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EDIT :: largesize.h

#ifndef RBIMPL_INTERN_SELECT_LARGESIZE_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_INTERN_SELECT_LARGESIZE_H /** * @file * @author Ruby developers <ruby-core@ruby-lang.org> * @copyright This file is a part of the programming language Ruby. * Permission is hereby granted, to either redistribute and/or * modify this file, provided that the conditions mentioned in the * file COPYING are met. Consult the file for details. * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are * implementation details. Don't take them as canon. They could * rapidly appear then vanish. The name (path) of this header file * is also an implementation detail. Do not expect it to persist * at the place it is now. Developers are free to move it anywhere * anytime at will. * @note To ruby-core: remember that this header can be possibly * recursively included from extension libraries written in C++. * Do not expect for instance `__VA_ARGS__` is always available. * We assume C99 for ruby itself but we don't assume languages of * extension libraries. They could be written in C++98. * @brief Public APIs to provide ::rb_fd_select(). * * Several Unix platforms support file descriptors bigger than FD_SETSIZE in * `select(2)` system call. * * - Linux 2.2.12 (?) * * - NetBSD 1.2 (src/sys/kern/sys_generic.c:1.25) * `select(2)` documents how to allocate fd_set dynamically. * http://netbsd.gw.com/cgi-bin/man-cgi?select++NetBSD-4.0 * * - FreeBSD 2.2 (src/sys/kern/sys_generic.c:1.19) * * - OpenBSD 2.0 (src/sys/kern/sys_generic.c:1.4) * `select(2)` documents how to allocate fd_set dynamically. * http://www.openbsd.org/cgi-bin/man.cgi?query=select&manpath=OpenBSD+4.4 * * - Solaris 8 has `select_large_fdset` * * - Mac OS X 10.7 (Lion) * `select(2)` returns `EINVAL` if `nfds` is greater than `FD_SET_SIZE` and * `_DARWIN_UNLIMITED_SELECT` (or `_DARWIN_C_SOURCE`) isn't defined. * http://developer.apple.com/library/mac/#releasenotes/Darwin/SymbolVariantsRelNotes/_index.html * * When `fd_set` is not big enough to hold big file descriptors, it should be * allocated dynamically. Note that this assumes `fd_set` is structured as * bitmap. * * `rb_fd_init` allocates the memory. * `rb_fd_term` frees the memory. * `rb_fd_set` may re-allocate bitmap. * * So `rb_fd_set` doesn't reject file descriptors bigger than `FD_SETSIZE`. */ #include "ruby/internal/attr/nonnull.h" #include "ruby/internal/attr/pure.h" #include "ruby/internal/dllexport.h" /**@cond INTERNAL_MACRO */ #define rb_fd_ptr rb_fd_ptr #define rb_fd_max rb_fd_max /** @endcond */ struct timeval; /** * The data structure which wraps the fd_set bitmap used by select(2). This * allows Ruby to use FD sets larger than that allowed by historic limitations * on modern platforms. */ typedef struct { int maxfd; /**< Maximum allowed number of FDs. */ fd_set *fdset; /**< File descriptors buffer */ } rb_fdset_t; RBIMPL_SYMBOL_EXPORT_BEGIN() RBIMPL_ATTR_NONNULL(()) /** * (Re-)initialises a fdset. One must be initialised before other `rb_fd_*` * operations. Analogous to calling `malloc(3)` to allocate an `fd_set`. * * @param[out] f An fdset to squash. * @post `f` holds no file descriptors. */ void rb_fd_init(rb_fdset_t *f); RBIMPL_ATTR_NONNULL(()) /** * Destroys the ::rb_fdset_t, releasing any memory and resources it used. It * must be reinitialised using rb_fd_init() before future use. Analogous to * calling `free(3)` to release memory for an `fd_set`. * * @param[out] f An fdset to squash. * @post `f` holds no file descriptors. */ void rb_fd_term(rb_fdset_t *f); RBIMPL_ATTR_NONNULL(()) /** * Wipes out the current set of FDs. * * @param[out] f The fdset to clear. * @post `f` has no FDs. */ void rb_fd_zero(rb_fdset_t *f); RBIMPL_ATTR_NONNULL(()) /** * Sets an fd to a fdset. * * @param[in] fd A file descriptor. * @param[out] f Target fdset. * @post `f` holds `fd`. */ void rb_fd_set(int fd, rb_fdset_t *f); RBIMPL_ATTR_NONNULL(()) /** * Releases a specific FD from the given fdset. * * @param[in] fd Target FD. * @param[out] f The fdset that holds `fd`. * @post `f` doesn't hold n. */ void rb_fd_clr(int fd, rb_fdset_t *f); RBIMPL_ATTR_NONNULL(()) RBIMPL_ATTR_PURE() /** * Queries if the given FD is in the given set. * * @param[in] fd Target FD. * @param[in] f The fdset to scan. * @retval 1 Yes there is. * @retval 0 No there isn't. * @see http://www.freebsd.org/cgi/query-pr.cgi?pr=91421 */ int rb_fd_isset(int fd, const rb_fdset_t *f); /** * Destructively overwrites an fdset with another. * * @param[out] dst Target fdset. * @param[in] src Source fdset. * @param[in] max Maximum number of file descriptors to copy. * @post `dst` is a copy of `src`. */ void rb_fd_copy(rb_fdset_t *dst, const fd_set *src, int max); /** * Identical to rb_fd_copy(), except it copies unlimited number of file * descriptors. * * @param[out] dst Target fdset. * @param[in] src Source fdset. * @post `dst` is a copy of `src`. */ void rb_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src); /** * Waits for multiple file descriptors at once. * * @param[in] nfds Max FD in everything passed, plus one. * @param[in,out] rfds Set of FDs to wait for reads. * @param[in,out] wfds Set of FDs to wait for writes. * @param[in,out] efds Set of FDs to wait for OOBs. * @param[in,out] timeout Max blocking duration. * @retval -1 Failed, errno set. * @retval 0 Timeout exceeded. * @retval otherwise Total number of file descriptors returned. * @post `rfds` contains readable FDs. * @post `wfds` contains writable FDs. * @post `efds` contains exceptional FDs. * @post `timeout` is the time left. * @note All pointers are allowed to be null pointers. */ int rb_fd_select(int nfds, rb_fdset_t *rfds, rb_fdset_t *wfds, rb_fdset_t *efds, struct timeval *timeout); RBIMPL_SYMBOL_EXPORT_END() RBIMPL_ATTR_NONNULL(()) RBIMPL_ATTR_PURE() /** * Raw pointer to `fd_set`. * * @param[in] f Target fdset. * @retval NULL `f` is already terminated by rb_fd_term(). * @retval otherwise Underlying fd_set. * * @internal * * Extension library must not touch raw pointers. It was a bad idea to let * them use it. */ static inline fd_set * rb_fd_ptr(const rb_fdset_t *f) { return f->fdset; } RBIMPL_ATTR_NONNULL(()) RBIMPL_ATTR_PURE() /** * It seems this function has no use. Maybe just remove? * * @param[in] f A set. * @return Number of file descriptors stored. */ static inline int rb_fd_max(const rb_fdset_t *f) { return f->maxfd; } #endif /* RBIMPL_INTERN_SELECT_LARGESIZE_H */

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