Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Merge change to drop the mutex on the multiplexor before entering the xRead VFS call, in order to enhance parallelizability. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
3c566e41e4c9c66960cc5a3ddee85568 |
User & Date: | drh 2013-11-08 12:14:50.705 |
Context
2013-11-08
| ||
15:19 | Performance improvements: Avoid unnecessary seeks when doing a single-row UPDATE on a WITHOUT ROWID table. (check-in: 6f187a0fb1 user: drh tags: trunk) | |
12:14 | Merge change to drop the mutex on the multiplexor before entering the xRead VFS call, in order to enhance parallelizability. (check-in: 3c566e41e4 user: drh tags: trunk) | |
01:09 | Optimize out a NotExists/NotFound opcode that occurs in UPDATE processing after constraint checks if there is no possiblity that the constraint checking code might have moved the cursor. (check-in: 74e3ee2ee6 user: drh tags: trunk) | |
2013-10-21
| ||
13:15 | Drop the mutex on the multiplexor before entering the xRead VFS call. (Closed-Leaf check-in: a00d2ed49c user: drh tags: multiplex-parallel-read) | |
Changes
Changes to src/test_multiplex.c.
︙ | ︙ | |||
751 752 753 754 755 756 757 | void *pBuf, int iAmt, sqlite3_int64 iOfst ){ multiplexConn *p = (multiplexConn*)pConn; multiplexGroup *pGroup = p->pGroup; int rc = SQLITE_OK; | > | > > > > | | 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 | void *pBuf, int iAmt, sqlite3_int64 iOfst ){ multiplexConn *p = (multiplexConn*)pConn; multiplexGroup *pGroup = p->pGroup; int rc = SQLITE_OK; int nMutex = 0; multiplexEnter(); nMutex++; if( !pGroup->bEnabled ){ sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0); multiplexLeave(); nMutex--; if( pSubOpen==0 ){ rc = SQLITE_IOERR_READ; }else{ rc = pSubOpen->pMethods->xRead(pSubOpen, pBuf, iAmt, iOfst); } }else{ while( iAmt > 0 ){ int i = (int)(iOfst / pGroup->szChunk); if( nMutex==0 ){ multiplexEnter(); nMutex++; } sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, i, &rc, NULL, 1); multiplexLeave(); nMutex--; if( pSubOpen ){ int extra = ((int)(iOfst % pGroup->szChunk) + iAmt) - pGroup->szChunk; if( extra<0 ) extra = 0; iAmt -= extra; rc = pSubOpen->pMethods->xRead(pSubOpen, pBuf, iAmt, iOfst % pGroup->szChunk); if( rc!=SQLITE_OK ) break; pBuf = (char *)pBuf + iAmt; iOfst += iAmt; iAmt = extra; }else{ rc = SQLITE_IOERR_READ; break; } } } assert( nMutex==0 || nMutex==1 ); if( nMutex ) multiplexLeave(); return rc; } /* Pass xWrite requests thru to the original VFS after ** determining the correct chunk to operate on. ** Break up writes across chunk boundaries. */ |
︙ | ︙ |