xref: /sqlite-3.40.0/test/tkt3793.test (revision e5dc4a20)
1# 2009 April 10
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file implements regression tests for SQLite library.
12#
13# This file implements tests to verify that ticket #3793 has been
14# fixed.
15#
16
17
18set testdir [file dirname $argv0]
19source $testdir/tester.tcl
20
21ifcapable !shared_cache||!attach {
22  finish_test
23  return
24}
25set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
26
27do_test tkt3793-1.1 {
28  db close
29  sqlite3 db "file:test.db" -uri 1
30  sqlite3 db1 "file:test.db?cache=private" -uri 1
31  sqlite3 db2 "file:test.db?cache=shared" -uri 1
32  execsql {
33    BEGIN;
34    CREATE TABLE t1(a, b);
35    CREATE TABLE t2(a PRIMARY KEY, b);
36    INSERT INTO t1 VALUES(randstr(50,50), randstr(50,50));
37    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
38    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
39    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
40    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
41    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
42    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
43    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
44    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
45    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
46    INSERT INTO t1 SELECT randstr(50,50), randstr(50,50) FROM t1;
47    INSERT INTO t2 SELECT * FROM t1;
48    COMMIT;
49  }
50} {}
51
52proc busyhandler {db args} { set ::busyconnection $db ; return 1 }
53db2 busy {busyhandler db2}
54db1 busy {busyhandler db1}
55
56# Establish a read-lock on the database file using connection [db].
57#
58do_test tkt3793-1.2 {
59  execsql {
60    BEGIN;
61    SELECT count(*) FROM t1;
62  }
63} {1024}
64
65# Set the size of the cache shared by [db1] and [db2] to 10. Then update
66# more than 10 pages of table t1. At this point the shared-cache will
67# hold a RESERVED lock on the database file. Even though there are now
68# more than 10 dirty pages in memory, it cannot upgrade to an EXCLUSIVE
69# lock because of the read-lock held by [db].
70#
71do_test tkt3793-1.3 {
72  execsql {
73    PRAGMA cache_size = 10;
74    BEGIN;
75    UPDATE t1 SET b = randstr(50,50);
76  } db1
77} {}
78
79set x 0
80
81# Run one SELECT query on the shared-cache using [db1], then from within
82# the callback run another via [db2]. Because of the large number of dirty
83# pages within the cache, each time a new page is read from the database
84# SQLite will attempt to upgrade to an EXCLUSIVE lock, and hence invoke
85# the busy-handler. The tests here verify that the correct busy-handler
86# function is invoked (the busy-handler associated with the database
87# connection that called sqlite3_step()). When bug #3793 existed, sometimes
88# the [db2] busy-handler was invoked from within the call to sqlite3_step()
89# associated with [db1].
90#
91# Note: Before the bug was fixed, if [db2] was opened with the "-fullmutex 1"
92# option, then this test case would cause an assert() to fail.
93#
94ifcapable threadsafe {
95  set ::busyconnection db1
96  db1 eval {SELECT * FROM t2 ORDER BY a LIMIT 20} {
97    do_test tkt3793-2.[incr x] { set ::busyconnection } db1
98    set ::busyconnection db2
99
100    db2 eval { SELECT count(*) FROM t2 }
101    do_test tkt3793-2.[incr x] { set ::busyconnection } db2
102    set ::busyconnection db1
103  }
104}
105
106do_test tkt3793-3 {
107  db1 close
108  db2 close
109} {}
110
111sqlite3_enable_shared_cache $::enable_shared_cache
112finish_test
113