/* Functions to execute SQL */
#define sql_script(x,y,z)       (SEL(x), sql_script_x(x,y,z))
#define integrity_check(x,y)    (SEL(x), integrity_check_x(x,y))
#define execsql_i64(x,y,...)    (SEL(x), execsql_i64_x(x,y,__VA_ARGS__))
#define execsql_text(x,y,z,...) (SEL(x), execsql_text_x(x,y,z,__VA_ARGS__))
#define execsql(x,y,...)        (SEL(x), (void)execsql_i64_x(x,y,__VA_ARGS__))




/* Thread functions */
#define launch_thread(w,x,y,z)  (SEL(w), launch_thread_x(w,x,y,z))
#define join_all_threads(y,z)   (SEL(y), join_all_threads_x(y,z))

/* Timer functions */
#define setstoptime(y,z)        (SEL(y), setstoptime_x(y,z))
#define timetostop(z)           (SEL(z), timetostop_x(z))

/* Report/clear errors. */
#define test_error(z, ...)      test_error_x(z, sqlite3_mprintf(__VA_ARGS__))
#define clear_error(y,z)        clear_error_x(y, z)

/* File-system operations */
#define filesize(y,z)           (SEL(y), filesize_x(y,z))
#define filecopy(x,y,z)         (SEL(x), filecopy_x(x,y,z))




/*
** End of test code/infrastructure interface macros.
*************************************************************************/




................................................................................
  /* Append length in bits and transform */
  ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
  ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

  MD5Transform(ctx->buf, (uint32 *)ctx->in);
  byteReverse((unsigned char *)ctx->buf, 4);
  memcpy(digest, ctx->buf, 16);
  memset(ctx, 0, sizeof(ctx));    /* In case it is sensitive */
}

/*
** Convert a 128-bit MD5 digest into a 32-digit base-16 number.
*/
static void MD5DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
................................................................................

typedef struct Threadset Threadset;
typedef struct Thread Thread;

/* Total number of errors in this process so far. */
static int nGlobalErr = 0;

/* Set to true to run in "process" instead of "thread" mode. */
static int bProcessMode = 0;

struct Error {
  int rc;
  int iLine;
  char *zErr;
};

struct Sqlite {
................................................................................
struct Statement {
  sqlite3_stmt *pStmt;            /* Pre-compiled statement handle */
  Statement *pNext;               /* Next statement in linked-list */
};

struct Thread {
  int iTid;                       /* Thread number within test */
  int iArg;                       /* Integer argument passed by caller */

  pthread_t tid;                  /* Thread id */
  char *(*xProc)(int, int);       /* Thread main proc */
  Thread *pNext;                  /* Next in this list of threads */
};

struct Threadset {
  int iMaxTid;                    /* Largest iTid value allocated so far */
  Thread *pThread;                /* Linked list of threads */
};
................................................................................
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* OUT: Database handle */
  const char *zFile,              /* Database file name */
  int bDelete                     /* True to delete db file before opening */
){
  if( pErr->rc==SQLITE_OK ){
    int rc;

    if( bDelete ) unlink(zFile);
    rc = sqlite3_open(zFile, &pDb->db);
    if( rc ){
      sqlite_error(pErr, pDb, "open");
      sqlite3_close(pDb->db);
      pDb->db = 0;
    }else{
      sqlite3_create_function(
          pDb->db, "md5sum", -1, SQLITE_UTF8, 0, 0, md5step, md5finalize
................................................................................
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL script to execute */
){
  if( pErr->rc==SQLITE_OK ){
    pErr->rc = sqlite3_exec(pDb->db, zSql, 0, 0, &pErr->zErr);
  }
}

















static Statement *getSqlStatement(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL statement */
){
  Statement *pRet;
................................................................................
  Sqlite *pDb,                    /* Database handle */
  ...                             /* SQL and pointers to parameter values */
){
  i64 iRet = 0;
  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */
    int i;                        /* Used to iterate through parameters */
    va_start(ap, pDb);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){
      int rc;
      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          iRet = sqlite3_column_int64(pStmt, 0);
        }
        first = 0;
      }
................................................................................
    memset(&pDb->aText[pDb->nText], 0, sizeof(char*)*(iSlot+1-pDb->nText));
    pDb->nText = iSlot+1;
  }

  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */
    int i;                        /* Used to iterate through parameters */
    va_start(ap, iSlot);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){
      int rc;
      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          zRet = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
          sqlite3_free(pDb->aText[iSlot]);
          pDb->aText[iSlot] = zRet;
        }
................................................................................

static void integrity_check_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb                     /* Database handle */
){
  if( pErr->rc==SQLITE_OK ){
    Statement *pStatement;        /* Statement to execute */
    int rc;                       /* Return code */
    char *zErr = 0;               /* Integrity check error */

    pStatement = getSqlStatement(pErr, pDb, "PRAGMA integrity_check");
    if( pStatement ){
      sqlite3_stmt *pStmt = pStatement->pStmt;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        const char *z = sqlite3_column_text(pStmt, 0);
        if( strcmp(z, "ok") ){
          if( zErr==0 ){
            zErr = sqlite3_mprintf("%s", z);
          }else{
            zErr = sqlite3_mprintf("%z\n%s", zErr, z);
          }
        }
................................................................................
      }
    }
  }
}

static void *launch_thread_main(void *pArg){
  Thread *p = (Thread *)pArg;
  return (void *)p->xProc(p->iTid, p->iArg);
}

static void launch_thread_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Threadset *pThreads,            /* Thread set */
  char *(*xProc)(int, int),       /* Proc to run */
  int iArg                        /* Argument passed to thread proc */
){
  if( pErr->rc==SQLITE_OK ){
    int iTid = ++pThreads->iMaxTid;
    Thread *p;
    int rc;

    p = (Thread *)sqlite3_malloc(sizeof(Thread));
    memset(p, 0, sizeof(Thread));
    p->iTid = iTid;
    p->iArg = iArg;
    p->xProc = xProc;

    rc = pthread_create(&p->tid, NULL, launch_thread_main, (void *)p);
    if( rc!=0 ){
      system_error(pErr, rc);
      sqlite3_free(p);
    }else{
................................................................................
**************************************************************************
** End infrastructure. Begin tests.
*/

#define WALTHREAD1_NTHREAD  10
#define WALTHREAD3_NTHREAD  6

static char *walthread1_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nIter = 0;                  /* Iterations so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    const char *azSql[] = {
................................................................................
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return sqlite3_mprintf("%d iterations", nIter);
}

static char *walthread1_ckpt_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nCkpt = 0;                  /* Checkpoints so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    usleep(500*1000);
................................................................................
  }
  launch_thread(&err, &threads, walthread1_ckpt_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread2_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int anTrans[2] = {0, 0};        /* Number of WAL and Rollback transactions */


  const char *zJournal = "PRAGMA journal_mode = WAL";
  if( iArg ){ zJournal = "PRAGMA journal_mode = DELETE"; }

  while( !timetostop(&err) ){
    int journal_exists = 0;
    int wal_exists = 0;
................................................................................
  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, "CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE)");
  closedb(&err, &db);

  setstoptime(&err, nMs);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, 1);
  launch_thread(&err, &threads, walthread2_thread, 1);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread3_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iNextWrite;                 /* Next value this thread will write */


  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 10");

  iNextWrite = iArg+1;
  while( 1 ){
    i64 sum1;
................................................................................
      "CREATE INDEX i2 ON t1(sum2);"
      "INSERT INTO t1 VALUES(0, 0, 0);"
  );
  closedb(&err, &db);

  setstoptime(&err, nMs);
  for(i=0; i<WALTHREAD3_NTHREAD; i++){
    launch_thread(&err, &threads, walthread3_thread, i);
  }
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread4_reader_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    integrity_check(&err, &db);
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return 0;
}

static char *walthread4_writer_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iRow = 1;

  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 15;");
  while( !timetostop(&err) ){
................................................................................
  launch_thread(&err, &threads, walthread4_reader_thread, 0);
  launch_thread(&err, &threads, walthread4_writer_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread5_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 nRow;

  opendb(&err, &db, "test.db", 0);
  nRow = execsql_i64(&err, &db, "SELECT count(*) FROM t1");
  closedb(&err, &db);
................................................................................
** Test case "dynamic_triggers"
**
**   Two threads executing statements that cause deeply nested triggers
**   to fire. And one thread busily creating and deleting triggers. This
**   is an attempt to find a bug reported to us.
*/

static char *dynamic_triggers_1(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nDrop = 0;
  int nCreate = 0;

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
................................................................................
    }
  }

  print_and_free_err(&err);
  return sqlite3_mprintf("%d created, %d dropped", nCreate, nDrop);
}

static char *dynamic_triggers_2(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iVal = 0;
  int nInsert = 0;
  int nDelete = 0;

  opendb(&err, &db, "test.db", 0);
................................................................................
  );

  setstoptime(&err, nMs);

  sqlite3_enable_shared_cache(1);
  launch_thread(&err, &threads, dynamic_triggers_2, 0);
  launch_thread(&err, &threads, dynamic_triggers_2, 0);
  sqlite3_enable_shared_cache(0);

  sleep(2);


  launch_thread(&err, &threads, dynamic_triggers_2, 0);
  launch_thread(&err, &threads, dynamic_triggers_1, 0);

  join_all_threads(&err, &threads);

  print_and_free_err(&err);
................................................................................
    { checkpoint_starvation_1, "checkpoint_starvation_1", 10000 },
    { checkpoint_starvation_2, "checkpoint_starvation_2", 10000 },

    { create_drop_index_1, "create_drop_index_1", 10000 },
    { lookaside1,          "lookaside1", 10000 },
    { vacuum1,             "vacuum1", 10000 },
    { stress1,             "stress1", 10000 },

  };

  int i;
  char *zTest = 0;
  int nTest = 0;
  int bTestfound = 0;
  int bPrefix = 0;
................................................................................
    nTest = strlen(zTest);
    if( zTest[nTest-1]=='*' ){
      nTest--;
      bPrefix = 1;
    }
  }


  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);

  for(i=0; i<sizeof(aTest)/sizeof(aTest[0]); i++){
    char const *z = aTest[i].zTest;
    int n = strlen(z);
    if( !zTest || ((bPrefix || n==nTest) && 0==strncmp(zTest, z, nTest)) ){
      printf("Running %s for %d seconds...\n", z, aTest[i].nMs/1000);

/* Functions to execute SQL */
#define sql_script(x,y,z)       (SEL(x), sql_script_x(x,y,z))
#define integrity_check(x,y)    (SEL(x), integrity_check_x(x,y))
#define execsql_i64(x,y,...)    (SEL(x), execsql_i64_x(x,y,__VA_ARGS__))
#define execsql_text(x,y,z,...) (SEL(x), execsql_text_x(x,y,z,__VA_ARGS__))
#define execsql(x,y,...)        (SEL(x), (void)execsql_i64_x(x,y,__VA_ARGS__))
#define sql_script_printf(x,y,z,...) (                \
    SEL(x), sql_script_printf_x(x,y,z,__VA_ARGS__)    \
) 

/* Thread functions */
#define launch_thread(w,x,y,z)     (SEL(w), launch_thread_x(w,x,y,z))
#define join_all_threads(y,z)      (SEL(y), join_all_threads_x(y,z))

/* Timer functions */
#define setstoptime(y,z)        (SEL(y), setstoptime_x(y,z))
#define timetostop(z)           (SEL(z), timetostop_x(z))

/* Report/clear errors. */
#define test_error(z, ...)      test_error_x(z, sqlite3_mprintf(__VA_ARGS__))
#define clear_error(y,z)        clear_error_x(y, z)

/* File-system operations */
#define filesize(y,z)           (SEL(y), filesize_x(y,z))
#define filecopy(x,y,z)         (SEL(x), filecopy_x(x,y,z))

#define PTR2INT(x) ((int)((intptr_t)x))
#define INT2PTR(x) ((void*)((intptr_t)x))

/*
** End of test code/infrastructure interface macros.
*************************************************************************/




................................................................................
  /* Append length in bits and transform */
  ((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
  ((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

  MD5Transform(ctx->buf, (uint32 *)ctx->in);
  byteReverse((unsigned char *)ctx->buf, 4);
  memcpy(digest, ctx->buf, 16);
  memset(ctx, 0, sizeof(*ctx));    /* In case it is sensitive */
}

/*
** Convert a 128-bit MD5 digest into a 32-digit base-16 number.
*/
static void MD5DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
................................................................................

typedef struct Threadset Threadset;
typedef struct Thread Thread;

/* Total number of errors in this process so far. */
static int nGlobalErr = 0;




struct Error {
  int rc;
  int iLine;
  char *zErr;
};

struct Sqlite {
................................................................................
struct Statement {
  sqlite3_stmt *pStmt;            /* Pre-compiled statement handle */
  Statement *pNext;               /* Next statement in linked-list */
};

struct Thread {
  int iTid;                       /* Thread number within test */
  void* pArg;                     /* Pointer argument passed by caller */

  pthread_t tid;                  /* Thread id */
  char *(*xProc)(int, void*);     /* Thread main proc */
  Thread *pNext;                  /* Next in this list of threads */
};

struct Threadset {
  int iMaxTid;                    /* Largest iTid value allocated so far */
  Thread *pThread;                /* Linked list of threads */
};
................................................................................
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* OUT: Database handle */
  const char *zFile,              /* Database file name */
  int bDelete                     /* True to delete db file before opening */
){
  if( pErr->rc==SQLITE_OK ){
    int rc;
    int flags = SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE | SQLITE_OPEN_URI;
    if( bDelete ) unlink(zFile);
    rc = sqlite3_open_v2(zFile, &pDb->db, flags, 0);
    if( rc ){
      sqlite_error(pErr, pDb, "open");
      sqlite3_close(pDb->db);
      pDb->db = 0;
    }else{
      sqlite3_create_function(
          pDb->db, "md5sum", -1, SQLITE_UTF8, 0, 0, md5step, md5finalize
................................................................................
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL script to execute */
){
  if( pErr->rc==SQLITE_OK ){
    pErr->rc = sqlite3_exec(pDb->db, zSql, 0, 0, &pErr->zErr);
  }
}

static void sql_script_printf_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  const char *zFormat,            /* SQL printf format string */
  ...                             /* Printf args */
){
  va_list ap;                     /* ... printf arguments */
  va_start(ap, zFormat);
  if( pErr->rc==SQLITE_OK ){
    char *zSql = sqlite3_vmprintf(zFormat, ap);
    pErr->rc = sqlite3_exec(pDb->db, zSql, 0, 0, &pErr->zErr);
    sqlite3_free(zSql);
  }
  va_end(ap);
}

static Statement *getSqlStatement(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb,                    /* Database handle */
  const char *zSql                /* SQL statement */
){
  Statement *pRet;
................................................................................
  Sqlite *pDb,                    /* Database handle */
  ...                             /* SQL and pointers to parameter values */
){
  i64 iRet = 0;
  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */

    va_start(ap, pDb);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){

      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          iRet = sqlite3_column_int64(pStmt, 0);
        }
        first = 0;
      }
................................................................................
    memset(&pDb->aText[pDb->nText], 0, sizeof(char*)*(iSlot+1-pDb->nText));
    pDb->nText = iSlot+1;
  }

  if( pErr->rc==SQLITE_OK ){
    sqlite3_stmt *pStmt;          /* SQL statement to execute */
    va_list ap;                   /* ... arguments */

    va_start(ap, iSlot);
    pStmt = getAndBindSqlStatement(pErr, pDb, ap);
    if( pStmt ){

      int first = 1;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        if( first && sqlite3_column_count(pStmt)>0 ){
          zRet = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
          sqlite3_free(pDb->aText[iSlot]);
          pDb->aText[iSlot] = zRet;
        }
................................................................................

static void integrity_check_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Sqlite *pDb                     /* Database handle */
){
  if( pErr->rc==SQLITE_OK ){
    Statement *pStatement;        /* Statement to execute */

    char *zErr = 0;               /* Integrity check error */

    pStatement = getSqlStatement(pErr, pDb, "PRAGMA integrity_check");
    if( pStatement ){
      sqlite3_stmt *pStmt = pStatement->pStmt;
      while( SQLITE_ROW==sqlite3_step(pStmt) ){
        const char *z = (const char*)sqlite3_column_text(pStmt, 0);
        if( strcmp(z, "ok") ){
          if( zErr==0 ){
            zErr = sqlite3_mprintf("%s", z);
          }else{
            zErr = sqlite3_mprintf("%z\n%s", zErr, z);
          }
        }
................................................................................
      }
    }
  }
}

static void *launch_thread_main(void *pArg){
  Thread *p = (Thread *)pArg;
  return (void *)p->xProc(p->iTid, p->pArg);
}

static void launch_thread_x(
  Error *pErr,                    /* IN/OUT: Error code */
  Threadset *pThreads,            /* Thread set */
  char *(*xProc)(int, void*),     /* Proc to run */
  void *pArg                      /* Argument passed to thread proc */
){
  if( pErr->rc==SQLITE_OK ){
    int iTid = ++pThreads->iMaxTid;
    Thread *p;
    int rc;

    p = (Thread *)sqlite3_malloc(sizeof(Thread));
    memset(p, 0, sizeof(Thread));
    p->iTid = iTid;
    p->pArg = pArg;
    p->xProc = xProc;

    rc = pthread_create(&p->tid, NULL, launch_thread_main, (void *)p);
    if( rc!=0 ){
      system_error(pErr, rc);
      sqlite3_free(p);
    }else{
................................................................................
**************************************************************************
** End infrastructure. Begin tests.
*/

#define WALTHREAD1_NTHREAD  10
#define WALTHREAD3_NTHREAD  6

static char *walthread1_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nIter = 0;                  /* Iterations so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    const char *azSql[] = {
................................................................................
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return sqlite3_mprintf("%d iterations", nIter);
}

static char *walthread1_ckpt_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nCkpt = 0;                  /* Checkpoints so far */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    usleep(500*1000);
................................................................................
  }
  launch_thread(&err, &threads, walthread1_ckpt_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread2_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int anTrans[2] = {0, 0};        /* Number of WAL and Rollback transactions */
  int iArg = PTR2INT(pArg);

  const char *zJournal = "PRAGMA journal_mode = WAL";
  if( iArg ){ zJournal = "PRAGMA journal_mode = DELETE"; }

  while( !timetostop(&err) ){
    int journal_exists = 0;
    int wal_exists = 0;
................................................................................
  opendb(&err, &db, "test.db", 1);
  sql_script(&err, &db, "CREATE TABLE t1(x INTEGER PRIMARY KEY, y UNIQUE)");
  closedb(&err, &db);

  setstoptime(&err, nMs);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, 0);
  launch_thread(&err, &threads, walthread2_thread, (void*)1);
  launch_thread(&err, &threads, walthread2_thread, (void*)1);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread3_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iNextWrite;                 /* Next value this thread will write */
  int iArg = PTR2INT(pArg);

  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 10");

  iNextWrite = iArg+1;
  while( 1 ){
    i64 sum1;
................................................................................
      "CREATE INDEX i2 ON t1(sum2);"
      "INSERT INTO t1 VALUES(0, 0, 0);"
  );
  closedb(&err, &db);

  setstoptime(&err, nMs);
  for(i=0; i<WALTHREAD3_NTHREAD; i++){
    launch_thread(&err, &threads, walthread3_thread, INT2PTR(i));
  }
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread4_reader_thread(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) ){
    integrity_check(&err, &db);
  }
  closedb(&err, &db);

  print_and_free_err(&err);
  return 0;
}

static char *walthread4_writer_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iRow = 1;

  opendb(&err, &db, "test.db", 0);
  sql_script(&err, &db, "PRAGMA wal_autocheckpoint = 15;");
  while( !timetostop(&err) ){
................................................................................
  launch_thread(&err, &threads, walthread4_reader_thread, 0);
  launch_thread(&err, &threads, walthread4_writer_thread, 0);
  join_all_threads(&err, &threads);

  print_and_free_err(&err);
}

static char *walthread5_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 nRow;

  opendb(&err, &db, "test.db", 0);
  nRow = execsql_i64(&err, &db, "SELECT count(*) FROM t1");
  closedb(&err, &db);
................................................................................
** Test case "dynamic_triggers"
**
**   Two threads executing statements that cause deeply nested triggers
**   to fire. And one thread busily creating and deleting triggers. This
**   is an attempt to find a bug reported to us.
*/

static char *dynamic_triggers_1(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int nDrop = 0;
  int nCreate = 0;

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
................................................................................
    }
  }

  print_and_free_err(&err);
  return sqlite3_mprintf("%d created, %d dropped", nCreate, nDrop);
}

static char *dynamic_triggers_2(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  i64 iVal = 0;
  int nInsert = 0;
  int nDelete = 0;

  opendb(&err, &db, "test.db", 0);
................................................................................
  );

  setstoptime(&err, nMs);

  sqlite3_enable_shared_cache(1);
  launch_thread(&err, &threads, dynamic_triggers_2, 0);
  launch_thread(&err, &threads, dynamic_triggers_2, 0);


  sleep(2);
  sqlite3_enable_shared_cache(0);

  launch_thread(&err, &threads, dynamic_triggers_2, 0);
  launch_thread(&err, &threads, dynamic_triggers_1, 0);

  join_all_threads(&err, &threads);

  print_and_free_err(&err);
................................................................................
    { checkpoint_starvation_1, "checkpoint_starvation_1", 10000 },
    { checkpoint_starvation_2, "checkpoint_starvation_2", 10000 },

    { create_drop_index_1, "create_drop_index_1", 10000 },
    { lookaside1,          "lookaside1", 10000 },
    { vacuum1,             "vacuum1", 10000 },
    { stress1,             "stress1", 10000 },
    { stress2,             "stress2", 10000 },
  };

  int i;
  char *zTest = 0;
  int nTest = 0;
  int bTestfound = 0;
  int bPrefix = 0;
................................................................................
    nTest = strlen(zTest);
    if( zTest[nTest-1]=='*' ){
      nTest--;
      bPrefix = 1;
    }
  }

  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);
  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);

  for(i=0; i<sizeof(aTest)/sizeof(aTest[0]); i++){
    char const *z = aTest[i].zTest;
    int n = strlen(z);
    if( !zTest || ((bPrefix || n==nTest) && 0==strncmp(zTest, z, nTest)) ){
      printf("Running %s for %d seconds...\n", z, aTest[i].nMs/1000);

  }
  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");

  }
  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, void *pArg){
  Error err = {0};
  Sqlite db = {0};

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    i64 iCount1, iCount2;
    sql_script(&err, &db, "BEGIN");

**
*************************************************************************
**
**     create_drop_index_1
*/


static char *create_drop_index_thread(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  while( !timetostop(&err) ){
    opendb(&err, &db, "test.db", 0);

    sql_script(&err, &db, 

**
*************************************************************************
**
**     create_drop_index_1
*/


static char *create_drop_index_thread(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  while( !timetostop(&err) ){
    opendb(&err, &db, "test.db", 0);

    sql_script(&err, &db, 

*/

/*
** 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, int iArg){
  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;
................................................................................
  }

  closedb(&err, &db);
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

static char *lookaside1_thread_writer(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  opendb(&err, &db, "test.db", 0);

  do{
    sql_script(&err, &db, 

*/

/*
** 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;
................................................................................
  }

  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, 

**
*/


/*
** Thread 1. CREATE and DROP a table.
*/
static char *stress_thread_1(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    sql_script(&err, &db, "CREATE TABLE IF NOT EXISTS t1(a PRIMARY KEY, b)");
    clear_error(&err, SQLITE_LOCKED);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

/*
** Thread 2. Open and close database connections.
*/
static char *stress_thread_2(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  while( !timetostop(&err) ){
    opendb(&err, &db, "test.db", 0);
    sql_script(&err, &db, "SELECT * FROM sqlite_master;");
    clear_error(&err, SQLITE_LOCKED);
    closedb(&err, &db);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

/*
** Thread 3. Attempt many small SELECT statements.
*/
static char *stress_thread_3(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  int i1 = 0;
  int i2 = 0;

  opendb(&err, &db, "test.db", 0);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("read t1 %d/%d attempts", i2, i1);
}

/*
** Thread 5. Attempt INSERT statements.
*/
static char *stress_thread_4(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int i1 = 0;
  int i2 = 0;


  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    if( iArg ){
      closedb(&err, &db);
      opendb(&err, &db, "test.db", 0);
    }
    sql_script(&err, &db, 
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("wrote t1 %d/%d attempts", i2, i1);
}

/*
** Thread 6. Attempt DELETE operations.
*/
static char *stress_thread_5(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */


  int i1 = 0;
  int i2 = 0;

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    i64 i = (i1 % 4);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("deleted from t1 %d/%d attempts", i2, i1);
}


static void stress1(int nMs){
  Error err = {0};
  Sqlite db = {0};
  Threadset threads = {0};


  setstoptime(&err, nMs);

  sqlite3_enable_shared_cache(1);

  launch_thread(&err, &threads, stress_thread_1, 0);
  launch_thread(&err, &threads, stress_thread_1, 0);

  launch_thread(&err, &threads, stress_thread_2, 0);
  launch_thread(&err, &threads, stress_thread_2, 0);
................................................................................
  launch_thread(&err, &threads, stress_thread_3, 0);
  launch_thread(&err, &threads, stress_thread_3, 0);

  launch_thread(&err, &threads, stress_thread_4, 0);
  launch_thread(&err, &threads, stress_thread_4, 0);

  launch_thread(&err, &threads, stress_thread_5, 0);
  launch_thread(&err, &threads, stress_thread_5, 1);

  join_all_threads(&err, &threads);
  sqlite3_enable_shared_cache(0);

  print_and_free_err(&err);
}

**
*/


/*
** Thread 1. CREATE and DROP a table.
*/
static char *stress_thread_1(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) ){
    sql_script(&err, &db, "CREATE TABLE IF NOT EXISTS t1(a PRIMARY KEY, b)");
    clear_error(&err, SQLITE_LOCKED);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

/*
** Thread 2. Open and close database connections.
*/
static char *stress_thread_2(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  while( !timetostop(&err) ){
    opendb(&err, &db, "test.db", 0);
    sql_script(&err, &db, "SELECT * FROM sqlite_master;");
    clear_error(&err, SQLITE_LOCKED);
    closedb(&err, &db);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

/*
** Thread 3. Attempt many small SELECT statements.
*/
static char *stress_thread_3(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */

  int i1 = 0;
  int i2 = 0;

  opendb(&err, &db, "test.db", 0);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("read t1 %d/%d attempts", i2, i1);
}

/*
** Thread 5. Attempt INSERT statements.
*/
static char *stress_thread_4(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int i1 = 0;
  int i2 = 0;
  int iArg = PTR2INT(pArg);

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    if( iArg ){
      closedb(&err, &db);
      opendb(&err, &db, "test.db", 0);
    }
    sql_script(&err, &db, 
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("wrote t1 %d/%d attempts", i2, i1);
}

/*
** Thread 6. Attempt DELETE operations.
*/
static char *stress_thread_5(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int iArg = PTR2INT(pArg);

  int i1 = 0;
  int i2 = 0;

  opendb(&err, &db, "test.db", 0);
  while( !timetostop(&err) ){
    i64 i = (i1 % 4);
................................................................................
  print_and_free_err(&err);
  return sqlite3_mprintf("deleted from t1 %d/%d attempts", i2, i1);
}


static void stress1(int nMs){
  Error err = {0};

  Threadset threads = {0};


  setstoptime(&err, nMs);

  sqlite3_enable_shared_cache(1);

  launch_thread(&err, &threads, stress_thread_1, 0);
  launch_thread(&err, &threads, stress_thread_1, 0);

  launch_thread(&err, &threads, stress_thread_2, 0);
  launch_thread(&err, &threads, stress_thread_2, 0);
................................................................................
  launch_thread(&err, &threads, stress_thread_3, 0);
  launch_thread(&err, &threads, stress_thread_3, 0);

  launch_thread(&err, &threads, stress_thread_4, 0);
  launch_thread(&err, &threads, stress_thread_4, 0);

  launch_thread(&err, &threads, stress_thread_5, 0);
  launch_thread(&err, &threads, stress_thread_5, (void*)1);

  join_all_threads(&err, &threads);
  sqlite3_enable_shared_cache(0);

  print_and_free_err(&err);
}

/**************************************************************************
***************************************************************************
** Start of test case "stress2"
*/



/*
** 1.  CREATE TABLE statements.
** 2.  DROP TABLE statements.
** 3.  Small SELECT statements.
** 4.  Big SELECT statements.
** 5.  Small INSERT statements.
** 6.  Big INSERT statements.
** 7.  Small UPDATE statements.
** 8.  Big UPDATE statements.
** 9.  Small DELETE statements.
** 10. Big DELETE statements.
** 11. VACUUM.
** 14. Integrity-check.
** 17. Switch the journal mode from delete to wal and back again.
** 19. Open and close database connections rapidly.
*/

#define STRESS2_TABCNT 5

static void stress2_workload1(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb, 
      "CREATE TABLE IF NOT EXISTS t%d(x PRIMARY KEY, y, z);", iTab
  );
}

static void stress2_workload2(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb, "DROP TABLE IF EXISTS t%d;", iTab);
}

static void stress2_workload3(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb, "SELECT * FROM t%d WHERE z = 'small'", iTab);
}

static void stress2_workload4(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb, "SELECT * FROM t%d WHERE z = 'big'", iTab);
}

static void stress2_workload5(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "INSERT INTO t%d VALUES(random(), hex(randomblob(57)), 'small');", iTab
  );
}

static void stress2_workload6(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "INSERT INTO t%d VALUES(random(), hex(randomblob(2000)), 'big');", iTab
  );
}

static void stress2_workload7(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "UPDATE t%d SET y = hex(randomblob(57)) "
      "WHERE (x %% 5)==(%d %% 5) AND z='small';"
      ,iTab, i
  );
}
static void stress2_workload8(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "UPDATE t%d SET y = hex(randomblob(2000)) "
      "WHERE (x %% 5)==(%d %% 5) AND z='big';"
      ,iTab, i
  );
}

static void stress2_workload9(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "DELETE FROM t%d WHERE (x %% 5)==(%d %% 5) AND z='small';"
      ,iTab, i
  );
}
static void stress2_workload10(Error *pErr, Sqlite *pDb, int i){
  int iTab = (i % STRESS2_TABCNT);
  sql_script_printf(pErr, pDb,
      "DELETE FROM t%d WHERE (x %% 5)==(%d %% 5) AND z='big';"
      ,iTab, i
  );
}

static void stress2_workload11(Error *pErr, Sqlite *pDb, int i){
  sql_script(pErr, pDb, "VACUUM");
}

static void stress2_workload14(Error *pErr, Sqlite *pDb, int i){
  sql_script(pErr, pDb, "PRAGMA integrity_check");
}

static void stress2_workload17(Error *pErr, Sqlite *pDb, int i){
  sql_script_printf(pErr, pDb, 
      "PRAGMA journal_mode = %q", (i%2) ? "delete" : "wal"
  );
}

static char *stress2_workload19(int iTid, void *pArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  const char *zDb = (const char*)pArg;
  while( !timetostop(&err) ){
    opendb(&err, &db, zDb, 0);
    sql_script(&err, &db, "SELECT * FROM sqlite_master;");
    clear_error(&err, SQLITE_LOCKED);
    closedb(&err, &db);
  }
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}


typedef struct Stress2Ctx Stress2Ctx;
struct Stress2Ctx {
  const char *zDb;
  void (*xProc)(Error*, Sqlite*, int);
};

static char *stress2_thread_wrapper(int iTid, void *pArg){
  Stress2Ctx *pCtx = (Stress2Ctx*)pArg;
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  int i1 = 0;
  int i2 = 0;

  opendb(&err, &db, pCtx->zDb, 0);
  while( !timetostop(&err) ){
    pCtx->xProc(&err, &db, i1);
    i2 += (err.rc==SQLITE_OK);
    clear_error(&err, SQLITE_LOCKED);
    clear_error(&err, SQLITE_ERROR);
    i1++;
  }

  print_and_free_err(&err);
  return sqlite3_mprintf("ok %d/%d", i2, i1);
}

static void stress2_launch_thread_loop(
  Error *pErr,                    /* IN/OUT: Error code */
  Threadset *pThreads,            /* Thread set */
  const char *zDb,                /* Database name */
  void (*x)(Error*,Sqlite*,int)   /* Run this until error or timeout */
){
  Stress2Ctx *pCtx = sqlite3_malloc(sizeof(Stress2Ctx));
  pCtx->zDb = zDb;
  pCtx->xProc = x;
  launch_thread(pErr, pThreads, stress2_thread_wrapper, (void*)pCtx);
}

static void stress2(int nMs){
  struct Stress2Task {
    void (*x)(Error*,Sqlite*,int);
  } aTask[] = {
    { stress2_workload1 },
    { stress2_workload2 },
    { stress2_workload3 },
    { stress2_workload4 },
    { stress2_workload5 },
    { stress2_workload6 },
    { stress2_workload7 },
    { stress2_workload8 },
    { stress2_workload9 },
    { stress2_workload10 },
    { stress2_workload11 },
    { stress2_workload14 },
    { stress2_workload17 },
  };
  const char *azDb[] = {
    "test.db",
    "file::memory:?cache=shared"
  };
  int j;

  for(j=0; j<sizeof(azDb)/sizeof(azDb[0]); j++){
    int i;
    Error err = {0};
    Sqlite db = {0};
    Threadset threads = {0};
    const char *zDb = azDb[j];

    /* To make sure the db file is empty before commencing */
    opendb(&err, &db, zDb, 1);
    closedb(&err, &db);

    setstoptime(&err, nMs);
    sqlite3_enable_shared_cache(1);

    for(i=0; i<sizeof(aTask)/sizeof(aTask[0]); i++){
      stress2_launch_thread_loop(&err, &threads, zDb, aTask[i].x);
    }
    launch_thread(&err, &threads, stress2_workload19, (void*)zDb);
    launch_thread(&err, &threads, stress2_workload19, (void*)zDb);

    join_all_threads(&err, &threads);
    sqlite3_enable_shared_cache(0);
    print_and_free_err(&err);
    if( j==0 ){
      printf("Running stress2 (again, with in-memory db) for %d seconds...\n",
          nMs / 1000
      );
    }
  }
}

** Tests:
**
**     vacuum1
**
*/


static char *vacuum1_thread_writer(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  opendb(&err, &db, "test.db", 0);
  i64 i = 0;

  while( !timetostop(&err) ){
    i++;
................................................................................
  }

  closedb(&err, &db);
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

static char *vacuum1_thread_vacuumer(int iTid, int iArg){
  Error err = {0};                /* Error code and message */
  Sqlite db = {0};                /* SQLite database connection */
  opendb(&err, &db, "test.db", 0);

  do{
    sql_script(&err, &db, "VACUUM");
    clear_error(&err, SQLITE_LOCKED);

** Tests:
**
**     vacuum1
**
*/


static char *vacuum1_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);
  i64 i = 0;

  while( !timetostop(&err) ){
    i++;
................................................................................
  }

  closedb(&err, &db);
  print_and_free_err(&err);
  return sqlite3_mprintf("ok");
}

static char *vacuum1_thread_vacuumer(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, "VACUUM");
    clear_error(&err, SQLITE_LOCKED);