intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 60 insertions, 0 deletions

diff --git a/library/cpp/coroutine/engine/trampoline.h b/library/cpp/coroutine/engine/trampoline.h
new file mode 100644
index 0000000000..37b61cf015
--- /dev/null
+++ b/library/cpp/coroutine/engine/trampoline.h
@@ -0,0 +1,60 @@
+#pragma once
+
+#include "stack/stack_common.h"
+#include "stack/stack.h"
+
+#include <util/generic/noncopyable.h>
+#include <util/generic/ptr.h>
+#include <util/system/context.h>
+#include <util/system/defaults.h>
+
+#if !defined(STACK_GROW_DOWN)
+#   error "unsupported"
+#endif
+
+class TCont;
+typedef void (*TContFunc)(TCont*, void*);
+
+namespace NCoro {
+
+    namespace NStack {
+        class IAllocator;
+    }
+
+    class TTrampoline : public ITrampoLine, TNonCopyable {
+    public:
+        typedef std::function<void (TCont*)> TFunc;
+
+        TTrampoline(
+            NCoro::NStack::IAllocator& allocator,
+            uint32_t stackSize,
+            TFunc f,
+            TCont* cont
+        ) noexcept;
+
+        TArrayRef<char> Stack() noexcept;
+
+        TExceptionSafeContext* Context() noexcept {
+            return &Ctx_;
+        }
+
+        void SwitchTo(TExceptionSafeContext* ctx) noexcept {
+            Y_VERIFY(Stack_.LowerCanaryOk(), "Stack overflow (%s)", ContName());
+            Y_VERIFY(Stack_.UpperCanaryOk(), "Stack override (%s)", ContName());
+            Ctx_.SwitchTo(ctx);
+        }
+
+        void DoRun() override;
+
+        void DoRunNaked() override;
+
+    private:
+        const char* ContName() const noexcept;
+    private:
+        NStack::TStackHolder Stack_;
+        const TContClosure Clo_;
+        TExceptionSafeContext Ctx_;
+        TFunc Func_;
+        TCont* const Cont_;
+    };
+}