3 files changed, 309 insertions, 0 deletions
diff --git a/include/ruby/impl/intern/select/largesize.h b/include/ruby/impl/intern/select/largesize.h
new file mode 100644
index 0000000000..b54ac116dd
--- /dev/null
+++ b/include/ruby/impl/intern/select/largesize.h
@@ -0,0 +1,103 @@
+#ifndef RUBY3_INTERN_SELECT_LARGESIZE_H              /*-*-C++-*-vi:se ft=cpp:*/
+#define RUBY3_INTERN_SELECT_LARGESIZE_H
+/**
+ * @file
+ * @author     Ruby developers <[email protected]>
+ * @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  `RUBY3`   or   `ruby3`   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
+ *
+ * - HP-UX documents how to allocate fd_set dynamically.
+ *   http://docs.hp.com/en/B2355-60105/select.2.html
+ *
+ * - 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/3/attr/nonnull.h"
+#include "ruby/3/attr/pure.h"
+#include "ruby/3/dllexport.h"
+
+/**@cond INTERNAL_MACRO */
+#define rb_fd_ptr rb_fd_ptr
+#define rb_fd_max rb_fd_max
+/** @endcond */
+
+struct timeval;
+
+typedef struct {
+    int maxfd;
+    fd_set *fdset;
+} rb_fdset_t;
+
+RUBY3_SYMBOL_EXPORT_BEGIN()
+void rb_fd_init(rb_fdset_t *);
+void rb_fd_term(rb_fdset_t *);
+void rb_fd_zero(rb_fdset_t *);
+void rb_fd_set(int, rb_fdset_t *);
+void rb_fd_clr(int, rb_fdset_t *);
+int rb_fd_isset(int, const rb_fdset_t *);
+void rb_fd_copy(rb_fdset_t *, const fd_set *, int);
+void rb_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src);
+int rb_fd_select(int, rb_fdset_t *, rb_fdset_t *, rb_fdset_t *, struct timeval *);
+RUBY3_SYMBOL_EXPORT_END()
+
+RUBY3_ATTR_NONNULL(())
+RUBY3_ATTR_PURE()
+/* :TODO: can this function be __attribute__((returns_nonnull)) or not? */
+static inline fd_set *
+rb_fd_ptr(const rb_fdset_t *f)
+{
+    return f->fdset;
+}
+
+RUBY3_ATTR_NONNULL(())
+RUBY3_ATTR_PURE()
+static inline int
+rb_fd_max(const rb_fdset_t *f)
+{
+    return f->maxfd;
+}
+
+#endif /* RUBY3_INTERN_SELECT_LARGESIZE_H */
diff --git a/include/ruby/impl/intern/select/posix.h b/include/ruby/impl/intern/select/posix.h
new file mode 100644
index 0000000000..156962c0bb
--- /dev/null
+++ b/include/ruby/impl/intern/select/posix.h
@@ -0,0 +1,82 @@
+#ifndef RUBY3_INTERN_SELECT_POSIX_H                  /*-*-C++-*-vi:se ft=cpp:*/
+#define RUBY3_INTERN_SELECT_POSIX_H
+/**
+ * @file
+ * @author     Ruby developers <[email protected]>
+ * @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  `RUBY3`   or   `ruby3`   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().
+ */
+#include "ruby/3/config.h"
+
+#ifdef HAVE_SYS_SELECT_H
+# include <sys/select.h>        /* for select(2) (modern POSIX) */
+#endif
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>            /* for select(2) (archaic UNIX) */
+#endif
+
+#include "ruby/3/attr/pure.h"
+#include "ruby/3/attr/const.h"
+
+typedef fd_set rb_fdset_t;
+
+#define rb_fd_zero   FD_ZERO
+#define rb_fd_set    FD_SET
+#define rb_fd_clr    FD_CLR
+#define rb_fd_isset  FD_ISSET
+#define rb_fd_init   FD_ZERO
+#define rb_fd_select select
+/**@cond INTERNAL_MACRO */
+#define rb_fd_copy  rb_fd_copy
+#define rb_fd_dup   rb_fd_dup
+#define rb_fd_ptr   rb_fd_ptr
+#define rb_fd_max   rb_fd_max
+/** @endcond */
+
+static inline void
+rb_fd_copy(rb_fdset_t *dst, const fd_set *src, int n)
+{
+    *dst = *src;
+}
+
+static inline void
+rb_fd_dup(rb_fdset_t *dst, const fd_set *src, int n)
+{
+    *dst = *src;
+}
+
+RUBY3_ATTR_PURE()
+/* :TODO: can this function be __attribute__((returns_nonnull)) or not? */
+static inline fd_set *
+rb_fd_ptr(rb_fdset_t *f)
+{
+    return f;
+}
+
+RUBY3_ATTR_CONST()
+static inline int
+rb_fd_max(const rb_fdset_t *f)
+{
+    return FD_SETSIZE;
+}
+
+/* :FIXME: What are these?  They don't exist for shibling implementations. */
+#define rb_fd_init_copy(d, s) (*(d) = *(s))
+#define rb_fd_term(f)   ((void)(f))
+
+#endif /* RUBY3_INTERN_SELECT_POSIX_H */
diff --git a/include/ruby/impl/intern/select/win32.h b/include/ruby/impl/intern/select/win32.h
new file mode 100644
index 0000000000..fb42b5e77d
--- /dev/null
+++ b/include/ruby/impl/intern/select/win32.h
@@ -0,0 +1,124 @@
+#ifndef RUBY3_INTERN_SELECT_WIN32_H                  /*-*-C++-*-vi:se ft=cpp:*/
+#define RUBY3_INTERN_SELECT_WIN32_H
+/**
+ * @file
+ * @author     Ruby developers <[email protected]>
+ * @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  `RUBY3`   or   `ruby3`   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().
+ */
+#include "ruby/3/dosish.h"      /* for rb_w32_select */
+#include "ruby/3/attr/nonnull.h"
+#include "ruby/3/attr/pure.h"
+#include "ruby/3/attr/noalias.h"
+#include "ruby/3/dllexport.h"
+#include "ruby/assert.h"
+
+/**@cond INTERNAL_MACRO */
+#define rb_fd_zero  rb_fd_zero
+#define rb_fd_clr   rb_fd_clr
+#define rb_fd_isset rb_fd_isset
+#define rb_fd_copy  rb_fd_copy
+#define rb_fd_dup   rb_fd_dup
+#define rb_fd_ptr   rb_fd_ptr
+#define rb_fd_max   rb_fd_max
+/** @endcond */
+
+RUBY3_SYMBOL_EXPORT_BEGIN()
+
+struct timeval;
+
+typedef struct {
+    int capa;
+    fd_set *fdset;
+} rb_fdset_t;
+
+void rb_fd_init(rb_fdset_t *);
+void rb_fd_term(rb_fdset_t *);
+void rb_fd_set(int, rb_fdset_t *);
+void rb_w32_fd_copy(rb_fdset_t *, const fd_set *, int);
+void rb_w32_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src);
+
+RUBY3_SYMBOL_EXPORT_END()
+
+RUBY3_ATTR_NONNULL(())
+RUBY3_ATTR_NOALIAS()
+static inline void
+rb_fd_zero(rb_fdset_t *f)
+{
+    f->fdset->fd_count = 0;
+}
+
+RUBY3_ATTR_NONNULL(())
+static inline void
+rb_fd_clr(int n, rb_fdset_t *f)
+{
+    rb_w32_fdclr(n, f->fdset);
+}
+
+RUBY3_ATTR_NONNULL(())
+static inline int
+rb_fd_isset(int n, rb_fdset_t *f)
+{
+    return rb_w32_fdisset(n, f->fdset);
+}
+
+RUBY3_ATTR_NONNULL(())
+static inline void
+rb_fd_copy(rb_fdset_t *dst, const fd_set *src, int n)
+{
+    rb_w32_fd_copy(dst, src, n);
+}
+
+RUBY3_ATTR_NONNULL(())
+static inline void
+rb_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src)
+{
+    rb_w32_fd_dup(dst, src);
+}
+
+static inline int
+rb_fd_select(int n, rb_fdset_t *rfds, rb_fdset_t *wfds, rb_fdset_t *efds, struct timeval *timeout)
+{
+    return rb_w32_select(
+        n,
+        rfds ? rfds->fdset : NULL,
+        wfds ? wfds->fdset : NULL,
+        efds ? efds->fdset : NULL,
+        timeout);
+}
+
+RUBY3_ATTR_NONNULL(())
+RUBY3_ATTR_PURE()
+/* :TODO: can this function be __attribute__((returns_nonnull)) or not? */
+static inline fd_set *
+rb_fd_ptr(const rb_fdset_t *f)
+{
+    return f->fdset;
+}
+
+RUBY3_ATTR_NONNULL(())
+RUBY3_ATTR_PURE()
+static inline int
+rb_fd_max(const rb_fdset_t *f)
+{
+    const fd_set *p = f->fdset;
+
+    RUBY3_ASSERT_OR_ASSUME(p);
+    return p->fd_count;
+}
+
+#endif /* RUBY3_INTERN_SELECT_WIN32_H */