| // |
| // detail/impl/descriptor_ops.ipp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| // |
| |
| #ifndef ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP |
| #define ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/config.hpp" |
| #include <cerrno> |
| #include "asio/detail/descriptor_ops.hpp" |
| #include "asio/error.hpp" |
| |
| #if !defined(ASIO_WINDOWS) \ |
| && !defined(ASIO_WINDOWS_RUNTIME) \ |
| && !defined(__CYGWIN__) |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| namespace descriptor_ops { |
| |
| int open(const char* path, int flags, asio::error_code& ec) |
| { |
| errno = 0; |
| int result = error_wrapper(::open(path, flags), ec); |
| if (result >= 0) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| int close(int d, state_type& state, asio::error_code& ec) |
| { |
| int result = 0; |
| if (d != -1) |
| { |
| errno = 0; |
| result = error_wrapper(::close(d), ec); |
| |
| if (result != 0 |
| && (ec == asio::error::would_block |
| || ec == asio::error::try_again)) |
| { |
| // According to UNIX Network Programming Vol. 1, it is possible for |
| // close() to fail with EWOULDBLOCK under certain circumstances. What |
| // isn't clear is the state of the descriptor after this error. The one |
| // current OS where this behaviour is seen, Windows, says that the socket |
| // remains open. Therefore we'll put the descriptor back into blocking |
| // mode and have another attempt at closing it. |
| #if defined(__SYMBIAN32__) |
| int flags = ::fcntl(d, F_GETFL, 0); |
| if (flags >= 0) |
| ::fcntl(d, F_SETFL, flags & ~O_NONBLOCK); |
| #else // defined(__SYMBIAN32__) |
| ioctl_arg_type arg = 0; |
| ::ioctl(d, FIONBIO, &arg); |
| #endif // defined(__SYMBIAN32__) |
| state &= ~non_blocking; |
| |
| errno = 0; |
| result = error_wrapper(::close(d), ec); |
| } |
| } |
| |
| if (result == 0) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| bool set_user_non_blocking(int d, state_type& state, |
| bool value, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return false; |
| } |
| |
| errno = 0; |
| #if defined(__SYMBIAN32__) |
| int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec); |
| if (result >= 0) |
| { |
| errno = 0; |
| int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK)); |
| result = error_wrapper(::fcntl(d, F_SETFL, flag), ec); |
| } |
| #else // defined(__SYMBIAN32__) |
| ioctl_arg_type arg = (value ? 1 : 0); |
| int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec); |
| #endif // defined(__SYMBIAN32__) |
| |
| if (result >= 0) |
| { |
| ec = asio::error_code(); |
| if (value) |
| state |= user_set_non_blocking; |
| else |
| { |
| // Clearing the user-set non-blocking mode always overrides any |
| // internally-set non-blocking flag. Any subsequent asynchronous |
| // operations will need to re-enable non-blocking I/O. |
| state &= ~(user_set_non_blocking | internal_non_blocking); |
| } |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool set_internal_non_blocking(int d, state_type& state, |
| bool value, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return false; |
| } |
| |
| if (!value && (state & user_set_non_blocking)) |
| { |
| // It does not make sense to clear the internal non-blocking flag if the |
| // user still wants non-blocking behaviour. Return an error and let the |
| // caller figure out whether to update the user-set non-blocking flag. |
| ec = asio::error::invalid_argument; |
| return false; |
| } |
| |
| errno = 0; |
| #if defined(__SYMBIAN32__) |
| int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec); |
| if (result >= 0) |
| { |
| errno = 0; |
| int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK)); |
| result = error_wrapper(::fcntl(d, F_SETFL, flag), ec); |
| } |
| #else // defined(__SYMBIAN32__) |
| ioctl_arg_type arg = (value ? 1 : 0); |
| int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec); |
| #endif // defined(__SYMBIAN32__) |
| |
| if (result >= 0) |
| { |
| ec = asio::error_code(); |
| if (value) |
| state |= internal_non_blocking; |
| else |
| state &= ~internal_non_blocking; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| std::size_t sync_read(int d, state_type state, buf* bufs, |
| std::size_t count, bool all_empty, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return 0; |
| } |
| |
| // A request to read 0 bytes on a stream is a no-op. |
| if (all_empty) |
| { |
| ec = asio::error_code(); |
| return 0; |
| } |
| |
| // Read some data. |
| for (;;) |
| { |
| // Try to complete the operation without blocking. |
| errno = 0; |
| signed_size_type bytes = error_wrapper(::readv( |
| d, bufs, static_cast<int>(count)), ec); |
| |
| // Check if operation succeeded. |
| if (bytes > 0) |
| return bytes; |
| |
| // Check for EOF. |
| if (bytes == 0) |
| { |
| ec = asio::error::eof; |
| return 0; |
| } |
| |
| // Operation failed. |
| if ((state & user_set_non_blocking) |
| || (ec != asio::error::would_block |
| && ec != asio::error::try_again)) |
| return 0; |
| |
| // Wait for descriptor to become ready. |
| if (descriptor_ops::poll_read(d, 0, ec) < 0) |
| return 0; |
| } |
| } |
| |
| bool non_blocking_read(int d, buf* bufs, std::size_t count, |
| asio::error_code& ec, std::size_t& bytes_transferred) |
| { |
| for (;;) |
| { |
| // Read some data. |
| errno = 0; |
| signed_size_type bytes = error_wrapper(::readv( |
| d, bufs, static_cast<int>(count)), ec); |
| |
| // Check for end of stream. |
| if (bytes == 0) |
| { |
| ec = asio::error::eof; |
| return true; |
| } |
| |
| // Retry operation if interrupted by signal. |
| if (ec == asio::error::interrupted) |
| continue; |
| |
| // Check if we need to run the operation again. |
| if (ec == asio::error::would_block |
| || ec == asio::error::try_again) |
| return false; |
| |
| // Operation is complete. |
| if (bytes > 0) |
| { |
| ec = asio::error_code(); |
| bytes_transferred = bytes; |
| } |
| else |
| bytes_transferred = 0; |
| |
| return true; |
| } |
| } |
| |
| std::size_t sync_write(int d, state_type state, const buf* bufs, |
| std::size_t count, bool all_empty, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return 0; |
| } |
| |
| // A request to write 0 bytes on a stream is a no-op. |
| if (all_empty) |
| { |
| ec = asio::error_code(); |
| return 0; |
| } |
| |
| // Write some data. |
| for (;;) |
| { |
| // Try to complete the operation without blocking. |
| errno = 0; |
| signed_size_type bytes = error_wrapper(::writev( |
| d, bufs, static_cast<int>(count)), ec); |
| |
| // Check if operation succeeded. |
| if (bytes > 0) |
| return bytes; |
| |
| // Operation failed. |
| if ((state & user_set_non_blocking) |
| || (ec != asio::error::would_block |
| && ec != asio::error::try_again)) |
| return 0; |
| |
| // Wait for descriptor to become ready. |
| if (descriptor_ops::poll_write(d, 0, ec) < 0) |
| return 0; |
| } |
| } |
| |
| bool non_blocking_write(int d, const buf* bufs, std::size_t count, |
| asio::error_code& ec, std::size_t& bytes_transferred) |
| { |
| for (;;) |
| { |
| // Write some data. |
| errno = 0; |
| signed_size_type bytes = error_wrapper(::writev( |
| d, bufs, static_cast<int>(count)), ec); |
| |
| // Retry operation if interrupted by signal. |
| if (ec == asio::error::interrupted) |
| continue; |
| |
| // Check if we need to run the operation again. |
| if (ec == asio::error::would_block |
| || ec == asio::error::try_again) |
| return false; |
| |
| // Operation is complete. |
| if (bytes >= 0) |
| { |
| ec = asio::error_code(); |
| bytes_transferred = bytes; |
| } |
| else |
| bytes_transferred = 0; |
| |
| return true; |
| } |
| } |
| |
| int ioctl(int d, state_type& state, long cmd, |
| ioctl_arg_type* arg, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| errno = 0; |
| int result = error_wrapper(::ioctl(d, cmd, arg), ec); |
| |
| if (result >= 0) |
| { |
| ec = asio::error_code(); |
| |
| // When updating the non-blocking mode we always perform the ioctl syscall, |
| // even if the flags would otherwise indicate that the descriptor is |
| // already in the correct state. This ensures that the underlying |
| // descriptor is put into the state that has been requested by the user. If |
| // the ioctl syscall was successful then we need to update the flags to |
| // match. |
| if (cmd == static_cast<long>(FIONBIO)) |
| { |
| if (*arg) |
| { |
| state |= user_set_non_blocking; |
| } |
| else |
| { |
| // Clearing the non-blocking mode always overrides any internally-set |
| // non-blocking flag. Any subsequent asynchronous operations will need |
| // to re-enable non-blocking I/O. |
| state &= ~(user_set_non_blocking | internal_non_blocking); |
| } |
| } |
| } |
| |
| return result; |
| } |
| |
| int fcntl(int d, int cmd, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| errno = 0; |
| int result = error_wrapper(::fcntl(d, cmd), ec); |
| if (result != -1) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| int fcntl(int d, int cmd, long arg, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| errno = 0; |
| int result = error_wrapper(::fcntl(d, cmd, arg), ec); |
| if (result != -1) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| int poll_read(int d, state_type state, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| pollfd fds; |
| fds.fd = d; |
| fds.events = POLLIN; |
| fds.revents = 0; |
| int timeout = (state & user_set_non_blocking) ? 0 : -1; |
| errno = 0; |
| int result = error_wrapper(::poll(&fds, 1, timeout), ec); |
| if (result == 0) |
| ec = (state & user_set_non_blocking) |
| ? asio::error::would_block : asio::error_code(); |
| else if (result > 0) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| int poll_write(int d, state_type state, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| pollfd fds; |
| fds.fd = d; |
| fds.events = POLLOUT; |
| fds.revents = 0; |
| int timeout = (state & user_set_non_blocking) ? 0 : -1; |
| errno = 0; |
| int result = error_wrapper(::poll(&fds, 1, timeout), ec); |
| if (result == 0) |
| ec = (state & user_set_non_blocking) |
| ? asio::error::would_block : asio::error_code(); |
| else if (result > 0) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| int poll_error(int d, state_type state, asio::error_code& ec) |
| { |
| if (d == -1) |
| { |
| ec = asio::error::bad_descriptor; |
| return -1; |
| } |
| |
| pollfd fds; |
| fds.fd = d; |
| fds.events = POLLPRI | POLLERR | POLLHUP; |
| fds.revents = 0; |
| int timeout = (state & user_set_non_blocking) ? 0 : -1; |
| errno = 0; |
| int result = error_wrapper(::poll(&fds, 1, timeout), ec); |
| if (result == 0) |
| ec = (state & user_set_non_blocking) |
| ? asio::error::would_block : asio::error_code(); |
| else if (result > 0) |
| ec = asio::error_code(); |
| return result; |
| } |
| |
| } // namespace descriptor_ops |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #endif // !defined(ASIO_WINDOWS) |
| // && !defined(ASIO_WINDOWS_RUNTIME) |
| // && !defined(__CYGWIN__) |
| |
| #endif // ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP |