On Fri, Jun 15, 2012 at 12:45:28PM +0200, Felix wrote:
> > Other than figuring that out, it would be a good idea to test on mingw
> > and OS X (I was going to do this). However testing on other platforms
> > like cygwin or Solaris (or more obscure?) is problematic. It is not
> > really a question of whether _setjmp works but if every platform supports
> > _setjmp. I don't know if this is something to throw in before the
> > release, if one is coming soon, unless we are going to test every
> > supported platform before release. Anyone else?
>
> Changing this IMHO should be postponed until we have a new release.
After some more consideration, I think the signal mask reset bug warrants
fixing it before the next release. Attached is a better patch which
tries to avoid using fringe POSIX functions and instead simply using
sigsetjmp()/siglongjmp() on platforms where we know they are supported.
After asking on #chicken, "creidiki" tried the old patch on Windows and
mentioned it didn't compile due to an undeclared function _longjmp
(oddly, _setjmp *does* seem to exist...) so I haven't added sigsetjmp
to Windows either. In any case, Windows doesn't have POSIX signals
anyway so it doesn't matter which flavor of "*jmp" we use there.
If someone using, say, Solaris or Haiku figures that sigsetjmp is
supported on their platform after all, it's a simple matter of adding
the define to Makefile.solaris or Makefile.haiku. At least this way
it gets fixed on platforms that are known to have the signal problem.
Cheers,
Peter
--
http://sjamaan.ath.cx
--
"The process of preparing programs for a digital computer
is especially attractive, not only because it can be economically
and scientifically rewarding, but also because it can be an aesthetic
experience much like composing poetry or music."
-- Donald Knuth
>From 5999d00ed9b35db1f645890001ed941093a4a6bb Mon Sep 17 00:00:00 2001
From: Peter Bex <peter....@xs4all.nl>
Date: Wed, 13 Jun 2012 22:54:26 +0200
Subject: [PATCH] Use sigsetjmp/siglongjmp instead of setjmp/longjmp on
platforms where these are available to prevent inadvertent
resetting of signal mask and the associated unneccessary
system call overhead
---
Makefile.bsd | 1 +
Makefile.linux | 1 +
Makefile.macosx | 1 +
NEWS | 2 ++
chicken.h | 13 +++++++++++--
5 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/Makefile.bsd b/Makefile.bsd
index 7c545af..4402c03 100644
--- a/Makefile.bsd
+++ b/Makefile.bsd
@@ -84,6 +84,7 @@ chicken-config.h: chicken-defaults.h
echo "#define HAVE_MEMMOVE 1" >>$@
echo "#define HAVE_MEMORY_H 1" >>$@
echo "#define HAVE_SIGACTION 1" >>$@
+ echo "#define HAVE_SIGSETJMP 1" >>$@
echo "#define HAVE_STDINT_H 1" >>$@
echo "#define HAVE_STDLIB_H 1" >>$@
echo "#define HAVE_STRERROR 1" >>$@
diff --git a/Makefile.linux b/Makefile.linux
index 37f848c..c55d55e 100644
--- a/Makefile.linux
+++ b/Makefile.linux
@@ -73,6 +73,7 @@ chicken-config.h: chicken-defaults.h
echo "#define HAVE_MEMMOVE 1" >>$@
echo "#define HAVE_MEMORY_H 1" >>$@
echo "#define HAVE_SIGACTION 1" >>$@
+ echo "#define HAVE_SIGSETJMP 1" >>$@
echo "#define HAVE_STDINT_H 1" >>$@
echo "#define HAVE_STDLIB_H 1" >>$@
echo "#define HAVE_STRERROR 1" >>$@
diff --git a/Makefile.macosx b/Makefile.macosx
index fdb2483..a0a73fa 100644
--- a/Makefile.macosx
+++ b/Makefile.macosx
@@ -97,6 +97,7 @@ chicken-config.h: chicken-defaults.h
echo "#define HAVE_MEMMOVE 1" >>$@
echo "#define HAVE_MEMORY_H 1" >>$@
echo "#define HAVE_SIGACTION 1" >>$@
+ echo "#define HAVE_SIGSETJMP 1" >>$@
echo "#define HAVE_STDINT_H 1" >>$@
echo "#define HAVE_STDLIB_H 1" >>$@
echo "#define HAVE_STRERROR 1" >>$@
diff --git a/NEWS b/NEWS
index 4b31d83..136dbc9 100644
--- a/NEWS
+++ b/NEWS
@@ -241,6 +241,8 @@
and "-heap-shrinkage"
- the assembly-language stub routine for the implementation of "apply"
was broken for Sparc64 systems and has been disabled for this platform
+ - signal masks were accedentally reset upon GC for some platforms; use
+ sigsetjmp/siglongjmp on BSD, Linux and MacOS X
- Type system
- added new type-specifiers "input-port", "output-port", "(list-of T)"
diff --git a/chicken.h b/chicken.h
index 837a51c..6e9e009 100644
--- a/chicken.h
+++ b/chicken.h
@@ -874,8 +874,17 @@ DECL_C_PROC_p0 (128, 1,0,0,0,0,0,0,0)
# define C_gettimeofday gettimeofday
# define C_gmtime gmtime
# define C_localtime localtime
-# define C_setjmp setjmp
-# define C_longjmp longjmp
+/*
+ * It is undefined whether regular setjmp/longjmp save/restore signal mask
+ * so try to use versions that we know won't try to save & restore.
+ */
+# if defined(HAVE_SIGSETJMP)
+# define C_setjmp(e) sigsetjmp(e, 0)
+# define C_longjmp(e,v) siglongjmp(e, v)
+# else
+# define C_setjmp setjmp
+# define C_longjmp longjmp
+# endif
# define C_alloca alloca
# define C_strerror strerror
# define C_isalpha isalpha
--
1.7.9.1
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