[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/test/notify2.test

+# 2009 March 04
+#
+# 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.
+#
+#***********************************************************************
+#
+# $Id: notify2.test,v 1.7 2009/03/30 11:59:31 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+if {[run_thread_tests]==0} { finish_test ; return }
+ifcapable !unlock_notify||!shared_cache { finish_test ; return }
+
+# The tests in this file test the sqlite3_blocking_step() function in
+# test_thread.c. sqlite3_blocking_step() is not an SQLite API function,
+# it is just a demonstration of how the sqlite3_unlock_notify() function
+# can be used to synchronize multi-threaded access to SQLite databases
+# in shared-cache mode.
+#
+# Since the implementation of sqlite3_blocking_step() is included on the
+# website as example code, it is important to test that it works.
+#
+# notify2-1.*:
+#
+#   This test uses $nThread threads. Each thread opens the main database
+#   and attaches two other databases. Each database contains a single table.
+#
+#   Each thread repeats transactions over and over for 20 seconds. Each
+#   transaction consists of 3 operations. Each operation is either a read
+#   or a write of one of the tables. The read operations verify an invariant
+#   to make sure that things are working as expected. If an SQLITE_LOCKED
+#   error is returned the current transaction is rolled back immediately.
+#
+#   This exercise is repeated twice, once using sqlite3_step(), and the
+#   other using sqlite3_blocking_step(). The results are compared to ensure
+#   that sqlite3_blocking_step() resulted in higher transaction throughput.
+#
+
+db close
+set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
+
+# Number of threads to run simultaneously.
+#
+set nThread 6
+set nSecond 5
+
+# The Tcl script executed by each of the $nThread threads used by this test.
+#
+set ThreadProgram {
+
+  # Proc used by threads to execute SQL.
+  #
+  proc execsql_blocking {db zSql} {
+    set lRes [list]
+    set rc SQLITE_OK
+
+set sql $zSql
+
+    while {$rc=="SQLITE_OK" && $zSql ne ""} {
+      set STMT [$::xPrepare $db $zSql -1 zSql]
+      while {[set rc [$::xStep $STMT]] eq "SQLITE_ROW"} {
+        for {set i 0} {$i < [sqlite3_column_count $STMT]} {incr i} {
+          lappend lRes [sqlite3_column_text $STMT 0]
+        }
+      }
+      set rc [sqlite3_finalize $STMT]
+    }
+
+    if {$rc != "SQLITE_OK"} { error "$rc $sql [sqlite3_errmsg $db]" }
+    return $lRes
+  }
+
+  proc execsql_retry {db sql} { 
+    set msg "SQLITE_LOCKED blah..."
+    while { [string match SQLITE_LOCKED* $msg] } {
+      catch { execsql_blocking $db $sql } msg
+    }
+  }
+
+  proc select_one {args} {
+    set n [llength $args]
+    lindex $args [expr int($n*rand())]
+  }
+
+  proc opendb {} {
+    # Open a database connection. Attach the two auxillary databases.
+    set ::DB [sqlite3_open test.db]
+    execsql_retry $::DB { ATTACH 'test2.db' AS aux2; }
+    execsql_retry $::DB { ATTACH 'test3.db' AS aux3; }
+  }
+
+  opendb
+
+  #after 2000
+
+  # This loop runs for ~20 seconds.
+  #
+  set iStart [clock_seconds]
+  set nOp 0
+  set nAttempt 0
+  while { ([clock_seconds]-$iStart) < $nSecond } {
+
+    # Each transaction does 3 operations. Each operation is either a read
+    # or write of a randomly selected table (t1, t2 or t3). Set the variables
+    # $SQL(1), $SQL(2) and $SQL(3) to the SQL commands used to implement
+    # each operation.
+    #
+    for {set ii 1} {$ii <= 3} {incr ii} {
+      foreach {tbl database} [select_one {t1 main} {t2 aux2} {t3 aux3}] {}
+
+      set SQL($ii) [string map [list xxx $tbl yyy $database] [select_one {
+            SELECT 
+              (SELECT b FROM xxx WHERE a=(SELECT max(a) FROM xxx))==total(a) 
+              FROM xxx WHERE a!=(SELECT max(a) FROM xxx);
+      } {
+            DELETE FROM xxx WHERE a<(SELECT max(a)-100 FROM xxx);
+            INSERT INTO xxx SELECT NULL, total(a) FROM xxx;
+      } {
+            CREATE INDEX IF NOT EXISTS yyy.xxx_i ON xxx(b);
+      } {
+            DROP INDEX IF EXISTS yyy.xxx_i;
+      }
+      ]]
+    }
+
+    # Execute the SQL transaction.
+    #
+    incr nAttempt
+    set rc [catch { execsql_blocking $::DB "
+        BEGIN;
+          $SQL(1);
+          $SQL(2);
+          $SQL(3);
+        COMMIT;
+      "
+    } msg]
+
+    if {$rc && [string match "SQLITE_LOCKED*" $msg]
+            || [string match "SQLITE_SCHEMA*" $msg]
+    } {
+      # Hit an SQLITE_LOCKED error. Rollback the current transaction.
+      set rc [catch { execsql_blocking $::DB ROLLBACK } msg]
+      if {$rc && [string match "SQLITE_LOCKED*" $msg]} {
+        sqlite3_close $::DB
+        opendb
+      } 
+    } elseif {$rc} {
+      # Hit some other kind of error. This is a malfunction.
+      error $msg
+    } else {
+      # No error occurred. Check that any SELECT statements in the transaction
+      # returned "1". Otherwise, the invariant was false, indicating that
+      # some malfunction has occurred.
+      foreach r $msg { if {$r != 1} { puts "Invariant check failed: $msg" } }
+      incr nOp
+    }
+  }
+
+  # Close the database connection and return 0.
+  #
+  sqlite3_close $::DB
+  list $nOp $nAttempt
+}
+
+foreach {iTest xStep xPrepare} {
+  1 sqlite3_blocking_step sqlite3_blocking_prepare_v2
+  2 sqlite3_step          sqlite3_nonblocking_prepare_v2
+} {
+  forcedelete test.db test2.db test3.db
+
+  set ThreadSetup "set xStep $xStep;set xPrepare $xPrepare;set nSecond $nSecond"
+
+  # Set up the database schema used by this test. Each thread opens file
+  # test.db as the main database, then attaches files test2.db and test3.db
+  # as auxillary databases. Each file contains a single table (t1, t2 and t3, in
+  # files test.db, test2.db and test3.db, respectively). 
+  #
+  do_test notify2-$iTest.1.1 {
+    sqlite3 db test.db
+    execsql {
+      ATTACH 'test2.db' AS aux2;
+      ATTACH 'test3.db' AS aux3;
+      CREATE TABLE main.t1(a INTEGER PRIMARY KEY, b);
+      CREATE TABLE aux2.t2(a INTEGER PRIMARY KEY, b);
+      CREATE TABLE aux3.t3(a INTEGER PRIMARY KEY, b);
+      INSERT INTO t1 SELECT NULL, 0;
+      INSERT INTO t2 SELECT NULL, 0;
+      INSERT INTO t3 SELECT NULL, 0;
+    }
+  } {}
+  do_test notify2-$iTest.1.2 {
+    db close
+  } {}
+
+
+  # Launch $nThread threads. Then wait for them to finish.
+  #
+  puts "Running $xStep test for $nSecond seconds"
+  unset -nocomplain finished
+  for {set ii 0} {$ii < $nThread} {incr ii} {
+    thread_spawn finished($ii) $ThreadSetup $ThreadProgram
+  }
+  for {set ii 0} {$ii < $nThread} {incr ii} {
+    do_test notify2-$iTest.2.$ii {
+      if {![info exists finished($ii)]} { vwait finished($ii) }
+      incr anSuccess($xStep) [lindex $finished($ii) 0]
+      incr anAttempt($xStep) [lindex $finished($ii) 1]
+      expr 0
+    } {0}
+  }
+
+  # Count the total number of succesful writes.
+  do_test notify2-$iTest.3.1 {
+    sqlite3 db test.db
+    execsql {
+      ATTACH 'test2.db' AS aux2;
+      ATTACH 'test3.db' AS aux3;
+    }
+    set anWrite($xStep) [execsql {
+      SELECT (SELECT max(a) FROM t1)
+           + (SELECT max(a) FROM t2)
+           + (SELECT max(a) FROM t3)
+    }]
+    db close
+  } {}
+}
+
+# The following tests checks to make sure sqlite3_blocking_step() is
+# faster than sqlite3_step(). "Faster" in this case means uses fewer
+# CPU cycles. This is not always the same as faster in wall-clock time 
+# for this type of test. The number of CPU cycles per transaction is 
+# roughly proportional to the number of attempts made (i.e. one plus the 
+# number of SQLITE_BUSY or SQLITE_LOCKED errors that require the transaction 
+# to be retried). So this test just measures that a greater percentage of
+# transactions attempted using blocking_step() succeed.
+#
+# The blocking_step() function is almost always faster on multi-core and is
+# usually faster on single-core.  But sometimes, by chance, step() will be
+# faster on a single core, in which case the
+# following test will fail.
+#
+puts "The following test seeks to demonstrate that the sqlite3_unlock_notify()"
+puts "interface helps multi-core systems to run more efficiently.  This test"
+puts "sometimes fails on single-core machines."
+puts [array get anWrite]
+do_test notify2-3 {
+  set blocking [expr {
+    double($anSuccess(sqlite3_blocking_step)) /
+    double($anAttempt(sqlite3_blocking_step)) 
+  }]
+  set non [expr {
+    double($anSuccess(sqlite3_step)) /
+    double($anAttempt(sqlite3_step)) 
+  }]
+  puts -nonewline [format " blocking: %.1f%% non-blocking %.1f%% ..." \
+    [expr $blocking*100.0] [expr $non*100.0]]
+
+  expr {$blocking > $non}
+} {1}
+
+sqlite3_enable_shared_cache $::enable_shared_cache
+finish_test