# 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 implements regression tests for SQLite library.  The

# focus of this script is database locks between competing processes.

#

# $Id: lock2.test,v 1.9 2007/12/13 21:54:11 drh Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

# Launch another testfixture process to be controlled by this one. A

# channel name is returned that may be passed as the first argument to proc

# 'testfixture' to execute a command. The child testfixture process is shut

# down by closing the channel.

proc launch_testfixture {} {

  set prg [info nameofexec]

  if {$prg eq ""} {

    set prg [file join . testfixture]

  }

  set chan [open "|$prg tf_main.tcl" r+]

  fconfigure $chan -buffering line

  return $chan

}

# Execute a command in a child testfixture process, connected by two-way

# channel $chan. Return the result of the command, or an error message.

proc testfixture {chan cmd} {

  puts $chan $cmd

  puts $chan OVER

  set r ""

  while { 1 } {

    set line [gets $chan]

    if { $line == "OVER" } { 

      return $r

    }

    append r $line

  }

}

# Write the main loop for the child testfixture processes into file

# tf_main.tcl. The parent (this script) interacts with the child processes

# via a two way pipe. The parent writes a script to the stdin of the child

# process, followed by the word "OVER" on a line of its own. The child

# process evaluates the script and writes the results to stdout, followed

# by an "OVER" of its own.

set f [open tf_main.tcl w]

puts $f {

  set l [open log w]

  set script ""

  while {![eof stdin]} {

    flush stdout

    set line [gets stdin]

    puts $l "READ $line"

    if { $line == "OVER" } {

      catch {eval $script} result

      puts $result

      puts $l "WRITE $result"

      puts OVER

      puts $l "WRITE OVER"

      flush stdout

      set script ""

    } else {

      append script $line

      append script " ; "

    }

  }

  close $l

}

close $f

# Simple locking test case:

#

# lock2-1.1: Connect a second process to the database.

# lock2-1.2: Establish a RESERVED lock with this process.

# lock2-1.3: Get a SHARED lock with the second process.

# lock2-1.4: Try for a RESERVED lock with process 2. This fails.

# lock2-1.5: Try to upgrade the first process to EXCLUSIVE, this fails so

#            it gets PENDING.

# lock2-1.6: Release the SHARED lock held by the second process. 

# lock2-1.7: Attempt to reaquire a SHARED lock with the second process.

#            this fails due to the PENDING lock.

# lock2-1.8: Ensure the first process can now upgrade to EXCLUSIVE.

#

do_test lock2-1.1 {

  set ::tf1 [launch_testfixture]

  testfixture $::tf1 "set sqlite_pending_byte $::sqlite_pending_byte"

  testfixture $::tf1 {

    sqlite3 db test.db -key xyzzy

    db eval {select * from sqlite_master}

  }

} {}

do_test lock2-1.1.1 {

  execsql {pragma lock_status}

} {main unlocked temp closed}

sqlite3_soft_heap_limit 0

do_test lock2-1.2 {

  execsql {

    BEGIN;

    CREATE TABLE abc(a, b, c);

  }

} {}

do_test lock2-1.3 {

  testfixture $::tf1 {

    db eval {

      BEGIN;

      SELECT * FROM sqlite_master;

    }

  }

} {}

do_test lock2-1.4 {

  testfixture $::tf1 {

    db eval {

      CREATE TABLE def(d, e, f)

    }

  }

} {database is locked}

do_test lock2-1.5 {

  catchsql {

    COMMIT;

  }

} {1 {database is locked}}

do_test lock2-1.6 {

  testfixture $::tf1 {

    db eval {

      SELECT * FROM sqlite_master;

      COMMIT;

    }

  }

} {}

do_test lock2-1.7 {

  testfixture $::tf1 {

    db eval {

      BEGIN;

      SELECT * FROM sqlite_master;

    }

  }

} {database is locked}

do_test lock2-1.8 {

  catchsql {

    COMMIT;

  }

} {0 {}}

do_test lock2-1.9 {

  execsql {

    SELECT * FROM sqlite_master;

  }

} "table abc abc [expr $AUTOVACUUM?3:2] {CREATE TABLE abc(a, b, c)}"

do_test lock2-1.10 {

  testfixture $::tf1 {

    db eval {

      SELECT * FROM sqlite_master;

    }

  }

} "table abc abc [expr $AUTOVACUUM?3:2] {CREATE TABLE abc(a, b, c)}"

catch {testfixture $::tf1 {db close}}

catch {close $::tf1}

sqlite3_soft_heap_limit $soft_limit

finish_test