#
#    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 exclusive transactions.  In
# BDB exclusive transactions do not block the entire database, but force
# non-exclusive transactions to abort if there is ever deadlock.  If two
# exclusive transactions are created at the same time then one will block
# the other until it completes.
#

set testdir [file dirname $argv0]/../../lang/sql/sqlite/test

source $testdir/../../../../test/sql/bdb_util.tcl
if {[run_thread_tests]==0} { finish_test ; return }

sqlite3 db test.db -fullmutex 1

do_test bdb_exclusive.1.0 {
   db eval { 
   CREATE TABLE t1(a);
   CREATE TABLE t2(a);
  }
} {}

do_test bdb_exclusive.1.1 {
   db eval {
   BEGIN EXCLUSIVE;
   ROLLBACK;
   select * from t1;
  }
} {} 

# Create deadlock between an exclusive and non-exclusive 
# transactions
set exclusive_test2 {
  set key ""
  if {[sqlite -has-codec]} {
    set key "xyzzy"
  }
  set ::DB [sqlthread open test.db $key]
  set rc [
    for {set i 0} {$i < 100} {incr i} {
      do_test e1.$i {
        execsql { BEGIN EXCLUSIVE }
      } {SQLITE_OK}
      do_test e2.$i {
        execsql { INSERT INTO t2 VALUES(2) }
      } {SQLITE_OK}
      do_test e3.$i {
        execsql { INSERT INTO t1 VALUES(2) } 
      } {SQLITE_OK}
      do_test e4.$i {
        execsql { COMMIT } 
      } {SQLITE_OK}
    } 
  ]
  sqlite3_close $::DB
  set rc
}

set nonexclusive_test2 {
  set key ""
  if {[sqlite -has-codec]} {
    set key "xyzzy"
  }
  set ::DB [sqlthread open test.db $key]
  set rc [
    for {set i 0} {$i < 100} {incr i} {
      do_test n1.$i {
        execsql { BEGIN } 
      } {SQLITE_OK}
      do_test n2.$i {
        set res [ execsql {INSERT INTO t1 VALUES(2) } ] 
        if {$res eq "SQLITE_LOCKED" || $res eq "SQLITE_BUSY"} {
          execsql { ROLLBACK } 
          execsql { BEGIN }
          set res SQLITE_OK
        }
        set res
      } {SQLITE_OK}
      do_test n3.$i {
        set res [ execsql {INSERT INTO t2 VALUES(2) } ] 
        if {$res eq "SQLITE_LOCKED" || $res eq "SQLITE_BUSY"} {
          execsql { ROLLBACK } 
          execsql { BEGIN }
          set res SQLITE_OK
        }
        set res
      } {SQLITE_OK}
      do_test n4.$i {
        execsql { ROLLBACK } 
      } {SQLITE_OK}
    }
  ]
  sqlite3_close $::DB
  set rc
}

# Check that deadlock cannot occur between two exclusive
# transactions
set exclusive1_test3 {
  set key ""
  if {[sqlite -has-codec]} {
    set key "xyzzy"
  }
  set ::DB [sqlthread open test.db $key]
  set rc [
    for {set i 0} {$i < 100} {incr i} {
      do_test 1e1.$i {
        execsql { BEGIN EXCLUSIVE }
      } {SQLITE_OK}
      do_test 1e2.$i {
        execsql { INSERT INTO t2 VALUES(2) }
      } {SQLITE_OK}
      do_test 1e3.$i {
        execsql { INSERT INTO t1 VALUES(2) } 
      } {SQLITE_OK}
      do_test 1e4.$i {
        execsql { COMMIT } 
      } {SQLITE_OK}
    } 
  ]
  sqlite3_close $::DB
  set rc
}

set exclusive2_test3 {
  set key ""
  if {[sqlite -has-codec]} {
    set key "xyzzy"
  }
  set ::DB [sqlthread open test.db $key]
  set rc [
    for {set i 0} {$i < 100} {incr i} {
      do_test 2e1.$i {
        execsql { BEGIN EXCLUSIVE }
      } {SQLITE_OK}
      do_test 2e2.$i {
        execsql { INSERT INTO t1 VALUES(2) }
      } {SQLITE_OK}
      do_test 2e3.$i {
        execsql { INSERT INTO t2 VALUES(2) } 
      } {SQLITE_OK}
      do_test 2e4.$i {
        execsql { COMMIT } 
      } {SQLITE_OK}
    } 
  ]
  sqlite3_close $::DB
  set rc
}
  
# Start the exclusive and non-exclusive threads
#
array unset finished
thread_spawn finished(0) "" $bdb_thread_procs $exclusive_test2
thread_spawn finished(1) "" $bdb_thread_procs $nonexclusive_test2
  
for {set i 0} {$i < 2} {incr i} {
  if {![info exists finished($i)]} {
    vwait finished($i)
  }
  do_test exclusive_nonexclusive.2.$i {
    set ::finished($i)
  } {}
}

# Start the two exclusive threads
#
array unset finished
thread_spawn finished(0) "" $bdb_thread_procs $exclusive1_test3
thread_spawn finished(1) "" $bdb_thread_procs $exclusive2_test3
  
for {set i 0} {$i < 2} {incr i} {
  if {![info exists finished($i)]} {
    vwait finished($i)
  }
  do_test exclusive_exclusive.3.$i {
    set ::finished($i)
  } {}
}

db close

finish_test