From 4af1cd99cb58ab76a044ba4ac258ceedfb87e5cd Mon Sep 17 00:00:00 2001
From: Derek Bruening <bruening@google.com>
Date: Fri, 4 Aug 2023 20:46:24 -0400
Subject: [PATCH] i#725 attach: Remove flakiness from attach test (#6244)

Removes the printing of "event_post_attach" in the client.attach test,
as it had non-deterministic ordering versus the "thread init" printing
(and runall.cmake requires "thread init"). Replaces with a boolean check
and error print at exit to ensure we saw the attach event.

This completes the base attach feature. Future problems should open new
issues.

Fixes #725
---
 suite/tests/client-interface/attach_blocking.expect |  1 -
 suite/tests/client-interface/attach_test.dll.c      | 10 +++++++---
 suite/tests/client-interface/attach_test.template   |  6 ------
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/suite/tests/client-interface/attach_blocking.expect b/suite/tests/client-interface/attach_blocking.expect
index 8c81d0b06f0..fe3e4f72bc3 100644
--- a/suite/tests/client-interface/attach_blocking.expect
+++ b/suite/tests/client-interface/attach_blocking.expect
@@ -1,5 +1,4 @@
 starting
 thank you for testing attach
 thread init
-event_post_attach
 done
diff --git a/suite/tests/client-interface/attach_test.dll.c b/suite/tests/client-interface/attach_test.dll.c
index 9112834d6b0..ceeefb9a6fd 100644
--- a/suite/tests/client-interface/attach_test.dll.c
+++ b/suite/tests/client-interface/attach_test.dll.c
@@ -1,5 +1,5 @@
 /* **********************************************************
- * Copyright (c) 2021-2022 Google, Inc.  All rights reserved.
+ * Copyright (c) 2021-2023 Google, Inc.  All rights reserved.
  * Copyright (c) 2008-2010 VMware, Inc.  All rights reserved.
  * **********************************************************/
 
@@ -39,14 +39,17 @@
 
 static thread_id_t injection_tid;
 static bool first_thread = true;
+static bool saw_attach_event = false;
 
 static void
 dr_exit(void)
 {
+    if (!saw_attach_event)
+        dr_fprintf(STDERR, "Error: never saw attach event!\n");
 #ifdef WINDOWS
     dr_fprintf(STDERR, "done\n");
 #else
-    /* The app prints 'done' for us. */
+        /* The app prints 'done' for us. */
 #endif
 }
 
@@ -91,7 +94,8 @@ dr_exception_event(void *drcontext, dr_exception_t *excpt)
 static void
 event_post_attach(void)
 {
-    dr_fprintf(STDERR, "%s\n", __FUNCTION__);
+    // We do not print here as the ordering is non-deterministic vs thread init.
+    saw_attach_event = true;
 }
 
 DR_EXPORT
diff --git a/suite/tests/client-interface/attach_test.template b/suite/tests/client-interface/attach_test.template
index 2870bba300d..b6e88d2236b 100644
--- a/suite/tests/client-interface/attach_test.template
+++ b/suite/tests/client-interface/attach_test.template
@@ -4,13 +4,7 @@ starting attachee
 starting
 #endif
 thank you for testing attach
-#ifdef WINDOWS
-event_post_attach
-thread init
-#else
 thread init
-event_post_attach
-#endif
 #ifdef WINDOWS
 MessageBox closed
 #endif