Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Drop the mutex on the multiplexor before entering the xRead VFS call. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | multiplex-parallel-read |
Files: | files | file ages | folders |
SHA1: |
a00d2ed49c9f53263cd76ad41dad9e35 |
User & Date: | drh 2013-10-21 13:15:55.814 |
Context
2013-11-08
| ||
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) | |
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) | |
2013-10-19
| ||
16:51 | Improved header comment with better instructions on the vfslog.c extension. (check-in: 4bd592c8f0 user: drh tags: trunk) | |
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. */ |
︙ | ︙ |