> [zm]: Based on the documentation, applications can have multiple connections > to a file database by calling sqlite3_open() repeatedly. Is there a way to > have multiple connections to the ":memory:" database.
No. In-memory databases are special, see http://www.sqlite.org/inmemorydb.html. If you want several connections to the same database that will be completely in-memory you should consider placing your database file into /dev/shm. > [zm]: I did not change sqlite3 sources. libaimdb.so is a library that I > have compiled. This includes my (application) code and links with > libsqlite3.so. Did you compile the whole glibc into your application statically? Or do you have some other completely unrelated function called read()? If the latter then you screwed up your application. Rename your function and I guess everything will work fine. Pavel On Thu, Feb 10, 2011 at 2:22 PM, Zaryab M. Munir <zaryabmu...@yahoo.com> wrote: > Thanks, my reply inline: > Sincerely, > Zaryab > > > --- On Thu, 2/10/11, Pavel Ivanov <paiva...@gmail.com> wrote: > >> From: Pavel Ivanov <paiva...@gmail.com> >> Subject: Re: [sqlite] SIGSEGV Error when using sqlite3_exec( ) >> To: "General Discussion of SQLite Database" <sqlite-users@sqlite.org> >> Cc: "Zaryab Munir (zmunir)" <zmu...@cisco.com> >> Date: Thursday, February 10, 2011, 5:11 AM >> Zaryab, >> >> There's no need to repeat your email several times. >> >> > Question1: Can I have multiple connections >> opened for each thread to >> > the same in-memory dbase. >> >> No. Each connection to ":memory:" creates unique in-memory >> database >> which will be deleted when that connection is closed. > [zm]: Based on the documentation, applications can have multiple connections > to a file database by calling sqlite3_open() repeatedly. Is there a way to > have multiple connections to the ":memory:" database. >> >> > Question2: Why is sqlite3_exec( ) giving >> Segmentation Fault error: >> >> Did you change you SQLite sources? I can't find any >> information on >> what libaimdb.so is and why it is used in your >> environment. > [zm]: I did not change sqlite3 sources. libaimdb.so is a library that I > have compiled. This includes my (application) code and links with > libsqlite3.so. >> >> >> Pavel >> >> On Wed, Feb 9, 2011 at 8:07 PM, Zaryab Munir (zmunir) >> <zmu...@cisco.com> >> wrote: >> > Hi, >> > >> > I am using an in-memory dbase in a multi-threaded >> application and have >> > the following two questions: >> > I create dbase connections by each thread using >> the API: >> > { >> > Sqlite3 *db =3D NULL; >> > Sqlite3_open(":memory:", &db); >> > When I try to use sqlite3_exec( ) I get >> segmentation faults. >> > } >> > Question1: Can I have multiple connections >> opened for each thread >> > to >> > the same in-memory dbase. According to the >> documentation, the >> > sqlite3_open( ) API can be used multiple times to >> open multiple >> > connections to the same database, but its not >> clear is same applies >> > to >> > in-memory databases too. >> > Question2: Why is sqlite3_exec( ) giving >> Segmentation Fault error: >> > segfault at 00002b90153ac905 rip 00002b90153ac905 >> rsp >> > 00007fff95b1d938 >> > error 15 >> > Segmentation fault >> > >> > >> > Below is my code: >> > uint32 aim_sql_open (char *ptr, sqlite3 **db) >> > { >> > >> > int n; >> > n =3D sqlite3_open(ptr,db); >> > >> > if( n !=3D SQLITE_OK ) >> > { >> > /* zz get the wt_id */ >> > printf("Error opening database for >> thread =3D %d.\n",n); >> > return (0); >> > } >> > else { >> > /* zz get the wt_id */ >> > printf("Database open for thread =3D >> %d ok.\n",n); >> > } >> > } >> > NOTE: sqlite3_open( ) returns SQLITE_OK and the >> value of db is >> > updated. >> > >> > uint32 aim_db_init( ) { >> > char dbname[10]; >> > char tbname[13]; >> > char statement[760], *db_err; >> > sqlite3 *db =3D NULL; >> > int n; >> > bzero(dbname,10); >> > bzero(tbname,13); >> > bzero(statement,760); >> > memcpy(dbname,DB_NAME,9); >> > /* no need for dbname for inmemory dbase >> */ >> > n =3D aim_sql_open(":memory:", &db); >> > memcpy(tbname,AIM_TABLE_NAME,12); >> > if(!strcmp(tbname,"")) >> > return(FALSE); >> > sprintf(statement, "CREATE TABLE %s (%s >> INTEGER PRIMARY KEY,%s >> > DATE,%s INTEGER,%s INTEGER,%s INTEGER,%s TEXT,%s >> TEXT,%s TEXT,%s >> > INTEGER,%s INTEGER,%s INTEGER,%s INTEGER,%s >> DATE,%s INTEGER,%s >> > DATE,%s >> > INTEGER,%s DATE,%s INTEGER,%s DATE,%s INTEGER,%s >> INTEGER,%s DATE);", >> > >> > >> tbname,COL1,COL2,COL3,COL4,COL5,COL6,COL7,COL8,COL9,COL10,COL11,COL12,CO >> > >> L13,COL14,COL15,COL16,COL17,COL18,COL19,COL20,COL21,COL22); >> > n =3D sqlite3_exec(db, statement, NULL, 0, >> &db_err); >> > if( n !=3D SQLITE_OK ) >> > { >> > printf("Error executing: >> %s\n",db_err); >> > sqlite3_free(db_err); >> > return (FALSE); >> > } >> > =20 >> > >> > The backtrace from GDB is as follows: >> > Program received signal SIGSEGV, Segmentation >> fault. >> > [Switching to Thread 0x2b7070afe1a0 (LWP 699)] >> > 0x00002b706fcc6905 in read () from >> /usr/lib64/libaimdb.so >> > (gdb) bt >> > #0 0x00002b706fcc6905 in read () from >> /usr/lib64/libaimdb.so >> > #1 0x00002b70703a4120 in unixRandomness >> (NotUsed=3D<value optimized >> > = >> > out>, >> > nBuf=3D<value optimized out>, >> zBuf=3D0x7fff3b203050 "") at >> > ../sqlite3.c:27932 >> > #2 0x00002b707035b0f5 in sqlite3_randomness >> (N=3D4, pBuf=3D<value = >> > optimized >> > out>) >> > at ../sqlite3.c:13876 >> > #3 0x00002b707035b28f in writeJournalHdr >> (pPager=3D0x62b788) >> > at ../sqlite3.c:36096 >> > #4 0x00002b707035b4fb in pager_write >> (pPg=3D0x639e08) at >> > ../sqlite3.c:39815 >> > #5 0x00002b7070366195 in sqlite3PagerWrite >> (pDbPage=3D0x7) at >> > ../sqlite3.c:40151 >> > #6 0x00002b7070368466 in newDatabase >> (pBt=3D0x62b6d8) at >> > ../sqlite3.c:47668 >> > #7 0x00002b707037a18c in sqlite3BtreeBeginTrans >> (p=3D0x62b678, = >> > wrflag=3D1) >> > at ../sqlite3.c:47798 >> > #8 0x00002b707037fa78 in sqlite3Step >> (p=3D0x63a988) at = >> > ../sqlite3.c:63062 >> > #9 0x00002b7070383803 in sqlite3_step >> (pStmt=3D<value optimized >> > out>) >> > at ../sqlite3.c:58768 >> > #10 0x00002b7070386592 in sqlite3_exec >> (db=3D0x62b078, >> > zSql=3D0x7fff3b203b10 "CREATE TABLE >> aim_db_table (hash4ADandDC = >> > INTEGER >> > PRIMARY KEY,entrytime DATE,state INTEGER,bwgain >> INTEGER,cctimestamp >> > INTEGER,foreignkeyAD TEXT,popclass >> TEXT,deviceclass TEXT,vdoBitrate >> > INTEGER,qualityI"..., >> > xCallback=3D0, pArg=3D0x0, >> pzErrMsg=3D0x7fff3b203e38) at >> > ../sqlite3.c:84165 >> > #11 0x00002b706fac52ac in aim_db_init () at >> aim_db_main.c:645 >> > #12 0x000000000040566d in main () >> > >> > >> > Regards, >> > Zaryab >> > >> > >> > _______________________________________________ >> > sqlite-users mailing list >> > sqlite-users@sqlite.org >> > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
