# 2013 May 14 # # 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. # #*********************************************************************** # # Test some specific circumstances to do with shared cache mode. # set testdir [file dirname $argv0] source $testdir/tester.tcl if {[run_thread_tests]==0} { finish_test ; return } db close set ::testprefix sharedA set ::enable_shared_cache [sqlite3_enable_shared_cache 1] #------------------------------------------------------------------------- # do_test 0.1 { sqlite3 db1 test.db sqlite3 db2 test.db db1 eval { CREATE TABLE t1(x); INSERT INTO t1 VALUES(randomblob(100)); INSERT INTO t1 SELECT randomblob(100) FROM t1; INSERT INTO t1 SELECT randomblob(100) FROM t1; INSERT INTO t1 SELECT randomblob(100) FROM t1; INSERT INTO t1 SELECT randomblob(100) FROM t1; INSERT INTO t1 SELECT randomblob(100) FROM t1; INSERT INTO t1 SELECT randomblob(100) FROM t1; CREATE INDEX i1 ON t1(x); } db1 eval { BEGIN; DROP INDEX i1; } db2 close db1 eval { INSERT INTO t1 SELECT randomblob(100) FROM t1; ROLLBACK; PRAGMA integrity_check; } } {ok} db1 close forcedelete test.db #------------------------------------------------------------------------- # do_test 1.1 { sqlite3 db1 test.db sqlite3 db2 test.db db2 eval { CREATE TABLE t1(x); INSERT INTO t1 VALUES(123); } db1 eval { SELECT * FROM t1; CREATE INDEX i1 ON t1(x); } } {123} do_test 1.2 { db2 eval { SELECT * FROM t1 ORDER BY x; } db1 eval { BEGIN; DROP INDEX i1; } db1 close db2 eval { SELECT * FROM t1 ORDER BY x; } } {123} do_test 1.3 { db2 close } {} #------------------------------------------------------------------------- # # sqlite3RollbackAll() loops through all attached b-trees and rolls # back each one separately. Then if the SQLITE_InternChanges flag is # set, it resets the schema. Both of the above steps must be done # while holding a mutex, otherwise another thread might slip in and # try to use the new schema with the old data. # # The following sequence of tests attempt to verify that the actions # taken by sqlite3RollbackAll() are thread-atomic (that they cannot be # interrupted by a separate thread.) # # Note that a TCL interpreter can only be used within the thread in which # it was originally created (because it uses thread-local-storage). # The tvfs callbacks must therefore only run on the main thread. # There is some trickery in the read_callback procedure to ensure that # this is the case. # testvfs tvfs # Set up two databases and two database connections. # # db1: main(test.db), two(test2.db) # db2: main(test.db) # # The cache for test.db is shared between db1 and db2. # do_test 2.1 { forcedelete test.db test.db2 sqlite3 db1 test.db -vfs tvfs db1 eval { ATTACH 'test.db2' AS two } db1 eval { CREATE TABLE t1(x); INSERT INTO t1 VALUES(1); INSERT INTO t1 VALUES(2); INSERT INTO t1 VALUES(3); CREATE TABLE two.t2(x); INSERT INTO t2 SELECT * FROM t1; } sqlite3 db2 test.db -vfs tvfs db2 eval { SELECT * FROM t1 } } {1 2 3} # Create a prepared statement on db2 that will attempt a schema change # in test.db. Meanwhile, start a transaction on db1 that changes # the schema of test.db and that creates a rollback journal on test2.db # do_test 2.2 { set ::STMT [sqlite3_prepare db2 "CREATE INDEX i1 ON t1(x)" -1 tail] db1 eval { BEGIN; CREATE INDEX i1 ON t1(x); INSERT INTO t2 VALUES('value!'); } } {} # Set up a callback that will cause db2 to try to execute its # schema change when db1 accesses the journal file of test2.db. # # This callback will be invoked after the content of test.db has # be rolled back but before the schema has been reset. If the # sqlite3RollbackAll() operation is not thread-atomic, then the # db2 statement in the callback will see old content with the newer # schema, which is wrong. # tvfs filter xRead tvfs script read_callback unset -nocomplain ::some_time_laster unset -nocomplain ::thread_result proc read_callback {call file args} { if {[string match *test.db2-journal $file]} { tvfs filter {} ;# Ensure that tvfs callbacks to do run on the # child thread sqlthread spawn ::thread_result [subst -nocommands { sqlite3_step $::STMT set rc [sqlite3_finalize $::STMT] }] after 1000 { set ::some_time_later 1 } vwait ::some_time_later } } do_test 2.3 { db1 eval ROLLBACK } {} # Verify that the db2 statement invoked by the callback detected the # schema change. # if {[info exists ::thread_result]==0} { vwait ::thread_result } do_test 2.4 { list $::thread_result [sqlite3_errmsg db2] } {SQLITE_SCHEMA {database schema has changed}} db1 close db2 close tvfs delete sqlite3_enable_shared_cache $::enable_shared_cache finish_test