A unit test for linda wake_period

1 files changed, 41 insertions, 0 deletions

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)