affinity: remove darwin implementation and make it no-op

It seems it is not possible to actually set affinity on macOS so we make it a
no-op and make all CPU cores available

https://developer.apple.com/forums/thread/44002

.gitignore

@@ -33,6 +33,7 @@ build/
 /build-aux/depcomp
 /build-aux/texinfo.tex
 /fibers.info
+/fibers/affinity.scm
 /fibers/config.scm
 /fibers/posix-clocks.scm
 /fibers/events-impl.scm

Makefile.am

@@ -28,7 +28,6 @@ info_TEXINFOS=fibers.texi
 
 SOURCES = \
 	fibers.scm \
-	fibers/affinity.scm \
 	fibers/channels.scm \
 	fibers/conditions.scm \
 	fibers/config.scm \
@@ -40,7 +39,6 @@ SOURCES = \
 	fibers/nameset.scm \
 	fibers/operations.scm \
 	fibers/psq.scm \
-	fibers/posix-clocks.scm \
 	fibers/repl.scm \
 	fibers/scheduler.scm \
 	fibers/stack.scm \
@@ -49,9 +47,10 @@ SOURCES = \
 	web/server/fibers.scm
 
 BUILT_SOURCES = \
+	fibers/affinity.scm \
 	fibers/config.scm \
-	fibers/posix-clocks.scm \
-	fibers/events-impl.scm
+	fibers/events-impl.scm \
+	fibers/posix-clocks.scm
 
 extlibdir = $(libdir)/guile/$(GUILE_EFFECTIVE_VERSION)/extensions
 AM_CFLAGS = -I$(srcdir) $(WARN_CFLAGS) $(DEBUG_CFLAGS)
@@ -81,13 +80,6 @@ fibers/events-impl.scm: Makefile fibers/epoll.scm
 endif
 endif
 
-if ! GUILE_HAVE_AFFINITY
-extlib_LTLIBRARIES += fibers-affinity.la
-fibers_affinity_la_SOURCES = extensions/$(PLATFORM)/affinity.c
-fibers_affinity_la_CFLAGS = $(AM_CFLAGS) $(GUILE_CFLAGS) -Iextensions
-fibers_affinity_la_LDFLAGS = -module -no-undefined $(GUILE_LDFLAGS)
-endif
-
 if ! HAVE_CLOCK_NANOSLEEP
 extlib_LTLIBRARIES += fibers-clocks.la
 fibers_clocks_la_SOURCES = extensions/$(PLATFORM)/clock-nanosleep.c
@@ -100,10 +92,17 @@ fibers/config.scm: Makefile fibers/config.scm.in
 	sed -e "s|@extlibdir\@|$(extlibdir)|" \
 	    $(srcdir)/fibers/config.scm.in > fibers/config.scm
 
+fibers/affinity.scm: Makefile fibers/affinity-$(PLATFORM).scm
+	cp -f $(abs_top_srcdir)/fibers/affinity-$(PLATFORM).scm $(abs_top_builddir)/fibers/affinity.scm
+
 fibers/posix-clocks.scm: Makefile fibers/posix-clocks-$(PLATFORM).scm
 	cp -f $(abs_top_srcdir)/fibers/posix-clocks-$(PLATFORM).scm $(abs_top_builddir)/fibers/posix-clocks.scm
 
-CLEANFILES += fibers/config.scm fibers/posix-clocks.scm fibers/events-impl.scm
+CLEANFILES += \
+	fibers/affinity.scm \
+	fibers/config.scm \
+	fibers/events-impl.scm \
+	fibers/posix-clocks.scm
 
 TESTS = \
 	tests/basic.scm \
@@ -136,6 +135,8 @@ EXTRA_DIST += \
 	fibers/config.scm.in \
 	fibers/epoll.scm \
 	fibers/libevent.scm \
+	fibers/affinity-darwin.scm \
+	fibers/affinity-generic.scm \
 	fibers/posix-clocks-darwin.scm \
 	fibers/posix-clocks-generic.scm \
 	examples
@@ -144,7 +145,6 @@ EXTRA_DIST += \
 EXTRA_DIST += \
 	extensions/epoll.c \
 	extensions/libevent.c \
-	extensions/darwin/affinity.c \
+	extensions/clock-nanosleep.h \
 	extensions/darwin/clock-nanosleep.c \
-	extensions/generic/affinity.c \
 	extensions/generic/clock-nanosleep.c

configure.ac

@@ -53,9 +53,6 @@ AC_ARG_ENABLE([epoll], AS_HELP_STRING([--disable-epoll],[Disable epoll support])
 AC_CHECK_FUNCS(epoll_wait)
 AM_CONDITIONAL([HAVE_EPOLL_WAIT], [test "x$ac_cv_func_epoll_wait" = "xyes"])
 
-GUILE_CHECK([GUILE_HAVE_AFFINITY], (exit (or (defined? 'setaffinity) 2)))
-AM_CONDITIONAL([GUILE_HAVE_AFFINITY], [test "x$GUILE_HAVE_AFFINITY" = "x0"])
-
 AC_CHECK_FUNCS(clock_nanosleep)
 AM_CONDITIONAL([HAVE_CLOCK_NANOSLEEP], [test "x$ac_cv_func_clock_nanosleep" = "xyes"])
 

fibers/affinity-darwin.scm

@@ -0,0 +1,37 @@
+;; CPU affinity (Darwin)
+
+;;;; Copyright (C) 2022 Aleix Conchillo Flaqué <[email protected]>
+;;;;
+;;;; 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 program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Guile defines setaffinity and getaffinity in some systems (e.g. Linux). For
+;;; those systems where those procedures are not available there should be a
+;;; Fibers' specific implementation available through the fibers-affinity
+;;; library.
+
+(define-module (fibers affinity)
+  #:use-module (ice-9 threads)
+  #:export (getaffinity* setaffinity*))
+
+;;
+;; It seems it is not possible to link a thread to a specific core on
+;; macOS. See, for example: https://developer.apple.com/forums/thread/44002.
+;;
+;; So for now getaffinity/setaffinity are no-ops.
+;;
+
+(define (getaffinity* pid)
+  (make-bitvector (current-processor-count) 1))
+
+(define (setaffinity* pid affinity) *unspecified*)

fibers/affinity.scm → fibers/affinity-generic.scm

@@ -25,17 +25,6 @@
   #:use-module (fibers config)
   #:export (getaffinity* setaffinity*))
 
-(eval-when (eval load compile)
-  (unless (defined? 'getaffinity)
-    ;; When cross-compiling, the cross-compiled 'fibers-affinity.so' cannot be
-    ;; loaded by the 'guild compile' process; skip it.
-    (unless (getenv "FIBERS_CROSS_COMPILING")
-      (catch #t
-        (lambda ()
-          (dynamic-call "init_fibers_affinity" (dynamic-link (extension-library "fibers-affinity"))))
-        (lambda _ (error "Ooops, getaffinity/setaffinity are not available in this platform and we were \
-unable to load fibers-affinity extension."))))))
-
-;; getaffinity/setaffinity should be loaded at this point.
+;; getaffinity/setaffinity should be defined in Guile
 (define getaffinity* (if (defined? 'getaffinity) getaffinity))
 (define setaffinity* (if (defined? 'setaffinity) setaffinity))