-// btree version threads2i linux futex concurrency version
-// 09 JAN 2014
+// btree version threads2i sched_yield version
+// with reworked bt_deletekey code
+// 17 FEB 2014
// author: karl malbrain, malbrain@cal.berkeley.edu
#ifdef linux
#define _GNU_SOURCE
-#include <linux/futex.h>
-#define SYS_futex 202
#endif
#ifdef unix
#include <sys/mman.h>
#include <errno.h>
#include <pthread.h>
-#include <limits.h>
#else
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <memory.h>
#include <string.h>
+#include <stddef.h>
typedef unsigned long long uid;
typedef unsigned int uint;
#endif
+#define BT_latchtable 128 // number of latch manager slots
+
#define BT_ro 0x6f72 // ro
#define BT_rw 0x7772 // rw
BtLockParent
} BtLock;
-// mode & definition for latch implementation
-
-enum {
- Mutex = 1 << 0, // the mutex bit
- Write = 1 << 1, // the writers bit
- Share = 1 << 2, // reader count
- PendRd = 1 << 12, // reader contended count
- PendWr = 1 << 22 // writer contended count
-} LockMode;
-
-enum {
- QueRd = 1, // reader queue
- QueWr = 2 // writer queue
-} RWQueue;
+// definition for latch implementation
+// exclusive is set for write access
// share is count of read accessors
// grant write lock when share == 0
+volatile typedef struct {
+ unsigned char mutex[1];
+ unsigned char exclusive:1;
+ unsigned char pending:1;
+ ushort share;
+} BtSpinLatch;
+
+// hash table entries
+
typedef struct {
- volatile uint mutex:1; // 1 = busy
- volatile uint write:1; // 1 = exclusive
- volatile uint share:10; // count of readers holding locks
- volatile uint readwait:10; // count of readers waiting
- volatile uint writewait:10; // count of writers waiting
-} BtLatch;
+ BtSpinLatch latch[1];
+ volatile ushort slot; // Latch table entry at head of chain
+} BtHashEntry;
+
+// latch manager table structure
typedef struct {
- BtLatch readwr[1]; // read/write page lock
- BtLatch access[1]; // Access Intent/Page delete
- BtLatch parent[1]; // Parent modification
+ BtSpinLatch readwr[1]; // read/write page lock
+ BtSpinLatch access[1]; // Access Intent/Page delete
+ BtSpinLatch parent[1]; // Posting of fence key in parent
+ BtSpinLatch busy[1]; // slot is being moved between chains
+ volatile ushort next; // next entry in hash table chain
+ volatile ushort prev; // prev entry in hash table chain
+ volatile ushort pin; // number of outstanding locks
+ volatile ushort hash; // hash slot entry is under
+ volatile uid page_no; // latch set page number
} BtLatchSet;
// Define the length of the page and key pointers
} BtSlot;
// The key structure occupies space at the upper end of
-// each page. It's a length byte followed by the value
+// each page. It's a length byte followed by the key
// bytes.
typedef struct {
// It is immediately followed
// by the BtSlot array of keys.
-typedef struct Page {
- BtLatchSet latch[1]; // Set of three latches
+typedef struct BtPage_ {
uint cnt; // count of keys in page
uint act; // count of active keys
uint min; // next key offset
- unsigned char bits; // page size in bits
+ unsigned char bits:7; // page size in bits
+ unsigned char free:1; // page is on free chain
unsigned char lvl:6; // level of page
unsigned char kill:1; // page is being deleted
unsigned char dirty:1; // page has deleted keys
// The memory mapping pool table buffer manager entry
typedef struct {
- unsigned long long int lru; // number of times accessed
uid basepage; // mapped base page number
char *map; // mapped memory pointer
- uint slot; // slot index in this array
- volatile uint pin; // mapped page pin counter
+ ushort slot; // slot index in this array
+ ushort pin; // mapped page pin counter
void *hashprev; // previous pool entry for the same hash idx
void *hashnext; // next pool entry for the same hash idx
#ifndef unix
- HANDLE hmap;
+ HANDLE hmap; // Windows memory mapping handle
#endif
} BtPool;
+#define CLOCK_bit 0x8000 // bit in pool->pin
+
+// The loadpage interface object
+
+typedef struct {
+ uid page_no; // current page number
+ BtPage page; // current page pointer
+ BtPool *pool; // current page pool
+ BtLatchSet *latch; // current page latch set
+} BtPageSet;
+
+// structure for latch manager on ALLOC_page
+
+typedef struct {
+ struct BtPage_ alloc[2]; // next & free page_nos in right ptr
+ BtSpinLatch lock[1]; // allocation area lite latch
+ ushort latchdeployed; // highest number of latch entries deployed
+ ushort nlatchpage; // number of latch pages at BT_latch
+ ushort latchtotal; // number of page latch entries
+ ushort latchhash; // number of latch hash table slots
+ ushort latchvictim; // next latch entry to examine
+ BtHashEntry table[0]; // the hash table
+} BtLatchMgr;
+
// The object structure for Btree access
typedef struct {
uint seg_bits; // seg size in pages in bits
uint mode; // read-write mode
#ifdef unix
- char *pooladvise; // bit maps for pool page advisements
int idx;
#else
HANDLE idx;
#endif
- volatile uint poolcnt; // highest page pool node in use
+ ushort poolcnt; // highest page pool node in use
+ ushort poolmax; // highest page pool node allocated
+ ushort poolmask; // total number of pages in mmap segment - 1
+ ushort hashsize; // size of Hash Table for pool entries
volatile uint evicted; // last evicted hash table slot
- uint poolmax; // highest page pool node allocated
- uint poolmask; // total size of pages in mmap segment - 1
- uint hashsize; // size of Hash Table for pool entries
ushort *hash; // pool index for hash entries
- BtLatch *latch; // latches for hash table slots
+ BtSpinLatch *latch; // latches for hash table slots
+ BtLatchMgr *latchmgr; // mapped latch page from allocation page
+ BtLatchSet *latchsets; // mapped latch set from latch pages
BtPool *pool; // memory pool page segments
+#ifndef unix
+ HANDLE halloc; // allocation and latch table handle
+#endif
} BtMgr;
typedef struct {
BtMgr *mgr; // buffer manager for thread
- BtPage temp; // temporary frame buffer (memory mapped/file IO)
- BtPage alloc; // frame buffer for alloc page ( mapped to page 0 )
BtPage cursor; // cached frame for start/next (never mapped)
BtPage frame; // spare frame for the page split (never mapped)
- BtPage zero; // page of zeroes to extend the file (never mapped)
- BtPage page; // current page mapped from file
- uid page_no; // current page number
+ BtPage zero; // page frame for zeroes at end of file
uid cursor_page; // current cursor page number
unsigned char *mem; // frame, cursor, page memory buffer
+ int found; // last delete or insert was found
int err; // last error
} BtDb;
// B-Tree functions
extern void bt_close (BtDb *bt);
extern BtDb *bt_open (BtMgr *mgr);
-extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod);
+extern BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod);
extern BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl);
extern uid bt_findkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_startkey (BtDb *bt, unsigned char *key, uint len);
extern uint bt_tod (BtDb *bt, uint slot);
// BTree page number constants
-#define ALLOC_page 0
-#define ROOT_page 1
-#define LEAF_page 2
+#define ALLOC_page 0 // allocation & lock manager hash table
+#define ROOT_page 1 // root of the btree
+#define LEAF_page 2 // first page of leaves
+#define LATCH_page 3 // pages for lock manager
// Number of levels to create in a new BTree
// A key consists of a length byte, two bytes of
// index number (0 - 65534), and up to 253 bytes
// of key value. Duplicate keys are discarded.
-// Associated with each key is a 48 bit row-id.
+// Associated with each key is a 48 bit row-id,
+// or any other value desired.
// The b-tree root is always located at page 1.
// The first leaf page of level zero is always
// one with two keys.
// Deleted keys are marked with a dead bit until
-// page cleanup The fence key for a node is always
-// present, even after deletion and cleanup.
+// page cleanup. The fence key for a node is
+// always present
// Groups of pages called segments from the btree are optionally
// cached with a memory mapped pool. A hash table is used to keep
// Page 0 is dedicated to lock for new page extensions,
// and chains empty pages together for reuse.
-// The ParentModification lock on a node is obtained to prevent resplitting
-// or deleting a node before its fence is posted into its upper level.
+// The ParentModification lock on a node is obtained to serialize posting
+// or changing the fence key for a node.
// Empty pages are chained together through the ALLOC page and reused.
// Access macros to address slot and key values from the page
+// Page slots use 1 based indexing.
#define slotptr(page, slot) (((BtSlot *)(page+1)) + (slot-1))
#define keyptr(page, slot) ((BtKey)((unsigned char*)(page) + slotptr(page, slot)->off))
return id;
}
+// Latch Manager
+
+// wait until write lock mode is clear
+// and add 1 to the share count
+
+void bt_spinreadlock(BtSpinLatch *latch)
+{
+ushort prev;
+
+ do {
+ // obtain latch mutex
+#ifdef unix
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
+ continue;
+#else
+ if( _InterlockedExchange8(latch->mutex, 1) )
+ continue;
+#endif
+ // see if exclusive request is granted or pending
+
+ if( prev = !(latch->exclusive | latch->pending) )
+ latch->share++;
+
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
+#endif
+
+ if( prev )
+ return;
+
+#ifdef unix
+ } while( sched_yield(), 1 );
+#else
+ } while( SwitchToThread(), 1 );
+#endif
+}
+
+// wait for other read and write latches to relinquish
+
+void bt_spinwritelock(BtSpinLatch *latch)
+{
+uint prev;
+
+ do {
+#ifdef unix
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
+ continue;
+#else
+ if( _InterlockedExchange8(latch->mutex, 1) )
+ continue;
+#endif
+ if( prev = !(latch->share | latch->exclusive) )
+ latch->exclusive = 1, latch->pending = 0;
+ else
+ latch->pending = 1;
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
+#endif
+ if( prev )
+ return;
+#ifdef unix
+ } while( sched_yield(), 1 );
+#else
+ } while( SwitchToThread(), 1 );
+#endif
+}
+
+// try to obtain write lock
+
+// return 1 if obtained,
+// 0 otherwise
+
+int bt_spinwritetry(BtSpinLatch *latch)
+{
+uint prev;
+
+#ifdef unix
+ if( __sync_lock_test_and_set(latch->mutex, 1) )
+ return 0;
+#else
+ if( _InterlockedExchange8(latch->mutex, 1) )
+ return 0;
+#endif
+ // take write access if all bits are clear
+
+ if( prev = !(latch->exclusive | latch->share) )
+ latch->exclusive = 1;
+
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
+#endif
+ return prev;
+}
+
+// clear write mode
+
+void bt_spinreleasewrite(BtSpinLatch *latch)
+{
+#ifdef unix
+ while( __sync_lock_test_and_set(latch->mutex, 1) )
+ sched_yield();
+#else
+ while( _InterlockedExchange8(latch->mutex, 1) )
+ SwitchToThread();
+#endif
+ latch->exclusive = 0;
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
+#endif
+}
+
+// decrement reader count
+
+void bt_spinreleaseread(BtSpinLatch *latch)
+{
+#ifdef unix
+ while( __sync_lock_test_and_set(latch->mutex, 1) )
+ sched_yield();
+#else
+ while( _InterlockedExchange8(latch->mutex, 1) )
+ SwitchToThread();
+#endif
+ latch->share--;
+#ifdef unix
+ *latch->mutex = 0;
+#else
+ _InterlockedExchange8(latch->mutex, 0);
+#endif
+}
+
+// link latch table entry into latch hash table
+
+void bt_latchlink (BtDb *bt, ushort hashidx, ushort victim, uid page_no)
+{
+BtLatchSet *set = bt->mgr->latchsets + victim;
+
+ if( set->next = bt->mgr->latchmgr->table[hashidx].slot )
+ bt->mgr->latchsets[set->next].prev = victim;
+
+ bt->mgr->latchmgr->table[hashidx].slot = victim;
+ set->page_no = page_no;
+ set->hash = hashidx;
+ set->prev = 0;
+}
+
+// release latch pin
+
+void bt_unpinlatch (BtLatchSet *set)
+{
+#ifdef unix
+ __sync_fetch_and_add(&set->pin, -1);
+#else
+ _InterlockedDecrement16 (&set->pin);
+#endif
+}
+
+// find existing latchset or inspire new one
+// return with latchset pinned
+
+BtLatchSet *bt_pinlatch (BtDb *bt, uid page_no)
+{
+ushort hashidx = page_no % bt->mgr->latchmgr->latchhash;
+ushort slot, avail = 0, victim, idx;
+BtLatchSet *set;
+
+ // obtain read lock on hash table entry
+
+ bt_spinreadlock(bt->mgr->latchmgr->table[hashidx].latch);
+
+ if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
+ {
+ set = bt->mgr->latchsets + slot;
+ if( page_no == set->page_no )
+ break;
+ } while( slot = set->next );
+
+ if( slot ) {
+#ifdef unix
+ __sync_fetch_and_add(&set->pin, 1);
+#else
+ _InterlockedIncrement16 (&set->pin);
+#endif
+ }
+
+ bt_spinreleaseread (bt->mgr->latchmgr->table[hashidx].latch);
+
+ if( slot )
+ return set;
+
+ // try again, this time with write lock
+
+ bt_spinwritelock(bt->mgr->latchmgr->table[hashidx].latch);
+
+ if( slot = bt->mgr->latchmgr->table[hashidx].slot ) do
+ {
+ set = bt->mgr->latchsets + slot;
+ if( page_no == set->page_no )
+ break;
+ if( !set->pin && !avail )
+ avail = slot;
+ } while( slot = set->next );
+
+ // found our entry, or take over an unpinned one
+
+ if( slot || (slot = avail) ) {
+ set = bt->mgr->latchsets + slot;
+#ifdef unix
+ __sync_fetch_and_add(&set->pin, 1);
+#else
+ _InterlockedIncrement16 (&set->pin);
+#endif
+ set->page_no = page_no;
+ bt_spinreleasewrite(bt->mgr->latchmgr->table[hashidx].latch);
+ return set;
+ }
+
+ // see if there are any unused entries
+#ifdef unix
+ victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, 1) + 1;
+#else
+ victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchdeployed);
+#endif
+
+ if( victim < bt->mgr->latchmgr->latchtotal ) {
+ set = bt->mgr->latchsets + victim;
+#ifdef unix
+ __sync_fetch_and_add(&set->pin, 1);
+#else
+ _InterlockedIncrement16 (&set->pin);
+#endif
+ bt_latchlink (bt, hashidx, victim, page_no);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
+ return set;
+ }
+
+#ifdef unix
+ victim = __sync_fetch_and_add (&bt->mgr->latchmgr->latchdeployed, -1);
+#else
+ victim = _InterlockedDecrement16 (&bt->mgr->latchmgr->latchdeployed);
+#endif
+ // find and reuse previous lock entry
+
+ while( 1 ) {
+#ifdef unix
+ victim = __sync_fetch_and_add(&bt->mgr->latchmgr->latchvictim, 1);
+#else
+ victim = _InterlockedIncrement16 (&bt->mgr->latchmgr->latchvictim) - 1;
+#endif
+ // we don't use slot zero
+
+ if( victim %= bt->mgr->latchmgr->latchtotal )
+ set = bt->mgr->latchsets + victim;
+ else
+ continue;
+
+ // take control of our slot
+ // from other threads
+
+ if( set->pin || !bt_spinwritetry (set->busy) )
+ continue;
+
+ idx = set->hash;
+
+ // try to get write lock on hash chain
+ // skip entry if not obtained
+ // or has outstanding locks
+
+ if( !bt_spinwritetry (bt->mgr->latchmgr->table[idx].latch) ) {
+ bt_spinreleasewrite (set->busy);
+ continue;
+ }
+
+ if( set->pin ) {
+ bt_spinreleasewrite (set->busy);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
+ continue;
+ }
+
+ // unlink our available victim from its hash chain
+
+ if( set->prev )
+ bt->mgr->latchsets[set->prev].next = set->next;
+ else
+ bt->mgr->latchmgr->table[idx].slot = set->next;
+
+ if( set->next )
+ bt->mgr->latchsets[set->next].prev = set->prev;
+
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[idx].latch);
+#ifdef unix
+ __sync_fetch_and_add(&set->pin, 1);
+#else
+ _InterlockedIncrement16 (&set->pin);
+#endif
+ bt_latchlink (bt, hashidx, victim, page_no);
+ bt_spinreleasewrite (bt->mgr->latchmgr->table[hashidx].latch);
+ bt_spinreleasewrite (set->busy);
+ return set;
+ }
+}
+
void bt_mgrclose (BtMgr *mgr)
{
BtPool *pool;
#endif
}
+#ifdef unix
+ munmap (mgr->latchsets, mgr->latchmgr->nlatchpage * mgr->page_size);
+ munmap (mgr->latchmgr, mgr->page_size);
+#else
+ FlushViewOfFile(mgr->latchmgr, 0);
+ UnmapViewOfFile(mgr->latchmgr);
+ CloseHandle(mgr->halloc);
+#endif
#ifdef unix
close (mgr->idx);
free (mgr->pool);
free (mgr->hash);
- free (mgr->latch);
- free (mgr->pooladvise);
+ free ((void *)mgr->latch);
free (mgr);
#else
FlushFileBuffers(mgr->idx);
CloseHandle(mgr->idx);
GlobalFree (mgr->pool);
GlobalFree (mgr->hash);
- GlobalFree (mgr->latch);
+ GlobalFree ((void *)mgr->latch);
GlobalFree (mgr);
#endif
}
void bt_close (BtDb *bt)
{
#ifdef unix
- if ( bt->mem )
+ if( bt->mem )
free (bt->mem);
#else
- if ( bt->mem)
+ if( bt->mem)
VirtualFree (bt->mem, 0, MEM_RELEASE);
#endif
free (bt);
BtMgr *bt_mgr (char *name, uint mode, uint bits, uint poolmax, uint segsize, uint hashsize)
{
-uint lvl, attr, cacheblk, last;
-BtPage alloc;
-int lockmode;
+uint lvl, attr, cacheblk, last, slot, idx;
+uint nlatchpage, latchhash;
+BtLatchMgr *latchmgr;
off64_t size;
uint amt[1];
BtMgr* mgr;
BtKey key;
+int flag;
#ifndef unix
SYSTEM_INFO sysinfo[1];
#ifdef unix
mgr = calloc (1, sizeof(BtMgr));
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- lockmode = 1;
- break;
+ mgr->idx = open ((char*)name, O_RDWR | O_CREAT, 0666);
- case BT_ro:
- default:
- mgr->idx = open ((char*)name, O_RDONLY);
- lockmode = 0;
- break;
- }
if( mgr->idx == -1 )
return free(mgr), NULL;
#else
mgr = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, sizeof(BtMgr));
attr = FILE_ATTRIBUTE_NORMAL;
- switch (mode & 0x7fff)
- {
- case BT_rw:
- mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- lockmode = 1;
- break;
+ mgr->idx = CreateFile(name, GENERIC_READ| GENERIC_WRITE, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, attr, NULL);
- case BT_ro:
- default:
- mgr->idx = CreateFile(name, GENERIC_READ, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, attr, NULL);
- lockmode = 0;
- break;
- }
if( mgr->idx == INVALID_HANDLE_VALUE )
return GlobalFree(mgr), NULL;
#endif
#ifdef unix
- alloc = malloc (BT_maxpage);
+ latchmgr = malloc (BT_maxpage);
*amt = 0;
// read minimum page size to get root info
if( size = lseek (mgr->idx, 0L, 2) ) {
- if( pread(mgr->idx, alloc, BT_minpage, 0) == BT_minpage )
- bits = alloc->bits;
+ if( pread(mgr->idx, latchmgr, BT_minpage, 0) == BT_minpage )
+ bits = latchmgr->alloc->bits;
else
- return free(mgr), free(alloc), NULL;
+ return free(mgr), free(latchmgr), NULL;
} else if( mode == BT_ro )
- return bt_mgrclose (mgr), NULL;
+ return free(latchmgr), bt_mgrclose (mgr), NULL;
#else
- alloc = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
+ latchmgr = VirtualAlloc(NULL, BT_maxpage, MEM_COMMIT, PAGE_READWRITE);
size = GetFileSize(mgr->idx, amt);
if( size || *amt ) {
- if( !ReadFile(mgr->idx, (char *)alloc, BT_minpage, amt, NULL) )
+ if( !ReadFile(mgr->idx, (char *)latchmgr, BT_minpage, amt, NULL) )
return bt_mgrclose (mgr), NULL;
- bits = alloc->bits;
+ bits = latchmgr->alloc->bits;
} else if( mode == BT_ro )
return bt_mgrclose (mgr), NULL;
#endif
#ifdef unix
mgr->pool = calloc (poolmax, sizeof(BtPool));
mgr->hash = calloc (hashsize, sizeof(ushort));
- mgr->latch = calloc (hashsize, sizeof(BtLatch));
- mgr->pooladvise = calloc (poolmax, (mgr->poolmask + 8) / 8);
+ mgr->latch = calloc (hashsize, sizeof(BtSpinLatch));
#else
mgr->pool = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, poolmax * sizeof(BtPool));
mgr->hash = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(ushort));
- mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtLatch));
+ mgr->latch = GlobalAlloc (GMEM_FIXED|GMEM_ZEROINIT, hashsize * sizeof(BtSpinLatch));
#endif
if( size || *amt )
- goto mgrxit;
+ goto mgrlatch;
+
+ // initialize an empty b-tree with latch page, root page, page of leaves
+ // and page(s) of latches
+
+ memset (latchmgr, 0, 1 << bits);
+ nlatchpage = BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1;
+ bt_putid(latchmgr->alloc->right, MIN_lvl+1+nlatchpage);
+ latchmgr->alloc->bits = mgr->page_bits;
+
+ latchmgr->nlatchpage = nlatchpage;
+ latchmgr->latchtotal = nlatchpage * (mgr->page_size / sizeof(BtLatchSet));
- // initializes an empty b-tree with root page and page of leaves
+ // initialize latch manager
- memset (alloc, 0, 1 << bits);
- bt_putid(alloc->right, MIN_lvl+1);
- alloc->bits = mgr->page_bits;
+ latchhash = (mgr->page_size - sizeof(BtLatchMgr)) / sizeof(BtHashEntry);
+
+ // size of hash table = total number of latchsets
+
+ if( latchhash > latchmgr->latchtotal )
+ latchhash = latchmgr->latchtotal;
+
+ latchmgr->latchhash = latchhash;
#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
+ if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
return bt_mgrclose (mgr), NULL;
#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
+ if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
return bt_mgrclose (mgr), NULL;
if( *amt < mgr->page_size )
return bt_mgrclose (mgr), NULL;
#endif
- memset (alloc, 0, 1 << bits);
- alloc->bits = mgr->page_bits;
+ memset (latchmgr, 0, 1 << bits);
+ latchmgr->alloc->bits = mgr->page_bits;
for( lvl=MIN_lvl; lvl--; ) {
- slotptr(alloc, 1)->off = mgr->page_size - 3;
- bt_putid(slotptr(alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
- key = keyptr(alloc, 1);
- key->len = 2; // create stopper key
+ slotptr(latchmgr->alloc, 1)->off = mgr->page_size - 3;
+ bt_putid(slotptr(latchmgr->alloc, 1)->id, lvl ? MIN_lvl - lvl + 1 : 0); // next(lower) page number
+ key = keyptr(latchmgr->alloc, 1);
+ key->len = 2; // create stopper key
key->key[0] = 0xff;
key->key[1] = 0xff;
- alloc->min = mgr->page_size - 3;
- alloc->lvl = lvl;
- alloc->cnt = 1;
- alloc->act = 1;
+ latchmgr->alloc->min = mgr->page_size - 3;
+ latchmgr->alloc->lvl = lvl;
+ latchmgr->alloc->cnt = 1;
+ latchmgr->alloc->act = 1;
#ifdef unix
- if( write (mgr->idx, alloc, mgr->page_size) < mgr->page_size )
+ if( write (mgr->idx, latchmgr, mgr->page_size) < mgr->page_size )
return bt_mgrclose (mgr), NULL;
#else
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
+ if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
return bt_mgrclose (mgr), NULL;
if( *amt < mgr->page_size )
#endif
}
- // create empty page area by writing last page of first
- // segment area (other pages are zeroed by O/S)
-
- if( mgr->poolmask ) {
- memset(alloc, 0, mgr->page_size);
- last = mgr->poolmask;
+ // clear out latch manager locks
+ // and rest of pages to round out segment
- while( last < MIN_lvl + 1 )
- last += mgr->poolmask + 1;
+ memset(latchmgr, 0, mgr->page_size);
+ last = MIN_lvl + 1;
+ while( last <= ((MIN_lvl + 1 + nlatchpage) | mgr->poolmask) ) {
#ifdef unix
- pwrite(mgr->idx, alloc, mgr->page_size, last << mgr->page_bits);
+ pwrite(mgr->idx, latchmgr, mgr->page_size, last << mgr->page_bits);
#else
SetFilePointer (mgr->idx, last << mgr->page_bits, NULL, FILE_BEGIN);
- if( !WriteFile (mgr->idx, (char *)alloc, mgr->page_size, amt, NULL) )
+ if( !WriteFile (mgr->idx, (char *)latchmgr, mgr->page_size, amt, NULL) )
return bt_mgrclose (mgr), NULL;
if( *amt < mgr->page_size )
return bt_mgrclose (mgr), NULL;
#endif
+ last++;
}
-mgrxit:
+mgrlatch:
+#ifdef unix
+ flag = PROT_READ | PROT_WRITE;
+ mgr->latchmgr = mmap (0, mgr->page_size, flag, MAP_SHARED, mgr->idx, ALLOC_page * mgr->page_size);
+ if( mgr->latchmgr == MAP_FAILED )
+ return bt_mgrclose (mgr), NULL;
+ mgr->latchsets = (BtLatchSet *)mmap (0, mgr->latchmgr->nlatchpage * mgr->page_size, flag, MAP_SHARED, mgr->idx, LATCH_page * mgr->page_size);
+ if( mgr->latchsets == MAP_FAILED )
+ return bt_mgrclose (mgr), NULL;
+#else
+ flag = PAGE_READWRITE;
+ mgr->halloc = CreateFileMapping(mgr->idx, NULL, flag, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size, NULL);
+ if( !mgr->halloc )
+ return bt_mgrclose (mgr), NULL;
+
+ flag = FILE_MAP_WRITE;
+ mgr->latchmgr = MapViewOfFile(mgr->halloc, flag, 0, 0, (BT_latchtable / (mgr->page_size / sizeof(BtLatchSet)) + 1 + LATCH_page) * mgr->page_size);
+ if( !mgr->latchmgr )
+ return GetLastError(), bt_mgrclose (mgr), NULL;
+
+ mgr->latchsets = (void *)((char *)mgr->latchmgr + LATCH_page * mgr->page_size);
+#endif
+
#ifdef unix
- free (alloc);
+ free (latchmgr);
#else
- VirtualFree (alloc, 0, MEM_RELEASE);
+ VirtualFree (latchmgr, 0, MEM_RELEASE);
#endif
return mgr;
}
return 0;
}
-// Latch Manager
-
-int sys_futex(void *addr1, int op, int val1, struct timespec *timeout, void *addr2, int val3)
-{
- return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
-}
-
-// wait until write lock mode is clear
-// and add 1 to the share count
-
-void bt_readlock(BtLatch *latch, int private)
-{
-uint prev;
-
- if( private )
- private = FUTEX_PRIVATE_FLAG;
-
- while( 1 ) {
- // obtain latch mutex
- if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) {
- sched_yield();
- continue;
- }
-
- // wait for writers to clear
- // increment read waiters and wait
-
- if( latch->write || latch->writewait ) {
- __sync_fetch_and_add ((uint *)latch, PendRd);
- prev = __sync_fetch_and_and ((uint *)latch, ~Mutex) & ~Mutex;
- sys_futex( (uint *)latch, FUTEX_WAIT_BITSET | private, prev, NULL, NULL, QueRd );
- __sync_fetch_and_sub ((uint *)latch, PendRd);
- continue;
- }
-
- // increment reader lock count
- // and release latch mutex
-
- __sync_fetch_and_add ((uint *)latch, Share);
- __sync_fetch_and_and ((uint *)latch, ~Mutex);
- return;
- }
-}
-
-// wait for other read and write latches to relinquish
-
-void bt_writelock(BtLatch *latch, int private)
-{
-uint prev;
-
- if( private )
- private = FUTEX_PRIVATE_FLAG;
-
- while( 1 ) {
- // obtain latch mutex
- if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex ) {
- sched_yield();
- continue;
- }
-
- // wait for write and reader count to clear
-
- if( latch->write || latch->share ) {
- __sync_fetch_and_add ((uint *)latch, PendWr);
- prev = __sync_fetch_and_and ((uint *)latch, ~Mutex) & ~Mutex;
- sys_futex( (uint *)latch, FUTEX_WAIT_BITSET | private, prev, NULL, NULL, QueWr );
- __sync_fetch_and_sub ((uint *)latch, PendWr);
- continue;
- }
-
- // take write mutex
- // release latch mutex
-
- __sync_fetch_and_or ((uint *)latch, Write);
- __sync_fetch_and_and ((uint *)latch, ~Mutex);
- return;
- }
-}
-
-// try to obtain write lock
-
-// return 1 if obtained,
-// 0 otherwise
-
-int bt_writetry(BtLatch *latch)
-{
-int ans;
-
- // try for mutex,
- // abandon request if not taken
-
- if( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
- return 0;
-
- // see if write mode is available
-
- if( !latch->write && !latch->share ) {
- __sync_fetch_and_or ((uint *)latch, Write);
- ans = 1;
- } else
- ans = 0;
-
- // release latch mutex
-
- __sync_fetch_and_and ((uint *)latch, ~Mutex);
- return ans;
-}
-
-// clear write lock
-
-void bt_releasewrite(BtLatch *latch, int private)
-{
- if( private )
- private = FUTEX_PRIVATE_FLAG;
-
- // obtain latch mutex
-
- while( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
- sched_yield();
-
- __sync_fetch_and_and ((uint *)latch, ~Write);
-
- // favor writers
-
- if( latch->writewait )
- if( sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, 1, NULL, NULL, QueWr ) )
- goto wakexit;
-
- if( latch->readwait )
- sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, INT_MAX, NULL, NULL, QueRd );
-
- // release latch mutex
-
-wakexit:
- __sync_fetch_and_and ((uint *)latch, ~Mutex);
-}
-
-// decrement reader count
-
-void bt_releaseread(BtLatch *latch, int private)
-{
- if( private )
- private = FUTEX_PRIVATE_FLAG;
-
- // obtain latch mutex
-
- while( __sync_fetch_and_or((uint *)latch, Mutex) & Mutex )
- sched_yield();
-
- __sync_fetch_and_sub ((uint *)latch, Share);
-
- // wake waiting writers
-
- if( !latch->share && latch->writewait )
- sys_futex( (uint *)latch, FUTEX_WAKE_BITSET | private, 1, NULL, NULL, QueWr );
-
- // release latch mutex
-
- __sync_fetch_and_and ((uint *)latch, ~Mutex);
-}
-
// Buffer Pool mgr
// find segment in pool
pool->hashprev = pool->hashnext = NULL;
pool->basepage = page_no & ~bt->mgr->poolmask;
- pool->lru = 1;
+ pool->pin = CLOCK_bit + 1;
if( slot = bt->mgr->hash[idx] ) {
node = bt->mgr->pool + slot;
bt->mgr->hash[idx] = pool->slot;
}
-// find best segment to evict from buffer pool
-
-BtPool *bt_findlru (BtDb *bt, uint hashslot)
-{
-unsigned long long int target = ~0LL;
-BtPool *pool = NULL, *node;
-
- if( !hashslot )
- return NULL;
-
- node = bt->mgr->pool + hashslot;
-
- // scan pool entries under hash table slot
-
- do {
- if( node->pin )
- continue;
- if( node->lru > target )
- continue;
- target = node->lru;
- pool = node;
- } while( node = node->hashnext );
-
- return pool;
-}
-
// map new buffer pool segment to virtual memory
BTERR bt_mapsegment(BtDb *bt, BtPool *pool, uid page_no)
if( pool->map == MAP_FAILED )
return bt->err = BTERR_map;
- // clear out madvise issued bits
- memset (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8) / 8), 0, (bt->mgr->poolmask + 8)/8);
#else
flag = ( bt->mgr->mode == BT_ro ? PAGE_READONLY : PAGE_READWRITE );
pool->hmap = CreateFileMapping(bt->mgr->idx, NULL, flag, (DWORD)(limit >> 32), (DWORD)limit, NULL);
return bt->err = 0;
}
-// find or place requested page in segment-pool
-// return pool table entry, incrementing pin
+// calculate page within pool
-BtPool *bt_pinpage(BtDb *bt, uid page_no)
+BtPage bt_page (BtDb *bt, BtPool *pool, uid page_no)
{
-BtPool *pool, *node, *next;
-uint slot, idx, victim;
-
- // lock hash table chain
+uint subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
+BtPage page;
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx], 1);
+ page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
+ return page;
+}
- // look up in hash table
+// release pool pin
- if( pool = bt_findpool(bt, page_no, idx) ) {
+void bt_unpinpool (BtPool *pool)
+{
#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
+ __sync_fetch_and_add(&pool->pin, -1);
#else
- _InterlockedIncrement (&pool->pin);
+ _InterlockedDecrement16 (&pool->pin);
#endif
- bt_releaseread (&bt->mgr->latch[idx], 1);
- pool->lru++;
- return pool;
- }
+}
- // upgrade to write lock
+// find or place requested page in segment-pool
+// return pool table entry, incrementing pin
- bt_releaseread (&bt->mgr->latch[idx], 1);
- bt_writelock (&bt->mgr->latch[idx], 1);
+BtPool *bt_pinpool(BtDb *bt, uid page_no)
+{
+uint slot, hashidx, idx, victim;
+BtPool *pool, *node, *next;
- // try to find page in pool with write lock
+ // lock hash table chain
+
+ hashidx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
+ bt_spinwritelock (&bt->mgr->latch[hashidx]);
+
+ // look up in hash table
- if( pool = bt_findpool(bt, page_no, idx) ) {
+ if( pool = bt_findpool(bt, page_no, hashidx) ) {
#ifdef unix
+ __sync_fetch_and_or(&pool->pin, CLOCK_bit);
__sync_fetch_and_add(&pool->pin, 1);
#else
- _InterlockedIncrement (&pool->pin);
+ _InterlockedOr16 (&pool->pin, CLOCK_bit);
+ _InterlockedIncrement16 (&pool->pin);
#endif
- bt_releasewrite (&bt->mgr->latch[idx], 1);
- pool->lru++;
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
#ifdef unix
slot = __sync_fetch_and_add(&bt->mgr->poolcnt, 1);
#else
- slot = _InterlockedIncrement (&bt->mgr->poolcnt) - 1;
+ slot = _InterlockedIncrement16 (&bt->mgr->poolcnt) - 1;
#endif
if( ++slot < bt->mgr->poolmax ) {
if( bt_mapsegment(bt, pool, page_no) )
return NULL;
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx], 1);
+ bt_linkhash(bt, pool, page_no, hashidx);
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
#ifdef unix
__sync_fetch_and_add(&bt->mgr->poolcnt, -1);
#else
- _InterlockedDecrement (&bt->mgr->poolcnt);
+ _InterlockedDecrement16 (&bt->mgr->poolcnt);
#endif
while( 1 ) {
#else
victim = _InterlockedIncrement (&bt->mgr->evicted) - 1;
#endif
- victim %= bt->mgr->hashsize;
+ victim %= bt->mgr->poolmax;
+ pool = bt->mgr->pool + victim;
+ idx = (uint)(pool->basepage >> bt->mgr->seg_bits) % bt->mgr->hashsize;
+
+ if( !victim )
+ continue;
// try to get write lock
// skip entry if not obtained
- if( !bt_writetry (&bt->mgr->latch[victim]) )
+ if( !bt_spinwritetry (&bt->mgr->latch[idx]) )
continue;
- // if pool entry is empty
- // or any pages are pinned
- // skip this entry
+ // skip this entry if
+ // page is pinned
+ // or clock bit is set
- if( !(pool = bt_findlru(bt, bt->mgr->hash[victim])) ) {
- bt_releasewrite (&bt->mgr->latch[victim], 1);
+ if( pool->pin ) {
+#ifdef unix
+ __sync_fetch_and_and(&pool->pin, ~CLOCK_bit);
+#else
+ _InterlockedAnd16 (&pool->pin, ~CLOCK_bit);
+#endif
+ bt_spinreleasewrite (&bt->mgr->latch[idx]);
continue;
}
if( node = pool->hashprev )
node->hashnext = pool->hashnext;
else if( node = pool->hashnext )
- bt->mgr->hash[victim] = node->slot;
+ bt->mgr->hash[idx] = node->slot;
else
- bt->mgr->hash[victim] = 0;
+ bt->mgr->hash[idx] = 0;
if( node = pool->hashnext )
node->hashprev = pool->hashprev;
- bt_releasewrite (&bt->mgr->latch[victim], 1);
+ bt_spinreleasewrite (&bt->mgr->latch[idx]);
// remove old file mapping
#ifdef unix
if( bt_mapsegment(bt, pool, page_no) )
return NULL;
- bt_linkhash(bt, pool, page_no, idx);
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, 1);
-#else
- _InterlockedIncrement (&pool->pin);
-#endif
- bt_releasewrite (&bt->mgr->latch[idx], 1);
+ bt_linkhash(bt, pool, page_no, hashidx);
+ bt_spinreleasewrite (&bt->mgr->latch[hashidx]);
return pool;
}
}
// place write, read, or parent lock on requested page_no.
-// pin to buffer pool and return page pointer
-BTERR bt_lockpage(BtDb *bt, uid page_no, BtLock mode, BtPage *pageptr)
+void bt_lockpage(BtLock mode, BtLatchSet *set)
{
-uint subpage;
-BtPool *pool;
-BtPage page;
-
- // find/create maping in pool table
- // and pin our pool slot
-
- if( pool = bt_pinpage(bt, page_no) )
- subpage = (uint)(page_no & bt->mgr->poolmask); // page within mapping
- else
- return bt->err;
-
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-#ifdef unix
- {
- uint idx = subpage / 8;
- uint bit = subpage % 8;
-
- if( ~((bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] >> bit) & 1 ) {
- madvise (page, bt->mgr->page_size, MADV_WILLNEED);
- (bt->mgr->pooladvise + pool->slot * ((bt->mgr->poolmask + 8)/8))[idx] |= 1 << bit;
- }
- }
-#endif
-
switch( mode ) {
case BtLockRead:
- bt_readlock (page->latch->readwr, 0);
+ bt_spinreadlock (set->readwr);
break;
case BtLockWrite:
- bt_writelock (page->latch->readwr, 0);
+ bt_spinwritelock (set->readwr);
break;
case BtLockAccess:
- bt_readlock (page->latch->access, 0);
+ bt_spinreadlock (set->access);
break;
case BtLockDelete:
- bt_writelock (page->latch->access, 0);
+ bt_spinwritelock (set->access);
break;
case BtLockParent:
- bt_writelock (page->latch->parent, 0);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
- if( pageptr )
- *pageptr = page;
- return bt->err = 0;
-}
-
-// remove write, read, or parent lock on requested page
-
-BTERR bt_unlockpage(BtDb *bt, uid page_no, BtLock mode)
-{
-uint subpage, idx;
-BtPool *pool;
-BtPage page;
-
- // since page is pinned
- // it should still be in the buffer pool
- // and is in no danger of being a victim for reuse
-
- idx = (uint)(page_no >> bt->mgr->seg_bits) % bt->mgr->hashsize;
- bt_readlock (&bt->mgr->latch[idx], 1);
-
- if( pool = bt_findpool(bt, page_no, idx) )
- subpage = (uint)(page_no & bt->mgr->poolmask);
- else
- return bt->err = BTERR_hash;
-
- bt_releaseread (&bt->mgr->latch[idx], 1);
- page = (BtPage)(pool->map + (subpage << bt->mgr->page_bits));
-
- switch( mode ) {
- case BtLockRead:
- bt_releaseread (page->latch->readwr, 0);
- break;
- case BtLockWrite:
- bt_releasewrite (page->latch->readwr, 0);
- break;
- case BtLockAccess:
- bt_releaseread (page->latch->access, 0);
- break;
- case BtLockDelete:
- bt_releasewrite (page->latch->access, 0);
- break;
- case BtLockParent:
- bt_releasewrite (page->latch->parent, 0);
- break;
- default:
- return bt->err = BTERR_lock;
- }
-
-#ifdef unix
- __sync_fetch_and_add(&pool->pin, -1);
-#else
- _InterlockedDecrement (&pool->pin);
-#endif
- return bt->err = 0;
-}
-
-// deallocate a deleted page
-// place on free chain out of allocator page
-
-BTERR bt_freepage(BtDb *bt, uid page_no)
-{
- // obtain delete lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockDelete, NULL) )
- return bt->err;
-
- // obtain write lock on deleted page
-
- if( bt_lockpage(bt, page_no, BtLockWrite, &bt->temp) )
- return bt->err;
-
- // lock allocation page
-
- if ( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return bt->err;
-
- // store chain in second right
- bt_putid(bt->temp->right, bt_getid(bt->alloc[1].right));
- bt_putid(bt->alloc[1].right, page_no);
-
- // unlock page zero
-
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return bt->err;
-
- // remove write lock on deleted node
-
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
-
- // remove delete lock on deleted node
+ bt_spinwritelock (set->parent);
+ break;
+ }
+}
- if( bt_unlockpage(bt, page_no, BtLockDelete) )
- return bt->err;
+// remove write, read, or parent lock on requested page
- return 0;
+void bt_unlockpage(BtLock mode, BtLatchSet *set)
+{
+ switch( mode ) {
+ case BtLockRead:
+ bt_spinreleaseread (set->readwr);
+ break;
+ case BtLockWrite:
+ bt_spinreleasewrite (set->readwr);
+ break;
+ case BtLockAccess:
+ bt_spinreleaseread (set->access);
+ break;
+ case BtLockDelete:
+ bt_spinreleasewrite (set->access);
+ break;
+ case BtLockParent:
+ bt_spinreleasewrite (set->parent);
+ break;
+ }
}
// allocate a new page and write page into it
uid bt_newpage(BtDb *bt, BtPage page)
{
+BtPageSet set[1];
uid new_page;
-BtPage pmap;
-int subpage;
int reuse;
- // lock page zero
+ // lock allocation page
- if( bt_lockpage(bt, ALLOC_page, BtLockWrite, &bt->alloc) )
- return 0;
+ bt_spinwritelock(bt->mgr->latchmgr->lock);
// use empty chain first
// else allocate empty page
- if( new_page = bt_getid(bt->alloc[1].right) ) {
- if( bt_lockpage (bt, new_page, BtLockWrite, &bt->temp) )
- return 0;
- bt_putid(bt->alloc[1].right, bt_getid(bt->temp->right));
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
+ if( new_page = bt_getid(bt->mgr->latchmgr->alloc[1].right) ) {
+ if( set->pool = bt_pinpool (bt, new_page) )
+ set->page = bt_page (bt, set->pool, new_page);
+ else
return 0;
+
+ bt_putid(bt->mgr->latchmgr->alloc[1].right, bt_getid(set->page->right));
+ bt_unpinpool (set->pool);
reuse = 1;
} else {
- new_page = bt_getid(bt->alloc->right);
- bt_putid(bt->alloc->right, new_page+1);
+ new_page = bt_getid(bt->mgr->latchmgr->alloc->right);
+ bt_putid(bt->mgr->latchmgr->alloc->right, new_page+1);
reuse = 0;
}
-
#ifdef unix
- // if writing first page of pool block
- // expand file thru last page in the block
-
- if( !reuse && (new_page & bt->mgr->poolmask) == 0 )
- if( pwrite(bt->mgr->idx, bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
+ if( pwrite(bt->mgr->idx, page, bt->mgr->page_size, new_page << bt->mgr->page_bits) < bt->mgr->page_size )
return bt->err = BTERR_wrt, 0;
-#endif
- // unlock page allocation page
- if( bt_unlockpage(bt, ALLOC_page, BtLockWrite) )
- return 0;
+ // if writing first page of pool block, zero last page in the block
+ if( !reuse && bt->mgr->poolmask > 0 && (new_page & bt->mgr->poolmask) == 0 )
+ {
+ // use zero buffer to write zeros
+ if( pwrite(bt->mgr->idx,bt->zero, bt->mgr->page_size, (new_page | bt->mgr->poolmask) << bt->mgr->page_bits) < bt->mgr->page_size )
+ return bt->err = BTERR_wrt, 0;
+ }
+#else
// bring new page into pool and copy page.
- // on Windows, this will extend the file into the new page.
+ // this will extend the file into the new pages.
- if( bt_lockpage(bt, new_page, BtLockWrite, &pmap) )
+ if( set->pool = bt_pinpool (bt, new_page) )
+ set->page = bt_page (bt, set->pool, new_page);
+ else
return 0;
- // copy source page but leave latch area intact
-
- memcpy((char *)pmap + sizeof(BtLatchSet), (char *)page + sizeof(BtLatchSet), bt->mgr->page_size - sizeof(BtLatchSet));
-
- if( bt_unlockpage (bt, new_page, BtLockWrite) )
- return 0;
+ memcpy(set->page, page, bt->mgr->page_size);
+ bt_unpinpool (set->pool);
+#endif
+ // unlock allocation latch and return new page no
+ bt_spinreleasewrite(bt->mgr->latchmgr->lock);
return new_page;
}
// find slot in page for given key at a given level
-int bt_findslot (BtDb *bt, unsigned char *key, uint len)
+int bt_findslot (BtPageSet *set, unsigned char *key, uint len)
{
-uint diff, higher = bt->page->cnt, low = 1, slot;
+uint diff, higher = set->page->cnt, low = 1, slot;
uint good = 0;
- // make stopper key an infinite fence value
+ // make stopper key an infinite fence value
- if( bt_getid (bt->page->right) )
+ if( bt_getid (set->page->right) )
higher++;
else
good++;
- // low is the next candidate, higher is already
- // tested as .ge. the given key, loop ends when they meet
+ // low is the lowest candidate.
+ // loop ends when they meet
+
+ // higher is already
+ // tested as .ge. the passed key.
while( diff = higher - low ) {
slot = low + ( diff >> 1 );
- if( keycmp (keyptr(bt->page, slot), key, len) < 0 )
+ if( keycmp (keyptr(set->page, slot), key, len) < 0 )
low = slot + 1;
else
higher = slot, good++;
// return zero if key is on right link page
- return good ? higher : 0;
+ return good ? higher : 0;
}
// find and load page at given level for given key
// leave page rd or wr locked as requested
-int bt_loadpage (BtDb *bt, unsigned char *key, uint len, uint lvl, uint lock)
+int bt_loadpage (BtDb *bt, BtPageSet *set, unsigned char *key, uint len, uint lvl, BtLock lock)
{
uid page_no = ROOT_page, prevpage = 0;
uint drill = 0xff, slot;
+BtLatchSet *prevlatch;
uint mode, prevmode;
+BtPool *prevpool;
// start at root of btree and drill down
do {
// determine lock mode of drill level
- mode = (lock == BtLockWrite) && (drill == lvl) ? BtLockWrite : BtLockRead;
+ mode = (drill == lvl) ? lock : BtLockRead;
+
+ set->latch = bt_pinlatch (bt, page_no);
+ set->page_no = page_no;
- bt->page_no = page_no;
+ // pin page contents
+
+ if( set->pool = bt_pinpool (bt, page_no) )
+ set->page = bt_page (bt, set->pool, page_no);
+ else
+ return 0;
// obtain access lock using lock chaining with Access mode
if( page_no > ROOT_page )
- if( bt_lockpage(bt, page_no, BtLockAccess, NULL) )
- return 0;
+ bt_lockpage(BtLockAccess, set->latch);
- if( prevpage )
- if( bt_unlockpage(bt, prevpage, prevmode) )
- return 0;
+ // release & unpin parent page
+
+ if( prevpage ) {
+ bt_unlockpage(prevmode, prevlatch);
+ bt_unpinlatch (prevlatch);
+ bt_unpinpool (prevpool);
+ prevpage = 0;
+ }
// obtain read lock using lock chaining
- // and pin page contents
- if( bt_lockpage(bt, page_no, mode, &bt->page) )
- return 0;
+ bt_lockpage(mode, set->latch);
+
+ if( set->page->free )
+ return bt->err = BTERR_struct, 0;
if( page_no > ROOT_page )
- if( bt_unlockpage(bt, page_no, BtLockAccess) )
- return 0;
+ bt_unlockpage(BtLockAccess, set->latch);
// re-read and re-lock root after determining actual level of root
- if( bt->page->lvl != drill) {
- if ( bt->page_no != ROOT_page )
+ if( set->page->lvl != drill) {
+ if( set->page_no != ROOT_page )
return bt->err = BTERR_struct, 0;
- drill = bt->page->lvl;
+ drill = set->page->lvl;
- if( lock == BtLockWrite && drill == lvl )
- if( bt_unlockpage(bt, page_no, mode) )
- return 0;
- else
- continue;
+ if( lock != BtLockRead && drill == lvl ) {
+ bt_unlockpage(mode, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ continue;
+ }
}
+ prevpage = set->page_no;
+ prevlatch = set->latch;
+ prevpool = set->pool;
+ prevmode = mode;
+
// find key on page at this level
// and descend to requested level
- if( !bt->page->kill && (slot = bt_findslot (bt, key, len)) ) {
+ if( !set->page->kill )
+ if( slot = bt_findslot (set, key, len) ) {
if( drill == lvl )
return slot;
- while( slotptr(bt->page, slot)->dead )
- if( slot++ < bt->page->cnt )
+ while( slotptr(set->page, slot)->dead )
+ if( slot++ < set->page->cnt )
continue;
- else {
- page_no = bt_getid(bt->page->right);
+ else
goto slideright;
- }
- page_no = bt_getid(slotptr(bt->page, slot)->id);
+ page_no = bt_getid(slotptr(set->page, slot)->id);
drill--;
- }
+ continue;
+ }
// or slide right into next page
- // (slide left from deleted page)
-
- else
- page_no = bt_getid(bt->page->right);
-
- // continue down / right using overlapping locks
- // to protect pages being killed or split.
slideright:
- prevpage = bt->page_no;
- prevmode = mode;
+ page_no = bt_getid(set->page->right);
+
} while( page_no );
// return error on end of right chain
return 0; // return error
}
+// return page to free list
+// page must be delete & write locked
+
+void bt_freepage (BtDb *bt, BtPageSet *set)
+{
+ // lock allocation page
+
+ bt_spinwritelock (bt->mgr->latchmgr->lock);
+
+ // store chain in second right
+ bt_putid(set->page->right, bt_getid(bt->mgr->latchmgr->alloc[1].right));
+ bt_putid(bt->mgr->latchmgr->alloc[1].right, set->page_no);
+ set->page->free = 1;
+
+ // unlock released page
+
+ bt_unlockpage (BtLockDelete, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+
+ // unlock allocation page
+
+ bt_spinreleasewrite (bt->mgr->latchmgr->lock);
+}
+
+// a fence key was deleted from a page
+// push new fence value upwards
+
+BTERR bt_fixfence (BtDb *bt, BtPageSet *set, uint lvl)
+{
+unsigned char leftkey[256], rightkey[256];
+uid page_no;
+BtKey ptr;
+
+ // remove the old fence value
+
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (rightkey, ptr, ptr->len + 1);
+
+ memset (slotptr(set->page, set->page->cnt--), 0, sizeof(BtSlot));
+ set->page->dirty = 1;
+
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (leftkey, ptr, ptr->len + 1);
+ page_no = set->page_no;
+
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
+
+ // insert new (now smaller) fence key
+
+ if( bt_insertkey (bt, leftkey+1, *leftkey, lvl+1, page_no, time(NULL)) )
+ return bt->err;
+
+ // now delete old fence key
+
+ if( bt_deletekey (bt, rightkey+1, *rightkey, lvl+1) )
+ return bt->err;
+
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch(set->latch);
+ bt_unpinpool (set->pool);
+ return 0;
+}
+
+// root has a single child
+// collapse a level from the tree
+
+BTERR bt_collapseroot (BtDb *bt, BtPageSet *root)
+{
+BtPageSet child[1];
+uint idx;
+
+ // find the child entry and promote as new root contents
+
+ do {
+ for( idx = 0; idx++ < root->page->cnt; )
+ if( !slotptr(root->page, idx)->dead )
+ break;
+
+ child->page_no = bt_getid (slotptr(root->page, idx)->id);
+
+ child->latch = bt_pinlatch (bt, child->page_no);
+ bt_lockpage (BtLockDelete, child->latch);
+ bt_lockpage (BtLockWrite, child->latch);
+
+ if( child->pool = bt_pinpool (bt, child->page_no) )
+ child->page = bt_page (bt, child->pool, child->page_no);
+ else
+ return bt->err;
+
+ memcpy (root->page, child->page, bt->mgr->page_size);
+ bt_freepage (bt, child);
+
+ } while( root->page->lvl > 1 && root->page->act == 1 );
+
+ bt_unlockpage (BtLockWrite, root->latch);
+ bt_unpinlatch (root->latch);
+ bt_unpinpool (root->pool);
+ return 0;
+}
+
// find and delete key on page by marking delete flag bit
-// when page becomes empty, delete it
+// if page becomes empty, delete it from the btree
BTERR bt_deletekey (BtDb *bt, unsigned char *key, uint len, uint lvl)
{
-unsigned char lowerkey[256], higherkey[256];
-uid page_no, right;
-uint slot, tod;
+unsigned char lowerfence[256], higherfence[256];
+uint slot, idx, dirty = 0, fence, found;
+BtPageSet set[1], right[1];
BtKey ptr;
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
+ if( slot = bt_loadpage (bt, set, key, len, lvl, BtLockWrite) )
+ ptr = keyptr(set->page, slot);
else
return bt->err;
+ // are we deleting a fence slot?
+
+ fence = slot == set->page->cnt;
+
// if key is found delete it, otherwise ignore request
- if( !keycmp (ptr, key, len) )
- if( slotptr(bt->page, slot)->dead == 0 ) {
- slotptr(bt->page,slot)->dead = 1;
- if( slot < bt->page->cnt )
- bt->page->dirty = 1;
- bt->page->act--;
- }
+ if( found = !keycmp (ptr, key, len) )
+ if( found = slotptr(set->page, slot)->dead == 0 ) {
+ dirty = slotptr(set->page, slot)->dead = 1;
+ set->page->dirty = 1;
+ set->page->act--;
- // return if page is not empty, or it has no right sibling
+ // collapse empty slots
- right = bt_getid(bt->page->right);
- page_no = bt->page_no;
+ while( idx = set->page->cnt - 1 )
+ if( slotptr(set->page, idx)->dead ) {
+ *slotptr(set->page, idx) = *slotptr(set->page, idx + 1);
+ memset (slotptr(set->page, set->page->cnt--), 0, sizeof(BtSlot));
+ } else
+ break;
+ }
- if( !right || bt->page->act )
- return bt_unlockpage(bt, page_no, BtLockWrite);
+ // did we delete a fence key in an upper level?
+
+ if( dirty && lvl && set->page->act && fence )
+ if( bt_fixfence (bt, set, lvl) )
+ return bt->err;
+ else
+ return bt->found = found, 0;
- // obtain Parent lock over write lock
+ // is this a collapsed root?
- if( bt_lockpage(bt, page_no, BtLockParent, NULL) )
+ if( lvl > 1 && set->page_no == ROOT_page && set->page->act == 1 )
+ if( bt_collapseroot (bt, set) )
return bt->err;
+ else
+ return bt->found = found, 0;
- // keep copy of key to delete
+ // return if page is not empty
- ptr = keyptr(bt->page, bt->page->cnt);
- memcpy(lowerkey, ptr, ptr->len + 1);
+ if( set->page->act ) {
+ bt_unlockpage(BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ return bt->found = found, 0;
+ }
- // lock and map right page
+ // cache copy of fence key
+ // to post in parent
- if ( bt_lockpage(bt, right, BtLockWrite, &bt->temp) )
- return bt->err;
+ ptr = keyptr(set->page, set->page->cnt);
+ memcpy (lowerfence, ptr, ptr->len + 1);
- // pull contents of next page into current empty page
- memcpy((char *)bt->page + sizeof(BtLatchSet), (char *)bt->temp + sizeof(BtLatchSet), bt->mgr->page_size - sizeof(BtLatchSet));
+ // obtain lock on right page
- // keep copy of key to update
- ptr = keyptr(bt->temp, bt->temp->cnt);
- memcpy(higherkey, ptr, ptr->len + 1);
+ right->page_no = bt_getid(set->page->right);
+ right->latch = bt_pinlatch (bt, right->page_no);
+ bt_lockpage (BtLockWrite, right->latch);
- // Mark right page as deleted and point it to left page
- // until we can post updates at higher level.
+ // pin page contents
- bt_putid(bt->temp->right, page_no);
- bt->temp->kill = 1;
- bt->temp->cnt = 0;
+ if( right->pool = bt_pinpool (bt, right->page_no) )
+ right->page = bt_page (bt, right->pool, right->page_no);
+ else
+ return 0;
- if( bt_unlockpage(bt, right, BtLockWrite) )
- return bt->err;
- if( bt_unlockpage(bt, page_no, BtLockWrite) )
- return bt->err;
+ if( right->page->kill )
+ return bt->err = BTERR_struct;
- // delete old lower key to consolidated node
+ // pull contents of right peer into our empty page
- if( bt_deletekey (bt, lowerkey + 1, *lowerkey, lvl + 1) )
- return bt->err;
+ memcpy (set->page, right->page, bt->mgr->page_size);
- // redirect higher key directly to consolidated node
+ // cache copy of key to update
- tod = (uint)time(NULL);
+ ptr = keyptr(right->page, right->page->cnt);
+ memcpy (higherfence, ptr, ptr->len + 1);
- if( bt_insertkey (bt, higherkey+1, *higherkey, lvl + 1, page_no, tod) )
- return bt->err;
+ // mark right page deleted and point it to left page
+ // until we can post parent updates
- // obtain write lock and
- // add right block to free chain
+ bt_putid (right->page->right, set->page_no);
+ right->page->kill = 1;
- if( bt_freepage (bt, right) )
- return bt->err;
+ bt_lockpage (BtLockParent, right->latch);
+ bt_unlockpage (BtLockWrite, right->latch);
- // remove ParentModify lock
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
- if( bt_unlockpage(bt, page_no, BtLockParent) )
- return bt->err;
-
+ // redirect higher key directly to our new node contents
+
+ if( bt_insertkey (bt, higherfence+1, *higherfence, lvl+1, set->page_no, time(NULL)) )
+ return bt->err;
+
+ // delete old lower key to our node
+
+ if( bt_deletekey (bt, lowerfence+1, *lowerfence, lvl+1) )
+ return bt->err;
+
+ // obtain delete and write locks to right node
+
+ bt_unlockpage (BtLockParent, right->latch);
+ bt_lockpage (BtLockDelete, right->latch);
+ bt_lockpage (BtLockWrite, right->latch);
+ bt_freepage (bt, right);
+
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ bt->found = found;
return 0;
}
uid bt_findkey (BtDb *bt, unsigned char *key, uint len)
{
+BtPageSet set[1];
uint slot;
+uid id = 0;
BtKey ptr;
-uid id;
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- ptr = keyptr(bt->page, slot);
+ if( slot = bt_loadpage (bt, set, key, len, 0, BtLockRead) )
+ ptr = keyptr(set->page, slot);
else
return 0;
// if key exists, return row-id
// otherwise return 0
- if( ptr->len == len && !memcmp (ptr->key, key, len) )
- id = bt_getid(slotptr(bt->page,slot)->id);
- else
- id = 0;
-
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
+ if( slot <= set->page->cnt )
+ if( !keycmp (ptr, key, len) )
+ id = bt_getid(slotptr(set->page,slot)->id);
+ bt_unlockpage (BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
return id;
}
// check page for space available,
// clean if necessary and return
// 0 - page needs splitting
-// 1 - go ahead
+// >0 new slot value
-uint bt_cleanpage(BtDb *bt, uint amt)
+uint bt_cleanpage(BtDb *bt, BtPage page, uint amt, uint slot)
{
uint nxt = bt->mgr->page_size;
-BtPage page = bt->page;
uint cnt = 0, idx = 0;
uint max = page->cnt;
+uint newslot = max;
BtKey key;
- if( page->min >= (page->cnt+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
+ if( page->min >= (max+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
+ return slot;
// skip cleanup if nothing to reclaim
page->dirty = 0;
page->act = 0;
+ // try cleaning up page first
+ // by removing deleted keys
+
while( cnt++ < max ) {
- // always leave fence key in list
+ if( cnt == slot )
+ newslot = idx + 1;
if( cnt < max && slotptr(bt->frame,cnt)->dead )
continue;
- // copy key
+ // copy the key across
+
key = keyptr(bt->frame, cnt);
nxt -= key->len + 1;
memcpy ((unsigned char *)page + nxt, key, key->len + 1);
// copy slot
+
memcpy(slotptr(page, ++idx)->id, slotptr(bt->frame, cnt)->id, BtId);
if( !(slotptr(page, idx)->dead = slotptr(bt->frame, cnt)->dead) )
page->act++;
slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
slotptr(page, idx)->off = nxt;
}
+
page->min = nxt;
page->cnt = idx;
- if( page->min >= (page->cnt+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
- return 1;
+ // see if page has enough space now, or does it need splitting?
+
+ if( page->min >= (idx+1) * sizeof(BtSlot) + sizeof(*page) + amt + 1 )
+ return newslot;
return 0;
}
// split the root and raise the height of the btree
-BTERR bt_splitroot(BtDb *bt, unsigned char *newkey, unsigned char *oldkey, uid page_no2)
+BTERR bt_splitroot(BtDb *bt, BtPageSet *root, unsigned char *leftkey, uid page_no2)
{
uint nxt = bt->mgr->page_size;
-BtPage root = bt->page;
-uid new_page;
+uid left;
// Obtain an empty page to use, and copy the current
- // root contents into it which is the lower half of
- // the old root.
+ // root contents into it, e.g. lower keys
- if( !(new_page = bt_newpage(bt, root)) )
+ if( !(left = bt_newpage(bt, root->page)) )
return bt->err;
// preserve the page info at the bottom
- // and set rest to zero
+ // of higher keys and set rest to zero
- memset(root+1, 0, bt->mgr->page_size - sizeof(*root));
+ memset(root->page+1, 0, bt->mgr->page_size - sizeof(*root->page));
- // insert first key on newroot page
+ // insert lower keys page fence key on newroot page as first key
- nxt -= *newkey + 1;
- memcpy ((unsigned char *)root + nxt, newkey, *newkey + 1);
- bt_putid(slotptr(root, 1)->id, new_page);
- slotptr(root, 1)->off = nxt;
+ nxt -= *leftkey + 1;
+ memcpy ((unsigned char *)root->page + nxt, leftkey, *leftkey + 1);
+ bt_putid(slotptr(root->page, 1)->id, left);
+ slotptr(root->page, 1)->off = nxt;
- // insert second key on newroot page
+ // insert stopper key on newroot page
// and increase the root height
- nxt -= *oldkey + 1;
- memcpy ((unsigned char *)root + nxt, oldkey, *oldkey + 1);
- bt_putid(slotptr(root, 2)->id, page_no2);
- slotptr(root, 2)->off = nxt;
+ nxt -= 3;
+ ((unsigned char *)root->page)[nxt] = 2;
+ ((unsigned char *)root->page)[nxt+1] = 0xff;
+ ((unsigned char *)root->page)[nxt+2] = 0xff;
+ bt_putid(slotptr(root->page, 2)->id, page_no2);
+ slotptr(root->page, 2)->off = nxt;
- bt_putid(root->right, 0);
- root->min = nxt; // reset lowest used offset and key count
- root->cnt = 2;
- root->act = 2;
- root->lvl++;
+ bt_putid(root->page->right, 0);
+ root->page->min = nxt; // reset lowest used offset and key count
+ root->page->cnt = 2;
+ root->page->act = 2;
+ root->page->lvl++;
- // release root (bt->page)
+ // release and unpin root
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
+ bt_unlockpage(BtLockWrite, root->latch);
+ bt_unpinlatch (root->latch);
+ bt_unpinpool (root->pool);
+ return 0;
}
// split already locked full node
// return unlocked.
-BTERR bt_splitpage (BtDb *bt)
+BTERR bt_splitpage (BtDb *bt, BtPageSet *set)
{
uint cnt = 0, idx = 0, max, nxt = bt->mgr->page_size;
-unsigned char oldkey[256], lowerkey[256];
-uid page_no = bt->page_no, right;
-BtPage page = bt->page;
-uint lvl = page->lvl;
-uid new_page;
+unsigned char fencekey[256], rightkey[256];
+uint lvl = set->page->lvl;
+BtPageSet right[1];
+uint prev;
BtKey key;
-uint tod;
// split higher half of keys to bt->frame
- // the last key (fence key) might be dead
-
- tod = (uint)time(NULL);
memset (bt->frame, 0, bt->mgr->page_size);
- max = (int)page->cnt;
+ max = set->page->cnt;
cnt = max / 2;
idx = 0;
while( cnt++ < max ) {
- key = keyptr(page, cnt);
+ key = keyptr(set->page, cnt);
nxt -= key->len + 1;
memcpy ((unsigned char *)bt->frame + nxt, key, key->len + 1);
- memcpy(slotptr(bt->frame,++idx)->id, slotptr(page,cnt)->id, BtId);
- if( !(slotptr(bt->frame, idx)->dead = slotptr(page, cnt)->dead) )
+
+ memcpy(slotptr(bt->frame,++idx)->id, slotptr(set->page,cnt)->id, BtId);
+ if( !(slotptr(bt->frame, idx)->dead = slotptr(set->page, cnt)->dead) )
bt->frame->act++;
- slotptr(bt->frame, idx)->tod = slotptr(page, cnt)->tod;
+ slotptr(bt->frame, idx)->tod = slotptr(set->page, cnt)->tod;
slotptr(bt->frame, idx)->off = nxt;
}
// remember existing fence key for new page to the right
- memcpy (oldkey, key, key->len + 1);
+ memcpy (rightkey, key, key->len + 1);
bt->frame->bits = bt->mgr->page_bits;
bt->frame->min = nxt;
// link right node
- if( page_no > ROOT_page ) {
- right = bt_getid (page->right);
- bt_putid(bt->frame->right, right);
- }
+ if( set->page_no > ROOT_page )
+ memcpy (bt->frame->right, set->page->right, BtId);
- // get new free page and write frame to it.
+ // get new free page and write higher keys to it.
- if( !(new_page = bt_newpage(bt, bt->frame)) )
+ if( !(right->page_no = bt_newpage(bt, bt->frame)) )
return bt->err;
// update lower keys to continue in old page
- memcpy (bt->frame, page, bt->mgr->page_size);
- memset (page+1, 0, bt->mgr->page_size - sizeof(*page));
+ memcpy (bt->frame, set->page, bt->mgr->page_size);
+ memset (set->page+1, 0, bt->mgr->page_size - sizeof(*set->page));
nxt = bt->mgr->page_size;
- page->act = 0;
+ set->page->dirty = 0;
+ set->page->act = 0;
cnt = 0;
idx = 0;
// assemble page of smaller keys
- // (they're all active keys)
while( cnt++ < max / 2 ) {
key = keyptr(bt->frame, cnt);
nxt -= key->len + 1;
- memcpy ((unsigned char *)page + nxt, key, key->len + 1);
- memcpy(slotptr(page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
- slotptr(page, idx)->tod = slotptr(bt->frame, cnt)->tod;
- slotptr(page, idx)->off = nxt;
- page->act++;
+ memcpy ((unsigned char *)set->page + nxt, key, key->len + 1);
+ memcpy(slotptr(set->page,++idx)->id, slotptr(bt->frame,cnt)->id, BtId);
+ slotptr(set->page, idx)->tod = slotptr(bt->frame, cnt)->tod;
+ slotptr(set->page, idx)->off = nxt;
+ set->page->act++;
}
- // remember fence key for old page
+ // remember fence key for smaller page
- memcpy(lowerkey, key, key->len + 1);
- bt_putid(page->right, new_page);
- page->min = nxt;
- page->cnt = idx;
-
- // if current page is the root page, split it
+ memcpy(fencekey, key, key->len + 1);
- if( page_no == ROOT_page )
- return bt_splitroot (bt, lowerkey, oldkey, new_page);
+ bt_putid(set->page->right, right->page_no);
+ set->page->min = nxt;
+ set->page->cnt = idx;
- // obtain Parent/Write locks
- // for left and right node pages
-
- if( bt_lockpage (bt, new_page, BtLockParent, NULL) )
- return bt->err;
-
- if( bt_lockpage (bt, page_no, BtLockParent, NULL) )
- return bt->err;
+ // if current page is the root page, split it
- // release wr lock on left page
+ if( set->page_no == ROOT_page )
+ return bt_splitroot (bt, set, fencekey, right->page_no);
- if( bt_unlockpage (bt, page_no, BtLockWrite) )
- return bt->err;
+ // insert new fences in their parent pages
- // insert new fence for reformulated left block
+ right->latch = bt_pinlatch (bt, right->page_no);
+ bt_lockpage (BtLockParent, right->latch);
- if( bt_insertkey (bt, lowerkey+1, *lowerkey, lvl + 1, page_no, tod) )
- return bt->err;
+ bt_lockpage (BtLockParent, set->latch);
+ bt_unlockpage (BtLockWrite, set->latch);
- // fix old fence for newly allocated right block page
+ // insert new fence for reformulated left block of smaller keys
- if( bt_insertkey (bt, oldkey+1, *oldkey, lvl + 1, new_page, tod) )
+ if( bt_insertkey (bt, fencekey+1, *fencekey, lvl+1, set->page_no, time(NULL)) )
return bt->err;
- // release Parent & Write locks
+ // switch fence for right block of larger keys to new right page
- if( bt_unlockpage (bt, new_page, BtLockParent) )
+ if( bt_insertkey (bt, rightkey+1, *rightkey, lvl+1, right->page_no, time(NULL)) )
return bt->err;
- if( bt_unlockpage (bt, page_no, BtLockParent) )
- return bt->err;
+ bt_unlockpage (BtLockParent, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ bt_unlockpage (BtLockParent, right->latch);
+ bt_unpinlatch (right->latch);
return 0;
}
-
-// Insert new key into the btree at requested level.
-// Level zero pages are leaf pages and are unlocked at exit.
-// Interior pages remain locked.
+// Insert new key into the btree at given level.
BTERR bt_insertkey (BtDb *bt, unsigned char *key, uint len, uint lvl, uid id, uint tod)
{
+BtPageSet set[1];
uint slot, idx;
-BtPage page;
BtKey ptr;
- while( 1 ) {
- if( slot = bt_loadpage (bt, key, len, lvl, BtLockWrite) )
- ptr = keyptr(bt->page, slot);
- else
- {
- if ( !bt->err )
- bt->err = BTERR_ovflw;
- return bt->err;
- }
-
- // if key already exists, update id and return
-
- page = bt->page;
+ while( 1 ) {
+ if( slot = bt_loadpage (bt, set, key, len, lvl, BtLockWrite) )
+ ptr = keyptr(set->page, slot);
+ else
+ {
+ if( !bt->err )
+ bt->err = BTERR_ovflw;
+ return bt->err;
+ }
- if( !keycmp (ptr, key, len) ) {
- slotptr(page, slot)->dead = 0;
- slotptr(page, slot)->tod = tod;
- bt_putid(slotptr(page,slot)->id, id);
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
- }
+ // if key already exists, update id and return
+
+ if( !keycmp (ptr, key, len) ) {
+ if( slotptr(set->page, slot)->dead )
+ set->page->act++;
+ slotptr(set->page, slot)->dead = 0;
+ slotptr(set->page, slot)->tod = tod;
+ bt_putid(slotptr(set->page,slot)->id, id);
+ bt_unlockpage(BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ return 0;
+ }
- // check if page has enough space
+ // check if page has enough space
- if( bt_cleanpage (bt, len) )
- break;
+ if( slot = bt_cleanpage (bt, set->page, len, slot) )
+ break;
- if( bt_splitpage (bt) )
- return bt->err;
- }
+ if( bt_splitpage (bt, set) )
+ return bt->err;
+ }
- // calculate next available slot and copy key into page
+ // calculate next available slot and copy key into page
- page->min -= len + 1; // reset lowest used offset
- ((unsigned char *)page)[page->min] = len;
- memcpy ((unsigned char *)page + page->min +1, key, len );
+ set->page->min -= len + 1; // reset lowest used offset
+ ((unsigned char *)set->page)[set->page->min] = len;
+ memcpy ((unsigned char *)set->page + set->page->min +1, key, len );
- for( idx = slot; idx < page->cnt; idx++ )
- if( slotptr(page, idx)->dead )
+ for( idx = slot; idx < set->page->cnt; idx++ )
+ if( slotptr(set->page, idx)->dead )
break;
- // now insert key into array before slot
- // preserving the fence slot
+ // now insert key into array before slot
- if( idx == page->cnt )
- idx++, page->cnt++;
+ if( idx == set->page->cnt )
+ idx++, set->page->cnt++;
- page->act++;
+ set->page->act++;
- while( idx > slot )
- *slotptr(page, idx) = *slotptr(page, idx -1), idx--;
+ while( idx > slot )
+ *slotptr(set->page, idx) = *slotptr(set->page, idx -1), idx--;
- bt_putid(slotptr(page,slot)->id, id);
- slotptr(page, slot)->off = page->min;
- slotptr(page, slot)->tod = tod;
- slotptr(page, slot)->dead = 0;
+ bt_putid(slotptr(set->page,slot)->id, id);
+ slotptr(set->page, slot)->off = set->page->min;
+ slotptr(set->page, slot)->tod = tod;
+ slotptr(set->page, slot)->dead = 0;
- return bt_unlockpage(bt, bt->page_no, BtLockWrite);
+ bt_unlockpage (BtLockWrite, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ return 0;
}
// cache page of keys into cursor and return starting slot for given key
uint bt_startkey (BtDb *bt, unsigned char *key, uint len)
{
+BtPageSet set[1];
uint slot;
// cache page for retrieval
- if( slot = bt_loadpage (bt, key, len, 0, BtLockRead) )
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
- bt->cursor_page = bt->page_no;
- if ( bt_unlockpage(bt, bt->page_no, BtLockRead) )
- return 0;
+ if( slot = bt_loadpage (bt, set, key, len, 0, BtLockRead) )
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
+ else
+ return 0;
+
+ bt->cursor_page = set->page_no;
+
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
return slot;
}
uint bt_nextkey (BtDb *bt, uint slot)
{
-off64_t right;
+BtPageSet set[1];
+uid right;
do {
right = bt_getid(bt->cursor->right);
+
while( slot++ < bt->cursor->cnt )
if( slotptr(bt->cursor,slot)->dead )
continue;
- else if( right || (slot < bt->cursor->cnt))
+ else if( right || (slot < bt->cursor->cnt) ) // skip infinite stopper
return slot;
else
break;
bt->cursor_page = right;
- if( bt_lockpage(bt, right, BtLockRead, &bt->page) )
+ if( set->pool = bt_pinpool (bt, right) )
+ set->page = bt_page (bt, set->pool, right);
+ else
return 0;
- memcpy (bt->cursor, bt->page, bt->mgr->page_size);
+ set->latch = bt_pinlatch (bt, right);
+ bt_lockpage(BtLockRead, set->latch);
- if ( bt_unlockpage(bt, right, BtLockRead) )
- return 0;
+ memcpy (bt->cursor, set->page, bt->mgr->page_size);
+ bt_unlockpage(BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
slot = 0;
+
} while( 1 );
return bt->err = 0;
return slotptr(bt->cursor,slot)->tod;
}
-
#ifdef STANDALONE
+#ifndef unix
+double getCpuTime(int type)
+{
+FILETIME crtime[1];
+FILETIME xittime[1];
+FILETIME systime[1];
+FILETIME usrtime[1];
+SYSTEMTIME timeconv[1];
+double ans = 0;
+
+ memset (timeconv, 0, sizeof(SYSTEMTIME));
+
+ switch( type ) {
+ case 0:
+ GetSystemTimeAsFileTime (xittime);
+ FileTimeToSystemTime (xittime, timeconv);
+ ans = (double)timeconv->wDayOfWeek * 3600 * 24;
+ break;
+ case 1:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (usrtime, timeconv);
+ break;
+ case 2:
+ GetProcessTimes (GetCurrentProcess(), crtime, xittime, systime, usrtime);
+ FileTimeToSystemTime (systime, timeconv);
+ break;
+ }
+
+ ans += (double)timeconv->wHour * 3600;
+ ans += (double)timeconv->wMinute * 60;
+ ans += (double)timeconv->wSecond;
+ ans += (double)timeconv->wMilliseconds / 1000;
+ return ans;
+}
+#else
+#include <time.h>
+#include <sys/resource.h>
+
+double getCpuTime(int type)
+{
+struct rusage used[1];
+struct timeval tv[1];
+
+ switch( type ) {
+ case 0:
+ gettimeofday(tv, NULL);
+ return (double)tv->tv_sec + (double)tv->tv_usec / 1000000;
+
+ case 1:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_utime.tv_sec + (double)used->ru_utime.tv_usec / 1000000;
+
+ case 2:
+ getrusage(RUSAGE_SELF, used);
+ return (double)used->ru_stime.tv_sec + (double)used->ru_stime.tv_usec / 1000000;
+ }
+
+ return 0;
+}
+#endif
+
+void bt_latchaudit (BtDb *bt)
+{
+ushort idx, hashidx;
+uid next, page_no;
+BtLatchSet *latch;
+BtKey ptr;
+
+#ifdef unix
+ if( *(uint *)(bt->mgr->latchmgr->lock) )
+ fprintf(stderr, "Alloc page locked\n");
+ *(uint *)(bt->mgr->latchmgr->lock) = 0;
+
+ for( idx = 1; idx <= bt->mgr->latchmgr->latchdeployed; idx++ ) {
+ latch = bt->mgr->latchsets + idx;
+ if( *(uint *)latch->readwr )
+ fprintf(stderr, "latchset %d rwlocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->readwr = 0;
+
+ if( *(uint *)latch->access )
+ fprintf(stderr, "latchset %d accesslocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->access = 0;
+
+ if( *(uint *)latch->parent )
+ fprintf(stderr, "latchset %d parentlocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->parent = 0;
+
+ if( latch->pin ) {
+ fprintf(stderr, "latchset %d pinned for page %.8x\n", idx, latch->page_no);
+ latch->pin = 0;
+ }
+ }
+
+ for( hashidx = 0; hashidx < bt->mgr->latchmgr->latchhash; hashidx++ ) {
+ if( *(uint *)(bt->mgr->latchmgr->table[hashidx].latch) )
+ fprintf(stderr, "hash entry %d locked\n", hashidx);
+
+ *(uint *)(bt->mgr->latchmgr->table[hashidx].latch) = 0;
+
+ if( idx = bt->mgr->latchmgr->table[hashidx].slot ) do {
+ latch = bt->mgr->latchsets + idx;
+ if( *(uint *)latch->busy )
+ fprintf(stderr, "latchset %d busylocked for page %.8x\n", idx, latch->page_no);
+ *(uint *)latch->busy = 0;
+ if( latch->hash != hashidx )
+ fprintf(stderr, "latchset %d wrong hashidx\n", idx);
+ if( latch->pin )
+ fprintf(stderr, "latchset %d pinned for page %.8x\n", idx, latch->page_no);
+ } while( idx = latch->next );
+ }
+
+ next = bt->mgr->latchmgr->nlatchpage + LATCH_page;
+ page_no = LEAF_page;
+
+ while( page_no < bt_getid(bt->mgr->latchmgr->alloc->right) ) {
+ pread (bt->mgr->idx, bt->frame, bt->mgr->page_size, page_no << bt->mgr->page_bits);
+ if( !bt->frame->free )
+ for( idx = 0; idx++ < bt->frame->cnt - 1; ) {
+ ptr = keyptr(bt->frame, idx+1);
+ if( keycmp (keyptr(bt->frame, idx), ptr->key, ptr->len) >= 0 )
+ fprintf(stderr, "page %.8x idx %.2x out of order\n", page_no, idx);
+ }
+
+ if( page_no > LEAF_page )
+ next = page_no + 1;
+ page_no = next;
+ }
+#endif
+}
+
typedef struct {
char type, idx;
char *infile;
unsigned char key[256];
ThreadArg *args = arg;
int ch, len = 0, slot;
+BtPageSet set[1];
time_t tod[1];
-BtPage page;
BtKey ptr;
BtDb *bt;
FILE *in;
switch(args->type | 0x20)
{
+ case 'a':
+ fprintf(stderr, "started latch mgr audit\n");
+ bt_latchaudit (bt);
+ fprintf(stderr, "finished latch mgr audit\n");
+ break;
+
case 'w':
fprintf(stderr, "started indexing for %s\n", args->infile);
if( in = fopen (args->infile, "rb") )
if( args->num == 1 )
sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
+
else if( args->num )
- sprintf((char *)key+len, "%.9d", line+args->idx * args->num), len += 9;
+ sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
if( bt_insertkey (bt, key, len, 0, line, *tod) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
line++;
if( args->num == 1 )
sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
+
else if( args->num )
- sprintf((char *)key+len, "%.9d", line+args->idx * args->num), len += 9;
+ sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
if( bt_deletekey (bt, key, len, 0) )
fprintf(stderr, "Error %d Line: %d\n", bt->err, line), exit(0);
line++;
if( args->num == 1 )
sprintf((char *)key+len, "%.9d", 1000000000 - line), len += 9;
+
else if( args->num )
- sprintf((char *)key+len, "%.9d", line+args->idx * args->num), len += 9;
+ sprintf((char *)key+len, "%.9d", line + args->idx * args->num), len += 9;
if( bt_findkey (bt, key, len) )
found++;
break;
case 's':
- len = key[0] = 0;
-
- fprintf(stderr, "started reading\n");
-
- if( slot = bt_startkey (bt, key, len) )
- slot--;
- else
- fprintf(stderr, "Error %d in StartKey. Syserror: %d\n", bt->err, errno), exit(0);
-
- while( slot = bt_nextkey (bt, slot) ) {
- ptr = bt_key(bt, slot);
- fwrite (ptr->key, ptr->len, 1, stdout);
- fputc ('\n', stdout);
- }
+ fprintf(stderr, "started scanning\n");
+ do {
+ if( set->pool = bt_pinpool (bt, page_no) )
+ set->page = bt_page (bt, set->pool, page_no);
+ else
+ break;
+ set->latch = bt_pinlatch (bt, page_no);
+ bt_lockpage (BtLockRead, set->latch);
+ next = bt_getid (set->page->right);
+ cnt += set->page->act;
+
+ for( slot = 0; slot++ < set->page->cnt; )
+ if( next || slot < set->page->cnt )
+ if( !slotptr(set->page, slot)->dead ) {
+ ptr = keyptr(set->page, slot);
+ fwrite (ptr->key, ptr->len, 1, stdout);
+ fputc ('\n', stdout);
+ }
+
+ bt_unlockpage (BtLockRead, set->latch);
+ bt_unpinlatch (set->latch);
+ bt_unpinpool (set->pool);
+ } while( page_no = next );
+ cnt--; // remove stopper key
+ fprintf(stderr, " Total keys read %d\n", cnt);
break;
case 'c':
- fprintf(stderr, "started reading\n");
+ fprintf(stderr, "started counting\n");
+ next = bt->mgr->latchmgr->nlatchpage + LATCH_page;
+ page_no = LEAF_page;
- do {
- bt_lockpage (bt, page_no, BtLockRead, &page);
- cnt += page->act;
- next = bt_getid (page->right);
- bt_unlockpage (bt, page_no, BtLockRead);
- } while( page_no = next );
+ while( page_no < bt_getid(bt->mgr->latchmgr->alloc->right) ) {
+ uid off = page_no << bt->mgr->page_bits;
+#ifdef unix
+ pread (bt->mgr->idx, bt->frame, bt->mgr->page_size, off);
+#else
+ DWORD amt[1];
+ SetFilePointer (bt->mgr->idx, (long)off, (long*)(&off)+1, FILE_BEGIN);
+
+ if( !ReadFile(bt->mgr->idx, bt->frame, bt->mgr->page_size, amt, NULL))
+ return bt->err = BTERR_map;
+
+ if( *amt < bt->mgr->page_size )
+ return bt->err = BTERR_map;
+#endif
+ if( !bt->frame->free && !bt->frame->lvl )
+ cnt += bt->frame->act;
+ if( page_no > LEAF_page )
+ next = page_no + 1;
+ page_no = next;
+ }
+
cnt--; // remove stopper key
fprintf(stderr, " Total keys read %d\n", cnt);
break;
{
int idx, cnt, len, slot, err;
int segsize, bits = 16;
+double start, stop;
#ifdef unix
pthread_t *threads;
-timer start, stop;
#else
-time_t start[1], stop[1];
HANDLE *threads;
#endif
-double real_time;
ThreadArg *args;
uint poolsize = 0;
+float elapsed;
int num = 0;
char key[1];
BtMgr *mgr;
fprintf (stderr, " where page_bits is the page size in bits\n");
fprintf (stderr, " mapped_segments is the number of mmap segments in buffer pool\n");
fprintf (stderr, " seg_bits is the size of individual segments in buffer pool in pages in bits\n");
- fprintf (stderr, " line_numbers set to 1 to append line numbers to input lines\n");
+ fprintf (stderr, " line_numbers = 1 to append line numbers to keys\n");
fprintf (stderr, " src_file1 thru src_filen are files of keys separated by newline\n");
exit(0);
}
-#ifdef unix
- gettimeofday(&start, NULL);
-#else
- time(start);
-#endif
+ start = getCpuTime(0);
if( argc > 3 )
bits = atoi(argv[3]);
poolsize = atoi(argv[4]);
if( !poolsize )
- fprintf (stderr, "Warning: mapped_pool has no segments\n");
+ fprintf (stderr, "Warning: no mapped_pool\n");
if( poolsize > 65535 )
fprintf (stderr, "Warning: mapped_pool > 65535 segments\n");
#ifdef unix
for( idx = 0; idx < cnt; idx++ )
pthread_join (threads[idx], NULL);
- gettimeofday(&stop, NULL);
- real_time = 1000.0 * ( stop.tv_sec - start.tv_sec ) + 0.001 * (stop.tv_usec - start.tv_usec );
#else
WaitForMultipleObjects (cnt, threads, TRUE, INFINITE);
for( idx = 0; idx < cnt; idx++ )
CloseHandle(threads[idx]);
- time (stop);
- real_time = 1000 * (*stop - *start);
#endif
- fprintf(stderr, " Time to complete: %.2f seconds\n", real_time/1000);
+ elapsed = getCpuTime(0) - start;
+ fprintf(stderr, " real %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(1);
+ fprintf(stderr, " user %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+ elapsed = getCpuTime(2);
+ fprintf(stderr, " sys %dm%.3fs\n", (int)(elapsed/60), elapsed - (int)(elapsed/60)*60);
+
bt_mgrclose (mgr);
}
projects / btree / blobdiff