Add multi-threaded test for "INSERT ... RETURNING ..." and SQLITE_BUSY errors.

FossilOrigin-Name: 559cb1c6de384fd14160db005acaf1858b8b018d3d40d7f786a56a49d3cdbd59

manifest

@@ -1,5 +1,5 @@
-C Make\sthe\sregexp\sextension\smore\srobust\sagainst\sOOM\serrors\sduring\scompilation\nof\sthe\srecognizer\sengine.\n[forum:/forumpost/f50aecd5e8|Forum\spost\sf50aecd5e8].
-D 2023-05-12T15:45:34.949
+C Add\smulti-threaded\stest\sfor\s"INSERT\s...\sRETURNING\s..."\sand\sSQLITE_BUSY\serrors.
+D 2023-05-12T19:02:50.042
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@@ -1595,6 +1595,7 @@ F test/thread004.test f51dfc3936184aaf73ee85f315224baad272a87f
 F test/thread005.test 50d10b5684399676174bd96c94ad4250b1a2c8b6
 F test/thread1.test df115faa10a4ba1d456e9d4d9ec165016903eae4
 F test/thread2.test f35d2106452b77523b3a2b7d1dcde2e5ee8f9e46
+F test/thread3.test 5f53b6a8e7391d8653116fd0bee4f9774efee4410e039990821de39c6b4375a9
 F test/thread_common.tcl 334639cadcb9f912bf82aa73f49efd5282e6cadd
 F test/threadtest1.c 6029d9c5567db28e6dc908a0c63099c3ba6c383b
 F test/threadtest2.c a70a8e94bef23339d34226eb9521015ef99f4df8
@@ -2068,8 +2069,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
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+U dan
+Z c00872b8cf2e35e5cd276b5a40cad3e4
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-0772ddf56713d013cd1bd44f9c75977ca14f852e3a8f038b0a6b9814f6519d79
+559cb1c6de384fd14160db005acaf1858b8b018d3d40d7f786a56a49d3cdbd59

test/thread3.test

@@ -0,0 +1,78 @@
+# 2023 May 13
+#
+# 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.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+if {[run_thread_tests]==0} { finish_test ; return }
+
+set testprefix thread3
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b);
+  PRAGMA journal_mode = DELETE;
+} {delete}
+
+proc wait_for_var {varname} {
+  if {0==[uplevel [list info exists $varname]]} {
+    uplevel [list vwait $varname]
+  }
+  uplevel [list set $varname]
+}
+
+set nAttempt 250
+
+do_test 1.1 {
+  for {set i 0} {$i < $nAttempt} {incr i} {
+    unset -nocomplain X
+    unset -nocomplain Y
+
+    sqlthread spawn X {
+      sqlite3 dbI test.db
+      dbI timeout 100
+      set rc 1
+      set nBusy 0
+      while {$rc} {
+        set rc [catch {
+          dbI eval { INSERT INTO t1 VALUES(203, 'message') RETURNING a; }
+        } msg]
+        if {$rc} { incr nBusy }
+      }
+      dbI close
+      set nBusy
+    }
+
+    sqlthread spawn Y {
+      sqlite3 dbR test.db
+      catch {
+        dbR eval { SELECT count(*) FROM t1 }
+      } msg
+      dbR close
+      set msg
+    }
+
+    wait_for_var X
+    wait_for_var Y
+    incr nTotalBusy $X
+  }
+
+  execsql { SELECT count(*) FROM t1 }
+  set {} {}
+} {}
+
+do_execsql_test "1.Total BUSY errors: $nTotalBusy .2" {
+  SELECT count(*) FROM t1;
+} $nAttempt
+
+finish_test
+