add (ice-9 poll), a poll wrapper

* libguile/poll.c:
* libguile/poll.h:
* module/ice-9/poll.scm: New module, (ice-9 poll).

* module/Makefile.am:
* libguile/init.c:
* libguile/Makefile.am: Adapt.

* configure.ac: Check for poll.h and poll.

7 files changed, 367 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index 631198b04..1aa6f057a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -644,7 +644,7 @@ AC_CHECK_HEADERS([complex.h fenv.h io.h libc.h limits.h malloc.h memory.h proces
 regex.h rxposix.h rx/rxposix.h sys/dir.h sys/ioctl.h sys/select.h \
 sys/time.h sys/timeb.h sys/times.h sys/stdtypes.h sys/types.h \
 sys/utime.h time.h unistd.h utime.h pwd.h grp.h sys/utsname.h \
-direct.h langinfo.h nl_types.h machine/fpu.h])
+direct.h langinfo.h nl_types.h machine/fpu.h poll.h])
 
 # Reasons for testing:
 #   nl_item - lacking on Cygwin
@@ -741,6 +741,7 @@ AC_CHECK_HEADERS([assert.h crt_externs.h])
 #   gmtime_r - recent posix, not on old systems
 #   pipe - not in mingw
 #   _pipe - specific to mingw, taking 3 args
+#   poll - since posix 2001
 #   readdir_r - recent posix, not on old systems
 #   readdir64_r - not available on HP-UX 11.11
 #   stat64 - SuS largefile stuff, not on old systems
@@ -753,7 +754,7 @@ AC_CHECK_HEADERS([assert.h crt_externs.h])
 #   utimensat: posix.1-2008
 #   sched_getaffinity, sched_setaffinity: GNU extensions (glibc)
 #
-AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid fesetround ftime ftruncate fchown getcwd geteuid getsid gettimeofday gmtime_r ioctl lstat mkdir mknod nice pipe _pipe readdir_r readdir64_r readlink rename rmdir select setegid seteuid setlocale setpgid setsid sigaction siginterrupt stat64 strftime strptime symlink sync sysconf tcgetpgrp tcsetpgrp times uname waitpid strdup system usleep atexit on_exit chown link fcntl ttyname getpwent getgrent kill getppid getpgrp fork setitimer getitimer strchr strcmp index bcopy memcpy rindex truncate unsetenv isblank _NSGetEnviron strcoll strcoll_l newlocale nl_langinfo utimensat sched_getaffinity sched_setaffinity])
+AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid fesetround ftime ftruncate fchown getcwd geteuid getsid gettimeofday gmtime_r ioctl lstat mkdir mknod nice pipe _pipe poll readdir_r readdir64_r readlink rename rmdir select setegid seteuid setlocale setpgid setsid sigaction siginterrupt stat64 strftime strptime symlink sync sysconf tcgetpgrp tcsetpgrp times uname waitpid strdup system usleep atexit on_exit chown link fcntl ttyname getpwent getgrent kill getppid getpgrp fork setitimer getitimer strchr strcmp index bcopy memcpy rindex truncate unsetenv isblank _NSGetEnviron strcoll strcoll_l newlocale nl_langinfo utimensat sched_getaffinity sched_setaffinity])
 
 # Reasons for testing:
 #   netdb.h - not in mingw
diff --git a/libguile/Makefile.am b/libguile/Makefile.am
index 55a976445..dd797eaad 100644
--- a/libguile/Makefile.am
+++ b/libguile/Makefile.am
@@ -170,6 +170,7 @@ libguile_@GUILE_EFFECTIVE_VERSION@_la_SOURCES =				\
 	objprop.c				\
 	options.c				\
 	pairs.c					\
+	poll.c					\
 	ports.c					\
 	print.c					\
 	procprop.c				\
@@ -541,6 +542,7 @@ modinclude_HEADERS =				\
 	objprop.h				\
 	options.h				\
 	pairs.h					\
+	poll.h					\
 	ports.h					\
 	posix.h					\
 	print.h					\
diff --git a/libguile/init.c b/libguile/init.c
index bb916dcd2..c2b80e0b2 100644
--- a/libguile/init.c
+++ b/libguile/init.c
@@ -88,6 +88,7 @@
 #include "libguile/objprop.h"
 #include "libguile/options.h"
 #include "libguile/pairs.h"
+#include "libguile/poll.h"
 #include "libguile/ports.h"
 #include "libguile/posix.h"
 #ifdef HAVE_REGCOMP
@@ -459,6 +460,7 @@ scm_i_init_guile (SCM_STACKITEM *base)
   scm_register_foreign ();
   scm_register_srfi_1 ();
   scm_register_srfi_60 ();
+  scm_register_poll ();
 
   scm_init_strings ();            /* Requires array-handle */
   scm_init_struct ();             /* Requires strings */
diff --git a/libguile/poll.c b/libguile/poll.c
new file mode 100644
index 000000000..0304448fa
--- /dev/null
+++ b/libguile/poll.c
@@ -0,0 +1,146 @@
+/* Copyright (C) 2010 Free Software Foundation, Inc.
+ * 
+ * This library 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.
+ *
+ * This library 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+
+
+
+#define _GNU_SOURCE
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+#include "libguile/bytevectors.h"
+#include "libguile/numbers.h"
+#include "libguile/error.h"
+#include "libguile/validate.h"
+
+#include "libguile/poll.h"
+
+
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#endif
+
+
+
+/* {Poll}
+ */
+
+/* Poll a set of file descriptors, waiting until one or more of them is
+   ready to perform input or output.
+
+   This is a low-level interface.  See the `(ice-9 poll)' module for a more
+   usable wrapper.
+
+   `pollfds' is expected to be a bytevector, laid out in contiguous blocks of 64
+   bits.  Each block has the format of one `struct pollfd': a 32-bit int file
+   descriptor, a 16-bit int events mask, and a 16-bit int revents mask.
+
+   The number of pollfd structures in `pollfds' is specified in
+   `nfds'. `pollfds' must be at least long enough to support that number of
+   structures. It may be longer, in which case the trailing entries are left
+   untouched.
+
+   The pollfds bytevector is modified directly, setting the returned events in
+   the final two bytes (the revents member).
+
+   If timeout is given and is non-negative, the poll will return after that
+   number of milliseconds if no fd became active.
+   */
+#ifdef HAVE_POLL
+static SCM
+scm_primitive_poll (SCM pollfds, SCM nfds, SCM timeout)
+#define FUNC_NAME "primitive-poll"
+{
+  int rv;
+  nfds_t c_nfds;
+  int c_timeout;
+  struct pollfd *fds;
+
+  SCM_VALIDATE_BYTEVECTOR (SCM_ARG1, pollfds);
+  c_nfds = scm_to_uint32 (nfds);
+  c_timeout = scm_to_int (timeout);
+  
+  if (SCM_UNLIKELY (SCM_BYTEVECTOR_LENGTH (pollfds)
+                    < c_nfds * sizeof(struct pollfd)))
+    SCM_OUT_OF_RANGE (SCM_ARG1, nfds);
+  
+  fds = (struct pollfd*)SCM_BYTEVECTOR_CONTENTS (pollfds);
+  
+  SCM_SYSCALL (rv = poll (fds, c_nfds, c_timeout));
+
+  if (rv == -1)
+    SCM_SYSERROR;
+
+  return scm_from_int (rv);
+}
+#undef FUNC_NAME
+#endif /* HAVE_POLL */
+
+
+
+
+static void
+scm_init_poll (void)
+{
+#if HAVE_POLL
+  scm_c_define_gsubr ("primitive-poll", 3, 0, 0, scm_primitive_poll);
+#else
+  scm_misc_error ("%init-poll", "`poll' unavailable on this platform", SCM_EOL);
+#endif
+
+#ifdef POLLIN
+  scm_c_define ("POLLIN", scm_from_int (POLLIN));
+#endif 	       
+#ifdef POLLPRI
+  scm_c_define ("POLLPRI", scm_from_int (POLLPRI));
+#endif 	       
+#ifdef POLLOUT
+  scm_c_define ("POLLOUT", scm_from_int (POLLOUT));
+#endif 	       
+#ifdef POLLRDHUP
+  scm_c_define ("POLLRDHUP", scm_from_int (POLLRDHUP));
+#endif 	       
+#ifdef POLLERR
+  scm_c_define ("POLLERR", scm_from_int (POLLERR));
+#endif 	       
+#ifdef POLLHUP
+  scm_c_define ("POLLHUP", scm_from_int (POLLHUP));
+#endif 	       
+#ifdef POLLNVAL
+  scm_c_define ("POLLNVAL", scm_from_int (POLLNVAL));
+#endif 	       
+
+}
+
+void
+scm_register_poll (void)
+{
+  scm_c_register_extension ("libguile-" SCM_EFFECTIVE_VERSION,
+                            "scm_init_poll",
+			    (scm_t_extension_init_func) scm_init_poll,
+			    NULL);
+}
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/
diff --git a/libguile/poll.h b/libguile/poll.h
new file mode 100644
index 000000000..ab3195008
--- /dev/null
+++ b/libguile/poll.h
@@ -0,0 +1,38 @@
+/* classes: h_files */
+
+#ifndef SCM_POLL_H
+#define SCM_POLL_H
+
+/* Copyright (C) 2010 Free Software Foundation, Inc.
+ *
+ * This library 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.
+ *
+ * This library 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 library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+
+
+#include "libguile/__scm.h"
+
+
+
+SCM_INTERNAL void scm_register_poll (void);
+
+#endif  /* SCM_POLL_H */
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/
diff --git a/module/Makefile.am b/module/Makefile.am
index e16cd557f..67d530ada 100644
--- a/module/Makefile.am
+++ b/module/Makefile.am
@@ -200,6 +200,7 @@ ICE_9_SOURCES = \
   ice-9/occam-channel.scm \
   ice-9/optargs.scm \
   ice-9/poe.scm \
+  ice-9/poll.scm \
   ice-9/popen.scm \
   ice-9/posix.scm \
   ice-9/q.scm \
diff --git a/module/ice-9/poll.scm b/module/ice-9/poll.scm
new file mode 100644
index 000000000..e506e2ac4
--- /dev/null
+++ b/module/ice-9/poll.scm
@@ -0,0 +1,175 @@
+;; poll
+
+;;;; Copyright (C) 2010 Free Software Foundation, Inc.
+;;;; 
+;;;; This library 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.
+;;;; 
+;;;; This library 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 library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;;;; 
+
+(define-module (ice-9 poll)
+  #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-9 gnu)
+  #:use-module (rnrs bytevectors)
+  #:export (make-empty-poll-set
+            poll-set?
+            poll-set-nfds
+            poll-set-find-port
+            poll-set-port
+            poll-set-events
+            set-poll-set-events!
+            poll-set-revents
+            set-poll-set-revents!
+            poll-set-add!
+            poll-set-remove!
+            poll))
+
+(eval-when (eval load compile)
+  (load-extension (string-append "libguile-" (effective-version))
+                  "scm_init_poll"))
+
+(if (defined? 'POLLIN)
+    (export POLLIN))
+
+(if (defined? 'POLLPRI)
+    (export POLLPRI))
+
+(if (defined? 'POLLOUT)
+    (export POLLOUT))
+
+(if (defined? 'POLLRDHUP)
+    (export POLLRDHUP))
+
+(if (defined? 'POLLERR)
+    (export POLLERR))
+
+(if (defined? 'POLLHUP)
+    (export POLLHUP))
+
+(if (defined? 'POLLNVAL)
+    (export POLLNVAL))
+
+
+(define-record-type <poll-set>
+  (make-poll-set pollfds nfds ports)
+  poll-set?
+  (pollfds pset-pollfds set-pset-pollfds!)
+  (nfds poll-set-nfds set-pset-nfds!)
+  (ports pset-ports set-pset-ports!)
+  )
+
+(define-syntax pollfd-offset
+  (syntax-rules ()
+    ((_ n) (* n 8))))
+
+(define* (make-empty-poll-set #:optional (pre-allocated 4))
+  (make-poll-set (make-bytevector (pollfd-offset pre-allocated) 0)
+                 0
+                 (make-vector pre-allocated #f)))
+
+(define (pset-size set)
+  (vector-length (pset-ports set)))
+
+(define (ensure-pset-size! set size)
+  (let ((prev (pset-size set)))
+    (if (< prev size)
+        (let lp ((new prev))
+          (if (< new size)
+              (lp (* new 2))
+              (let ((old-pollfds (pset-pollfds set))
+                    (nfds (poll-set-nfds set))
+                    (old-ports (pset-ports set))
+                    (new-pollfds (make-bytevector (pollfd-offset new) 0))
+                    (new-ports (make-vector new #f)))
+                (bytevector-copy! old-pollfds 0 new-pollfds 0
+                                  (pollfd-offset nfds))
+                (vector-move-left! old-ports 0 nfds new-ports 0)
+                (set-pset-pollfds! set new-pollfds)
+                (set-pset-ports! set new-ports)))))))
+
+(define (poll-set-find-port set port)
+  (let lp ((i 0))
+    (if (< i (poll-set-nfds set))
+        (if (equal? (vector-ref (pset-ports set) i) port)
+            i
+            (lp (1+ i)))
+        #f)))
+
+(define (poll-set-port set idx)
+  (if (< idx (poll-set-nfds set))
+      (vector-ref (pset-ports set) idx)
+      (error "poll set index out of bounds" set idx)))
+
+(define (poll-set-events set idx)
+  (if (< idx (poll-set-nfds set))
+      (bytevector-u16-native-ref (pset-pollfds set) (+ (pollfd-offset idx) 4))
+      (error "poll set index out of bounds" set idx)))
+
+(define (set-poll-set-events! set idx events)
+  (if (< idx (poll-set-nfds set))
+      (bytevector-u16-native-set! (pset-pollfds set) (+ (pollfd-offset idx) 4)
+                                  events)
+      (error "poll set index out of bounds" set idx)))
+
+(define (poll-set-revents set idx)
+  (if (< idx (poll-set-nfds set))
+      (bytevector-u16-native-ref (pset-pollfds set) (+ (pollfd-offset idx) 6))
+      (error "poll set index out of bounds" set idx)))
+
+(define (set-poll-set-revents! set idx revents)
+  (if (< idx (poll-set-nfds set))
+      (bytevector-u16-native-set! (pset-pollfds set) (+ (pollfd-offset idx) 6)
+                                  revents)
+      (error "poll set index out of bounds" set idx)))
+
+(define (poll-set-add! set fd-or-port events)
+  (let* ((idx (poll-set-nfds set))
+         (off (pollfd-offset idx))
+         (fd (if (integer? fd-or-port)
+                 fd-or-port
+                 (port->fdes fd-or-port))))
+
+    (if (port? fd-or-port)
+        ;; As we store the port in the fdset, there is no need to
+        ;; increment the revealed count to prevent the fd from being
+        ;; closed by a gc'd port.
+        (release-port-handle fd-or-port))
+
+    (ensure-pset-size! set (1+ idx))
+    (bytevector-s32-native-set! (pset-pollfds set) off fd)
+    (bytevector-u16-native-set! (pset-pollfds set) (+ off 4) events)
+    (bytevector-u16-native-set! (pset-pollfds set) (+ off 6) 0) ; revents
+    (vector-set! (pset-ports set) idx fd-or-port)
+    (set-pset-nfds! set (1+ idx))))
+
+(define (poll-set-remove! set idx)
+  (if (not (< idx (poll-set-nfds set)))
+      (error "poll set index out of bounds" set idx))
+  (let ((nfds (poll-set-nfds set))
+        (off (pollfd-offset idx))
+        (port (vector-ref (pset-ports set) idx)))
+    (vector-move-left! (pset-ports set) (1+ idx) nfds
+                       (pset-ports set) idx)
+    (vector-set! (pset-ports set) (1- nfds) #f)
+    (bytevector-copy! (pset-pollfds set) (pollfd-offset (1+ idx))
+                      (pset-pollfds set) off
+                      (- (pollfd-offset nfds) (pollfd-offset (1+ idx))))
+    ;; zero the struct pollfd all at once
+    (bytevector-u64-native-set! (pset-pollfds set) (pollfd-offset (1- nfds)) 0)
+    (set-pset-nfds! set (1- nfds))
+    port))
+
+(define* (poll poll-set #:optional (timeout -1))
+  (primitive-poll (pset-pollfds poll-set)
+                  (poll-set-nfds poll-set)
+                  timeout))