1/*
2 Copyright (c) 2007-2017 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28*/
29
30#ifndef __ZMQ_CTX_HPP_INCLUDED__
31#define __ZMQ_CTX_HPP_INCLUDED__
32
33#include <map>
34#include <vector>
35#include <string>
36#include <stdarg.h>
37
38#include "mailbox.hpp"
39#include "array.hpp"
40#include "config.hpp"
41#include "mutex.hpp"
42#include "stdint.hpp"
43#include "options.hpp"
44#include "atomic_counter.hpp"
45#include "thread.hpp"
46
47namespace zmq
48{
49class object_t;
50class io_thread_t;
51class socket_base_t;
52class reaper_t;
53class pipe_t;
54
55// Information associated with inproc endpoint. Note that endpoint options
56// are registered as well so that the peer can access them without a need
57// for synchronisation, handshaking or similar.
58struct endpoint_t
59{
60 socket_base_t *socket;
61 options_t options;
62};
63
64class thread_ctx_t
65{
66 public:
67 thread_ctx_t ();
68
69 // Start a new thread with proper scheduling parameters.
70 void start_thread (thread_t &thread_,
71 thread_fn *tfn_,
72 void *arg_,
73 const char *name_ = NULL) const;
74
75 int set (int option_, const void *optval_, size_t optvallen_);
76 int get (int option_, void *optval_, const size_t *optvallen_);
77
78 protected:
79 // Synchronisation of access to context options.
80 mutex_t _opt_sync;
81
82 private:
83 // Thread parameters.
84 int _thread_priority;
85 int _thread_sched_policy;
86 std::set<int> _thread_affinity_cpus;
87 std::string _thread_name_prefix;
88};
89
90// Context object encapsulates all the global state associated with
91// the library.
92
93class ctx_t : public thread_ctx_t
94{
95 public:
96 // Create the context object.
97 ctx_t ();
98
99 // Returns false if object is not a context.
100 bool check_tag ();
101
102 // This function is called when user invokes zmq_ctx_term. If there are
103 // no more sockets open it'll cause all the infrastructure to be shut
104 // down. If there are open sockets still, the deallocation happens
105 // after the last one is closed.
106 int terminate ();
107
108 // This function starts the terminate process by unblocking any blocking
109 // operations currently in progress and stopping any more socket activity
110 // (except zmq_close).
111 // This function is non-blocking.
112 // terminate must still be called afterwards.
113 // This function is optional, terminate will unblock any current
114 // operations as well.
115 int shutdown ();
116
117 // Set and get context properties.
118 int set (int option_, const void *optval_, size_t optvallen_);
119 int get (int option_, void *optval_, size_t *optvallen_);
120 int get (int option_);
121
122 // Create and destroy a socket.
123 zmq::socket_base_t *create_socket (int type_);
124 void destroy_socket (zmq::socket_base_t *socket_);
125
126 // Send command to the destination thread.
127 void send_command (uint32_t tid_, const command_t &command_);
128
129 // Returns the I/O thread that is the least busy at the moment.
130 // Affinity specifies which I/O threads are eligible (0 = all).
131 // Returns NULL if no I/O thread is available.
132 zmq::io_thread_t *choose_io_thread (uint64_t affinity_);
133
134 // Returns reaper thread object.
135 zmq::object_t *get_reaper ();
136
137 // Management of inproc endpoints.
138 int register_endpoint (const char *addr_, const endpoint_t &endpoint_);
139 int unregister_endpoint (const std::string &addr_, socket_base_t *socket_);
140 void unregister_endpoints (zmq::socket_base_t *socket_);
141 endpoint_t find_endpoint (const char *addr_);
142 void pend_connection (const std::string &addr_,
143 const endpoint_t &endpoint_,
144 pipe_t **pipes_);
145 void connect_pending (const char *addr_, zmq::socket_base_t *bind_socket_);
146
147#ifdef ZMQ_HAVE_VMCI
148 // Return family for the VMCI socket or -1 if it's not available.
149 int get_vmci_socket_family ();
150#endif
151
152 enum
153 {
154 term_tid = 0,
155 reaper_tid = 1
156 };
157
158 ~ctx_t ();
159
160 bool valid () const;
161
162 private:
163 bool start ();
164
165 struct pending_connection_t
166 {
167 endpoint_t endpoint;
168 pipe_t *connect_pipe;
169 pipe_t *bind_pipe;
170 };
171
172 // Used to check whether the object is a context.
173 uint32_t _tag;
174
175 // Sockets belonging to this context. We need the list so that
176 // we can notify the sockets when zmq_ctx_term() is called.
177 // The sockets will return ETERM then.
178 typedef array_t<socket_base_t> sockets_t;
179 sockets_t _sockets;
180
181 // List of unused thread slots.
182 typedef std::vector<uint32_t> empty_slots_t;
183 empty_slots_t _empty_slots;
184
185 // If true, zmq_init has been called but no socket has been created
186 // yet. Launching of I/O threads is delayed.
187 bool _starting;
188
189 // If true, zmq_ctx_term was already called.
190 bool _terminating;
191
192 // Synchronisation of accesses to global slot-related data:
193 // sockets, empty_slots, terminating. It also synchronises
194 // access to zombie sockets as such (as opposed to slots) and provides
195 // a memory barrier to ensure that all CPU cores see the same data.
196 mutex_t _slot_sync;
197
198 // The reaper thread.
199 zmq::reaper_t *_reaper;
200
201 // I/O threads.
202 typedef std::vector<zmq::io_thread_t *> io_threads_t;
203 io_threads_t _io_threads;
204
205 // Array of pointers to mailboxes for both application and I/O threads.
206 std::vector<i_mailbox *> _slots;
207
208 // Mailbox for zmq_ctx_term thread.
209 mailbox_t _term_mailbox;
210
211 // List of inproc endpoints within this context.
212 typedef std::map<std::string, endpoint_t> endpoints_t;
213 endpoints_t _endpoints;
214
215 // List of inproc connection endpoints pending a bind
216 typedef std::multimap<std::string, pending_connection_t>
217 pending_connections_t;
218 pending_connections_t _pending_connections;
219
220 // Synchronisation of access to the list of inproc endpoints.
221 mutex_t _endpoints_sync;
222
223 // Maximum socket ID.
224 static atomic_counter_t max_socket_id;
225
226 // Maximum number of sockets that can be opened at the same time.
227 int _max_sockets;
228
229 // Maximum allowed message size
230 int _max_msgsz;
231
232 // Number of I/O threads to launch.
233 int _io_thread_count;
234
235 // Does context wait (possibly forever) on termination?
236 bool _blocky;
237
238 // Is IPv6 enabled on this context?
239 bool _ipv6;
240
241 // Should we use zero copy message decoding in this context?
242 bool _zero_copy;
243
244 ZMQ_NON_COPYABLE_NOR_MOVABLE (ctx_t)
245
246#ifdef HAVE_FORK
247 // the process that created this context. Used to detect forking.
248 pid_t _pid;
249#endif
250 enum side
251 {
252 connect_side,
253 bind_side
254 };
255 void
256 connect_inproc_sockets (zmq::socket_base_t *bind_socket_,
257 options_t &bind_options_,
258 const pending_connection_t &pending_connection_,
259 side side_);
260
261#ifdef ZMQ_HAVE_VMCI
262 int _vmci_fd;
263 int _vmci_family;
264 mutex_t _vmci_sync;
265#endif
266};
267}
268
269#endif
270