| /* |
| ** 2001 September 15 |
| ** |
| ** 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. |
| ** |
| ************************************************************************* |
| ** This file is part of the test program "threadtest3". Despite being a C |
| ** file it is not compiled separately, but included by threadtest3.c using |
| ** the #include directive normally used with header files. |
| ** |
| ** This file contains the implementation of test cases: |
| ** |
| ** checkpoint_starvation_1 |
| ** checkpoint_starvation_2 |
| */ |
| |
| /* |
| ** Both test cases involve 1 writer/checkpointer thread and N reader threads. |
| ** |
| ** Each reader thread performs a series of read transactions, one after |
| ** another. Each read transaction lasts for 100 ms. |
| ** |
| ** The writer writes transactions as fast as possible. It uses a callback |
| ** registered with sqlite3_wal_hook() to try to keep the WAL-size limited to |
| ** around 50 pages. |
| ** |
| ** In test case checkpoint_starvation_1, the auto-checkpoint uses |
| ** SQLITE_CHECKPOINT_PASSIVE. In checkpoint_starvation_2, it uses RESTART. |
| ** The expectation is that in the first case the WAL file will grow very |
| ** large, and in the second will be limited to the 50 pages or thereabouts. |
| ** However, the overall transaction throughput will be lower for |
| ** checkpoint_starvation_2, as every checkpoint will block for up to 200 ms |
| ** waiting for readers to clear. |
| */ |
| |
| /* Frame limit used by the WAL hook for these tests. */ |
| #define CHECKPOINT_STARVATION_FRAMELIMIT 50 |
| |
| /* Duration in ms of each read transaction */ |
| #define CHECKPOINT_STARVATION_READMS 100 |
| |
| struct CheckpointStarvationCtx { |
| int eMode; |
| int nMaxFrame; |
| }; |
| typedef struct CheckpointStarvationCtx CheckpointStarvationCtx; |
| |
| static int checkpoint_starvation_walhook( |
| void *pCtx, |
| sqlite3 *db, |
| const char *zDb, |
| int nFrame |
| ){ |
| CheckpointStarvationCtx *p = (CheckpointStarvationCtx *)pCtx; |
| if( nFrame>p->nMaxFrame ){ |
| p->nMaxFrame = nFrame; |
| } |
| if( nFrame>=CHECKPOINT_STARVATION_FRAMELIMIT ){ |
| sqlite3_wal_checkpoint_v2(db, zDb, p->eMode, 0, 0); |
| } |
| return SQLITE_OK; |
| } |
| |
| static char *checkpoint_starvation_reader(int iTid, int iArg){ |
| Error err = {0}; |
| Sqlite db = {0}; |
| |
| opendb(&err, &db, "test.db", 0); |
| while( !timetostop(&err) ){ |
| i64 iCount1, iCount2; |
| sql_script(&err, &db, "BEGIN"); |
| iCount1 = execsql_i64(&err, &db, "SELECT count(x) FROM t1"); |
| usleep(CHECKPOINT_STARVATION_READMS*1000); |
| iCount2 = execsql_i64(&err, &db, "SELECT count(x) FROM t1"); |
| sql_script(&err, &db, "COMMIT"); |
| |
| if( iCount1!=iCount2 ){ |
| test_error(&err, "Isolation failure - %lld %lld", iCount1, iCount2); |
| } |
| } |
| closedb(&err, &db); |
| |
| print_and_free_err(&err); |
| return 0; |
| } |
| |
| static void checkpoint_starvation_main(int nMs, CheckpointStarvationCtx *p){ |
| Error err = {0}; |
| Sqlite db = {0}; |
| Threadset threads = {0}; |
| int nInsert = 0; |
| int i; |
| |
| opendb(&err, &db, "test.db", 1); |
| sql_script(&err, &db, |
| "PRAGMA page_size = 1024;" |
| "PRAGMA journal_mode = WAL;" |
| "CREATE TABLE t1(x);" |
| ); |
| |
| setstoptime(&err, nMs); |
| |
| for(i=0; i<4; i++){ |
| launch_thread(&err, &threads, checkpoint_starvation_reader, 0); |
| usleep(CHECKPOINT_STARVATION_READMS*1000/4); |
| } |
| |
| sqlite3_wal_hook(db.db, checkpoint_starvation_walhook, (void *)p); |
| while( !timetostop(&err) ){ |
| sql_script(&err, &db, "INSERT INTO t1 VALUES(randomblob(1200))"); |
| nInsert++; |
| } |
| |
| printf(" Checkpoint mode : %s\n", |
| p->eMode==SQLITE_CHECKPOINT_PASSIVE ? "PASSIVE" : "RESTART" |
| ); |
| printf(" Peak WAL : %d frames\n", p->nMaxFrame); |
| printf(" Transaction count: %d transactions\n", nInsert); |
| |
| join_all_threads(&err, &threads); |
| closedb(&err, &db); |
| print_and_free_err(&err); |
| } |
| |
| static void checkpoint_starvation_1(int nMs){ |
| Error err = {0}; |
| CheckpointStarvationCtx ctx = { SQLITE_CHECKPOINT_PASSIVE, 0 }; |
| checkpoint_starvation_main(nMs, &ctx); |
| if( ctx.nMaxFrame<(CHECKPOINT_STARVATION_FRAMELIMIT*10) ){ |
| test_error(&err, "WAL failed to grow - %d frames", ctx.nMaxFrame); |
| } |
| print_and_free_err(&err); |
| } |
| |
| static void checkpoint_starvation_2(int nMs){ |
| Error err = {0}; |
| CheckpointStarvationCtx ctx = { SQLITE_CHECKPOINT_RESTART, 0 }; |
| checkpoint_starvation_main(nMs, &ctx); |
| if( ctx.nMaxFrame>CHECKPOINT_STARVATION_FRAMELIMIT+10 ){ |
| test_error(&err, "WAL grew too large - %d frames", ctx.nMaxFrame); |
| } |
| print_and_free_err(&err); |
| } |
| |
| |