diff options
| -rw-r--r-- | src/zmq.cpp | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/src/zmq.cpp b/src/zmq.cpp index 1ed96df..c40be65 100644 --- a/src/zmq.cpp +++ b/src/zmq.cpp @@ -452,31 +452,25 @@ int zmq_poll (zmq_pollitem_t *items_, int nitems_, long timeout_) maxfd = notify_fd; } + bool block = (timeout_ < 0); timeval timeout = {timeout_ / 1000000, timeout_ % 1000000}; timeval zero_timeout = {0, 0}; int nevents = 0; - bool initial = true; - while (!nevents) { - // Wait for activity. In the first iteration just check for events, - // don't wait. Waiting would prevent exiting on any events that may - // already be signaled on 0MQ sockets. - int rc = select (maxfd, &pollset_in, &pollset_out, &pollset_err, - initial ? &zero_timeout : &timeout); + // First iteration just check for events, don't block. Waiting would + // prevent exiting on any events that may already been signaled on + // 0MQ sockets. + int rc = select (maxfd, &pollset_in, &pollset_out, &pollset_err, + &zero_timeout); #if defined ZMQ_HAVE_WINDOWS - wsa_assert (rc != SOCKET_ERROR); + wsa_assert (rc != SOCKET_ERROR); #else - if (rc == -1 && errno == EINTR) - break; + if (rc == -1 && errno == EINTR) + break; + errno_assert (rc >= 0); #endif - errno_assert (rc >= 0); - // If timeout was hit with no events signaled, return zero. - if (!initial && rc == 0) - return 0; - - // From now on, perform blocking select. - initial = false; + while (true) { // Process 0MQ commands if needed. if (nsockets && FD_ISSET (notify_fd, &pollset_in)) @@ -507,6 +501,32 @@ int zmq_poll (zmq_pollitem_t *items_, int nitems_, long timeout_) if (items_ [i].revents) nevents++; } + + // If there's at least one event, or if we are asked not to block, + // return immediately. + if (nevents || (timeout.tv_sec == 0 && timeout.tv_usec == 0)) + break; + + // Wait for events. + int rc = select (maxfd, &pollset_in, &pollset_out, &pollset_err, + block ? NULL : &timeout); +#if defined ZMQ_HAVE_WINDOWS + wsa_assert (rc != SOCKET_ERROR); +#else + if (rc == -1 && errno == EINTR) + break; + errno_assert (rc >= 0); +#endif + + // If timeout was hit with no events signaled, return zero. + if (rc == 0) + break; + + // If timeout was already applied, we don't want to poll anymore. + // Setting timeout to zero will cause termination of the function + // once the events we've got are processed. + if (!block) + timeout = zero_timeout; } return nevents; |