review request Bug 17116 - StackTrace::SlowUnwindStack dead locked

[Evgeniy Stepanov]

On Mon, Sep 9, 2013 at 2:09 PM, 林作健 <manjian2006 at gmail.com> wrote:
> Index: lib/asan/asan_thread.h
> ===================================================================
> --- lib/asan/asan_thread.h (revision 190121)
> +++ lib/asan/asan_thread.h (working copy)
> @@ -36,10 +36,12 @@
>    explicit AsanThreadContext(int tid)
>        : ThreadContextBase(tid),
>          announced(false),
> +        stacktracing(false),
>          thread(0) {
>      internal_memset(&stack, 0, sizeof(stack));
>    }
>    bool announced;
> +  bool stacktracing;

Thread context objects live forever. Please move this to AsanThread.

>    StackTrace stack;
>    AsanThread *thread;
>
> @@ -86,6 +88,12 @@
>      UnmapOrDie(fake_stack_, sizeof(FakeStack));
>    }
>    FakeStack *fake_stack() { return fake_stack_; }
> +  bool isStacktracing() {
> +    if (context()) {
> +      return context()->stacktracing;
> +    }
> +    return false;
> +  }
>
>    AsanThreadLocalMallocStorage &malloc_storage() { return malloc_storage_;
> }
>    AsanStats &stats() { return stats_; }
> @@ -107,6 +115,24 @@
>    AsanStats stats_;
>  };
>
> +// AsanStacktracingSink is a sink for stacktracing member of a context
> +class AsanStacktracingSink {

Please call it ScopedSomething. M/b ScopedInStackTrace or ScopedStacktracing.

> +  public:
> +    AsanStacktracingSink(AsanThread * t)
> +      : thread(t) {
> +      if(t->context()) {
> +        t->context()->stacktracing = true;
> +      }
> +    }
> +    ~AsanStacktracingSink() {
> +      if(thread->context()) {
> +        thread->context()->stacktracing = false;
> +      }
> +    }
> +  private:
> +    AsanThread * thread;
> +};
> +
>  struct CreateThreadContextArgs {
>    AsanThread *thread;
>    StackTrace *stack;
> Index: lib/asan/asan_stack.h
> ===================================================================
> --- lib/asan/asan_stack.h (revision 190121)
> +++ lib/asan/asan_stack.h (working copy)
> @@ -36,14 +36,16 @@
>  #define GET_STACK_TRACE_WITH_PC_AND_BP(max_s, pc, bp, fast)     \
>    StackTrace stack;                                             \
>    {                                                             \
> -    uptr stack_top = 0, stack_bottom = 0;                       \
>      AsanThread *t;                                              \
> -    if (asan_inited && (t = GetCurrentThread())) {              \
> -      stack_top = t->stack_top();                               \
> -      stack_bottom = t->stack_bottom();                         \
> +    stack.size = 0;                                             \
> +    if (asan_inited && (t = GetCurrentThread())                 \
> +        && !t->isStacktracing()) {                              \
> +      uptr stack_top = t->stack_top();                          \
> +      uptr stack_bottom = t->stack_bottom();                    \
> +      AsanStacktracingSink sink(t);                             \
> +      GetStackTrace(&stack, max_s, pc, bp,                      \
> +                    stack_top, stack_bottom, fast);             \
>      }                                                           \
> -    GetStackTrace(&stack, max_s, pc, bp,                        \
> -                  stack_top, stack_bottom, fast);               \
>    }
>  #endif  // SANITIZER_WINDOWS
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>