1# 2008 May 12
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#
12# This file tests that if sqlite3_release_memory() is called to reclaim
13# memory from a pager that is in the error-state, SQLite does not
14# incorrectly write dirty pages out to the database (not safe to do
15# once the pager is in error state).
16#
17# $Id: ioerr5.test,v 1.5 2008/08/28 18:35:34 danielk1977 Exp $
18
19set testdir [file dirname $argv0]
20source $testdir/tester.tcl
21
22ifcapable !memorymanage||!shared_cache {
23  finish_test
24  return
25}
26
27db close
28
29set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
30set ::soft_limit [sqlite3_soft_heap_limit 1048576]
31
32# This procedure prepares, steps and finalizes an SQL statement via the
33# UTF-16 APIs. The text representation of an SQLite error code is returned
34# ("SQLITE_OK", "SQLITE_IOERR" etc.). The actual results returned by the
35# SQL statement, if it is a SELECT, are not available.
36#
37# This can be useful for testing because it forces SQLite to make an extra
38# call to sqlite3_malloc() when translating from the supplied UTF-16 to
39# the UTF-8 encoding used internally.
40#
41proc dosql16 {zSql {db db}} {
42  set sql [encoding convertto unicode $zSql]
43  append sql "\00\00"
44  set stmt [sqlite3_prepare16 $db $sql -1 {}]
45  sqlite3_step $stmt
46  set rc [sqlite3_finalize $stmt]
47}
48
49proc compilesql16 {zSql {db db}} {
50  set sql [encoding convertto unicode $zSql]
51  append sql "\00\00"
52  set stmt [sqlite3_prepare16 $db $sql -1 {}]
53  set rc [sqlite3_finalize $stmt]
54}
55
56# Open two database connections (handle db and db2) to database "test.db".
57#
58proc opendatabases {} {
59  catch {db close}
60  catch {db2 close}
61  sqlite3 db test.db
62  sqlite3 db2 test.db
63  db2 cache size 0
64  db cache size 0
65  execsql {
66    pragma page_size=512;
67    pragma auto_vacuum=2;
68    pragma cache_size=16;
69  }
70}
71
72# Open two database connections and create a single table in the db.
73#
74do_test ioerr5-1.0 {
75  opendatabases
76  execsql { CREATE TABLE A(Id INTEGER, Name TEXT) }
77} {}
78
79foreach locking_mode {normal exclusive} {
80  set nPage 2
81  for {set iFail 1} {$iFail<200} {incr iFail} {
82    sqlite3_soft_heap_limit 1048576
83    opendatabases
84    execsql { pragma locking_mode=exclusive }
85    set nRow [db one {SELECT count(*) FROM a}]
86
87    # Dirty (at least) one of the pages in the cache.
88    do_test ioerr5-1.$locking_mode-$iFail.1 {
89      execsql {
90        BEGIN EXCLUSIVE;
91        INSERT INTO a VALUES(1, 'ABCDEFGHIJKLMNOP');
92      }
93    } {}
94
95    # Open a read-only cursor on table "a". If the COMMIT below is
96    # interrupted by a persistent IO error, the pager will transition to
97    # PAGER_ERROR state. If there are no other read-only cursors open,
98    # from there the pager immediately discards all cached data and
99    # switches to PAGER_OPEN state. This read-only cursor stops that
100    # from happening, leaving the pager stuck in PAGER_ERROR state.
101    #
102    set channel [db incrblob -readonly a Name [db last_insert_rowid]]
103
104    # Now try to commit the transaction. Cause an IO error to occur
105    # within this operation, which moves the pager into the error state.
106    #
107    set ::sqlite_io_error_persist 1
108    set ::sqlite_io_error_pending $iFail
109    do_test ioerr5-1.$locking_mode-$iFail.2 {
110      set rc [catchsql {COMMIT}]
111      list
112    } {}
113    set ::sqlite_io_error_hit 0
114    set ::sqlite_io_error_persist 0
115    set ::sqlite_io_error_pending 0
116
117    # Read the contents of the database file into a Tcl variable.
118    #
119    set fd [open test.db]
120    fconfigure $fd -translation binary -encoding binary
121    set zDatabase [read $fd]
122    close $fd
123
124    # Set a very low soft-limit and then try to compile an SQL statement
125    # from UTF-16 text. To do this, SQLite will need to reclaim memory
126    # from the pager that is in error state. Including that associated
127    # with the dirty page.
128    #
129    do_test ioerr5-1.$locking_mode-$iFail.3 {
130      sqlite3_soft_heap_limit 1024
131      compilesql16 "SELECT 10"
132    } {SQLITE_OK}
133
134    close $channel
135
136    # Ensure that nothing was written to the database while reclaiming
137    # memory from the pager in error state.
138    #
139    do_test ioerr5-1.$locking_mode-$iFail.4 {
140      set fd [open test.db]
141      fconfigure $fd -translation binary -encoding binary
142      set zDatabase2 [read $fd]
143      close $fd
144      expr {$zDatabase eq $zDatabase2}
145    } {1}
146
147    if {$rc eq [list 0 {}]} {
148      do_test ioerr5.1-$locking_mode-$iFail.3 {
149        execsql { SELECT count(*) FROM a }
150      } [expr $nRow+1]
151      break
152    }
153  }
154}
155
156# Make sure this test script doesn't leave any files open.
157#
158do_test ioerr5-1.X {
159  catch { db close }
160  catch { db2 close }
161  set sqlite_open_file_count
162} 0
163
164do_test ioerr5-2.0 {
165  sqlite3 db test.db
166  execsql { CREATE INDEX i1 ON a(id, name); }
167} {}
168
169foreach locking_mode {exclusive normal} {
170  for {set iFail 1} {$iFail<200} {incr iFail} {
171    sqlite3_soft_heap_limit 1048576
172    opendatabases
173    execsql { pragma locking_mode=exclusive }
174    set nRow [db one {SELECT count(*) FROM a}]
175
176    do_test ioerr5-2.$locking_mode-$iFail.1 {
177      execsql {
178        BEGIN EXCLUSIVE;
179        INSERT INTO a VALUES(1, 'ABCDEFGHIJKLMNOP');
180      }
181    } {}
182
183    set ::sqlite_io_error_persist 1
184    set ::sqlite_io_error_pending $iFail
185
186    sqlite3_release_memory 10000
187
188    set error_hit $::sqlite_io_error_hit
189    set ::sqlite_io_error_hit 0
190    set ::sqlite_io_error_persist 0
191    set ::sqlite_io_error_pending 0
192    if {$error_hit} {
193      do_test ioerr5-2.$locking_mode-$iFail.3a {
194        catchsql COMMIT
195      } {1 {disk I/O error}}
196    } else {
197      do_test ioerr5-2.$locking_mode-$iFail.3b {
198        execsql COMMIT
199      } {}
200      break
201    }
202  }
203}
204
205# Make sure this test script doesn't leave any files open.
206#
207do_test ioerr5-2.X {
208  catch { db close }
209  catch { db2 close }
210  set sqlite_open_file_count
211} 0
212
213sqlite3_enable_shared_cache $::enable_shared_cache
214sqlite3_soft_heap_limit $::soft_limit
215
216finish_test
217