| /* |
| ** 2014 December 9 |
| ** |
| ** The author disclaims copyright to this source code. In place of |
| ** a legal notice, here is a blessing: |
| ** |
| ** May you do good and not evil. |
| ** May you find forgiveness for yourself and forgive others. |
| ** May you share freely, never taking more than you give. |
| ** |
| ************************************************************************* |
| ** |
| ** lookaside1 |
| */ |
| |
| /* |
| ** The test in this file attempts to expose a specific race condition |
| ** that is suspected to exist at time of writing. |
| */ |
| |
| static char *lookaside1_thread_reader(int iTid, void *pArg){ |
| Error err = {0}; /* Error code and message */ |
| Sqlite db = {0}; /* SQLite database connection */ |
| |
| opendb(&err, &db, "test.db", 0); |
| |
| while( !timetostop(&err) ){ |
| sqlite3_stmt *pStmt = 0; |
| int rc; |
| |
| sqlite3_prepare_v2(db.db, "SELECT 1 FROM t1", -1, &pStmt, 0); |
| while( sqlite3_step(pStmt)==SQLITE_ROW ){ |
| execsql(&err, &db, "SELECT length(x||y||z) FROM t2"); |
| } |
| rc = sqlite3_finalize(pStmt); |
| if( err.rc==SQLITE_OK && rc!=SQLITE_OK ){ |
| sqlite_error(&err, &db, "finalize"); |
| } |
| } |
| |
| closedb(&err, &db); |
| print_and_free_err(&err); |
| return sqlite3_mprintf("ok"); |
| } |
| |
| static char *lookaside1_thread_writer(int iTid, void *pArg){ |
| Error err = {0}; /* Error code and message */ |
| Sqlite db = {0}; /* SQLite database connection */ |
| |
| opendb(&err, &db, "test.db", 0); |
| |
| do{ |
| sql_script(&err, &db, |
| "BEGIN;" |
| "UPDATE t3 SET i=i+1 WHERE x=1;" |
| "ROLLBACK;" |
| ); |
| }while( !timetostop(&err) ); |
| |
| closedb(&err, &db); |
| print_and_free_err(&err); |
| return sqlite3_mprintf("ok"); |
| } |
| |
| |
| static void lookaside1(int nMs){ |
| Error err = {0}; |
| Sqlite db = {0}; |
| Threadset threads = {0}; |
| |
| opendb(&err, &db, "test.db", 1); |
| sql_script(&err, &db, |
| "CREATE TABLE t1(x PRIMARY KEY) WITHOUT ROWID;" |
| "WITH data(x,y) AS (" |
| " SELECT 1, quote(randomblob(750)) UNION ALL " |
| " SELECT x*2, y||y FROM data WHERE x<5) " |
| "INSERT INTO t1 SELECT y FROM data;" |
| |
| "CREATE TABLE t3(x PRIMARY KEY,i) WITHOUT ROWID;" |
| "INSERT INTO t3 VALUES(1, 1);" |
| |
| "CREATE TABLE t2(x,y,z);" |
| "INSERT INTO t2 VALUES(randomblob(50), randomblob(50), randomblob(50));" |
| ); |
| closedb(&err, &db); |
| |
| setstoptime(&err, nMs); |
| |
| sqlite3_enable_shared_cache(1); |
| launch_thread(&err, &threads, lookaside1_thread_reader, 0); |
| launch_thread(&err, &threads, lookaside1_thread_reader, 0); |
| launch_thread(&err, &threads, lookaside1_thread_reader, 0); |
| launch_thread(&err, &threads, lookaside1_thread_reader, 0); |
| launch_thread(&err, &threads, lookaside1_thread_reader, 0); |
| launch_thread(&err, &threads, lookaside1_thread_writer, 0); |
| join_all_threads(&err, &threads); |
| sqlite3_enable_shared_cache(0); |
| print_and_free_err(&err); |
| } |