SQLite

      sqlite3PagerShrink(pPager);
    }
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Flush any dirty pages in the pager-cache for any attached database
** to disk.
*/
int sqlite3_db_cacheflush(sqlite3 *db){
  int i;
  int rc = SQLITE_OK;
  int bSeenBusy = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
      Pager *pPager = sqlite3BtreePager(pBt);
      rc = sqlite3PagerFlush(pPager);
      if( rc==SQLITE_BUSY ){
        bSeenBusy = 1;
        rc = SQLITE_OK;
      }
    }
  }
  if( rc!=SQLITE_OK ){
    sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
}

/*
** Configuration settings for an individual database connection
*/
int sqlite3_db_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc;

    PAGERTRACE(("STRESS %d page %d\n", PAGERID(pPager), pPg->pgno));
    sqlite3PcacheMakeClean(pPg);
  }

  return pager_error(pPager, rc); 
}

/*
** Flush all unreferenced dirty pages to disk.
*/
int sqlite3PagerFlush(Pager *pPager){
  int rc = SQLITE_OK;
  PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);

  while( rc==SQLITE_OK && pList ){
    PgHdr *pNext = pList->pDirty;
    if( pList->nRef==0 ){
      rc = pagerStress((void*)pPager, pList);
    }
    pList = pNext;
  }

  return rc;
}

/*
** Allocate and initialize a new Pager object and put a pointer to it
** in *ppPager. The pager should eventually be freed by passing it
** to sqlite3PagerClose().
**
** The zFilename argument is the path to the database file to open.

void sqlite3PagerSetFlags(Pager*,unsigned);
int sqlite3PagerLockingMode(Pager *, int);
int sqlite3PagerSetJournalMode(Pager *, int);
int sqlite3PagerGetJournalMode(Pager*);
int sqlite3PagerOkToChangeJournalMode(Pager*);
i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
int sqlite3PagerFlush(Pager*);

/* Functions used to obtain and release page references. */ 
int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
#define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
void sqlite3PagerRef(DbPage*);
void sqlite3PagerUnref(DbPage*);

** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
**
** This API is only available if the library is built with pre-processor
** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
*/
void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);

/*
** CAPI3REF: Flush caches to disk mid-transaction
**
** If a write-transaction is open when this function is called, any dirty
** pages in the pager-cache that are not currently in use are written out 
** to disk. A dirty page may be in use if a database cursor created by an
** active SQL statement is reading from it, or if it is page 1 of a database
** file (page 1 is always "in use"). Dirty pages are flushed for all
** databases - "main", "temp" and any attached databases.
**
** If this function needs to obtain extra database locks before dirty pages 
** can be flushed to disk, it does so. If said locks cannot be obtained 
** immediately and there is a busy-handler callback configured, it is invoked
** in the usual manner. If the required lock still cannot be obtained, then
** the database is skipped and an attempt made to flush any dirty pages
** belonging to the next (if any) database. If any databases are skipped
** because locks cannot be obtained, but no other error occurs, this
** function returns SQLITE_BUSY.
**
** If any other error occurs while flushing dirty pages to disk (for
** example an IO error or out-of-memory condition), then processing is
** abandoned and an SQLite error code returned to the caller immediately.
** In this case the open transaction may be automatically rolled back.
**
** Otherwise, if no error occurs, SQLITE_OK is returned.
**
** This function does not set the database handle error code or message
** returned by the sqlite3_errcode() and sqlite3_errmsg() functions.
*/
int sqlite3_db_cacheflush(sqlite3*);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double

    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  rc = sqlite3_db_release_memory(db);
  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
  return TCL_OK;
}

/*
** Usage:  sqlite3_db_cacheflush DB
**
** Attempt to flush any dirty pages to disk.
*/
static int test_db_cacheflush(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  int rc;
  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB");
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  rc = sqlite3_db_cacheflush(db);
  if( rc ){
    Tcl_SetResult(interp, (char *)sqlite3ErrStr(rc), TCL_STATIC);
    return TCL_ERROR;
  }

  Tcl_ResetResult(interp);
  return TCL_OK;
}

/*
** Usage:  sqlite3_db_filename DB DBNAME
**
** Return the name of a file associated with a database.
*/
static int test_db_filename(

     { "sqlite3_next_stmt",             test_next_stmt     ,0 },
     { "sqlite3_stmt_readonly",         test_stmt_readonly ,0 },
     { "sqlite3_stmt_busy",             test_stmt_busy     ,0 },
     { "uses_stmt_journal",             uses_stmt_journal ,0 },

     { "sqlite3_release_memory",        test_release_memory,     0},
     { "sqlite3_db_release_memory",     test_db_release_memory,  0},
     { "sqlite3_db_cacheflush",         test_db_cacheflush,      0},
     { "sqlite3_db_filename",           test_db_filename,        0},
     { "sqlite3_db_readonly",           test_db_readonly,        0},
     { "sqlite3_soft_heap_limit",       test_soft_heap_limit,    0},
     { "sqlite3_thread_cleanup",        test_thread_cleanup,     0},
     { "sqlite3_pager_refcounts",       test_pager_refcounts,    0},

     { "sqlite3_load_extension",        test_load_extension,     0},

# 2011 November 16
#
# 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 contains test cases for sqlite3_db_cacheflush API.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix cacheflush
test_set_config_pagecache 0 0

# Run the supplied SQL on a copy of the database currently stored on 
# disk in file $dbfile.
proc diskquery {dbfile sql} {
  forcecopy $dbfile dq.db
  sqlite3 dq dq.db
  set res [execsql $sql dq]
  dq close
  set res
}

# Simplest possible test.
#
do_execsql_test 1.1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, 2);
  BEGIN;
    INSERT INTO t1 VALUES(3, 4);
}
do_test 1.1.1 {
  diskquery test.db { SELECT * FROM t1 } 
} {1 2}
do_test 1.1.2 {
  sqlite3_db_cacheflush db
  diskquery test.db { SELECT * FROM t1 } 
} {1 2 3 4}

# Test that multiple pages may be flushed to disk.
#
do_execsql_test 1.2.0 {
  COMMIT;
  CREATE TABLE t2(a, b);
  BEGIN;
    INSERT INTO t1 VALUES(5, 6);
    INSERT INTO t2 VALUES('a', 'b');
}
do_test 1.2.1 {
  diskquery test.db { 
    SELECT * FROM t1;
    SELECT * FROM t2;
  }
} {1 2 3 4}
do_test 1.2.2 {
  sqlite3_db_cacheflush db
  diskquery test.db { 
    SELECT * FROM t1;
    SELECT * FROM t2;
  }
} {1 2 3 4 5 6 a b}

# Test that pages with nRef!=0 are not flushed to disk.
#
do_execsql_test 1.3.0 {
  COMMIT;
  CREATE TABLE t3(a, b);
  BEGIN;
    INSERT INTO t1 VALUES(7, 8);
    INSERT INTO t2 VALUES('c', 'd');
    INSERT INTO t3 VALUES('i', 'ii');
}
do_test 1.3.1 {
  diskquery test.db { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 3 4 5 6 a b}
do_test 1.3.2 {
  db eval { SELECT a FROM t1 } {
    if {$a==3} {
      sqlite3_db_cacheflush db
    }
  }
  diskquery test.db { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 3 4 5 6 a b c d i ii}
do_test 1.3.2 {
  sqlite3_db_cacheflush db
  diskquery test.db { 
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  }
} {1 2 3 4 5 6 7 8 a b c d i ii}

# Check that SQLITE_BUSY is returned if pages cannot be flushed due to
# conflicting read locks.
#
do_execsql_test 1.4.0 {
  COMMIT;
  BEGIN;
    INSERT INTO t1 VALUES(9, 10);
}
do_test 1.4.1 {
  sqlite3 db2 test.db
  db2 eval {
    BEGIN;
      SELECT * FROM t1;
  }
  diskquery test.db { 
    SELECT * FROM t1;
  }
} {1 2 3 4 5 6 7 8}
do_test 1.4.2 {
  list [catch { sqlite3_db_cacheflush db } msg] $msg
} {1 {database is locked}}
do_test 1.4.3 {
  diskquery test.db { 
    SELECT * FROM t1;
  }
} {1 2 3 4 5 6 7 8}
do_test 1.4.4 {
  db2 close
  sqlite3_db_cacheflush db
  diskquery test.db { 
    SELECT * FROM t1;
  }
} {1 2 3 4 5 6 7 8 9 10}
do_execsql_test 1.4.5 { COMMIT }

#-------------------------------------------------------------------------
# Test that ATTACHed database caches are also flushed.
#
forcedelete test.db2
do_execsql_test 2.1.0 {
  ATTACH 'test.db2' AS aux;
  CREATE TABLE aux.t4(x, y);
  INSERT INTO t4 VALUES('A', 'B');
  BEGIN;
    INSERT INTO t1 VALUES(11, 12);
    INSERT INTO t4 VALUES('C', 'D');
}
do_test 2.1.1 {
  diskquery test.db { SELECT * FROM t1; }
} {1 2 3 4 5 6 7 8 9 10}
do_test 2.1.2 {
  diskquery test.db2 { SELECT * FROM t4; }
} {A B}
do_test 2.1.3 {
  sqlite3_db_cacheflush db
  diskquery test.db { SELECT * FROM t1; }
} {1 2 3 4 5 6 7 8 9 10 11 12}
do_test 2.1.4 {
  sqlite3_db_cacheflush db
  diskquery test.db2 { SELECT * FROM t4; }
} {A B C D}
do_execsql_test 2.1.5 { COMMIT }

# And that hitting an SQLITE_BUSY when flushing "main" does not stop
# SQLite from going on to flush "aux".
#
do_execsql_test 2.2.0 {
  BEGIN;
    INSERT INTO t1 VALUES(13, 14);
    INSERT INTO t4 VALUES('E', 'F');
}
do_test 2.2.1 {
  diskquery test.db { SELECT * FROM t1; }
} {1 2 3 4 5 6 7 8 9 10 11 12}
do_test 2.2.2 {
  diskquery test.db2 { SELECT * FROM t4; }
} {A B C D}
do_test 2.2.3 {
  sqlite3 db2 test.db
  execsql {
    BEGIN;
      SELECT * FROM t1;
  } db2
  list [catch { sqlite3_db_cacheflush db } msg] $msg
} {1 {database is locked}}
do_test 2.2.4 {
  diskquery test.db { SELECT * FROM t1; }
} {1 2 3 4 5 6 7 8 9 10 11 12}
do_test 2.2.5 {
  diskquery test.db2 { SELECT * FROM t4; }
} {A B C D E F}
do_test 2.2.6 {
  db2 close
  sqlite3_db_cacheflush db
  diskquery test.db { SELECT * FROM t1; }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
do_execsql_test 2.2.7 { COMMIT }

test_restore_config_pagecache
finish_test

# 2011 November 16
#
# 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 contains fault-injection test cases for the 
# sqlite3_db_cacheflush API.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix cacheflush
source $testdir/malloc_common.tcl

# Run the supplied SQL on a copy of the database currently stored on 
# disk in file $dbfile.
proc diskquery {dbfile sql} {
  forcecopy $dbfile dq.db
  sqlite3 dq dq.db
  set res [execsql $sql dq]
  dq close
  set res
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a PRIMARY KEY, b);
  CREATE INDEX i1 ON t1(b);
  INSERT INTO t1 VALUES(1, 2);
  INSERT INTO t1 VALUES(3, 4);
  INSERT INTO t1 VALUES(5, 6);
  INSERT INTO t1 VALUES(7, 8);
}
faultsim_save_and_close

do_faultsim_test 1 -prep {
  faultsim_restore_and_reopen
  db eval {
    BEGIN;
      UPDATE t1 SET b=b+1;
  }
} -body {
  sqlite3_db_cacheflush db
} -test {
  faultsim_test_result {0 {}} {1 {disk I/O error}}
  catch { db eval COMMIT }
  faultsim_integrity_check
}


finish_test