dezombification procedure fixed

src/ctx.cpp

@@ -97,7 +97,7 @@ zmq::ctx_t::~ctx_t ()
 #endif
 }
 
-int zmq::ctx_t::term ()
+int zmq::ctx_t::terminate ()
 {
     //  First send stop command to sockets so that any
     //  blocking calls are interrupted.
@@ -115,12 +115,15 @@ int zmq::ctx_t::term ()
     if (no_sockets_notify)
         no_sockets_sync.wait ();
 
-    //  At this point there's only one application thread (this one) remaining.
-    //  We don't even have to synchronise access to data.
+    //  At this point there should be no active sockets. What we have is a set
+    //  of zombies waiting to be dezombified.
     zmq_assert (sockets.empty ());
 
-//  TODO: We are accessing the list of zombies in unsynchronised manner here!
-    //  Get rid of remaining zombie sockets.
+    //  Get rid of remaining zombie sockets. Note that the lock won't block
+    //  anyone here. There's noone else having open sockets anyway. The only
+    //  purpose of the lock is to double-check all the CPU caches have been
+    //  synchronised.
+    slot_sync.lock ();
     while (!zombies.empty ()) {
         dezombify ();
 
@@ -134,6 +137,7 @@ int zmq::ctx_t::term ()
         usleep (1000);
 #endif
     }
+    slot_sync.unlock ();
 
     //  Deallocate the resources.
     delete this;
@@ -197,6 +201,22 @@ void zmq::ctx_t::zombify_socket (socket_base_t *socket_)
     slot_sync.unlock ();
 }
 
+void zmq::ctx_t::dezombify_socket (socket_base_t *socket_)
+{
+    //  We assume that this function is called only within dezombification
+    //  process, which in turn is running within a slot_sync critical section.
+    //  Therefore, we need no locking here.
+
+    //  TODO: Can we do this better than O(n)?
+    zombies_t::iterator it = std::find (zombies.begin (), zombies.end (),
+        socket_);
+    zmq_assert (it != zombies.end ());
+
+    //  Move from the slot from 'zombie' to 'empty' state.
+    empty_slots.push_back ((*it)->get_slot ());
+    zombies.erase (it);
+}
+
 void zmq::ctx_t::send_command (uint32_t slot_, const command_t &command_)
 {
     slots [slot_]->send (command_);
@@ -287,12 +307,14 @@ void zmq::ctx_t::dezombify ()
 {
     //  Try to dezombify each zombie in the list. Note that caller is
     //  responsible for calling this method in the slot_sync critical section.
-    for (zombies_t::size_type i = 0; i != zombies.size ();)
-        if (zombies [i]->dezombify ()) {
-            empty_slots.push_back (zombies [i]->get_slot ());
-            zombies.erase (zombies [i]);
-        }
-        else
-            i++;
+    zombies_t::iterator it = zombies.begin ();
+    while (it != zombies.end ()) {
+        zombies_t::iterator old = it;
+        ++it;
+
+        //  dezombify_socket can be called here that will invalidate
+        //  the iterator. That's why we've got the next zombie beforehand.
+        (*old)->dezombify ();
+    }
 }
 

src/ctx.hpp

@@ -20,9 +20,10 @@
 #ifndef __ZMQ_CTX_HPP_INCLUDED__
 #define __ZMQ_CTX_HPP_INCLUDED__
 
-#include <vector>
 #include <set>
 #include <map>
+#include <list>
+#include <vector>
 #include <string>
 
 #include "signaler.hpp"
@@ -52,7 +53,7 @@ namespace zmq
         //  no more sockets open it'll cause all the infrastructure to be shut
         //  down. If there are open sockets still, the deallocation happens
         //  after the last one is closed.
-        int term ();
+        int terminate ();
 
         //  Create a socket.
         class socket_base_t *create_socket (int type_);
@@ -60,6 +61,9 @@ namespace zmq
         //  Make socket a zombie.
         void zombify_socket (socket_base_t *socket_);
 
+        //  Kill the zombie socket.
+        void dezombify_socket (socket_base_t *socket_);
+
         //  Send command to the destination slot.
         void send_command (uint32_t slot_, const command_t &command_);
 
@@ -83,9 +87,9 @@ namespace zmq
         typedef yarray_t <socket_base_t> sockets_t;
         sockets_t sockets;
 
-        //  Array of sockets that were already closed but not yet deallocated.
+        //  List of sockets that were already closed but not yet deallocated.
         //  These sockets still have some pipes and I/O objects attached.
-        typedef yarray_t <socket_base_t> zombies_t;
+        typedef std::list <socket_base_t*> zombies_t;
         zombies_t zombies;
 
         //  List of unused slots.

src/object.cpp

@@ -147,6 +147,11 @@ void zmq::object_t::zombify_socket (socket_base_t *socket_)
     ctx->zombify_socket (socket_);
 }
 
+void zmq::object_t::dezombify_socket (socket_base_t *socket_)
+{
+    ctx->dezombify_socket (socket_);
+}
+
 void zmq::object_t::send_stop ()
 {
     //  'stop' command goes always from administrative thread to

src/object.hpp

@@ -55,6 +55,9 @@ namespace zmq
         //  the context.
         void zombify_socket (class socket_base_t *socket_);
 
+        //  Dezombify particular socket, i.e. destroy it.
+        void dezombify_socket (class socket_base_t *socket_);
+
         //  Derived object can use these functions to send commands
         //  to other objects.
         void send_stop ();

src/socket_base.cpp

@@ -118,10 +118,15 @@ zmq::socket_base_t::socket_base_t (ctx_t *parent_, uint32_t slot_) :
 
 zmq::socket_base_t::~socket_base_t ()
 {
+    zmq_assert (zombie);
+
     //  Check whether there are no session leaks.
     sessions_sync.lock ();
     zmq_assert (sessions.empty ());
     sessions_sync.unlock ();
+
+    //  Mark the socket slot as empty.
+    dezombify_socket (this);
 }
 
 zmq::signaler_t *zmq::socket_base_t::get_signaler ()
@@ -599,16 +604,13 @@ zmq::session_t *zmq::socket_base_t::find_session (const blob_t &peer_identity_)
     return session;    
 }
 
-bool zmq::socket_base_t::dezombify ()
+void zmq::socket_base_t::dezombify ()
 {
     zmq_assert (zombie);
 
     //  Process any commands from other threads/sockets that may be available
     //  at the moment. Ultimately, socket will be destroyed.
     process_commands (false, false);
-
-//  TODO: ???
-    return true;
 }
 
 void zmq::socket_base_t::process_commands (bool block_, bool throttle_)

src/socket_base.hpp

@@ -85,8 +85,8 @@ namespace zmq
         void terminated (class writer_t *pipe_);
 
         //  This function should be called only on zombie sockets. It tries
-        //  to deallocate the zombie. Returns true if zombie is finally dead.
-        bool dezombify ();
+        //  to deallocate the zombie.
+        void dezombify ();
 
     protected:
 

src/zmq.cpp

@@ -269,7 +269,7 @@ void *zmq_init (int io_threads_)
 
 int zmq_term (void *ctx_)
 {
-    int rc = ((zmq::ctx_t*) ctx_)->term ();
+    int rc = ((zmq::ctx_t*) ctx_)->terminate ();
     int en = errno;
 
     if (!ctx_) {