prefork/multithread uwsgi.signal_wait() implementation

decoratortest.py

@@ -84,6 +84,9 @@ def fork_happened():
 
 @postfork
 def fork_happened2():
+    print("waiting for a signal...")
+    uwsgi.signal_wait()
+    print("signal received: %d" % uwsgi.signal_received())
     print("fork() has been called [2] wid: %d" % uwsgi.worker_id())
 
 @postfork

plugins/python/uwsgi_pymodule.c

@@ -10,8 +10,44 @@ extern struct uwsgi_python up;
 PyObject *py_uwsgi_signal_wait(PyObject * self, PyObject * args) {
 
         struct wsgi_request *wsgi_req = current_wsgi_req();
+	int wait_for_specific_signal = 0;
+	uint8_t uwsgi_signal = 0;
+	uint8_t received_signal;
+	int ret;
+
+	wsgi_req->signal_received = -1;
+
+	if (PyTuple_Size(args) > 0) {
+		if (!PyArg_ParseTuple(args, "|B:", &uwsgi_signal)) {
+                	return NULL;
+        	}
+		wait_for_specific_signal = 1;	
+	}
+
+#ifdef UWSGI_ASYNC
+	if (uwsgi.async > 1) {
+        	wsgi_req->sigwait = 1;
+	}
+	else {
+#endif
+cycle:
+		ret = uwsgi_waitfd(uwsgi.signal_socket, -1);
+		if (ret > 0) {
+			if (read(uwsgi.signal_socket, &received_signal, 1) != 1) {
+				uwsgi_error("read()");
+			}	
+			else {
+				wsgi_req->signal_received = received_signal;			
+				if (wait_for_specific_signal) {
+					if (received_signal != uwsgi_signal) goto cycle;
+				}
+			}
+		}
+
+#ifdef UWSGI_ASYNC
+	}
+#endif
 
-        wsgi_req->sigwait = 1;
 
         return PyString_FromString("");
 }

sigwait.py

@@ -0,0 +1,23 @@
+import uwsgi
+from uwsgidecorators import *
+
+@postfork
+def wait_for_signal():
+    if uwsgi.worker_id() == 2:
+        print("waiting for a signal...")
+        uwsgi.signal_wait()
+        print("signal %d received" % uwsgi.signal_received())
+    elif uwsgi.worker_id() == 3:
+        print("waiting for signal 30...")
+        uwsgi.signal_wait(30)
+        print("signal %d received" % uwsgi.signal_received())
+
+
+def application(e, s):
+    s('200 OK', [('Content-Type', 'text/html')])
+    if e['PATH_INFO'] == '/30':
+        uwsgi.signal(30)
+    else:
+        uwsgi.signal(17)
+    return "Signal raised"
+   

spooler.c

@@ -32,6 +32,7 @@ pid_t spooler_start() {
 		if (uwsgi.master_process) {
 			close(uwsgi.shared->spooler_signal_pipe[0]);
 		}
+		uwsgi.signal_socket = uwsgi.shared->spooler_signal_pipe[1];
 		spooler();
 	}
 	else if (pid > 0) {

uwsgi.h

@@ -811,7 +811,7 @@ struct wsgi_request {
 	int log_this;
 
 	int sigwait;
-	uint8_t signal_received;
+	int signal_received;
 
 	struct msghdr msg;
 	union {