# transaction.
#
# This test case verifies that if an exclusive lock cannot be obtained
# on any aReadMark[] slot (because there are already several readers),
# the client takes a shared-lock on a slot without modifying the value
# and continues.
#


do_test wal3-9.0 {
  file delete -force test.db test.db-journal test.db wal
  sqlite3 db test.db
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = WAL;
    CREATE TABLE whoami(x);
    INSERT INTO whoami VALUES('nobody');
  }
} {wal}
for {set i 0} {$i < 50} {incr i} {
  set c db$i
  do_test wal3-9.1.$i {
    sqlite3 $c test.db
    execsql { UPDATE whoami SET x = $c }
    execsql {
      BEGIN;
      SELECT * FROM whoami
    } $c
  } $c
}
for {set i 0} {$i < 50} {incr i} {
  set c db$i
  do_test wal3-9.2.$i {
    execsql { SELECT * FROM whoami } $c
  } $c
}

set sz [expr 1024 * (2+$AUTOVACUUM)]
do_test wal3-9.3 {
  for {set i 0} {$i < 49} {incr i} { db$i close }
  execsql { PRAGMA wal_checkpoint } 
  byte_is_zero test.db [expr $sz-1024]
} {1}
do_test wal3-9.4 {
  db49 close
  execsql { PRAGMA wal_checkpoint } 
  set sz2 [file size test.db]
  byte_is_zero test.db [expr $sz-1024]
} {0}

do_multiclient_test tn {
  do_test wal3-10.$tn.1 {

# transaction.
#
# This test case verifies that if an exclusive lock cannot be obtained
# on any aReadMark[] slot (because there are already several readers),
# the client takes a shared-lock on a slot without modifying the value
# and continues.
#
set nConn 50
if { [string match *BSD $tcl_platform(os)] } { set nConn 35 }
do_test wal3-9.0 {
  file delete -force test.db test.db-journal test.db wal
  sqlite3 db test.db
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = WAL;
    CREATE TABLE whoami(x);
    INSERT INTO whoami VALUES('nobody');
  }
} {wal}
for {set i 0} {$i < $nConn} {incr i} {
  set c db$i
  do_test wal3-9.1.$i {
    sqlite3 $c test.db
    execsql { UPDATE whoami SET x = $c }
    execsql {
      BEGIN;
      SELECT * FROM whoami
    } $c
  } $c
}
for {set i 0} {$i < $nConn} {incr i} {
  set c db$i
  do_test wal3-9.2.$i {
    execsql { SELECT * FROM whoami } $c
  } $c
}

set sz [expr 1024 * (2+$AUTOVACUUM)]
do_test wal3-9.3 {
  for {set i 0} {$i < ($nConn-1)} {incr i} { db$i close }
  execsql { PRAGMA wal_checkpoint } 
  byte_is_zero test.db [expr $sz-1024]
} {1}
do_test wal3-9.4 {
  db[expr $nConn-1] close
  execsql { PRAGMA wal_checkpoint } 
  set sz2 [file size test.db]
  byte_is_zero test.db [expr $sz-1024]
} {0}

do_multiclient_test tn {
  do_test wal3-10.$tn.1 {