Adding the sqlite sourcecode

test/walsetlk_snapshot.test

@@ -0,0 +1,109 @@
+# 2025 May 30
+#
+# 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.
+#
+#***********************************************************************
+#
+# TESTRUNNER: slow
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set testprefix walsetlk_snapshot
+
+ifcapable !wal {finish_test ; return }
+ifcapable !snapshot {finish_test; return}
+
+db close
+testvfs tvfs -fullshm 1
+sqlite3 db test.db -vfs tvfs
+tvfs script sleep_callback
+tvfs filter xSleep
+set ::sleep_count 0
+proc sleep_callback {args} {
+  incr ::sleep_count
+}
+
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a, b);
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES(3, 4);
+  INSERT INTO t1 VALUES(5, 6);
+} {wal}
+
+do_test 1.1 {
+  db eval BEGIN
+  set ::snap [sqlite3_snapshot_get db main]
+  db eval {
+    INSERT INTO t1 VALUES(7, 8);
+    COMMIT;
+  }
+} {}
+
+testfixture_nb myvar {
+
+  testvfs tvfs -fullshm 1
+  sqlite3 db test.db -vfs tvfs
+  tvfs script vfs_callback
+  tvfs filter {xWrite}
+
+  set ::done 0
+  proc vfs_callback {args} {
+    if {$::done==0} {
+      after 4000
+      set ::done 1
+    }
+    return "SQLITE_OK"
+  }
+
+  db eval {
+    PRAGMA wal_checkpoint;
+  }
+
+  db close
+}
+
+# Give the [testfixture_nb] command time to start
+after 1000 {set xyz 1}
+vwait xyz
+
+db timeout 500
+set tm [lindex [time {
+  catch {
+    db eval BEGIN
+      sqlite3_snapshot_open db main $::snap
+  } msg
+}] 0]
+
+do_test 1.2 { set ::msg } {SQLITE_BUSY}
+do_test 1.3.($::tm) { expr $::tm<2000000 } 1
+
+do_execsql_test 1.4 {
+  SELECT * FROM t1
+} {1 2 3 4 5 6 7 8}
+
+sqlite3_snapshot_free $::snap
+
+vwait myvar
+
+# All SQLite builds should pass the tests above. SQLITE_ENABLE_SETLK_TIMEOUT=1
+# builds do so without calling the VFS xSleep method.
+if {$::sqlite_options(setlk_timeout)==1} {
+  do_test 1.5.1 {
+    set ::sleep_count
+  } 0
+} else {
+  do_test 1.5.2 {
+    expr $::sleep_count>0
+  } 1
+}
+
+finish_test
+