Fix jonashaag#77: Don't abort running requests on ^C

The graceful shutdown is achieved by stopping the accept and signal
watchers. This way, we're not accepting any more clients and the main
loop ends as soon as all currently processed requests have been worked
off.

This patch also ports the libev API calls from libev v3 to v4.

bjoern/server.c

@@ -17,7 +17,6 @@
 #include "wsgi.h"
 #include "server.h"
 
-#define SERVER_INFO(loop) ((ServerInfo*)ev_userdata(loop))
 #define READ_BUFFER_SIZE 64*1024
 #define Py_XCLEAR(obj) do { if(obj) { Py_DECREF(obj); obj = NULL; } } while(0)
 #define GIL_LOCK(n) PyGILState_STATE _gilstate_##n = PyGILState_Ensure()
@@ -36,6 +35,11 @@ enum write_state {
   aborted,
 };
 
+typedef struct {
+  ServerInfo* server_info;
+  ev_io accept_watcher;
+} ThreadInfo;
+
 typedef void ev_io_callback(struct ev_loop*, ev_io*, const int);
 
 #if WANT_SIGINT_HANDLING
@@ -56,11 +60,13 @@ static bool handle_nonzero_errno(Request*);
 void server_run(ServerInfo* server_info)
 {
   struct ev_loop* mainloop = ev_loop_new(0);
-  ev_set_userdata(mainloop, server_info);
 
-  ev_io accept_watcher;
-  ev_io_init(&accept_watcher, ev_io_on_request, server_info->sockfd, EV_READ);
-  ev_io_start(mainloop, &accept_watcher);
+  ThreadInfo thread_info;
+  thread_info.server_info = server_info;
+  ev_set_userdata(mainloop, &thread_info);
+
+  ev_io_init(&thread_info.accept_watcher, ev_io_on_request, server_info->sockfd, EV_READ);
+  ev_io_start(mainloop, &thread_info.accept_watcher);
 
 #if WANT_SIGINT_HANDLING
   ev_signal signal_watcher;
@@ -70,19 +76,30 @@ void server_run(ServerInfo* server_info)
 
   /* This is the program main loop */
   Py_BEGIN_ALLOW_THREADS
-  ev_loop(mainloop, 0);
-  ev_default_destroy();
+  ev_run(mainloop, 0);
+  ev_loop_destroy(mainloop);
   Py_END_ALLOW_THREADS
 }
 
 #if WANT_SIGINT_HANDLING
+static void
+pyerr_set_interrupt(struct ev_loop* mainloop, struct ev_cleanup* watcher, const int events)
+{
+  PyErr_SetInterrupt();
+  free(watcher);
+}
+
 static void
 ev_signal_on_sigint(struct ev_loop* mainloop, ev_signal* watcher, const int events)
 {
   /* Clean up and shut down this thread.
    * (Shuts down the Python interpreter if this is the main thread) */
-  ev_unloop(mainloop, EVUNLOOP_ALL);
-  PyErr_SetInterrupt();
+  ev_cleanup* cleanup_watcher = malloc(sizeof(ev_cleanup));
+  ev_cleanup_init(cleanup_watcher, pyerr_set_interrupt);
+  ev_cleanup_start(mainloop, cleanup_watcher);
+
+  ev_io_stop(mainloop, &((ThreadInfo*)ev_userdata(mainloop))->accept_watcher);
+  ev_signal_stop(mainloop, watcher);
 }
 #endif
 
@@ -107,7 +124,7 @@ ev_io_on_request(struct ev_loop* mainloop, ev_io* watcher, const int events)
   }
 
   Request* request = Request_new(
-    SERVER_INFO(mainloop),
+    ((ThreadInfo*)ev_userdata(mainloop))->server_info,
     client_fd,
     inet_ntoa(sockaddr.sin_addr)
   );

tests/interrupt-during-request.py

@@ -0,0 +1,34 @@
+import time
+import threading
+import bjoern
+import os
+import signal
+import httplib
+
+HOST = ('127.0.0.1', 9000)
+
+request_completed = False
+
+def application(environ, start_response):
+    start_response('200 ok', [])
+    yield "chunk1"
+    os.kill(os.getpid(), signal.SIGINT)
+    yield "chunk2"
+    yield "chunk3"
+    global request_completed
+    request_completed = True
+
+
+def requester():
+    conn = httplib.HTTPConnection(*HOST)
+    conn.request("GET", "/")
+    conn.getresponse()
+
+
+threading.Thread(target=requester).start()
+try:
+    bjoern.run(application, *HOST)
+except KeyboardInterrupt:
+    assert request_completed
+else:
+    raise RuntimeError("Didn't receive KeyboardInterrupt")