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 = 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 = sqlite3_open(ptr,db);
if( n != SQLITE_OK )
{
/* zz get the wt_id */
printf("Error opening database for thread = %d.\n",n);
return (0);
}
else {
/* zz get the wt_id */
printf("Database open for thread = %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 = 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 = 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 = sqlite3_exec(db, statement, NULL, 0, &db_err);
if( n != SQLITE_OK )
{
printf("Error executing: %s\n",db_err);
sqlite3_free(db_err);
return (FALSE);
}
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=<value optimized out>,
nBuf=<value optimized out>, zBuf=0x7fff3b203050 "") at
../sqlite3.c:27932
#2 0x00002b707035b0f5 in sqlite3_randomness (N=4, pBuf=<value optimized
out>)
at ../sqlite3.c:13876
#3 0x00002b707035b28f in writeJournalHdr (pPager=0x62b788)
at ../sqlite3.c:36096
#4 0x00002b707035b4fb in pager_write (pPg=0x639e08) at
../sqlite3.c:39815
#5 0x00002b7070366195 in sqlite3PagerWrite (pDbPage=0x7) at
../sqlite3.c:40151
#6 0x00002b7070368466 in newDatabase (pBt=0x62b6d8) at
../sqlite3.c:47668
#7 0x00002b707037a18c in sqlite3BtreeBeginTrans (p=0x62b678, wrflag=1)
at ../sqlite3.c:47798
#8 0x00002b707037fa78 in sqlite3Step (p=0x63a988) at ../sqlite3.c:63062
#9 0x00002b7070383803 in sqlite3_step (pStmt=<value optimized out>)
at ../sqlite3.c:58768
#10 0x00002b7070386592 in sqlite3_exec (db=0x62b078,
zSql=0x7fff3b203b10 "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=0, pArg=0x0, pzErrMsg=0x7fff3b203e38) at
../sqlite3.c:84165
#11 0x00002b706fac52ac in aim_db_init () at aim_db_main.c:645
#12 0x000000000040566d in main ()
Regards,
Zaryab
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