1 files changed, 60 insertions, 0 deletions

diff --git a/src/cancel.hpp b/src/cancel.hpp
new file mode 100644
index 0000000..7230169
--- /dev/null
+++ b/src/cancel.hpp
@@ -0,0 +1,60 @@
+#pragma once
+
+#include "macros_and_utils.hpp"
+#include "uniquekey.hpp"
+
+// #################################################################################################
+
+// Lane cancellation request modes
+enum class CancelRequest
+{
+    None, // no pending cancel request
+    // TODO: add a Wake mode: user wants to wake the waiting lindas (in effect resulting in a timeout before the initial operation duration)
+    Soft, // user wants the lane to cancel itself manually on cancel_test()
+    Hard // user wants the lane to be interrupted (meaning code won't return from those functions) from inside linda:send/receive calls
+};
+
+enum class CancelResult
+{
+    Timeout,
+    Cancelled
+};
+
+enum class CancelOp
+{
+    Invalid = -2,
+    Hard = -1,
+    Soft = 0,
+    MaskCall = LUA_MASKCALL,
+    MaskRet = LUA_MASKRET,
+    MaskLine = LUA_MASKLINE,
+    MaskCount = LUA_MASKCOUNT,
+    MaskAll = LUA_MASKCALL | LUA_MASKRET | LUA_MASKLINE | LUA_MASKCOUNT
+};
+
+inline auto operator<=>(CancelOp const a_, CancelOp const b_)
+{
+    return static_cast<std::underlying_type_t<CancelOp>>(a_) <=> static_cast<std::underlying_type_t<CancelOp>>(b_);
+}
+
+// xxh64 of string "kCancelError" generated at https://www.pelock.com/products/hash-calculator
+static constexpr UniqueKey kCancelError{ 0x0630345FEF912746ull, "lanes.cancel_error" }; // 'raise_cancel_error' sentinel
+
+// #################################################################################################
+
+[[nodiscard]] CancelRequest CheckCancelRequest(lua_State* L_);
+[[nodiscard]] CancelOp WhichCancelOp(std::string_view const& opString_);
+
+// #################################################################################################
+
+[[noreturn]] static inline void raise_cancel_error(lua_State* const L_)
+{
+    STACK_GROW(L_, 1);
+    kCancelError.pushKey(L_); // special error value
+    raise_lua_error(L_);
+}
+
+// #################################################################################################
+
+LUAG_FUNC(cancel_test);
+LUAG_FUNC(lane_cancel);