change sigset() and signal() to sigaction()

The sigaction() API is the more modern, more portable one.

racket/src/racket/include/mzwin.def

@@ -645,3 +645,4 @@ EXPORTS
  scheme_free_key
  scheme_jit_find_code_end
  scheme_jit_now
+ scheme_set_signal_handler

racket/src/racket/include/mzwin3m.def

@@ -660,3 +660,4 @@ EXPORTS
  scheme_free_key
  scheme_jit_find_code_end
  scheme_jit_now
+ scheme_set_signal_handler

racket/src/racket/include/racket.exp

@@ -661,3 +661,4 @@ scheme_malloc_key
 scheme_free_key
 scheme_jit_find_code_end
 scheme_jit_now
+scheme_set_signal_handler

racket/src/racket/include/racket3m.exp

@@ -667,3 +667,4 @@ scheme_malloc_key
 scheme_free_key
 scheme_jit_find_code_end
 scheme_jit_now
+scheme_set_signal_handler

racket/src/racket/include/scheme.h

@@ -151,12 +151,6 @@ typedef long FILE;
 # define MSCBOR_IZE(x) MSC_IZE(x)
 #endif
 
-#ifdef SIGSET_IS_SIGNAL
-# define MZ_SIGSET(s, f) signal(s, f)
-#else
-# define MZ_SIGSET(s, f) sigset(s, f)
-#endif
-
 /* C99 allows an array in a struct to be declared
    with [] to indicate that its actual size can be
    any number. The old way was to declare the array
@@ -2035,6 +2029,12 @@ MZ_EXTERN Scheme_Object *scheme_register_parameter(Scheme_Prim *function, char *
 
 #endif /* SCHEME_DIRECT_EMBEDDED */
 
+/*========================================================================*/
+/*                             OS signals                                 */
+/*========================================================================*/
+
+typedef void (*Scheme_Signal_Handler_Proc)(int);
+
 /*========================================================================*/
 /*                              addrinfo                                  */
 /*========================================================================*/

racket/src/racket/main.c

@@ -236,10 +236,6 @@ static void user_break_hit(int ignore)
 {
   scheme_break_main_thread_at(break_handle);
   scheme_signal_received_at(signal_handle);
-
-#  ifdef SIGSET_NEEDS_REINSTALL
-  MZ_SIGSET(SIGINT, user_break_hit);
-#  endif
 }
 
 # ifndef NO_SIGTERM_HANDLER
@@ -248,10 +244,6 @@ static void term_hit(int ignore)
 {
   scheme_break_kind_main_thread_at(break_handle, MZEXN_BREAK_TERMINATE);
   scheme_signal_received_at(signal_handle);
-
-#  ifdef SIGSET_NEEDS_REINSTALL
-  MZ_SIGSET(SIGTERM, term_hit);
-#  endif
 }
 # endif
 
@@ -261,10 +253,6 @@ static void hup_hit(int ignore)
 {
   scheme_break_kind_main_thread_at(break_handle, MZEXN_BREAK_HANG_UP);
   scheme_signal_received_at(signal_handle);
-
-#  ifdef SIGSET_NEEDS_REINSTALL
-  MZ_SIGSET(SIGHUP, hup_hit);
-#  endif
 }
 # endif
 
@@ -438,12 +426,12 @@ static int main_after_stack(void *data)
   break_handle = scheme_get_main_thread_break_handle();
   signal_handle = scheme_get_signal_handle();
 # ifndef NO_USER_BREAK_HANDLER
-  MZ_SIGSET(SIGINT, user_break_hit);
+  scheme_set_signal_handler(SIGINT, user_break_hit);
 #  ifndef NO_SIGTERM_HANDLER
-  MZ_SIGSET(SIGTERM, term_hit);
+  scheme_set_signal_handler(SIGTERM, term_hit);
 #  endif
 #  ifndef NO_SIGHUP_HANDLER
-  MZ_SIGSET(SIGHUP, hup_hit);
+  scheme_set_signal_handler(SIGHUP, hup_hit);
 #  endif
 # endif
 # ifdef DOS_FILE_SYSTEM

racket/src/racket/sconfig.h

@@ -40,7 +40,6 @@
 # else
 /* SunOS4 */
 # define SCHEME_PLATFORM_LIBRARY_SUBPATH "sparc-sunos4"
-# define SIGSET_IS_SIGNAL
 # define NO_STRERROR_AVAILABLE
 # define USE_ON_EXIT_FOR_ATEXIT
 # endif
@@ -141,9 +140,6 @@
 # define USE_IEEE_FP_PREDS
 # define USE_EXPLICT_FP_FORM_CHECK
 
-# define SIGSET_IS_SIGNAL
-# define SIGSET_NEEDS_REINSTALL
-
 # define LINUX_FIND_STACK_BASE
 
 # define FLAGS_ALREADY_SET
@@ -189,8 +185,6 @@
 
 # define USE_IEEE_FP_PREDS
 
-# define SIGSET_IS_SIGNAL
-
 #if defined(__alpha__)
 # define USE_DIVIDE_MAKE_INFINITY
 #endif
@@ -253,8 +247,6 @@
 
 # define USE_IEEE_FP_PREDS
 
-# define SIGSET_IS_SIGNAL
-
 # define USE_MAP_ANON
 
 # if defined(__x86_64__)
@@ -310,8 +302,6 @@
 
 # define USE_IEEE_FP_PREDS
 
-# define SIGSET_IS_SIGNAL
-
 # define USE_MAP_ANON
 
 # if defined(__x86_64__)
@@ -376,8 +366,6 @@
 
 # define USE_IEEE_FP_PREDS
 
-# define SIGSET_IS_SIGNAL
-
 # define MZ_JIT_USE_MPROTECT
 
 # define FLAGS_ALREADY_SET
@@ -533,8 +521,6 @@
 #  define USE_WIN32_THREAD_TIMER
 # endif
 
-# define SIGSET_IS_SIGNAL
-# define SIGSET_NEEDS_REINSTALL
 # define NO_SIGHUP_HANDLER
 
 #define PRINTF_INTPTR_SIZE_PREFIX "I"
@@ -601,9 +587,6 @@
 
 # undef USE_ITIMER
 
-# define SIGSET_IS_SIGNAL
-# define SIGSET_NEEDS_REINSTALL
-
 # define USE_MZ_CYGWIN_SETJMP
 # define USE_MZ_SETJMP
 
@@ -665,8 +648,6 @@
 # define USE_IEEE_FP_PREDS
 # define TRIG_ZERO_NEEDS_SIGN_CHECK
 
-# define SIGSET_IS_SIGNAL
-
 # define USE_UNDERSCORE_SETJMP
 
 #ifndef XONX
@@ -710,8 +691,6 @@
 
 # define USE_MAP_ANON
 
-# define SIGSET_IS_SIGNAL
-
 # define USE_UNDERSCORE_SETJMP
 
 # define MZ_USE_JIT_I386
@@ -730,8 +709,6 @@
 # define ASSUME_FIXED_STACK_SIZE
 
 # include "uconfig.h"
-# define SIGSET_IS_SIGNAL
-# define SIGSET_NEEDS_REINSTALL
 
 # define FIXED_STACK_SIZE 524288
 
@@ -783,8 +760,6 @@
 #  define POW_HANDLES_INF_CORRECTLY
 # endif
 
-# define SIGSET_IS_SIGNAL
-
 # define MZ_JIT_USE_MPROTECT
 
 # define FLAGS_ALREADY_SET
@@ -800,8 +775,6 @@
 
 /* assume generic Unix: */
 #include "uconfig.h"
-# define SIGSET_IS_SIGNAL
-# define SIGSET_NEEDS_REINSTALL
 
   /*********************/
  /* Operating System  */
@@ -868,15 +841,6 @@
  /* USE_PTHREAD_THREAD_TIMER uses a background pthread to implement
     tread pre-emption. */
 
- /* SIGSET_IS_SIGNAL uses signal() in place of sigset() for Unix. This
-    flag is often paired with SIGSET_NEEDS_REINSTALL for traditional
-    Unix systems. */
-
- /* SIGSET_NEEDS_REINSTALL reinstalls a signal handler when it
-    is called to handle a signal. The expected semantics of sigset()
-    (when this flags is not defined) is that a signal handler is NOT
-    reset to SIG_DFL after a handler is called to handle a signal. */
-
  /* DONT_IGNORE_FPE_SIGNAL stops Racket from ignoring floating-point
     exception signals. */
 

racket/src/racket/src/number.c

@@ -301,7 +301,7 @@ void scheme_configure_floating_point(void)
 /* can be called in any thread */
 {    
 #ifndef DONT_IGNORE_FPE_SIGNAL
-  MZ_SIGSET(SIGFPE, SIG_IGN);
+  scheme_set_signal_handler(SIGFPE, NULL);
 #endif
 #ifdef FREEBSD_CONTROL_387
   (void)fpsetmask(0);

racket/src/racket/src/port.c

@@ -346,9 +346,7 @@ scheme_init_port (Scheme_Env *env)
   REGISTER_SO(scheme_redirect_output_port_type);
 
 #ifndef DONT_IGNORE_PIPE_SIGNAL
-  START_XFORM_SKIP;
+  scheme_set_signal_handler(SIGPIPE, NULL);
-  MZ_SIGSET(SIGPIPE, SIG_IGN);
-  END_XFORM_SKIP;
 #endif
 
   if (!scheme_sleep)
@@ -6523,9 +6521,6 @@ static void itimer_expired(int ignored)
 {
   scheme_fuel_counter = 0;
   scheme_jit_stack_boundary = (uintptr_t)-1;
-#  ifdef SIGSET_NEEDS_REINSTALL
-  MZ_SIGSET(SIGPROF, itimer_expired);
-#  endif
 }
 
 static void kickoff_itimer(intptr_t usec) 
@@ -6537,7 +6532,7 @@ static void kickoff_itimer(intptr_t usec)
 
   if (!itimer_handler_installed) {
     itimer_handler_installed = 1;
-    MZ_SIGSET(SIGPROF, itimer_expired);
+    scheme_set_signal_handler(SIGPROF, itimer_expired);
   }
 
   t.it_value.tv_sec = 0;

racket/src/racket/src/salloc.c

@@ -32,6 +32,9 @@
 #include <string.h>
 #include "schgc.h"
 #include "schrktio.h"
+#ifndef WINDOWS_PROCESSES
+# include <signal.h>
+#endif
 
 #ifdef DOS_FAR_POINTERS
 # include <alloc.h>
@@ -445,6 +448,17 @@ int scheme_is_place_main_os_thread() XFORM_SKIP_PROC
   return 1;
 }
 
+void scheme_set_signal_handler(int sig_id, Scheme_Signal_Handler_Proc proc) XFORM_SKIP_PROC
+{
+#ifndef WINDOWS_PROCESSES
+  struct sigaction sa;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = 0;
+  sa.sa_handler = (proc ? proc : SIG_IGN);
+  sigaction(sig_id, &sa, NULL);
+#endif
+}
+
 /************************************************************************/
 /*                           memory utils                               */
 /************************************************************************/

racket/src/racket/src/schemef.h

@@ -1232,3 +1232,5 @@ MZ_EXTERN void scheme_free_key(Scheme_Object *k);
 
 MZ_EXTERN void *scheme_jit_find_code_end(void *p);
 MZ_EXTERN void scheme_jit_now(Scheme_Object *f);
+
+MZ_EXTERN void scheme_set_signal_handler(int sig_id, Scheme_Signal_Handler_Proc proc);

racket/src/racket/src/schemex.h

@@ -1005,6 +1005,7 @@ Scheme_Object *(*scheme_malloc_key)(void);
 void (*scheme_free_key)(Scheme_Object *k);
 void *(*scheme_jit_find_code_end)(void *p);
 void (*scheme_jit_now)(Scheme_Object *f);
+void (*scheme_set_signal_handler)(int sig_id, Scheme_Signal_Handler_Proc proc);
 #ifndef SCHEME_EX_INLINE
 } Scheme_Extension_Table;
 #endif

racket/src/racket/src/schemex.inc

@@ -729,3 +729,4 @@
   scheme_extension_table->scheme_free_key = scheme_free_key;
   scheme_extension_table->scheme_jit_find_code_end = scheme_jit_find_code_end;
   scheme_extension_table->scheme_jit_now = scheme_jit_now;
+  scheme_extension_table->scheme_set_signal_handler = scheme_set_signal_handler;

racket/src/racket/src/schemexm.h

@@ -729,6 +729,7 @@
 #define scheme_free_key (scheme_extension_table->scheme_free_key)
 #define scheme_jit_find_code_end (scheme_extension_table->scheme_jit_find_code_end)
 #define scheme_jit_now (scheme_extension_table->scheme_jit_now)
+#define scheme_set_signal_handler (scheme_extension_table->scheme_set_signal_handler)
 #ifdef MZ_PRECISE_GC
 #pragma GC_VARIABLE_STACK_THOUGH_TABLE
 #endif

racket/src/rktio/rktio_platform.h

@@ -15,7 +15,6 @@
 #  define USE_TIMEZONE_AND_ALTZONE_VAR
 #  define USE_TZNAME_VAR
 #  define USE_NULL_TO_DISCONNECT_UDP
-#  define SIGNAL_NEEDS_REINSTALL
 # else
 /* SunOS4 */
 #  define USE_TM_GMTOFF_FIELD
@@ -333,11 +332,6 @@
  /* Signals             */
 /***********************/
 
- /* SIGNAL_NEEDS_REINSTALL reinstalls a signal handler when it
-    is called to handle a signal. The expected semantics of signal()
-    (when this flags is not defined) is that a signal handler is NOT
-    reset to SIG_DFL after a handler is called to handle a signal. */
-
  /* USE_CREATE_PIPE uses CreatePipe() instead of _pipe() for Windows. */
 
  /* SIGCHILD_DOESNT_INTERRUPT_SELECT indicates that the SIGCHILD

racket/src/rktio/rktio_process.c

@@ -36,10 +36,11 @@ struct rktio_process_t {
 };
 
 /*========================================================================*/
-/* Status helper                                                          */
+/* Status and signal helpers                                              */
 /*========================================================================*/
 
 #if defined(RKTIO_SYSTEM_UNIX)
+
 static int extract_child_status(int status)
 {
   if (WIFEXITED(status))
@@ -51,6 +52,16 @@ static int extract_child_status(int status)
 
   return status;
 }
+
+static void set_signal_handler(int sig_id, void (*proc)(int))
+{
+  struct sigaction sa;
+  sigemptyset(&sa.sa_mask);
+  sa.sa_flags = 0;
+  sa.sa_handler = proc;
+  sigaction(sig_id, &sa, NULL);
+}
+
 #endif
 
 /*========================================================================*/
@@ -422,7 +433,7 @@ void centralized_starting_child()
        does not block SIGCHLD.
        Solaris, meanwhile, seems to unmask SIGCHLD as a result of
        setting a handler, so do this before masking the signal. */
-    signal(SIGCHLD, got_sigchld);
+    set_signal_handler(SIGCHLD, got_sigchld);
     
     /* Block SIGCLHD (again), because the worker thread will use sigwait(). */
     block_sigchld();
@@ -568,17 +579,13 @@ static void child_done(int ingored)
     rktio_signal_received(rktio);
     rktio = rktio->next;
   }
-
-# ifdef SIGNAL_NEEDS_REINSTALL
-  signal(SIGCHLD, child_done);
-# endif
 }
 
 static void init_sigchld(rktio_t *rktio)
 {
 #if !defined(CENTRALIZED_SIGCHILD)
   if (!sigchld_installed) {
-    signal(SIGCHLD, child_done);
+    set_signal_handler(SIGCHLD, child_done);
     sigchld_installed = 1;
   }