diff options
| -rw-r--r-- | libbutl/fdstream.mxx | 53 |
1 files changed, 47 insertions, 6 deletions
diff --git a/libbutl/fdstream.mxx b/libbutl/fdstream.mxx index 894f85b..dd46ad2 100644 --- a/libbutl/fdstream.mxx +++ b/libbutl/fdstream.mxx @@ -100,6 +100,30 @@ LIBBUTL_MODEXPORT namespace butl int fd_; }; + inline bool + operator== (const auto_fd& x, const auto_fd& y) + { + return x.get () == y.get (); + } + + inline bool + operator!= (const auto_fd& x, const auto_fd& y) + { + return !(x == y); + } + + inline bool + operator== (const auto_fd& x, nullfd_t) + { + return x.get () == -1; + } + + inline bool + operator!= (const auto_fd& x, nullfd_t y) + { + return !(x == y); + } + // An [io]fstream that can be initialized with a file descriptor in addition // to a file name and that also by default enables exceptions on badbit and // failbit. So instead of a dance like this: @@ -804,15 +828,16 @@ LIBBUTL_MODEXPORT namespace butl LIBBUTL_SYMEXPORT bool fdterm (int); - // Wait until one or more file descriptors becomes ready for reading or - // writing. Return the pair of numbers of descriptors that are ready. Throw - // std::invalid_argument if anything is wrong with arguments (both sets are - // empty, invalid fd, etc). Throw ios::failure on the underlying OS error. + // Wait until one or more file descriptors becomes ready for input (reading) + // or output (writing). Return the pair of numbers of descriptors that are + // ready. Throw std::invalid_argument if anything is wrong with arguments + // (both sets are empty, invalid fd, etc). Throw ios::failure on the + // underlying OS error. // // Note that the function clears all the previously-ready entries on each // call. Entries with nullfd are ignored. // - // On Windows only pipes and only their read ends are supported. + // On Windows only pipes and only their input (read) ends are supported. // struct fdselect_state { @@ -828,11 +853,27 @@ LIBBUTL_MODEXPORT namespace butl using fdselect_set = small_vector<fdselect_state, 4>; LIBBUTL_SYMEXPORT std::pair<std::size_t, std::size_t> - fdselect (fdselect_set& read, fdselect_set& write); + fdselect (fdselect_set& ifds, fdselect_set& ofds); + + inline std::size_t + ifdselect (fdselect_set& ifds) + { + fdselect_set ofds; + return fdselect (ifds, ofds).first; + } + + inline std::size_t + ofdselect (fdselect_set& ofds) + { + fdselect_set ifds; + return fdselect (ifds, ofds).second; + } // As above but wait up to the specified timeout returning a pair of zeroes // if none of the descriptors became ready. // + // @@ Maybe merge it with the above via a default/optional value? + // // LIBBUTL_SYMEXPORT std::pair<std::size_t, std::size_t> // fdselect (fdselect_set&, fdselect_set&, const duration& timeout); |