Removed SIGCHLD handler from processes because it breaks popen. http://mail.python.org/pipermail/python-dev/2004-November/049987.html Replaced the signal handler functionality with an equivalent that we've been running over here for a while.

eventlet/processes.py

@@ -22,6 +22,7 @@ import os
 import popen2
 import signal
 
+from eventlet import api
 from eventlet import coros
 from eventlet import pools
 from eventlet import greenio
@@ -30,58 +31,31 @@ from eventlet import greenio
 class DeadProcess(RuntimeError):
     pass
 
+def cooperative_wait(pobj, check_interval=0.01):
+    """ Waits for a child process to exit, returning the status
+    code.
 
-CHILD_POBJS = []
+    Unlike os.wait, cooperative_wait does not block the entire
+    process, only the calling coroutine.  If the child process does
+    not die, cooperative_wait could wait forever.
 
-CHILD_EVENTS = {}
-
-
-def wait_on_children():
-    global CHILD_POBJS
-    unclosed_pobjs = []
-    for child_pobj in CHILD_POBJS:
-        try:
-            # We have to use poll() rather than os.waitpid because
-            # otherwise the popen2 module leaks fds; hat tip to Brian
-            # Brunswick
-            code = child_pobj.poll()
-            if code == -1:
-                unclosed_pobjs.append(child_pobj)
-                continue ## Wasn't this one that died
-
-            event = CHILD_EVENTS.pop(child_pobj, None)
-            if event:
-                event.send(code)
-        except OSError, e:
-            if e[0] == errno.ECHILD:
-                print "already dead"
-                # Already dead; signal, but assume success
-                event = CHILD_EVENTS.pop(child_pobj, None)
-                event.send(0)
-            else:
-                print "raising"
-                raise e
-    
-    CHILD_POBJS = unclosed_pobjs
-
-
-def sig_child(signal, frame):
-    from eventlet import api
-    api.call_after_global(0, wait_on_children)
-try:
-    signal.signal(signal.SIGCHLD, sig_child)
-except AttributeError:
-    pass  # Windows
-
-def _add_child_pobj(pobj):
-    """Add the given popen4 object to the list of child
-    processes we are tracking. Return an event object
-    that can be used to get the process' exit code.
+    The argument check_interval is the amount of time, in seconds,
+    that cooperative_wait will sleep between calls to os.waitpid.
     """
-    CHILD_POBJS.append(pobj)
-    event = coros.event()
-    CHILD_EVENTS[pobj] = event
-    return event
+    try:
+        while True:
+            status = pobj.poll()
+            if status >= 0:
+                return status
+            api.sleep(check_interval)
+    except OSError, e:
+        if e.errno == errno.ECHILD:
+            # no child process, this happens if the child process
+            # already died and has been cleaned up, or if you just
+            # called with a random pid value
+            return -1
+        else:
+            raise
 
 
 class Process(object):
@@ -101,7 +75,6 @@ class Process(object):
 
         ## We use popen4 so that read() will read from either stdout or stderr
         self.popen4 = popen2.Popen4([self.command] + self.args)
-        self.event = _add_child_pobj(self.popen4)
         child_stdout_stderr = self.popen4.fromchild
         child_stdin = self.popen4.tochild
         greenio.set_nonblocking(child_stdout_stderr)
@@ -116,7 +89,11 @@ class Process(object):
         self.recv = self.child_stdout_stderr.read
         self.readline = self.child_stdout_stderr.readline
 
+    def wait(self):
+        return cooperative_wait(self.popen4)
+
     def dead_callback(self):
+        self.wait()
         self.dead = True
         if self._dead_callback:
             self._dead_callback()
@@ -162,14 +139,12 @@ class Process(object):
     def kill(self, sig=None):
         if sig == None:
             sig = signal.SIGTERM
-        os.kill(self.popen4.pid, sig)
+        pid = self.getpid()
+        os.kill(pid, sig)
 
     def getpid(self):
         return self.popen4.pid
 
-    def wait(self):
-        return self.event.wait()
-
 
 class ProcessPool(pools.Pool):
     def __init__(self, command, args=None, min_size=0, max_size=4):