Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Fix a corner case in the opcode-array reuse logic where the number of bytes of reusable space might be computed to be a negative number, due to unusual system alignment restrictions and rounding error. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
1aa530144643582658c8c1dd66548662 |
| User & Date: | drh 2016-01-04 23:43:47 |
Context
|
2016-01-05
| ||
| 01:48 | Permit the 'test_fs' test module to be compiled and used on MinGW. (check-in: ac27f38e user: mistachkin tags: trunk) | |
|
2016-01-04
| ||
| 23:43 | Fix a corner case in the opcode-array reuse logic where the number of bytes of reusable space might be computed to be a negative number, due to unusual system alignment restrictions and rounding error. (check-in: 1aa53014 user: drh tags: trunk) | |
| 13:06 | Fix the conflict2.test module which was broken by check-in [e30062e9f6c]. (check-in: b779ca8a user: drh tags: trunk) | |
Changes
Changes to src/vdbeaux.c.
1844 1844 ** cursor 0 is stored in memory cell nMem. Memory cell (nMem-1) 1845 1845 ** stores the blob of memory associated with cursor 1, etc. 1846 1846 ** 1847 1847 ** See also: allocateCursor(). 1848 1848 */ 1849 1849 nMem += nCursor; 1850 1850 1851 - /* Allocate space for memory registers, SQL variables, VDBE cursors and 1852 - ** an array to marshal SQL function arguments in. 1851 + /* zCsr will initially point to nFree bytes of unused space at the 1852 + ** end of the opcode array, p->aOp. The computation of nFree is 1853 + ** conservative - it might be smaller than the true number of free 1854 + ** bytes, but never larger. nFree might be negative. But the allocation 1855 + ** loop will still function correctly. 1853 1856 */ 1854 1857 zCsr = ((u8*)p->aOp) + ROUND8(sizeof(Op)*p->nOp); /* Available space */ 1855 1858 nFree = pParse->szOpAlloc - ROUND8(sizeof(Op)*p->nOp); /* Size of zCsr */ 1859 + if( nFree>0 ) memset(zCsr, 0, nFree); 1856 1860 1857 1861 resolveP2Values(p, &nArg); 1858 1862 p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort); 1859 1863 if( pParse->explain && nMem<10 ){ 1860 1864 nMem = 10; 1861 1865 } 1862 - memset(zCsr, 0, nFree); 1863 1866 assert( EIGHT_BYTE_ALIGNMENT(&zCsr[nFree]) ); 1864 1867 p->expired = 0; 1865 1868 1866 1869 /* Memory for registers, parameters, cursor, etc, is allocated in two 1867 1870 ** passes. On the first pass, we try to reuse unused space at the 1868 1871 ** end of the opcode array. If we are unable to satisfy all memory 1869 1872 ** requirements by reusing the opcode array tail, then the second