SQLite

** The file suffix added to the data base filename in order to create the
** lock directory.
*/
#define DOTLOCK_SUFFIX ".lock"

/*
** This routine checks if there is a RESERVED lock held on the specified
** file by this or any other process. The caller always holds a SHARED
** lock when it is called. This means that no other connection could
** hold a RESERVED lock, as unix-dotfile uses just a single exclusive lock -

** the presence of the dotfile - for all 4 VFS locks. So this function sets


** (*pResOut) to 0 (no other connection holds RESERVED) and returns SQLITE_OK.
*/
static int dotlockCheckReservedLock(sqlite3_file *id, int *pResOut) {




  SimulateIOError( return SQLITE_IOERR_CHECKRESERVEDLOCK; );
  assert( ((unixFile*)id)->eFileLock>=SHARED_LOCK );



  *pResOut = 0;
  return SQLITE_OK;
}

/*
** Lock the file with the lock specified by parameter eFileLock - one
** of the following:
**
**     (1) SHARED_LOCK

# 2008 June 28
#
# 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 implements regression tests for SQLite library.  The
# focus of this script is database locks.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix lock5

# This file is only run if using the unix backend compiled with the
# SQLITE_ENABLE_LOCKING_STYLE macro.
db close
if {[catch {sqlite3 db test.db -vfs unix-none} msg]} {
  finish_test
  return

  db close
  file exists test.db.lock
} {0}

#####################################################################

forcedelete test.db
if {0==[catch {sqlite3 db test.db -vfs unix-flock} msg]} {




do_test lock5-flock.1 {
  sqlite3 db test.db -vfs unix-flock
  execsql {
    CREATE TABLE t1(a, b);
    BEGIN;
    INSERT INTO t1 VALUES(1, 2);

  db close
  catchsql { SELECT * FROM t1 } db2
} {0 {1 2}}

do_test lock5-flock.8 {
  db2 close
} {}

}

#####################################################################

reset_db

do_test lock5-none.1 {
  sqlite3 db test.db -vfs unix-none
  sqlite3 db2 test.db -vfs unix-none
  execsql { PRAGMA mmap_size = 0 } db2
  execsql {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    BEGIN;
    INSERT INTO t1 VALUES(3, 4);
  }
} {}
do_test lock5-none.2 {
  execsql { SELECT * FROM t1 }
} {1 2 3 4}

  db close
  db2 close
} {}

ifcapable lock_proxy_pragmas {
  set env(SQLITE_FORCE_PROXY_LOCKING) $::using_proxy
}

#####################################################################
reset_db

# 1. Create a large database using the unix-dotfile VFS
# 2. Write a large transaction to the db, so that the cache spills, but do
#    not commit it.
# 3. Make a copy of the database files on disk.
# 4. Try to read from the copy using unix-dotfile VFS. This fails because
#    the dotfile still exists, so SQLite things the database is locked.
# 5. Remove the dotfile.
# 6. Try to read the db again. This time, the old transaction is rolled
#    back and the read permitted.
#
do_test 2.dotfile.1 {
  sqlite3 db test.db -vfs unix-dotfile
  execsql {
    PRAGMA cache_size = 10;
    CREATE TABLE t1(x, y, z);
    CREATE INDEX t1x ON t1(x);
    WITH s(i) AS (
      SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<1000
    )
    INSERT INTO t1 SELECT hex(randomblob(20)), hex(randomblob(500)), i FROM s;
  }
} {}

do_execsql_test 2.dotfile.2 {
  BEGIN;
    UPDATE t1 SET z=z+1, x=hex(randomblob(20));
}

do_test 2.dotfile.3 {
  list                            \
    [file exists test.db]         \
    [file exists test.db-journal] \
    [file exists test.db.lock]
} {1 1 1}

do_test 2.dotfile.4 {
  forcecopy test.db test.db2
  forcecopy test.db-journal test.db2-journal
  file mkdir test.db2.lock

  sqlite3 db2 test.db2 -vfs unix-dotfile
  catchsql {
    SELECT count(*) FROM t1;
  } db2
} {1 {database is locked}}

do_test 2.dotfile.5 {
  file delete test.db2.lock
  execsql {
    PRAGMA integrity_check
  } db2
} {ok}

finish_test