First cut at signal handling support.

* Makefile (OBJS-y): Include signal.o if have_posix_sigs is "y".

* configure (have_posix_sigs): New variable, set by detecting POSIX
signal stuff.

* dep.mk: Regenerated.

* arith.c, debug.c, eval.c, filter.c, hash.c, match.c, parser.y,
parser.l, rand.c, regex.c, syslog.c, txr.c, utf8.c: Include new
signal.h header, now required by unwind, and the <signal.h> system
header.

* eval.c (exit_wrap): New function.
(eval_init): New functions registered as intrinsics: exit_wrap,
set_sig_handler, get_sig_handler, sig_check.

* gc.c (release): Unused functions removed.

* gc.h (release): Declaration removed.

* lib.c (init): Call sig_init.

* stream.c (set_putc, se_getc, se_fflush): New static functions.
(stdio_put_char_callback, stdio_get_char_callback, stdio_put_byte,
stdio_flush, stdio_get_byte): Use new functions to enable
signals when blocked on I/O.
(tail_strategy): Allow signals across sleep.
(pipev_close): Allow signals across waitpid.
(se_pclose): New static function.
(pipe_close): Use new function to enable signals across pclose.

* unwind.c (uw_unwind_to_exit_point): use extended_longjmp instead of
longjmp.

* unwind.h (struct uw_block, struct uw_catch): jb member changes from
jmp_buf to extended_jmp_buf.
(uw_block_begin, uw_simple_catch_begin, uw_catch_begin): Use
extended_setjmp instead of setjmp.

* signal.c: New file.

* signal.h: New file.

1 files changed, 4 insertions, 14 deletions

diff --git a/gc.c b/gc.c
index 04914783..33328b9e 100644
--- a/gc.c
+++ b/gc.c
@@ -31,6 +31,7 @@
 #include <setjmp.h>
 #include <dirent.h>
 #include <wchar.h>
+#include <signal.h>
 #include "config.h"
 #ifdef HAVE_VALGRIND
 #include <valgrind/memcheck.h>
@@ -41,6 +42,7 @@
 #include "txr.h"
 #include "eval.h"
 #include "gc.h"
+#include "signal.h"
 
 #define PROT_STACK_SIZE         1024
 #define HEAP_SIZE               16384
@@ -115,20 +117,6 @@ void protect(val *first, ...)
   va_end (vl);
 }
 
-void release(val *last, ...)
-{
-  val *next = last;
-  va_list vl;
-  va_start (vl, last);
-
-  while (next) {
-    rel1(next);
-    next = va_arg(vl, val *);
-  }
-
-  va_end (vl);
-}
-
 static void more(void)
 {
   heap_t *heap = (heap_t *) chk_malloc(sizeof *heap);
@@ -161,6 +149,8 @@ val make_obj(void)
 {
   int tries;
 
+  assert (!async_sig_enabled);
+
 #if CONFIG_GEN_GC
   if (opt_gc_debug || freshobj_idx >= FRESHOBJ_VEC_SIZE) {
     gc();