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Overview
| Comment: | Add code to this branch to emit a log message after each cumulative second that the WRITER lock has been held. |
|---|---|
| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | server-edition |
| Files: | files | file ages | folders |
| SHA3-256: |
a726d98122704e1e702cfa7ae61d6804 |
| User & Date: | dan 2017-05-22 08:01:58.394 |
Context
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2017-06-07
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| 15:55 | Add too/tserver.c - the implementation of a simple multi-threaded server designed for interactive testing of concurrency between connections used by different threads of the same process. (check-in: 05b4fc4340 user: dan tags: server-edition) | |
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2017-05-22
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| 08:01 | Add code to this branch to emit a log message after each cumulative second that the WRITER lock has been held. (check-in: a726d98122 user: dan tags: server-edition) | |
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2017-05-15
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| 19:32 | Avoid writer starvation by adding a RESERVED state to page locks. (check-in: 9b7f80246f user: dan tags: server-edition) | |
Changes
Changes to src/pager.c.
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7546 7547 7548 7549 7550 7551 7552 7553 7554 7555 7556 7557 7558 7559 7560 | 7546 7547 7548 7549 7550 7551 7552 7553 7554 7555 7556 7557 7558 7559 7560 7561 7562 | + + |
/* Close any rollback journal previously open */
sqlite3OsClose(pPager->jfd);
rc = pagerOpenWal(pPager);
if( rc==SQLITE_OK ){
pPager->journalMode = PAGER_JOURNALMODE_WAL;
pPager->eState = PAGER_OPEN;
#ifdef SQLITE_SERVER_EDITION
sqlite3WalServer(pPager->pWal, pPager->pServer);
#endif
}
}else{
*pbOpen = 1;
}
return rc;
}
|
| ︙ |
Changes to src/server.c.
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89 90 91 92 93 94 95 | 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 | - + + |
ino_t st_ino;
};
struct Server {
ServerHMA *pHma; /* Hma file object */
int iClient; /* Client id */
Pager *pPager; /* Associated pager object */
|
| ︙ | |||
450 451 452 453 454 455 456 457 458 459 460 461 462 463 | 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 | + + + + + + + + + + + + |
u32 n = v;
if( (v>>HMA_CLIENT_SLOTS)==p->iClient+1 ){
n = n & ((1 << HMA_CLIENT_SLOTS)-1);
}
n = n & ~(1 << p->iClient);
if( __sync_val_compare_and_swap(pSlot, v, n)==v ) break;
}
if( p->aLock[i]==0 ){
struct timeval t2;
i64 nUs;
gettimeofday(&t2, 0);
nUs = (i64)t2.tv_sec * 1000000 + t2.tv_usec - p->iUsWrite;
p->nUsWrite += nUs;
if( (p->nUsWrite / 1000000)!=((p->nUsWrite + nUs)/1000000) ){
sqlite3_log(SQLITE_WARNING,
"Cumulative WRITER time: %lldms\n", p->nUsWrite/1000
);
}
}
}
p->nLock = 0;
#if 1
return posixLock(p->pHma->fd, p->iClient+1, SERVER_READ_LOCK, 0);
#endif
return SQLITE_OK;
}
|
| ︙ | |||
564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 | 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 | + + + + + |
do{
v = *pSlot;
assert( serverWriteLocker(v)==p->iClient );
n = v & ((1<<HMA_CLIENT_SLOTS)-1);
}while( __sync_val_compare_and_swap(pSlot, v, n)!=v );
}
if( pgno==0 ){
struct timeval t1;
gettimeofday(&t1, 0);
p->iUsWrite = ((i64)t1.tv_sec * 1000000) + (i64)t1.tv_usec;
}
assert( rc!=SQLITE_OK || sqlite3ServerHasLock(p, pgno, bWrite) );
return rc;
}
int sqlite3ServerHasLock(Server *p, Pgno pgno, int bWrite){
u32 v = *serverPageLockSlot(p, pgno);
if( bWrite ){
return (v>>HMA_CLIENT_SLOTS)==(p->iClient+1);
}
return (v & (1 << p->iClient))!=0;
}
#endif /* ifdef SQLITE_SERVER_EDITION */
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