Improve error handling: add counters for internal, other and because of ban errors/fails, provide source of errors and reasons of coroutine cancellations

2 files changed, 20 insertions, 9 deletions

diff --git a/library/cpp/coroutine/engine/impl.cpp b/library/cpp/coroutine/engine/impl.cpp
index 08f358127da..ac116af0c1c 100644
--- a/library/cpp/coroutine/engine/impl.cpp
+++ b/library/cpp/coroutine/engine/impl.cpp
@@ -41,14 +41,18 @@ void TCont::PrintMe(IOutputStream& out) const noexcept {
         << ")";
 }
 
-bool TCont::Join(TCont* c, TInstant deadLine) noexcept {
+bool TCont::Join(TCont* c, TInstant deadLine, std::function<void(TJoinWait&, TCont*)> forceStop) noexcept {
     TJoinWait ev(*this);
     c->Waiters_.PushBack(&ev);
 
     do {
         if (SleepD(deadLine) == ETIMEDOUT || Cancelled()) {
             if (!ev.Empty()) {
-                c->Cancel();
+                if (forceStop) {
+                    forceStop(ev, c);
+                } else {
+                    c->Cancel();
+                }
 
                 do {
                     Switch();
@@ -108,7 +112,7 @@ void TCont::Cancel() noexcept {
 
 void TCont::Cancel(THolder<std::exception> exception) noexcept {
     if (!Cancelled()) {
-        Exception_ = std::move(exception);
+        SetException(std::move(exception));
         Cancel();
     }
 }
diff --git a/library/cpp/coroutine/engine/impl.h b/library/cpp/coroutine/engine/impl.h
index ca523cdaf30..ec4af17fcf9 100644
--- a/library/cpp/coroutine/engine/impl.h
+++ b/library/cpp/coroutine/engine/impl.h
@@ -30,6 +30,12 @@ namespace NCoro::NStack {
 }
 
 class TCont : private TIntrusiveListItem<TCont> {
+    friend class TContExecutor;
+    friend class TIntrusiveListItem<TCont>;
+    friend class NCoro::TEventWaitQueue;
+    friend class NCoro::TTrampoline;
+
+public:
     struct TJoinWait: public TIntrusiveListItem<TJoinWait> {
         TJoinWait(TCont& c) noexcept;
 
@@ -39,11 +45,6 @@ class TCont : private TIntrusiveListItem<TCont> {
         TCont& Cont_;
     };
 
-    friend class TContExecutor;
-    friend class TIntrusiveListItem<TCont>;
-    friend class NCoro::TEventWaitQueue;
-    friend class NCoro::TTrampoline;
-
 private:
     TCont(
         NCoro::NStack::IAllocator& allocator,
@@ -99,7 +100,9 @@ public:
     /// \param this корутина, которая будет ждать
     /// \param c корутина, которую будем ждать
     /// \param deadLine максимальное время ожидания
-    bool Join(TCont* c, TInstant deadLine = TInstant::Max()) noexcept;
+    /// \param forceStop кастомный обработчик ситуации, когда завершается время ожидания или отменяется ожидающая корутина (this)
+    /// дефолтное поведение - отменить ожидаемую корутину (c->Cancel())
+    bool Join(TCont* c, TInstant deadLine = TInstant::Max(), std::function<void(TJoinWait&, TCont*)> forceStop = {}) noexcept;
 
     void ReSchedule() noexcept;
 
@@ -113,6 +116,10 @@ public:
         return std::move(Exception_);
     }
 
+    void SetException(THolder<std::exception> exception) noexcept {
+        Exception_ = std::move(exception);
+    }
+
 private:
     void Terminate();