Add sockopt ZMQ_RCVTIMEO/ZMQ_SNDTIMEO.

- Add doc and tests
- Add options and setup
- Wait using poll/select

Signed-off-by: Fabien Ninoles <fabien@tzone.org>
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

9 files changed, 217 insertions, 48 deletions

diff --git a/src/ctx.cpp b/src/ctx.cpp
index fb5420d..783bcba 100644
--- a/src/ctx.cpp
+++ b/src/ctx.cpp
@@ -142,7 +142,7 @@ int zmq::ctx_t::terminate ()
 
     //  Wait till reaper thread closes all the sockets.
     command_t cmd;
-    int rc = term_mailbox.recv (&cmd, true);
+    int rc = term_mailbox.recv (&cmd, -1);
     if (rc == -1 && errno == EINTR)
         return -1;
     zmq_assert (rc == 0);
diff --git a/src/io_thread.cpp b/src/io_thread.cpp
index 9678392..c6f3880 100644
--- a/src/io_thread.cpp
+++ b/src/io_thread.cpp
@@ -70,7 +70,7 @@ void zmq::io_thread_t::in_event ()
 
         //  Get the next command. If there is none, exit.
         command_t cmd;
-        int rc = mailbox.recv (&cmd, false);
+        int rc = mailbox.recv (&cmd, 0);
         if (rc != 0 && errno == EINTR)
             continue;
         if (rc != 0 && errno == EAGAIN)
diff --git a/src/mailbox.cpp b/src/mailbox.cpp
index 221396b..402d025 100644
--- a/src/mailbox.cpp
+++ b/src/mailbox.cpp
@@ -18,8 +18,33 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "mailbox.hpp"
 #include "platform.hpp"
+
+#if defined ZMQ_FORCE_SELECT
+#define ZMQ_RCVTIMEO_BASED_ON_SELECT
+#elif defined ZMQ_FORCE_POLL
+#define ZMQ_RCVTIMEO_BASED_ON_POLL
+#elif defined ZMQ_HAVE_LINUX || defined ZMQ_HAVE_FREEBSD ||\
+    defined ZMQ_HAVE_OPENBSD || defined ZMQ_HAVE_SOLARIS ||\
+    defined ZMQ_HAVE_OSX || defined ZMQ_HAVE_QNXNTO ||\
+    defined ZMQ_HAVE_HPUX || defined ZMQ_HAVE_AIX ||\
+    defined ZMQ_HAVE_NETBSD
+#define ZMQ_RCVTIMEO_BASED_ON_POLL
+#elif defined ZMQ_HAVE_WINDOWS || defined ZMQ_HAVE_OPENVMS
+#define ZMQ_RCVTIMEO_BASED_ON_SELECT
+#endif
+
+//  On AIX, poll.h has to be included before zmq.h to get consistent
+//  definition of pollfd structure (AIX uses 'reqevents' and 'retnevents'
+//  instead of 'events' and 'revents' and defines macros to map from POSIX-y
+//  names to AIX-specific names).
+#if defined ZMQ_RCVTIMEO_BASED_ON_POLL
+#include <poll.h>
+#elif defined ZMQ_RCVTIMEO_BASED_ON_SELECT
+#include <sys/select.h>
+#endif
+
+#include "mailbox.hpp"
 #include "err.hpp"
 #include "fd.hpp"
 #include "ip.hpp"
@@ -79,10 +104,14 @@ void zmq::mailbox_t::send (const command_t &cmd_)
     zmq_assert (nbytes == sizeof (command_t));
 }
 
-int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
+int zmq::mailbox_t::recv (command_t *cmd_, int timeout_)
 {
+    //  If there's a finite timeout, poll on the fd.
+    if (timeout_ > 0)
+        return recv_timeout (cmd_, timeout_);
+
     //  If required, set the reader to blocking mode.
-    if (block_) {
+    if (timeout_ < 0) {
         unsigned long argp = 0;
         int rc = ioctlsocket (r, FIONBIO, &argp);
         wsa_assert (rc != SOCKET_ERROR);
@@ -97,7 +126,7 @@ int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
         err = EAGAIN;
 
     //  Re-set the reader to non-blocking mode.
-    if (block_) {
+    if (timeout_ < 0) {
         unsigned long argp = 1;
         int rc = ioctlsocket (r, FIONBIO, &argp);
         wsa_assert (rc != SOCKET_ERROR);
@@ -194,20 +223,24 @@ void zmq::mailbox_t::send (const command_t &cmd_)
     zmq_assert (nbytes == sizeof (command_t));
 }
 
-int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
+int zmq::mailbox_t::recv (command_t *cmd_, int timeout_)
 {
+    //  If there's a finite timeout, poll on the fd.
+    if (timeout_ > 0)
+        return recv_timeout (cmd_, timeout_);
+
 #ifdef MSG_DONTWAIT
 
     //  Attempt to read an entire command. Returns EAGAIN if non-blocking
     //  mode is requested and a command is not available.
     ssize_t nbytes = ::recv (r, cmd_, sizeof (command_t),
-        block_ ? 0 : MSG_DONTWAIT);
+        timeout_ < 0 ? 0 : MSG_DONTWAIT);
     if (nbytes == -1 && (errno == EAGAIN || errno == EINTR))
         return -1;
 #else
 
     //  If required, set the reader to blocking mode.
-    if (block_) {
+    if (timeout_ < 0) {
         int flags = fcntl (r, F_GETFL, 0);
         errno_assert (flags >= 0);
         int rc = fcntl (r, F_SETFL, flags & ~O_NONBLOCK);
@@ -223,7 +256,7 @@ int zmq::mailbox_t::recv (command_t *cmd_, bool block_)
         err = errno;
 
     //  Re-set the reader to non-blocking mode.
-    if (block_) {
+    if (timeout_ < 0) {
         int flags = fcntl (r, F_GETFL, 0);
         errno_assert (flags >= 0);
         int rc = fcntl (r, F_SETFL, flags | O_NONBLOCK);
@@ -380,3 +413,60 @@ int zmq::mailbox_t::make_socketpair (fd_t *r_, fd_t *w_)
 #endif
 }
 
+int zmq::mailbox_t::recv_timeout (command_t *cmd_, int timeout_)
+{
+#ifdef ZMQ_RCVTIMEO_BASED_ON_POLL
+
+    struct pollfd pfd;
+    pfd.fd = r;
+    pfd.events = POLLIN;
+    int rc = poll (&pfd, 1, timeout_);
+    if (unlikely (rc < 0)) {
+        zmq_assert (errno == EINTR);
+        return -1;
+    }
+    else if (unlikely (rc == 0)) {
+        errno = EAGAIN;
+        return -1;
+    }
+    zmq_assert (rc == 1);
+    zmq_assert (pfd.revents & POLLIN);
+
+#elif defined ZMQ_RCVTIMEO_BASED_ON_SELECT
+
+    fd_set fds;
+    FD_ZERO (&fds);
+    FD_SET (r, &fds);
+    struct timeval timeout;
+    timeout.tv_sec = timeout_ / 1000;
+    timeout.tv_usec = timeout_ % 1000 * 1000;
+    int rc = select (r + 1, &fds, NULL, NULL, &timeout);
+    if (unlikely (rc < 0)) {
+        zmq_assert (errno == EINTR);
+        return -1;
+    }
+    else if (unlikely (rc == 0)) {
+        errno = EAGAIN;
+        return -1;
+    }
+    zmq_assert (rc == 1);
+
+#else
+#error
+#endif
+
+    //  The file descriptor is ready for reading. Extract one command out of it.
+    ssize_t nbytes = ::recv (r, cmd_, sizeof (command_t), 0);
+    if (unlikely (rc < 0 && errno == EINTR))
+        return -1;
+    zmq_assert (nbytes == sizeof (command_t));
+    return 0;
+}
+
+#if defined ZMQ_RCVTIMEO_BASED_ON_SELECT
+#undef ZMQ_RCVTIMEO_BASED_ON_SELECT
+#endif
+#if defined ZMQ_RCVTIMEO_BASED_ON_POLL
+#undef ZMQ_RCVTIMEO_BASED_ON_POLL
+#endif
+
diff --git a/src/mailbox.hpp b/src/mailbox.hpp
index 96bf4eb..1b54aac 100644
--- a/src/mailbox.hpp
+++ b/src/mailbox.hpp
@@ -41,7 +41,7 @@ namespace zmq
 
         fd_t get_fd ();
         void send (const command_t &cmd_);
-        int recv (command_t *cmd_, bool block_);
+        int recv (command_t *cmd_, int timeout_);
         
     private:
 
@@ -52,6 +52,11 @@ namespace zmq
         //  Platform-dependent function to create a socketpair.
         static int make_socketpair (fd_t *r_, fd_t *w_);
 
+        //  Receives a command with the specific timeout.
+        //  This function is not to be used for non-blocking or inifinitely
+        //  blocking recvs.
+        int recv_timeout (command_t *cmd_, int timeout_);
+
         //  Disable copying of mailbox_t object.
         mailbox_t (const mailbox_t&);
         const mailbox_t &operator = (const mailbox_t&);
diff --git a/src/options.cpp b/src/options.cpp
index 29cf023..80ab294 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -39,6 +39,8 @@ zmq::options_t::options_t () :
     backlog (100),
     maxmsgsize (-1),
     filter (1),
+    rcvtimeo (-1),
+    sndtimeo (-1),
     immediate_connect (true)
 {
 }
@@ -182,6 +184,22 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
         filter = *((int*) optval_);
         return 0;
 
+    case ZMQ_RCVTIMEO:
+        if (optvallen_ != sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        rcvtimeo = *((int*) optval_);
+        return 0;
+
+    case ZMQ_SNDTIMEO:
+        if (optvallen_ != sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        sndtimeo = *((int*) optval_);
+        return 0;
+
     }
 
     errno = EINVAL;
@@ -336,6 +354,24 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *optvallen_ = sizeof (int);
         return 0;
 
+    case ZMQ_RCVTIMEO:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = rcvtimeo;
+        *optvallen_ = sizeof (int);
+        return 0;
+
+    case ZMQ_SNDTIMEO:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = sndtimeo;
+        *optvallen_ = sizeof (int);
+        return 0;
+
     }
 
     errno = EINVAL;
diff --git a/src/options.hpp b/src/options.hpp
index e055919..858ec2e 100644
--- a/src/options.hpp
+++ b/src/options.hpp
@@ -78,6 +78,10 @@ namespace zmq
         //  If 1, (X)SUB socket should filter the messages. If 0, it should not.
         int filter;
 
+        // The timeout for send/recv operations for this socket.
+        int rcvtimeo;
+        int sndtimeo;
+
         //  If true, when connecting, pipes are created immediately without
         //  waiting for the connection to be established. That way the socket
         //  is not aware of the peer's identity, however, it is able to send
diff --git a/src/reaper.cpp b/src/reaper.cpp
index 0295137..4c67b37 100644
--- a/src/reaper.cpp
+++ b/src/reaper.cpp
@@ -61,7 +61,7 @@ void zmq::reaper_t::in_event ()
 
         //  Get the next command. If there is none, exit.
         command_t cmd;
-        int rc = mailbox.recv (&cmd, false);
+        int rc = mailbox.recv (&cmd, 0);
         if (rc != 0 && errno == EINTR)
             continue;
         if (rc != 0 && errno == EAGAIN)
diff --git a/src/socket_base.cpp b/src/socket_base.cpp
index 2b1d8af..dc6b5f5 100644
--- a/src/socket_base.cpp
+++ b/src/socket_base.cpp
@@ -288,7 +288,7 @@ int zmq::socket_base_t::getsockopt (int option_, void *optval_,
             errno = EINVAL;
             return -1;
         }
-        int rc = process_commands (false, false);
+        int rc = process_commands (0, false);
         if (rc != 0 && (errno == EINTR || errno == ETERM))
             return -1;
         errno_assert (rc == 0);
@@ -475,7 +475,7 @@ int zmq::socket_base_t::send (msg_t *msg_, int flags_)
     }
 
     //  Process pending commands, if any.
-    int rc = process_commands (false, true);
+    int rc = process_commands (0, true);
     if (unlikely (rc != 0))
         return -1;
 
@@ -487,20 +487,38 @@ int zmq::socket_base_t::send (msg_t *msg_, int flags_)
     rc = xsend (msg_, flags_);
     if (rc == 0)
         return 0;
+    if (unlikely (errno != EAGAIN))
+        return -1;
 
     //  In case of non-blocking send we'll simply propagate
-    //  the error - including EAGAIN - upwards.
-    if (flags_ & ZMQ_DONTWAIT)
+    //  the error - including EAGAIN - up the stack.
+    if (flags_ & ZMQ_DONTWAIT || options.sndtimeo == 0)
         return -1;
 
+    //  Compute the time when the timeout should occur.
+    //  If the timeout is infite, don't care. 
+    clock_t clock ;
+    int timeout = options.sndtimeo;
+    uint64_t end = timeout < 0 ? 0 : (clock.now_ms () + timeout);
+
     //  Oops, we couldn't send the message. Wait for the next
     //  command, process it and try to send the message again.
-    while (rc != 0) {
-        if (errno != EAGAIN)
-            return -1;
-        if (unlikely (process_commands (true, false) != 0))
+    //  If timeout is reached in the meantime, return EAGAIN.
+    while (true) {
+        if (unlikely (process_commands (timeout, false) != 0))
             return -1;
         rc = xsend (msg_, flags_);
+        if (rc == 0)
+            break;
+        if (unlikely (errno != EAGAIN))
+            return -1;
+        if (timeout > 0) {
+            timeout = end - clock.now_ms ();
+            if (timeout <= 0) {
+                errno = EAGAIN;
+                return -1;
+            }
+        }
     }
     return 0;
 }
@@ -521,7 +539,8 @@ int zmq::socket_base_t::recv (msg_t *msg_, int flags_)
 
     //  Get the message.
     int rc = xrecv (msg_, flags_);
-    int err = errno;
+    if (unlikely (rc != 0 && errno != EAGAIN))
+        return -1;
 
     //  Once every inbound_poll_rate messages check for signals and process
     //  incoming commands. This happens only if we are not polling altogether
@@ -532,7 +551,7 @@ int zmq::socket_base_t::recv (msg_t *msg_, int flags_)
     //  described above) from the one used by 'send'. This is because counting
     //  ticks is more efficient than doing RDTSC all the time.
     if (++ticks == inbound_poll_rate) {
-        if (unlikely (process_commands (false, false) != 0))
+        if (unlikely (process_commands (0, false) != 0))
             return -1;
         ticks = 0;
     }
@@ -545,17 +564,12 @@ int zmq::socket_base_t::recv (msg_t *msg_, int flags_)
         return 0;
     }
 
-    //  If we don't have the message, restore the original cause of the problem.
-    errno = err;
-
     //  If the message cannot be fetched immediately, there are two scenarios.
     //  For non-blocking recv, commands are processed in case there's an
     //  activate_reader command already waiting int a command pipe.
     //  If it's not, return EAGAIN.
-    if (flags_ & ZMQ_DONTWAIT) {
-        if (errno != EAGAIN)
-            return -1;
-        if (unlikely (process_commands (false, false) != 0))
+    if (flags_ & ZMQ_DONTWAIT || options.rcvtimeo == 0) {
+        if (unlikely (process_commands (0, false) != 0))
             return -1;
         ticks = 0;
 
@@ -568,17 +582,33 @@ int zmq::socket_base_t::recv (msg_t *msg_, int flags_)
         return rc;
     }
 
+    //  Compute the time when the timeout should occur.
+    //  If the timeout is infite, don't care. 
+    clock_t clock ;
+    int timeout = options.rcvtimeo;
+    uint64_t end = timeout < 0 ? 0 : (clock.now_ms () + timeout);
+
     //  In blocking scenario, commands are processed over and over again until
     //  we are able to fetch a message.
     bool block = (ticks != 0);
-    while (rc != 0) {
-        if (errno != EAGAIN)
-            return -1;
-        if (unlikely (process_commands (block, false) != 0))
+    while (true) {
+        if (unlikely (process_commands (block ? timeout : 0, false) != 0))
             return -1;
         rc = xrecv (msg_, flags_);
-        ticks = 0;
+        if (rc == 0) {
+            ticks = 0;
+            break;
+        }
+        if (unlikely (errno != EAGAIN))
+            return -1;
         block = true;
+        if (timeout > 0) {
+            timeout = end - clock.now_ms ();
+            if (timeout <= 0) {
+                errno = EAGAIN;
+                return -1;
+            }
+        }
     }
 
     rcvmore = msg_->flags () & msg_t::more;
@@ -658,18 +688,20 @@ void zmq::socket_base_t::start_reaping (poller_t *poller_)
     check_destroy ();
 }
 
-int zmq::socket_base_t::process_commands (bool block_, bool throttle_)
+int zmq::socket_base_t::process_commands (int timeout_, bool throttle_)
 {
     int rc;
     command_t cmd;
-    if (block_) {
-        rc = mailbox.recv (&cmd, true);
-        if (rc == -1 && errno == EINTR)
-            return -1;
-        errno_assert (rc == 0);
+    if (timeout_ != 0) {
+
+        //  If we are asked to wait, simply ask mailbox to wait.
+        rc = mailbox.recv (&cmd, timeout_);
     }
     else {
 
+        //  If we are asked not to wait, check whether we haven't processed
+        //  commands recently, so that we can throttle the new commands.
+
         //  Get the CPU's tick counter. If 0, the counter is not available.
         uint64_t tsc = zmq::clock_t::rdtsc ();
 
@@ -690,7 +722,7 @@ int zmq::socket_base_t::process_commands (bool block_, bool throttle_)
         }
 
         //  Check whether there are any commands pending for this thread.
-        rc = mailbox.recv (&cmd, false);
+        rc = mailbox.recv (&cmd, 0);
     }
 
     //  Process all the commands available at the moment.
@@ -701,7 +733,7 @@ int zmq::socket_base_t::process_commands (bool block_, bool throttle_)
             return -1;
         errno_assert (rc == 0);
         cmd.destination->process_command (cmd);
-        rc = mailbox.recv (&cmd, false);
+        rc = mailbox.recv (&cmd, 0);
      }
 
     if (ctx_terminated) {
@@ -797,9 +829,11 @@ void zmq::socket_base_t::xhiccuped (pipe_t *pipe_)
 
 void zmq::socket_base_t::in_event ()
 {
-    //  Process any commands from other threads/sockets that may be available
-    //  at the moment. Ultimately, socket will be destroyed.
-    process_commands (false, false);
+    //  This function is invoked only once the socket is running in the context
+    //  of the reaper thread. Process any commands from other threads/sockets
+    //  that may be available at the moment. Ultimately, the socket will
+    //  be destroyed.
+    process_commands (0, false);
     check_destroy ();
 }
 
diff --git a/src/socket_base.hpp b/src/socket_base.hpp
index ed5620c..69a8aac 100644
--- a/src/socket_base.hpp
+++ b/src/socket_base.hpp
@@ -160,11 +160,11 @@ namespace zmq
         //  Register the pipe with this socket.
         void attach_pipe (class pipe_t *pipe_, const blob_t &peer_identity_);
 
-        //  Processes commands sent to this socket (if any). If 'block' is
-        //  set to true, returns only after at least one command was processed.
+        //  Processes commands sent to this socket (if any). If timeout is -1,
+        //  returns only after at least one command was processed.
         //  If throttle argument is true, commands are processed at most once
         //  in a predefined time period.
-        int process_commands (bool block_, bool throttle_);
+        int process_commands (int timeout_, bool throttle_);
 
         //  Handlers for incoming commands.
         void process_stop ();