[llvm-branch-commits] [NFC][sanitizer] Add Debug utility to print thread history (PR #111948)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Vitaly Buka (vitalybuka)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/111948.diff


3 Files Affected:

- (modified) compiler-rt/lib/sanitizer_common/CMakeLists.txt (+1) 
- (added) compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp (+73) 
- (added) compiler-rt/lib/sanitizer_common/sanitizer_thread_history.h (+24) 


``````````diff
diff --git a/compiler-rt/lib/sanitizer_common/CMakeLists.txt b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
index 556a64f3017488..09391e4f5f3704 100644
--- a/compiler-rt/lib/sanitizer_common/CMakeLists.txt
+++ b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
@@ -94,6 +94,7 @@ set(SANITIZER_SYMBOLIZER_SOURCES
   sanitizer_symbolizer_report.cpp
   sanitizer_symbolizer_report_fuchsia.cpp
   sanitizer_symbolizer_win.cpp
+  sanitizer_thread_history.cpp
   sanitizer_unwind_linux_libcdep.cpp
   sanitizer_unwind_fuchsia.cpp
   sanitizer_unwind_win.cpp
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp
new file mode 100644
index 00000000000000..32a6ab1b39d3f7
--- /dev/null
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.cpp
@@ -0,0 +1,73 @@
+//===-- sanitizer_thread_history.cpp --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_thread_history.h"
+
+#include "sanitizer_stackdepot.h"
+namespace __sanitizer {
+
+void PrintThreadHistory(ThreadRegistry &registry, InternalScopedString &out) {
+  ThreadRegistryLock l(&registry);
+  // Stack traces are largest part of printout and they offten the same for
+  // multiple threads, so we will deduplicate them.
+  InternalMmapVector<const ThreadContextBase *> stacks;
+
+  registry.RunCallbackForEachThreadLocked(
+      [](ThreadContextBase *context, void *arg) {
+        static_cast<decltype(&stacks)>(arg)->push_back(context);
+      },
+      &stacks);
+
+  Sort(stacks.data(), stacks.size(),
+       [](const ThreadContextBase *a, const ThreadContextBase *b) {
+         if (a->stack_id < b->stack_id)
+           return true;
+         if (a->stack_id > b->stack_id)
+           return false;
+         return a->tid < b->tid;
+       });
+
+  auto describe_thread = [&](const ThreadContextBase *context) {
+    if (!context) {
+      out.Append("T-1");
+      return;
+    }
+    out.AppendF("T%llu/%llu", context->unique_id, context->os_id);
+    if (internal_strlen(context->name))
+      out.AppendF(" (%s)", context->name);
+  };
+
+  auto get_parent =
+      [&](const ThreadContextBase *context) -> const ThreadContextBase * {
+    if (!context)
+      return nullptr;
+    ThreadContextBase *parent = registry.GetThreadLocked(context->parent_tid);
+    if (!parent)
+      return nullptr;
+    if (parent->unique_id >= context->unique_id)
+      return nullptr;
+    return parent;
+  };
+
+  u32 stack_id = 0;
+  for (const ThreadContextBase *context : stacks) {
+    if (stack_id != context->stack_id) {
+      StackDepotGet(stack_id).PrintTo(&out);
+      stack_id = context->stack_id;
+    }
+    out.Append("Thread ");
+    describe_thread(context);
+    out.Append(" was created by ");
+    describe_thread(get_parent(context));
+    out.Append("\n");
+  }
+  if (!stacks.empty())
+    StackDepotGet(stack_id).PrintTo(&out);
+}
+
+}  // namespace __sanitizer
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.h b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.h
new file mode 100644
index 00000000000000..2995f6015fe50e
--- /dev/null
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_thread_history.h
@@ -0,0 +1,24 @@
+//===-- sanitizer_thread_history.h ------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Utility to print thread histroy from ThreadRegistry.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_THREAD_HISTORY_H
+#define SANITIZER_THREAD_HISTORY_H
+
+#include "sanitizer_thread_registry.h"
+
+namespace __sanitizer {
+
+void PrintThreadHistory(ThreadRegistry& registry, InternalScopedString& out);
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_THREAD_HISTORY_H

``````````

</details>


https://github.com/llvm/llvm-project/pull/111948