Capture the traceback in thread jobs

2 files changed, 31 insertions, 3 deletions

diff --git a/test/test-traceback.lua b/test/test-traceback.lua
new file mode 100644
index 0000000..db50624
--- /dev/null
+++ b/test/test-traceback.lua
@@ -0,0 +1,19 @@
+local Threads = require 'threads'
+Threads.serialization('threads.sharedserialize')
+
+my_threads = Threads(1,
+            function()
+                -- nothing
+            end)
+
+my_threads:addjob(function()
+    function evil_func()
+        print('a'+1)
+    end
+    print("I'm doing fine")
+    evil_func()
+ end)
+
+ok, res = pcall(my_threads.synchronize, my_threads)
+assert(ok == false)
+assert(res:find("in function 'evil_func'"))
diff --git a/threads.lua b/threads.lua
index cc1ac6f..3bef540 100644
--- a/threads.lua
+++ b/threads.lua
@@ -1,6 +1,6 @@
 local Queue = require 'threads.queue'
 local clib = require 'libthreads'
-local unpack = unpack or table.unpack
+local _unpack = unpack or table.unpack
 
 local Threads = {}
 local Threads_ctor = {}
@@ -168,7 +168,9 @@ function Threads:dojob()
    local endcallbacks = self.endcallbacks
    local callstatus, args, endcallbackid, threadid = self.mainqueue:dojob()
    if callstatus then
-      local endcallstatus, msg = pcall(endcallbacks[endcallbackid], unpack(args))
+      local endcallstatus, msg = xpcall(
+        function() endcallbacks[endcallbackid](_unpack(args)) end,
+        debug.traceback)
       if not endcallstatus then
          table.insert(self.errors, string.format('[thread %d endcallback] %s', threadid, msg))
       end
@@ -224,7 +226,14 @@ function Threads:addjob(...) -- endcallback is passed with returned values of ca
    endcallbacks.n = endcallbacks.n + 1
 
    local func = function(...)
-      local res = {pcall(callback, ...)}
+      local args = {...}
+      local res = {
+          xpcall(
+             function() 
+                local _unpack = unpack or table.unpack
+                callback(_unpack(args))
+             end,
+             debug.traceback)}
       local status = table.remove(res, 1)
       return status, res, endcallbackid
    end