New Lanes finalizer API lanes.finally()

2 files changed, 46 insertions, 30 deletions

diff --git a/tests/basic.lua b/tests/basic.lua
index cfe6fd5..ab8a080 100644
--- a/tests/basic.lua
+++ b/tests/basic.lua
@@ -485,6 +485,6 @@ end
 
 local nameof_type, nameof_name = lanes.nameof(print)
 PRINT("name of " .. nameof_type .. " print = '" .. nameof_name .. "'")
-
---
-io.stderr:write "Done! :)\n"
+-- install a finalizer that gets called upon Lanes's internal Universe is GCed.
+-- that way, we print our message after anything that can be output by lanes that are still running at that point
+lanes.finally(function() io.stderr:write "\n=======================================\nTEST OK\n" end)
diff --git a/tests/finalizer.lua b/tests/finalizer.lua
index 060e0a6..2acc39d 100644
--- a/tests/finalizer.lua
+++ b/tests/finalizer.lua
@@ -10,20 +10,22 @@
 

 local lanes = require "lanes"

 lanes.configure{with_timers=false}

+local finally = lanes.finally

 

-local FN= "finalizer-test.tmp"

+local FN = "finalizer-test.tmp"

 

 local cleanup

 

-local which= os.time() % 2  -- 0/1

-

-local function lane()

-

+local function lane(error_)

     set_finalizer(cleanup)

 

-    local f,err= io.open(FN,"w")

+    local st,err = pcall(finally, cleanup) -- should cause an error because called from a lane

+    assert(not st, "finally() should have thrown an error")

+    io.stderr:write("finally() raised error '", err, "'\n")

+

+    local f,err = io.open(FN,"w")

     if not f then

-        error( "Could not create "..FN..": "..err )

+        error( "Could not create "..FN..": "..err)

     end

 

     f:write( "Test file that should get removed." )

@@ -32,11 +34,10 @@ local function lane()
     -- don't forget to close the file immediately, else we won't be able to delete it until f is collected

     f:close()

 

-    if which==0 then

-        print "you loose"

-        error("aa")    -- exception here; the value needs NOT be a string

+    if error_ then

+        io.stderr:write("Raising ", tostring(error_), "\n")

+        error(error_, 0)    -- exception here; the value needs NOT be a string

     end

-

     -- no exception

 end

 

@@ -44,8 +45,8 @@ end
 -- This is called at the end of the lane; whether succesful or not.

 -- Gets the 'error()' parameter as parameter ('nil' if normal return).

 --

-cleanup= function(err)

-

+cleanup = function(err)

+    io.stderr:write "------------------------ In Worker Finalizer -----------------------\n"

     -- An error in finalizer will override an error (or success) in the main

     -- chunk.

     --

@@ -57,30 +58,45 @@ cleanup= function(err)
         io.stderr:write( "Cleanup after normal return\n" )

     end

         

-    local _,err2= os.remove(FN)

-    print( "file removal result: ", tostring( err2))

+    local _,err2 = os.remove(FN)

+    io.stderr:write( "file removal result: ", tostring(err2), "\n")

     assert(not err2)    -- if this fails, it will be shown in the calling script

                         -- as an error from the lane itself

     

     io.stderr:write( "Removed file "..FN.."\n" )

 end

 

-local lgen = lanes.gen("*", lane)

+-- we need error_trace_level above "minimal" to get a stack trace out of h:join()

+local lgen = lanes.gen("*", {error_trace_level = "basic"}, lane)

+

+local do_test = function(error_)

 

-io.stderr:write "Launching the lane!\n"

+    io.stderr:write "======================== Launching the lane! =======================\n"

 

-local h= lgen()

+    local h = lgen(error_)

 

-local _,err,stack= h:join()   -- wait for the lane (no automatic error propagation)

-if err then

-    assert(stack)

-    io.stderr:write( "Lane error: "..tostring(err).."\n" )

-    io.stderr:write( "\t", table.concat(stack,"\t\n"), "\n" )

+    local _,err,stack = h:join()   -- wait for the lane (no automatic error propagation)

+    if err then

+        assert(stack, "no stack trace on error, check 'error_trace_level'")

+        io.stderr:write( "Lane error: "..tostring(err).."\n" )

+        io.stderr:write( "\t", table.concat(stack,"\t\n"), "\n" )

+    end

 end

 

-local f= io.open(FN,"r")

-if f then

-    error( "CLEANUP DID NOT WORK: "..FN.." still exists!" )

+do_test(nil)

+do_test("An error")

+

+local on_exit = function()

+    finally(nil)

+    io.stderr:write "=========================In Lanes Finalizer! =======================\n"

+    local f = io.open(FN,"r")

+    if f then

+        error( "CLEANUP DID NOT WORK: "..FN.." still exists!" )

+    else

+        io.stderr:write(FN .. " was successfully removed\n")

+    end

+    io.stderr:write "Finished!\n"

 end

 

-io.stderr:write "Finished!\n"

+-- this function is called after script exit, when the state is closed

+lanes.finally(on_exit)