Initial implementation of reaper thread.

Reaper thread destroys the socket asynchronously.
zmq_term() can be interrupted by a signal (EINTR).
zmq_socket() will return ETERM after zmq_term() was called.

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

1 files changed, 21 insertions, 22 deletions

diff --git a/src/ctx.hpp b/src/ctx.hpp
index 92684e6..c07711e 100644
--- a/src/ctx.hpp
+++ b/src/ctx.hpp
@@ -64,11 +64,9 @@ namespace zmq
         //  after the last one is closed.
         int terminate ();
 
-        //  Create a socket.
+        //  Create and destroy a socket.
         class socket_base_t *create_socket (int type_);
-
-        //  Make socket a zombie.
-        void zombify_socket (socket_base_t *socket_);
+        void destroy_socket (class socket_base_t *socket_);
 
         //  Send command to the destination thread.
         void send_command (uint32_t tid_, const command_t &command_);
@@ -78,6 +76,9 @@ namespace zmq
         //  Returns NULL is no I/O thread is available.
         class io_thread_t *choose_io_thread (uint64_t affinity_);
 
+        //  Returns reaper thread object.
+        class object_t *get_reaper ();
+
         //  Management of inproc endpoints.
         int register_endpoint (const char *addr_, endpoint_t &endpoint_);
         void unregister_endpoints (class socket_base_t *socket_);
@@ -86,41 +87,36 @@ namespace zmq
         //  Logging.
         void log (zmq_msg_t *msg_);
 
+        enum {
+            term_tid = 0,
+            reaper_tid = 1
+        };
+
     private:
 
         ~ctx_t ();
 
-        //  Sockets belonging to this context.
+        //  Sockets belonging to this context. We need the list so that
+        //  we can notify the sockets when zmq_term() is called. The sockets
+        //  will return ETERM then.
         typedef array_t <socket_base_t> sockets_t;
         sockets_t sockets;
 
-        //  List of sockets that were already closed but not yet deallocated.
-        //  These sockets still have some pipes and I/O objects attached.
-        typedef std::vector <socket_base_t*> zombies_t;
-        zombies_t zombies;
-
         //  List of unused thread slots.
         typedef std::vector <uint32_t> emtpy_slots_t;
         emtpy_slots_t empty_slots;
 
-        //  If true, shutdown thread wants to be informed when there are no
-        //  more open sockets. Do so by posting no_sockets_sync semaphore.
-        //  Note that this variable is synchronised by slot_sync mutex.
-        bool no_sockets_notify;
-
-        //  Object used by zmq_term to wait while all the sockets are closed
-        //  by different application threads.
-        semaphore_t no_sockets_sync;
+        //  If true, zmq_term was already called.
+        bool terminating;
 
         //  Synchronisation of accesses to global slot-related data:
-        //  sockets, zombies, empty_slots, terminated. It also synchronises
+        //  sockets, empty_slots, terminating. It also synchronises
         //  access to zombie sockets as such (as oposed to slots) and provides
         //  a memory barrier to ensure that all CPU cores see the same data.
         mutex_t slot_sync;
 
-        //  This function attempts to deallocate as many zombie sockets as
-        //  possible. It must be called within a slot_sync critical section.
-        void dezombify ();
+        //  The reaper thread.
+        class reaper_t *reaper;
 
         //  I/O threads.
         typedef std::vector <class io_thread_t*> io_threads_t;
@@ -130,6 +126,9 @@ namespace zmq
         uint32_t slot_count;
         mailbox_t **slots;
 
+        //  Mailbox for zmq_term thread.
+        mailbox_t term_mailbox;
+
         //  List of inproc endpoints within this context.
         typedef std::map <std::string, endpoint_t> endpoints_t;
         endpoints_t endpoints;