Re: [sqlite] SQLite BUSY error - single-threaded app
The application runs as a singleton; there are no other applications
accessing the data base.
I do not run the command-line tool while testing.
I've cut down the example code:
SqlStatus = sqlite3_open16 ( db_loc_string
, &SqlDB
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return DATASTORE_UNAVAILABLE ;
}
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"BEGIN TRANSACTION"
, 36
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return TXN_BEGIN_FAILED ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_FNLZ_ERROR ;
}
swprintf_s ( (PXID_CHAR)sql_statement
, sizeof ( sql_statement ) / sizeof ( XID_CHAR )
, L"DELETE"
L" FROM RSPNS"
L" WHERE . . .
) ;
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, sql_statement
, ( lstrlen ( sql_statement ) + 1 ) *
sizeof ( XID_CHAR )
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return SQL_DLET_ERROR ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_FNLZ_ERROR ;
}
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"COMMIT TRANSACTION"
, 38
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return TXN_COMMIT_FAILED ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_FNLZ_ERROR ;
}
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"BEGIN TRANSACTION"
, 36
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_PREP_ERROR ;
}
/*-*/
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return TXN_BEGIN_FAILED ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return SQL_FNLZ_ERROR ;
}
. . .
swprintf_s ( (PXID_CHAR)sql_statement
, sizeof ( sql_statement ) / sizeof ( XID_CHAR )
, L"INSERT"
L" INTO RSPNS"
L" ( SERVER_NAME"
. . .
L" , RESPONSE_TEXT"
L" )"
L" VALUES ( '%s'"
. , ,
L" , '%s'"
L" )"
, ServerName
. . .
, &InputBuffer[m]
) ;
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, (const char *)sql_statement
, ( lstrlen ( sql_statement ) + 1 ) *
sizeof ( XID_CHAR )
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( sql_statement
, L"sqlite3_prepare16_v2 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return SQL_ISRT_ERROR ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return XID_DBPA_SQL_FNLZ_ERROR ;
}
. . .
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"COMMIT TRANSACTION"
, 38
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
. . .
return XID_DBPA_SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
. . .
return XID_DBPA
[sqlite] SQLite BUSY error - single-threaded app
I'm currently working with version 3.6.14 on Windows XP/SP4 (32-bit). The
application is coded for Unicode.
I wrote all of the application (MS C++ native code) excluding SQLite, so I'm
confident that it is a single-threaded app. Threads have never been part of
its design.
The failure occurs in a common service routine called perhaps 300 times
before this error is reported.
The failure occurs every time I run the program and always occurs in the
same place.
While executing the following set BEGIN/DELETE/COMMIT/BEGIN/INSERT/COMMIT
commands approximately once per second, SQLite is returning 0x05 (BUSY) on
the first COMMIT in the second iteration of the loop. A journal file does
exist when the BUSY condition is returned.
Because this is a single-threaded app, waiting for the lock to clear doesn't
work.
In the following source code, "SQLiteError ( )" is a common services routine
that provides a message box and logging in the event of an error.
Source code:
SqlDB = NULL ;
SqlStmt = NULL ;
SqlStatus = sqlite3_open16 ( db_loc_string
, &SqlDB
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( NULL
, L"sqlite3_open16 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return DATASTORE_UNAVAILABLE ;
}
SqlStatus = sqlite3_open16 ( SqlDB
, L"BEGIN TRANSACTION"
, 36
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( L"BEGIN TRANSACTION 1"
, L"sqlite3_prepare16_V2 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"BEGIN TRANSACTION"
, 36
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( L"BEGIN TRANSACTION 1"
, L"sqlite3_prepare16_V2 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
SQLiteError ( L"BEGIN TRANSACTION 1"
, L"sqlite3_step ( )"
) ;
sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
sqlite3_close( SqlDB ) ; SqlDB = NULL ;
return TXN_BEGIN_FAILED ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( L"BEGIN TRANSACTION 1"
, L"sqlite3_finalize ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_FNLZ_ERROR ;
}
swprintf_s ( (PXID_CHAR)sql_statement
, sizeof ( sql_statement ) / sizeof ( XID_CHAR )
, L"DELETE"
L" FROM RSPNS"
L" WHERE . . .
) ;
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, sql_statement
, ( lstrlen ( sql_statement ) + 1 ) *
sizeof ( XID_CHAR )
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( sql_statement
, L"sqlite3_prepare16_v2 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_PREP_ERROR ; // IMPLICIT DATA BASE ROLLBACK
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
SQLiteError ( sql_statement
, L"sqlite3_step ( )"
) ;
sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
sqlite3_close( SqlDB ) ; SqlDB = NULL ;
return SQL_DLET_ERROR ;
}
SqlStatus = sqlite3_finalize ( SqlStmt ) ; SqlStmt = NULL ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( sql_statement
, L"sqlite3_finalize ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_FNLZ_ERROR ;
}
SqlStatus = sqlite3_prepare16_v2 ( SqlDB
, L"COMMIT TRANSACTION"
, 38
, &SqlStmt
, NULL
) ;
if ( SQLITE_OK != SqlStatus )
{
SQLiteError ( L"COMMIT TRANSACTION 1"
, L"sqlite3_prepare16_V2 ( )"
) ;
sqlite3_close ( SqlDB ) ; SqlDB = NULL ;
return SQL_PREP_ERROR ;
}
SqlStatus = sqlite3_step ( SqlStmt ) ;
if ( SQLITE_DONE != SqlStatus )
{
SQLiteError (
