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Diffstat (limited to 'src/signaler.cpp')
| -rw-r--r-- | src/signaler.cpp | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/src/signaler.cpp b/src/signaler.cpp new file mode 100644 index 0000000..f7ed1f1 --- /dev/null +++ b/src/signaler.cpp @@ -0,0 +1,402 @@ +/* + Copyright (c) 2010-2011 250bpm s.r.o. + Copyright (c) 2010-2011 Other contributors as noted in the AUTHORS file + + This file is part of 0MQ. + + 0MQ is free software; you can redistribute it and/or modify it under + the terms of the GNU Lesser 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 + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "platform.hpp" + +#if defined ZMQ_FORCE_SELECT +#define ZMQ_SIGNALER_WAIT_BASED_ON_SELECT +#elif defined ZMQ_FORCE_POLL +#define ZMQ_SIGNALER_WAIT_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_SIGNALER_WAIT_BASED_ON_POLL +#elif defined ZMQ_HAVE_WINDOWS || defined ZMQ_HAVE_OPENVMS ||\ + defined ZMQ_HAVE_CYGWIN +#define ZMQ_SIGNALER_WAIT_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_SIGNALER_WAIT_BASED_ON_POLL +#include <poll.h> +#elif defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT +#if defined ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#elif defined ZMQ_HAVE_HPUX +#include <sys/param.h> +#include <sys/types.h> +#include <sys/time.h> +#elif defined ZMQ_HAVE_OPENVMS +#include <sys/types.h> +#include <sys/time.h> +#else +#include <sys/select.h> +#endif +#endif + +#include "signaler.hpp" +#include "likely.hpp" +#include "stdint.hpp" +#include "config.hpp" +#include "err.hpp" +#include "fd.hpp" +#include "ip.hpp" + +#if defined ZMQ_HAVE_EVENTFD +#include <sys/eventfd.h> +#endif + +#if defined ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#else +#include <unistd.h> +#include <netinet/tcp.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#endif + +zmq::signaler_t::signaler_t () +{ + // Create the socketpair for signaling. + int rc = make_fdpair (&r, &w); + errno_assert (rc == 0); + + // Set both fds to non-blocking mode. + unblock_socket (w); + unblock_socket (r); +} + +zmq::signaler_t::~signaler_t () +{ +#if defined ZMQ_HAVE_EVENTFD + int rc = close (r); + errno_assert (rc == 0); +#elif defined ZMQ_HAVE_WINDOWS + int rc = closesocket (w); + wsa_assert (rc != SOCKET_ERROR); + rc = closesocket (r); + wsa_assert (rc != SOCKET_ERROR); +#else + int rc = close (w); + errno_assert (rc == 0); + rc = close (r); + errno_assert (rc == 0); +#endif +} + +zmq::fd_t zmq::signaler_t::get_fd () +{ + return r; +} + +void zmq::signaler_t::send () +{ +#if defined ZMQ_HAVE_EVENTFD + const uint64_t inc = 1; + ssize_t sz = write (w, &inc, sizeof (inc)); + errno_assert (sz == sizeof (inc)); +#elif defined ZMQ_HAVE_WINDOWS + unsigned char dummy = 0; + int nbytes = ::send (w, (char*) &dummy, sizeof (dummy), 0); + wsa_assert (nbytes != SOCKET_ERROR); + zmq_assert (nbytes == sizeof (dummy)); +#else + unsigned char dummy = 0; + while (true) { + ssize_t nbytes = ::send (w, &dummy, sizeof (dummy), 0); + if (unlikely (nbytes == -1 && errno == EINTR)) + continue; + zmq_assert (nbytes == sizeof (dummy)); + break; + } +#endif +} + +int zmq::signaler_t::wait (int timeout_) +{ +#ifdef ZMQ_SIGNALER_WAIT_BASED_ON_POLL + + struct pollfd pfd; + pfd.fd = r; + pfd.events = POLLIN; + int rc = poll (&pfd, 1, timeout_); + if (unlikely (rc < 0)) { + errno_assert (errno == EINTR); + return -1; + } + else if (unlikely (rc == 0)) { + errno = EAGAIN; + return -1; + } + zmq_assert (rc == 1); + zmq_assert (pfd.revents & POLLIN); + return 0; + +#elif defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT + + fd_set fds; + FD_ZERO (&fds); + FD_SET (r, &fds); + struct timeval timeout; + if (timeout_ >= 0) { + timeout.tv_sec = timeout_ / 1000; + timeout.tv_usec = timeout_ % 1000 * 1000; + } +#ifdef ZMQ_HAVE_WINDOWS + int rc = select (0, &fds, NULL, NULL, + timeout_ >= 0 ? &timeout : NULL); + wsa_assert (rc != SOCKET_ERROR); +#else + int rc = select (r + 1, &fds, NULL, NULL, + timeout_ >= 0 ? &timeout : NULL); + if (unlikely (rc < 0)) { + errno_assert (errno == EINTR); + return -1; + } +#endif + if (unlikely (rc == 0)) { + errno = EAGAIN; + return -1; + } + zmq_assert (rc == 1); + return 0; + +#else +#error +#endif +} + +void zmq::signaler_t::recv () +{ + // Attempt to read a signal. +#if defined ZMQ_HAVE_EVENTFD + uint64_t dummy; + ssize_t sz = read (r, &dummy, sizeof (dummy)); + errno_assert (sz == sizeof (dummy)); + + // If we accidentally grabbed the next signal along with the current + // one, return it back to the eventfd object. + if (unlikely (dummy == 2)) { + const uint64_t inc = 1; + ssize_t sz = write (w, &inc, sizeof (inc)); + errno_assert (sz == sizeof (inc)); + return; + } + + zmq_assert (dummy == 1); +#else + unsigned char dummy; +#if defined ZMQ_HAVE_WINDOWS + int nbytes = ::recv (r, (char*) &dummy, sizeof (dummy), 0); + wsa_assert (nbytes != SOCKET_ERROR); +#else + ssize_t nbytes = ::recv (r, &dummy, sizeof (dummy), 0); + errno_assert (nbytes >= 0); +#endif + zmq_assert (nbytes == sizeof (dummy)); + zmq_assert (dummy == 0); +#endif +} + +int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_) +{ +#if defined ZMQ_HAVE_EVENTFD + + // Create eventfd object. + fd_t fd = eventfd (0, 0); + errno_assert (fd != -1); + *w_ = fd; + *r_ = fd; + return 0; + +#elif defined ZMQ_HAVE_WINDOWS + SECURITY_DESCRIPTOR sd = {0}; + SECURITY_ATTRIBUTES sa = {0}; + + InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION); + SetSecurityDescriptorDacl(&sd, TRUE, 0, FALSE); + + sa.nLength = sizeof(SECURITY_ATTRIBUTES); + sa.lpSecurityDescriptor = &sd; + + // This function has to be in a system-wide critical section so that + // two instances of the library don't accidentally create signaler + // crossing the process boundary. + // We'll use named event object to implement the critical section. + // Note that if the event object already exists, the CreateEvent requests + // EVENT_ALL_ACCESS access right. If this fails, we try to open + // the event object asking for SYNCHRONIZE access only. + HANDLE sync = CreateEvent (&sa, FALSE, TRUE, TEXT ("Global\\zmq-signaler-port-sync")); + if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED) + sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, TEXT ("Global\\zmq-signaler-port-sync")); + + win_assert (sync != NULL); + + // Enter the critical section. + DWORD dwrc = WaitForSingleObject (sync, INFINITE); + zmq_assert (dwrc == WAIT_OBJECT_0); + + // Windows has no 'socketpair' function. CreatePipe is no good as pipe + // handles cannot be polled on. Here we create the socketpair by hand. + *w_ = INVALID_SOCKET; + *r_ = INVALID_SOCKET; + + // Create listening socket. + SOCKET listener; + listener = open_socket (AF_INET, SOCK_STREAM, 0); + wsa_assert (listener != INVALID_SOCKET); + + // Set SO_REUSEADDR and TCP_NODELAY on listening socket. + BOOL so_reuseaddr = 1; + int rc = setsockopt (listener, SOL_SOCKET, SO_REUSEADDR, + (char *)&so_reuseaddr, sizeof (so_reuseaddr)); + wsa_assert (rc != SOCKET_ERROR); + BOOL tcp_nodelay = 1; + rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, + (char *)&tcp_nodelay, sizeof (tcp_nodelay)); + wsa_assert (rc != SOCKET_ERROR); + + // Bind listening socket to any free local port. + struct sockaddr_in addr; + memset (&addr, 0, sizeof (addr)); + addr.sin_family = AF_INET; + addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK); + addr.sin_port = htons (signaler_port); + rc = bind (listener, (const struct sockaddr*) &addr, sizeof (addr)); + wsa_assert (rc != SOCKET_ERROR); + + // Listen for incomming connections. + rc = listen (listener, 1); + wsa_assert (rc != SOCKET_ERROR); + + // Create the writer socket. + *w_ = WSASocket (AF_INET, SOCK_STREAM, 0, NULL, 0, 0); + wsa_assert (*w_ != INVALID_SOCKET); + + // On Windows, preventing sockets to be inherited by child processes. + BOOL brc = SetHandleInformation ((HANDLE) *w_, HANDLE_FLAG_INHERIT, 0); + win_assert (brc); + + // Set TCP_NODELAY on writer socket. + rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, + (char *)&tcp_nodelay, sizeof (tcp_nodelay)); + wsa_assert (rc != SOCKET_ERROR); + + // Connect writer to the listener. + rc = connect (*w_, (struct sockaddr*) &addr, sizeof (addr)); + wsa_assert (rc != SOCKET_ERROR); + + // Accept connection from writer. + *r_ = accept (listener, NULL, NULL); + wsa_assert (*r_ != INVALID_SOCKET); + + // On Windows, preventing sockets to be inherited by child processes. + brc = SetHandleInformation ((HANDLE) *r_, HANDLE_FLAG_INHERIT, 0); + win_assert (brc); + + // We don't need the listening socket anymore. Close it. + rc = closesocket (listener); + wsa_assert (rc != SOCKET_ERROR); + + // Exit the critical section. + brc = SetEvent (sync); + win_assert (brc != 0); + + return 0; + +#elif defined ZMQ_HAVE_OPENVMS + + // Whilst OpenVMS supports socketpair - it maps to AF_INET only. Further, + // it does not set the socket options TCP_NODELAY and TCP_NODELACK which + // can lead to performance problems. + // + // The bug will be fixed in V5.6 ECO4 and beyond. In the meantime, we'll + // create the socket pair manually. + struct sockaddr_in lcladdr; + memset (&lcladdr, 0, sizeof (lcladdr)); + lcladdr.sin_family = AF_INET; + lcladdr.sin_addr.s_addr = htonl (INADDR_LOOPBACK); + lcladdr.sin_port = 0; + + int listener = open_socket (AF_INET, SOCK_STREAM, 0); + errno_assert (listener != -1); + + int on = 1; + int rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on)); + errno_assert (rc != -1); + + rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on)); + errno_assert (rc != -1); + + rc = bind(listener, (struct sockaddr*) &lcladdr, sizeof (lcladdr)); + errno_assert (rc != -1); + + socklen_t lcladdr_len = sizeof (lcladdr); + + rc = getsockname (listener, (struct sockaddr*) &lcladdr, &lcladdr_len); + errno_assert (rc != -1); + + rc = listen (listener, 1); + errno_assert (rc != -1); + + *w_ = open_socket (AF_INET, SOCK_STREAM, 0); + errno_assert (*w_ != -1); + + rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY, &on, sizeof (on)); + errno_assert (rc != -1); + + rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on)); + errno_assert (rc != -1); + + rc = connect (*w_, (struct sockaddr*) &lcladdr, sizeof (lcladdr)); + errno_assert (rc != -1); + + *r_ = accept (listener, NULL, NULL); + errno_assert (*r_ != -1); + + close (listener); + + return 0; + +#else // All other implementations support socketpair() + + int sv [2]; + int rc = socketpair (AF_UNIX, SOCK_STREAM, 0, sv); + errno_assert (rc == 0); + *w_ = sv [0]; + *r_ = sv [1]; + return 0; + +#endif +} + +#if defined ZMQ_SIGNALER_WAIT_BASED_ON_SELECT +#undef ZMQ_SIGNALER_WAIT_BASED_ON_SELECT +#endif +#if defined ZMQ_SIGNALER_WAIT_BASED_ON_POLL +#undef ZMQ_SIGNALER_WAIT_BASED_ON_POLL +#endif + |