[Lldb-commits] [lldb] 791b6eb - [lldb] Speculative fix to TestGuiExpandThreadsTree

[Pavel Labath via lldb-commits]

Author: Pavel Labath
Date: 2021-09-21T10:01:00+02:00
New Revision: 791b6ebc86680168d634103b67a92a354c075cc4

URL: https://github.com/llvm/llvm-project/commit/791b6ebc86680168d634103b67a92a354c075cc4
DIFF: https://github.com/llvm/llvm-project/commit/791b6ebc86680168d634103b67a92a354c075cc4.diff

LOG: [lldb] Speculative fix to TestGuiExpandThreadsTree

This test relies on being able to unwind from an arbitrary place inside
libc. While I am not sure this is the cause of the observed flakyness,
it is known that we are not able to unwind correctly from some places in
(linux) libc.

This patch adds additional synchronization to ensure that the inferior
is in the main function (instead of pthread guts) when lldb tries to
unwind it. At the very least, it should make the test runs more
predictable/repeatable.

Added: 
    lldb/test/API/commands/gui/expand-threads-tree/main.cpp

Modified: 
    lldb/test/API/commands/gui/expand-threads-tree/Makefile
    lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py

Removed: 
    lldb/test/API/commands/gui/expand-threads-tree/main.c


################################################################################
diff  --git a/lldb/test/API/commands/gui/expand-threads-tree/Makefile b/lldb/test/API/commands/gui/expand-threads-tree/Makefile
index 0c11fbdd8669c..566938ca0cc4e 100644
--- a/lldb/test/API/commands/gui/expand-threads-tree/Makefile
+++ b/lldb/test/API/commands/gui/expand-threads-tree/Makefile
@@ -1,3 +1,3 @@
-C_SOURCES := main.c
+CXX_SOURCES := main.cpp
 ENABLE_THREADS := YES
 include Makefile.rules

diff  --git a/lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py b/lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py
index c3ec4b285ecd0..9eed5b0ef6c39 100644
--- a/lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py
+++ b/lldb/test/API/commands/gui/expand-threads-tree/TestGuiExpandThreadsTree.py
@@ -22,7 +22,7 @@ def test_gui(self):
         self.build()
 
         self.launch(executable=self.getBuildArtifact("a.out"), dimensions=(100,500))
-        self.expect("breakpoint set -r thread_start_routine", substrs=["Breakpoint 1", "address ="])
+        self.expect("breakpoint set -n break_here", substrs=["Breakpoint 1", "address ="])
         self.expect("run", substrs=["stop reason ="])
 
         escape_key = chr(27).encode()
@@ -33,7 +33,7 @@ def test_gui(self):
         self.child.expect_exact("Threads")
 
         # The thread running thread_start_routine should be expanded.
-        self.child.expect_exact("frame #0: thread_start_routine")
+        self.child.expect_exact("frame #0: break_here")
 
         # Exit GUI.
         self.child.send(escape_key)

diff  --git a/lldb/test/API/commands/gui/expand-threads-tree/main.c b/lldb/test/API/commands/gui/expand-threads-tree/main.c
deleted file mode 100644
index 32e6d17c799a6..0000000000000
--- a/lldb/test/API/commands/gui/expand-threads-tree/main.c
+++ /dev/null
@@ -1,10 +0,0 @@
-#include <pthread.h>
-
-void *thread_start_routine(void *arg) { return NULL; }
-
-int main() {
-  pthread_t thread;
-  pthread_create(&thread, NULL, thread_start_routine, NULL);
-  pthread_join(thread, NULL);
-  return 0;
-}

diff  --git a/lldb/test/API/commands/gui/expand-threads-tree/main.cpp b/lldb/test/API/commands/gui/expand-threads-tree/main.cpp
new file mode 100644
index 0000000000000..5a7cbb78563c0
--- /dev/null
+++ b/lldb/test/API/commands/gui/expand-threads-tree/main.cpp
@@ -0,0 +1,24 @@
+#include "pseudo_barrier.h"
+#include <thread>
+
+
+pseudo_barrier_t barrier_before;
+pseudo_barrier_t barrier_after;
+
+void break_here() {}
+
+void thread_func() {
+    pseudo_barrier_wait(barrier_before);
+    break_here();
+    pseudo_barrier_wait(barrier_after);
+}
+
+int main() {
+  pseudo_barrier_init(barrier_before, 2);
+  pseudo_barrier_init(barrier_after, 2);
+  std::thread thread(thread_func);
+  pseudo_barrier_wait(barrier_before);
+  pseudo_barrier_wait(barrier_after);
+  thread.join();
+  return 0;
+}