test/tt3_lookaside1.c

   1 /*
   2 ** 2014 December 9
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 *************************************************************************
  12 **
  13 **     lookaside1
  14 */
  15
  16 /*
  17 ** The test in this file attempts to expose a specific race condition
  18 ** that is suspected to exist at time of writing.
  19 */
  20
  21 static char *lookaside1_thread_reader(int iTid, void *pArg){
  22   Error err = {0};                /* Error code and message */
  23   Sqlite db = {0};                /* SQLite database connection */
  24
  25   opendb(&err, &db, "test.db", 0);
  26
  27   while( !timetostop(&err) ){
  28     sqlite3_stmt *pStmt = 0;
  29     int rc;
  30
  31     sqlite3_prepare_v2(db.db, "SELECT 1 FROM t1", -1, &pStmt, 0);
  32     while( sqlite3_step(pStmt)==SQLITE_ROW ){
  33       execsql(&err, &db, "SELECT length(x||y||z) FROM t2");
  34     }
  35     rc = sqlite3_finalize(pStmt);
  36     if( err.rc==SQLITE_OK && rc!=SQLITE_OK ){
  37       sqlite_error(&err, &db, "finalize");
  38     }
  39   }
  40
  41   closedb(&err, &db);
  42   print_and_free_err(&err);
  43   return sqlite3_mprintf("ok");
  44 }
  45
  46 static char *lookaside1_thread_writer(int iTid, void *pArg){
  47   Error err = {0};                /* Error code and message */
  48   Sqlite db = {0};                /* SQLite database connection */
  49
  50   opendb(&err, &db, "test.db", 0);
  51
  52   do{
  53     sql_script(&err, &db,
  54       "BEGIN;"
  55         "UPDATE t3 SET i=i+1 WHERE x=1;"
  56       "ROLLBACK;"
  57     );
  58   }while( !timetostop(&err) );
  59
  60   closedb(&err, &db);
  61   print_and_free_err(&err);
  62   return sqlite3_mprintf("ok");
  63 }
  64
  65
  66 static void lookaside1(int nMs){
  67   Error err = {0};
  68   Sqlite db = {0};
  69   Threadset threads = {0};
  70
  71   opendb(&err, &db, "test.db", 1);
  72   sql_script(&err, &db,
  73      "CREATE TABLE t1(x PRIMARY KEY) WITHOUT ROWID;"
  74      "WITH data(x,y) AS ("
  75      "  SELECT 1, quote(randomblob(750)) UNION ALL "
  76      "  SELECT x*2, y||y FROM data WHERE x<5) "
  77      "INSERT INTO t1 SELECT y FROM data;"
  78
  79      "CREATE TABLE t3(x PRIMARY KEY,i) WITHOUT ROWID;"
  80      "INSERT INTO t3 VALUES(1, 1);"
  81
  82      "CREATE TABLE t2(x,y,z);"
  83      "INSERT INTO t2 VALUES(randomblob(50), randomblob(50), randomblob(50));"
  84   );
  85   closedb(&err, &db);
  86
  87   setstoptime(&err, nMs);
  88
  89   sqlite3_enable_shared_cache(1);
  90   launch_thread(&err, &threads, lookaside1_thread_reader, 0);
  91   launch_thread(&err, &threads, lookaside1_thread_reader, 0);
  92   launch_thread(&err, &threads, lookaside1_thread_reader, 0);
  93   launch_thread(&err, &threads, lookaside1_thread_reader, 0);
  94   launch_thread(&err, &threads, lookaside1_thread_reader, 0);
  95   launch_thread(&err, &threads, lookaside1_thread_writer, 0);
  96   join_all_threads(&err, &threads);
  97   sqlite3_enable_shared_cache(0);
  98   print_and_free_err(&err);
  99 }