libzmq/src/ctx.cpp
2010-06-10 12:57:42 +02:00

318 lines
9.5 KiB
C++

/*
Copyright (c) 2007-2010 iMatix Corporation
This file is part of 0MQ.
0MQ is free software; you can redistribute it and/or modify it under
the terms of the Lesser GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
0MQ is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
Lesser GNU General Public License for more details.
You should have received a copy of the Lesser GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <new>
#include <string.h>
#include "../include/zmq.h"
#include "ctx.hpp"
#include "socket_base.hpp"
#include "app_thread.hpp"
#include "io_thread.hpp"
#include "platform.hpp"
#include "err.hpp"
#include "pipe.hpp"
#if defined ZMQ_HAVE_WINDOWS
#include "windows.h"
#endif
zmq::ctx_t::ctx_t (uint32_t io_threads_) :
sockets (0),
terminated (false)
{
#ifdef ZMQ_HAVE_WINDOWS
// Intialise Windows sockets. Note that WSAStartup can be called multiple
// times given that WSACleanup will be called for each WSAStartup.
WORD version_requested = MAKEWORD (2, 2);
WSADATA wsa_data;
int rc = WSAStartup (version_requested, &wsa_data);
zmq_assert (rc == 0);
zmq_assert (LOBYTE (wsa_data.wVersion) == 2 &&
HIBYTE (wsa_data.wVersion) == 2);
#endif
// Initialise the array of signalers.
signalers_count = max_app_threads + io_threads_;
signalers = (signaler_t**) malloc (sizeof (signaler_t*) * signalers_count);
zmq_assert (signalers);
memset (signalers, 0, sizeof (signaler_t*) * signalers_count);
// Create I/O thread objects and launch them.
for (uint32_t i = 0; i != io_threads_; i++) {
io_thread_t *io_thread = new (std::nothrow) io_thread_t (this, i);
zmq_assert (io_thread);
io_threads.push_back (io_thread);
signalers [i] = io_thread->get_signaler ();
io_thread->start ();
}
}
int zmq::ctx_t::term ()
{
// First send stop command to application threads so that any
// blocking calls are interrupted.
for (app_threads_t::size_type i = 0; i != app_threads.size (); i++)
app_threads [i].app_thread->stop ();
// Then mark context as terminated.
term_sync.lock ();
zmq_assert (!terminated);
terminated = true;
bool destroy = (sockets == 0);
term_sync.unlock ();
// If there are no sockets open, destroy the context immediately.
if (destroy)
delete this;
return 0;
}
zmq::ctx_t::~ctx_t ()
{
// Ask I/O threads to terminate. If stop signal wasn't sent to I/O
// thread subsequent invocation of destructor would hang-up.
for (io_threads_t::size_type i = 0; i != io_threads.size (); i++)
io_threads [i]->stop ();
// Wait till I/O threads actually terminate.
for (io_threads_t::size_type i = 0; i != io_threads.size (); i++)
delete io_threads [i];
// Close all application theads, sockets, io_objects etc.
for (app_threads_t::size_type i = 0; i != app_threads.size (); i++)
delete app_threads [i].app_thread;
// Deallocate all the orphaned pipes.
while (!pipes.empty ())
delete *pipes.begin ();
// Deallocate the array of pointers to signalers. No special work is
// needed as signalers themselves were deallocated with their
// corresponding (app_/io_) thread objects.
free (signalers);
#ifdef ZMQ_HAVE_WINDOWS
// On Windows, uninitialise socket layer.
int rc = WSACleanup ();
wsa_assert (rc != SOCKET_ERROR);
#endif
}
zmq::socket_base_t *zmq::ctx_t::create_socket (int type_)
{
app_threads_sync.lock ();
// Find whether the calling thread has app_thread_t object associated
// already. At the same time find an unused app_thread_t so that it can
// be used if there's no associated object for the calling thread.
// Check whether thread ID is already assigned. If so, return it.
app_threads_t::size_type unused = app_threads.size ();
app_threads_t::size_type current;
for (current = 0; current != app_threads.size (); current++) {
if (app_threads [current].associated &&
thread_t::equal (thread_t::id (), app_threads [current].tid))
break;
if (!app_threads [current].associated)
unused = current;
}
// If no app_thread_t is associated with the calling thread,
// associate it with one of the unused app_thread_t objects.
if (current == app_threads.size ()) {
// If all the existing app_threads are already used, create one more.
if (unused == app_threads.size ()) {
// If max_app_threads limit was reached, return error.
if (app_threads.size () == max_app_threads) {
app_threads_sync.unlock ();
errno = EMTHREAD;
return NULL;
}
// Create the new application thread proxy object.
app_thread_info_t info;
memset (&info, 0, sizeof (info));
info.associated = false;
info.app_thread = new (std::nothrow) app_thread_t (this,
io_threads.size () + app_threads.size ());
zmq_assert (info.app_thread);
signalers [io_threads.size () + app_threads.size ()] =
info.app_thread->get_signaler ();
app_threads.push_back (info);
}
// Incidentally, this works both when there is an unused app_thread
// and when a new one is created.
current = unused;
// Associate the selected app_thread with the OS thread.
app_threads [current].associated = true;
app_threads [current].tid = thread_t::id ();
}
app_thread_t *thread = app_threads [current].app_thread;
app_threads_sync.unlock ();
socket_base_t *s = thread->create_socket (type_);
if (!s)
return NULL;
term_sync.lock ();
sockets++;
term_sync.unlock ();
return s;
}
void zmq::ctx_t::destroy_socket ()
{
// If zmq_term was already called and there are no more sockets,
// terminate the whole 0MQ infrastructure.
term_sync.lock ();
zmq_assert (sockets > 0);
sockets--;
bool destroy = (sockets == 0 && terminated);
term_sync.unlock ();
if (destroy)
delete this;
}
void zmq::ctx_t::no_sockets (app_thread_t *thread_)
{
app_threads_sync.lock ();
app_threads_t::size_type i;
for (i = 0; i != app_threads.size (); i++)
if (app_threads [i].app_thread == thread_) {
app_threads [i].associated = false;
break;
}
zmq_assert (i != app_threads.size ());
app_threads_sync.unlock ();
}
void zmq::ctx_t::send_command (uint32_t destination_,
const command_t &command_)
{
signalers [destination_]->send (command_);
}
bool zmq::ctx_t::recv_command (uint32_t thread_slot_,
command_t *command_, bool block_)
{
return signalers [thread_slot_]->recv (command_, block_);
}
zmq::io_thread_t *zmq::ctx_t::choose_io_thread (uint64_t affinity_)
{
// Find the I/O thread with minimum load.
zmq_assert (io_threads.size () > 0);
int min_load = -1;
io_threads_t::size_type result = 0;
for (io_threads_t::size_type i = 0; i != io_threads.size (); i++) {
if (!affinity_ || (affinity_ & (uint64_t (1) << i))) {
int load = io_threads [i]->get_load ();
if (min_load == -1 || load < min_load) {
min_load = load;
result = i;
}
}
}
zmq_assert (min_load != -1);
return io_threads [result];
}
void zmq::ctx_t::register_pipe (class pipe_t *pipe_)
{
pipes_sync.lock ();
bool inserted = pipes.insert (pipe_).second;
zmq_assert (inserted);
pipes_sync.unlock ();
}
void zmq::ctx_t::unregister_pipe (class pipe_t *pipe_)
{
pipes_sync.lock ();
pipes_t::size_type erased = pipes.erase (pipe_);
zmq_assert (erased == 1);
pipes_sync.unlock ();
}
int zmq::ctx_t::register_endpoint (const char *addr_,
socket_base_t *socket_)
{
endpoints_sync.lock ();
bool inserted = endpoints.insert (std::make_pair (std::string (addr_),
socket_)).second;
if (!inserted) {
errno = EADDRINUSE;
endpoints_sync.unlock ();
return -1;
}
endpoints_sync.unlock ();
return 0;
}
void zmq::ctx_t::unregister_endpoints (socket_base_t *socket_)
{
endpoints_sync.lock ();
endpoints_t::iterator it = endpoints.begin ();
while (it != endpoints.end ()) {
if (it->second == socket_) {
endpoints_t::iterator to_erase = it;
it++;
endpoints.erase (to_erase);
continue;
}
it++;
}
endpoints_sync.unlock ();
}
zmq::socket_base_t *zmq::ctx_t::find_endpoint (const char *addr_)
{
endpoints_sync.lock ();
endpoints_t::iterator it = endpoints.find (addr_);
if (it == endpoints.end ()) {
endpoints_sync.unlock ();
errno = ECONNREFUSED;
return NULL;
}
socket_base_t *endpoint = it->second;
// Increment the command sequence number of the peer so that it won't
// get deallocated until "bind" command is issued by the caller.
// The subsequent 'bind' has to be called with inc_seqnum parameter
// set to false, so that the seqnum isn't incremented twice.
endpoint->inc_seqnum ();
endpoints_sync.unlock ();
return endpoint;
}