Enter read-mode on segfault and other fatal errors

src/euslime/handler.py

@@ -200,10 +200,14 @@ def swank_eval(self, sexp):
                 yield EuslispResult(e.message, response_type='abort')
             else:
                 yield EuslispResult(None)
-        except Exception:
+        except Exception as e:
+            log.error(traceback.format_exc())
+            if self.euslisp.read_mode:
+                self.euslisp.read_mode = False
+                yield [Symbol(":read-aborted"), 0, 1]
             if lock.locked():
                 lock.release()
-            raise
+            raise e
 
     def swank_interactive_eval(self, sexp):
         return self.swank_eval(sexp)

src/euslime/protocol.py

@@ -43,12 +43,12 @@ def make_error(self, err):
             debug.stack and debug.stack[:10],  # stacktrace
             [None],  # pending continuation
         ]
-        yield self.dumps(res)
+        yield res
 
     def make_response(self, result_type, sexp):
         try:
             res = [Symbol(':return'), {result_type: sexp}, self.thread_local.comm_id]
-            yield self.dumps(res)
+            yield res
         except Exception as e:
             for r in self.make_error(e):
                 yield r
@@ -64,7 +64,7 @@ def process(self, data):
             cmd, comm_id, form = data
             for r in self.process(dumps(form)):
                 yield r
-            yield self.dumps([Symbol(":euslime-test"), comm_id])
+            yield [Symbol(":euslime-test"), comm_id]
             return
         else:
             form = data
@@ -91,7 +91,7 @@ def process(self, data):
                                                 resp.value):
                         yield r
                 else:
-                    yield self.dumps(resp)
+                    yield resp
         except Exception as e:
             log.error(traceback.format_exc())
             for r in self.make_error(e):

src/euslime/server.py

@@ -18,6 +18,9 @@
     'iso-utf-8-unix': 'utf-8'
 }
 HEADER_LENGTH = 6
+ERROR_STRING = """;; You are still in a signal handler.
+;;Try reset or throw to upper level as soon as possible.
+"""
 
 log = get_logger(__name__)
 
@@ -32,17 +35,26 @@ def __init__(self, request, client_address, server):
             request, client_address, server)
 
     def _process_data(self, recv_data):
-        for send_data in self.swank.process(recv_data):
-            log.debug('response: %s', send_data)
-            send_data = send_data.encode(self.encoding)
-            self.request.send(send_data)
+        for data in self.swank.process(recv_data):
+            log.debug('response: %s', data)
+            self.send_data(data)
 
     def _process_output(self, out=None):
         if not out:
             return
         log.debug('output: %s', out)
-        response = [Symbol(":write-string"), out]
-        send_data = self.swank.dumps(response)
+        self.send_data([Symbol(":write-string"), out])
+        if ERROR_STRING in out:
+            # TODO: find a better way to detect error signals
+            # Even if the user issues a command with same output,
+            # read-mode will be desativated when the evaluation ends
+            log.error("Error signal received!")
+            log.debug("Entering read mode...")
+            self.swank.handler.euslisp.read_mode = True
+            self.send_data([Symbol(":read-string"), 0, 1])
+
+    def send_data(self, data):
+        send_data = self.swank.dumps(data)
         send_data = send_data.encode(self.encoding)
         self.request.send(send_data)