7 files changed, 64 insertions, 15 deletions

diff --git a/src/linda.cpp b/src/linda.cpp
index a9ae61c..fa28385 100644
--- a/src/linda.cpp
+++ b/src/linda.cpp
@@ -1178,7 +1178,15 @@ LUAG_FUNC(linda)
         if (lua_isnil(L_, kIdxTop)) {
             lua_pop(L_, 1);
             lua_pushnumber(L_, _U->lindaWakePeriod.count());
-        } else {
+        } else if (luaG_type(L_, kIdxTop) == LuaType::STRING) {
+            if (luaG_tostring(L_, kIdxTop) != "never") {
+                luaL_argerror(L_, 1, "invalid wake_period");
+            } else {
+                lua_pop(L_, 1);
+                lua_pushnumber(L_, 0);
+            }
+        }
+        else {
             luaL_argcheck(L_, luaL_optnumber(L_, 2, 0) > 0, 1, "wake_period must be > 0");
         }
 
diff --git a/src/macros_and_utils.hpp b/src/macros_and_utils.hpp
index 16011f7..1aca818 100644
--- a/src/macros_and_utils.hpp
+++ b/src/macros_and_utils.hpp
@@ -21,6 +21,7 @@ inline void STACK_GROW(lua_State* const L_, int const n_)
 
 // #################################################################################################
 
+// 1 unit of lua_Duration lasts 1 second (using default period of std::ratio<1>)
 using lua_Duration = std::chrono::template duration<lua_Number>;
 
 // #################################################################################################
diff --git a/tests/track_lanes.lua b/tests/track_lanes.lua
index d1670ae..ef2ca06 100644
--- a/tests/track_lanes.lua
+++ b/tests/track_lanes.lua
@@ -59,8 +59,10 @@ local threads = track( "============= START", 2)
 --     two_seconds                        forever
 assert(threads[1].status == 'waiting' and threads[2].status == 'waiting')
 
--- wait until ephemeral1 has completed
-SLEEP(2.1)
+-- wait until ephemeral1 has completed, should take about 2 seconds
+repeat
+    SLEEP(0.1)
+until ephemeral1.status == "done"
 
 local threads = track( "============= two_seconds dead", 2)
 --     two_seconds                     forever
diff --git a/unit_tests/UnitTests.vcxproj b/unit_tests/UnitTests.vcxproj
index e1370c3..8c22653 100644
--- a/unit_tests/UnitTests.vcxproj
+++ b/unit_tests/UnitTests.vcxproj
@@ -968,6 +968,7 @@
   <ItemGroup>
     <None Include="..\.runsettings" />
     <None Include="scripts\lane\tasking_cancelling_with_hook.lua" />
+    <None Include="scripts\linda\wake_period.lua" />
     <None Include="UnitTests.makefile" />
     <None Include="scripts\coro\basics.lua" />
     <None Include="scripts\coro\error_handling.lua" />
diff --git a/unit_tests/UnitTests.vcxproj.filters b/unit_tests/UnitTests.vcxproj.filters
index b0ce216..ce8cb58 100644
--- a/unit_tests/UnitTests.vcxproj.filters
+++ b/unit_tests/UnitTests.vcxproj.filters
@@ -116,5 +116,8 @@
     <None Include="scripts\lane\tasking_cancelling_with_hook.lua">
       <Filter>Scripts\lane</Filter>
     </None>
+    <None Include="scripts\linda\wake_period.lua">
+      <Filter>Scripts\linda</Filter>
+    </None>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/unit_tests/linda_tests.cpp b/unit_tests/linda_tests.cpp
index 9dbaa85..d956ae2 100644
--- a/unit_tests/linda_tests.cpp
+++ b/unit_tests/linda_tests.cpp
@@ -104,16 +104,7 @@ TEST_CASE("linda.single_keeper.creation/wake_period")
     S.requireFailure("lanes.linda{wake_period = -1}");
     S.requireFailure("lanes.linda{wake_period = 0}");
     S.requireSuccess("lanes.linda{wake_period = 0.0001}");
-}
-
-// #################################################################################################
-
-TEST_CASE("linda.single_keeper.wake_period")
-{
-    FAIL("TODO: check that wake_period works as expected");
-    // - use configure default if not provided
-    // - overrides default when provided
-    // - blocking operation wakes at the specified period
+    S.requireSuccess("lanes.linda{wake_period = 'never'}");
 }
 
 // #################################################################################################
@@ -397,17 +388,19 @@ TEST_CASE("scripted_tests." #DIR "." #FILE) \
     _runner.performTest(FileRunnerParam{ #DIR "/" #FILE, TestType::AssertNoLuaError }); \
 }
 
+MAKE_TEST_CASE(linda, multiple_keepers)
 MAKE_TEST_CASE(linda, send_receive)
 MAKE_TEST_CASE(linda, send_registered_userdata)
-MAKE_TEST_CASE(linda, multiple_keepers)
+MAKE_TEST_CASE(linda, wake_period)
 
 /*
 TEST_CASE("linda.scripted_tests")
 {
     auto const& _testParam = GENERATE(
+        FileRunnerParam{ "linda/multiple_keepers", TestType::AssertNoLuaError },
         FileRunnerParam{ "linda/send_receive", TestType::AssertNoLuaError },
         FileRunnerParam{ "linda/send_registered_userdata", TestType::AssertNoLuaError },
-        FileRunnerParam{ "linda/multiple_keepers", TestType::AssertNoLuaError }
+        FileRunnerParam{ "linda/wake_period", TestType::AssertNoLuaError }
     );
 
     FileRunner _runner(R"(.\unit_tests\scripts)");
diff --git a/unit_tests/scripts/linda/wake_period.lua b/unit_tests/scripts/linda/wake_period.lua
new file mode 100644
index 0000000..e4a900d
--- /dev/null
+++ b/unit_tests/scripts/linda/wake_period.lua
@@ -0,0 +1,41 @@
+-- default wake period is 0.5 seconds
+local require_lanes_result_1, require_lanes_result_2 = require "lanes".configure{linda_wake_period = 0.5}
+local lanes = require_lanes_result_1
+
+-- a lane that performs a blocking operation for 2 seconds
+local body = function(linda_)
+        -- a blocking read that lasts longer than the tested wake_period values
+        linda_:receive(2, "empty_slot")
+        return true
+end
+
+-- if we don't cancel the lane, we should wait the whole duration
+local function check_wake_duration(linda_, expected_, do_cancel_)
+        local h = lanes.gen(body)(linda_)
+        -- wait until the linda is blocked
+        repeat until h.status == "waiting"
+        local t0 = lanes.now_secs()
+        -- soft cancel, no timeout, no waking
+        if do_cancel_ then
+                local result, reason = h:cancel('soft', 0, false)
+                -- should say there was a timeout, since the lane didn't actually cancel (normal since we did not wake it)
+                assert(result == false and reason == 'timeout', "unexpected cancel result")
+        end
+        -- this should wait until the linda wakes by itself before the actual receive timeout and sees the cancel request
+        h:join()
+        local t1 = lanes.now_secs()
+        local delta = t1 - t0
+        -- the linda should check for cancellation at about the expected period, not earlier
+        assert(delta >= expected_, tostring(linda_) .. " woke too early:" .. delta)
+        -- the lane shouldn't terminate too long after cancellation was processed
+        assert(delta <= expected_ * 1.1, tostring(linda_) .. " woke too late: " .. delta)
+end
+
+-- legacy behavior: linda waits until operation timeout
+check_wake_duration(lanes.linda{name = "A", wake_period = 'never'}, 2, true)
+-- early wake behavior: linda wakes after the expected time, sees a cancellation requests, and aborts the operation early
+check_wake_duration(lanes.linda{name = "B", wake_period = 0.25}, 0.25, true)
+check_wake_duration(lanes.linda{name = "C"}, 0.5, true) -- wake_period defaults to 0.5 (see above)
+check_wake_duration(lanes.linda{name = "D", wake_period = 1}, 1, true)
+-- even when there is a wake_period, the operation should reach full timeout if not cancelled early
+check_wake_duration(lanes.linda{name = "E", wake_period = 0.1}, 2, false)