucketInfo[bucket].lockPtr);
+ cachePtr->buckets[bucket].numLocks++;
+ sharedPtr->buckets[bucket].numLocks++;
+}
+
+static void
+UnlockBucket(
+ Cache *cachePtr,
+ int bucket)
+{
+ Tcl_MutexUnlock(bucketInfo[bucket].lockPtr);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * PutBlocks --
+ *
+ * Return unused blocks to the shared cache.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+PutBlocks(
+ Cache *cachePtr,
+ int bucket,
+ int numMove)
+{
+ /*
+ * We have numFree. Want to shed numMove. So compute how many
+ * Blocks to keep.
+ */
+
+ int keep = cachePtr->buckets[bucket].numFree - numMove;
+ Block *lastPtr = NULL, *firstPtr;
+
+ cachePtr->buckets[bucket].numFree = keep;
+ firstPtr = cachePtr->buckets[bucket].firstPtr;
+ if (keep == 0) {
+ cachePtr->buckets[bucket].firstPtr = NULL;
+ } else {
+ do {
+ lastPtr = firstPtr;
+ firstPtr = firstPtr->nextBlock;
+ } while (--keep > 0);
+ lastPtr->nextBlock = NULL;
+ }
+
+ /*
+ * Aquire the lock and place the list of blocks at the front of the shared
+ * cache bucket.
+ */
+
+ LockBucket(cachePtr, bucket);
+ cachePtr->buckets[bucket].lastPtr->nextBlock
+ = sharedPtr->buckets[bucket].firstPtr;
+ sharedPtr->buckets[bucket].firstPtr = firstPtr;
+ if (sharedPtr->buckets[bucket].numFree == 0) {
+ sharedPtr->buckets[bucket].lastPtr
+ = cachePtr->buckets[bucket].lastPtr;
+ }
+ sharedPtr->buckets[bucket].numFree += numMove;
+ UnlockBucket(cachePtr, bucket);
+
+ cachePtr->buckets[bucket].lastPtr = lastPtr;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetBlocks --
+ *
+ * Get more blocks for a bucket.
+ *
+ * Results:
+ * 1 if blocks where allocated, 0 otherwise.
+ *
+ * Side effects:
+ * Cache may be filled with available blocks.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+GetBlocks(
+ Cache *cachePtr,
+ int bucket)
+{
+ register Block *blockPtr;
+ register int n;
+
+ /*
+ * First, atttempt to move blocks from the shared cache. Note the
+ * potentially dirty read of numFree before acquiring the lock which is a
+ * slight performance enhancement. The value is verified after the lock is
+ * actually acquired.
+ */
+
+ if (cachePtr != sharedPtr && sharedPtr->buckets[bucket].numFree > 0) {
+ LockBucket(cachePtr, bucket);
+ if (sharedPtr->buckets[bucket].numFree > 0) {
+
+ /*
+ * Either move the entire list or walk the list to find the last
+ * block to move.
+ */
+
+ n = bucketInfo[bucket].numMove;
+ if (n >= sharedPtr->buckets[bucket].numFree) {
+ cachePtr->buckets[bucket].firstPtr =
+ sharedPtr->buckets[bucket].firstPtr;
+ cachePtr->buckets[bucket].lastPtr =
+ sharedPtr->buckets[bucket].lastPtr;
+ cachePtr->buckets[bucket].numFree =
+ sharedPtr->buckets[bucket].numFree;
+ sharedPtr->buckets[bucket].firstPtr = NULL;
+ sharedPtr->buckets[bucket].numFree = 0;
+ } else {
+ blockPtr = sharedPtr->buckets[bucket].firstPtr;
+ cachePtr->buckets[bucket].firstPtr = blockPtr;
+ sharedPtr->buckets[bucket].numFree -= n;
+ cachePtr->buckets[bucket].numFree = n;
+ while (--n > 0) {
+ blockPtr = blockPtr->nextBlock;
+ }
+ sharedPtr->buckets[bucket].firstPtr = blockPtr->nextBlock;
+ cachePtr->buckets[bucket].lastPtr = blockPtr;
+ blockPtr->nextBlock = NULL;
+ }
+ }
+ UnlockBucket(cachePtr, bucket);
+ }
+
+ if (cachePtr->buckets[bucket].numFree == 0) {
+ register size_t size;
+
+ /*
+ * If no blocks could be moved from shared, first look for a larger
+ * block in this cache to split up.
+ */
+
+ blockPtr = NULL;
+ n = NBUCKETS;
+ size = 0; /* lint */
+ while (--n > bucket) {
+ if (cachePtr->buckets[n].numFree > 0) {
+ size = bucketInfo[n].blockSize;
+ blockPtr = cachePtr->buckets[n].firstPtr;
+ cachePtr->buckets[n].firstPtr = blockPtr->nextBlock;
+ cachePtr->buckets[n].numFree--;
+ break;
+ }
+ }
+
+ /*
+ * Otherwise, allocate a big new block directly.
+ */
+
+ if (blockPtr == NULL) {
+ size = MAXALLOC;
+ blockPtr = TclpSysAlloc(size, 0);
+ if (blockPtr == NULL) {
+ return 0;
+ }
+ }
+
+ /*
+ * Split the larger block into smaller blocks for this bucket.
+ */
+
+ n = size / bucketInfo[bucket].blockSize;
+ cachePtr->buckets[bucket].numFree = n;
+ cachePtr->buckets[bucket].firstPtr = blockPtr;
+ while (--n > 0) {
+ blockPtr->nextBlock = (Block *)
+ ((char *) blockPtr + bucketInfo[bucket].blockSize);
+ blockPtr = blockPtr->nextBlock;
+ }
+ cachePtr->buckets[bucket].lastPtr = blockPtr;
+ blockPtr->nextBlock = NULL;
+ }
+ return 1;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFinalizeThreadAlloc --
+ *
+ * This procedure is used to destroy all private resources used in this
+ * file.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFinalizeThreadAlloc(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < NBUCKETS; ++i) {
+ TclpFreeAllocMutex(bucketInfo[i].lockPtr);
+ bucketInfo[i].lockPtr = NULL;
+ }
+
+ TclpFreeAllocMutex(objLockPtr);
+ objLockPtr = NULL;
+
+ TclpFreeAllocMutex(listLockPtr);
+ listLockPtr = NULL;
+
+ TclpFreeAllocCache(NULL);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFinalizeThreadAllocThread --
+ *
+ * This procedure is used to destroy single thread private resources used
+ * in this file.
+ * Called in TclpFinalizeThreadData when a thread exits (Tcl_FinalizeThread).
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFinalizeThreadAllocThread(void)
+{
+ Cache *cachePtr = TclpGetAllocCache();
+ if (cachePtr != NULL) {
+ TclpFreeAllocCache(cachePtr);
+ }
+}
+
+#else /* !(TCL_THREADS && USE_THREAD_ALLOC) */
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_GetMemoryInfo --
+ *
+ * Return a list-of-lists of memory stats.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * List appended to given dstring.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+Tcl_GetMemoryInfo(
+ Tcl_DString *dsPtr)
+{
+ Tcl_Panic("Tcl_GetMemoryInfo called when threaded memory allocator not in use");
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclFinalizeThreadAlloc --
+ *
+ * This procedure is used to destroy all private resources used in this
+ * file.
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFinalizeThreadAlloc(void)
+{
+ Tcl_Panic("TclFinalizeThreadAlloc called when threaded memory allocator not in use");
+}
+#endif /* TCL_THREADS && USE_THREAD_ALLOC */
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */