Revert r63758 and related commits

The change is unstable on Windows. Please re-commit it when it correctly
supports Windows.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 34 insertions, 113 deletions

diff --git a/signal.c b/signal.c
index e9f0708510..c781c38c62 100644
--- a/signal.c
+++ b/signal.c
@@ -62,11 +62,12 @@ ruby_atomic_compare_and_swap(rb_atomic_t *ptr, rb_atomic_t cmp,
 }
 #endif
 
-#define FOREACH_SIGNAL(sig, offset) \
-    for (sig = siglist + (offset); sig < siglist + numberof(siglist); ++sig)
-enum { LONGEST_SIGNAME = 7 }; /* MIGRATE and RETRACT */
+#ifndef NSIG
+# define NSIG (_SIGMAX + 1)      /* For QNX */
+#endif
+
 static const struct signals {
-    char signm[LONGEST_SIGNAME + 1];
+    const char *signm;
     int  signo;
 } siglist [] = {
     {"EXIT", 0},
@@ -128,9 +129,15 @@ static const struct signals {
 #ifdef SIGCONT
     {"CONT", SIGCONT},
 #endif
-#if RUBY_SIGCHLD
-    {"CHLD", RUBY_SIGCHLD },
-    {"CLD", RUBY_SIGCHLD },
+#ifdef SIGCHLD
+    {"CHLD", SIGCHLD},
+#endif
+#ifdef SIGCLD
+    {"CLD", SIGCLD},
+#else
+# ifdef SIGCHLD
+    {"CLD", SIGCHLD},
+# endif
 #endif
 #ifdef SIGTTIN
     {"TTIN", SIGTTIN},
@@ -195,6 +202,7 @@ static const struct signals {
 #ifdef SIGINFO
     {"INFO", SIGINFO},
 #endif
+    {NULL, 0}
 };
 
 static const char signame_prefix[3] = "SIG";
@@ -206,7 +214,7 @@ signm2signo(VALUE *sig_ptr, int negative, int exit, int *prefix_ptr)
     const struct signals *sigs;
     VALUE vsig = *sig_ptr;
     const char *nm;
-    long len, nmlen;
+    long len;
     int prefix = 0;
 
     if (RB_SYMBOL_P(vsig)) {
@@ -260,12 +268,9 @@ signm2signo(VALUE *sig_ptr, int negative, int exit, int *prefix_ptr)
     }
 
     if (prefix_ptr) *prefix_ptr = prefix;
-    nmlen = len - prefix;
-    nm += prefix;
-    if (nmlen > LONGEST_SIGNAME) goto unsupported;
-    FOREACH_SIGNAL(sigs, !exit) {
-	if (memcmp(sigs->signm, nm, nmlen) == 0 &&
-	    sigs->signm[nmlen] == '\0') {
+    for (sigs = siglist + !exit; sigs->signm; sigs++) {
+	if (memcmp(sigs->signm, nm + prefix, len - prefix) == 0 &&
+	    sigs->signm[len - prefix] == '\0') {
 	    return negative ? -sigs->signo : sigs->signo;
 	}
     }
@@ -277,10 +282,9 @@ signo2signm(int no)
 {
     const struct signals *sigs;
 
-    FOREACH_SIGNAL(sigs, 0) {
+    for (sigs = siglist; sigs->signm; sigs++)
 	if (sigs->signo == no)
 	    return sigs->signm;
-    }
     return 0;
 }
 
@@ -698,29 +702,12 @@ signal_enque(int sig)
     ATOMIC_INC(signal_buff.size);
 }
 
-static rb_atomic_t sigchld_hit;
-
-/* Prevent compiler from reordering access */
-#define ACCESS_ONCE(type,x) (*((volatile type *)&(x)))
-
 static RETSIGTYPE
 sighandler(int sig)
 {
     int old_errnum = errno;
 
-    /* the VM always needs to handle SIGCHLD for rb_waitpid */
-    if (sig == RUBY_SIGCHLD) {
-        rb_vm_t *vm = GET_VM();
-        ATOMIC_EXCHANGE(sigchld_hit, 1);
-
-        /* avoid spurious wakeup in main thread iff nobody uses trap(:CHLD) */
-        if (vm && ACCESS_ONCE(VALUE, vm->trap_list.cmd[sig])) {
-            signal_enque(sig);
-        }
-    }
-    else {
-        signal_enque(sig);
-    }
+    signal_enque(sig);
     rb_thread_wakeup_timer_thread();
 #if !defined(BSD_SIGNAL) && !defined(POSIX_SIGNAL)
     ruby_signal(sig, sighandler);
@@ -755,7 +742,6 @@ rb_enable_interrupt(void)
 #ifdef HAVE_PTHREAD_SIGMASK
     sigset_t mask;
     sigemptyset(&mask);
-    sigaddset(&mask, RUBY_SIGCHLD); /* timer-thread handles this */
     pthread_sigmask(SIG_SETMASK, &mask, NULL);
 #endif
 }
@@ -1066,17 +1052,6 @@ rb_trap_exit(void)
     }
 }
 
-void ruby_waitpid_all(rb_vm_t *); /* process.c */
-
-/* only runs in the timer-thread */
-void
-ruby_sigchld_handler(rb_vm_t *vm)
-{
-    if (SIGCHLD_LOSSY || ATOMIC_EXCHANGE(sigchld_hit, 0)) {
-        ruby_waitpid_all(vm);
-    }
-}
-
 void
 rb_signal_exec(rb_thread_t *th, int sig)
 {
@@ -1143,9 +1118,6 @@ default_handler(int sig)
 #ifdef SIGUSR2
       case SIGUSR2:
 #endif
-#if RUBY_SIGCHLD
-      case RUBY_SIGCHLD:
-#endif
         func = sighandler;
         break;
 #ifdef SIGBUS
@@ -1183,9 +1155,6 @@ trap_handler(VALUE *cmd, int sig)
     VALUE command;
 
     if (NIL_P(*cmd)) {
-	if (sig == RUBY_SIGCHLD) {
-	    goto sig_dfl;
-	}
 	func = SIG_IGN;
     }
     else {
@@ -1206,9 +1175,6 @@ trap_handler(VALUE *cmd, int sig)
 		break;
               case 14:
 		if (memcmp(cptr, "SYSTEM_DEFAULT", 14) == 0) {
-                    if (sig == RUBY_SIGCHLD) {
-                        goto sig_dfl;
-                    }
                     func = SIG_DFL;
                     *cmd = 0;
 		}
@@ -1216,9 +1182,6 @@ trap_handler(VALUE *cmd, int sig)
 	      case 7:
 		if (memcmp(cptr, "SIG_IGN", 7) == 0) {
 sig_ign:
-                    if (sig == RUBY_SIGCHLD) {
-                        goto sig_dfl;
-                    }
                     func = SIG_IGN;
                     *cmd = Qtrue;
 		}
@@ -1305,7 +1268,7 @@ trap(int sig, sighandler_t func, VALUE command)
 	break;
     }
 
-    ACCESS_ONCE(VALUE, vm->trap_list.cmd[sig]) = command;
+    vm->trap_list.cmd[sig] = command;
     vm->trap_list.safe[sig] = rb_safe_level();
 
     return oldcmd;
@@ -1421,7 +1384,7 @@ sig_list(void)
     VALUE h = rb_hash_new();
     const struct signals *sigs;
 
-    FOREACH_SIGNAL(sigs, 0) {
+    for (sigs = siglist; sigs->signm; sigs++) {
 	rb_hash_aset(h, rb_fstring_cstr(sigs->signm), INT2FIX(sigs->signo));
     }
     return h;
@@ -1450,18 +1413,20 @@ install_sighandler(int signum, sighandler_t handler)
 #  define install_sighandler(signum, handler) \
     INSTALL_SIGHANDLER(install_sighandler(signum, handler), #signum, signum)
 
-#if RUBY_SIGCHLD
+#if defined(SIGCLD) || defined(SIGCHLD)
 static int
 init_sigchld(int sig)
 {
     sighandler_t oldfunc;
-    sighandler_t func = sighandler;
 
     oldfunc = ruby_signal(sig, SIG_DFL);
     if (oldfunc == SIG_ERR) return -1;
-    ruby_signal(sig, func);
-    ACCESS_ONCE(VALUE, GET_VM()->trap_list.cmd[sig]) = 0;
-
+    if (oldfunc != SIG_DFL && oldfunc != SIG_IGN) {
+	ruby_signal(sig, oldfunc);
+    }
+    else {
+	GET_VM()->trap_list.cmd[sig] = 0;
+    }
     return 0;
 }
 
@@ -1577,55 +1542,11 @@ Init_signal(void)
     install_sighandler(SIGSYS, sig_do_nothing);
 #endif
 
-#if RUBY_SIGCHLD
-    init_sigchld(RUBY_SIGCHLD);
+#if defined(SIGCLD)
+    init_sigchld(SIGCLD);
+#elif defined(SIGCHLD)
+    init_sigchld(SIGCHLD);
 #endif
 
     rb_enable_interrupt();
 }
-
-#if defined(HAVE_GRANTPT)
-extern int grantpt(int);
-#else
-static int
-fake_grantfd(int masterfd)
-{
-    errno = ENOSYS;
-    return -1;
-}
-#define grantpt(fd) fake_grantfd(fd)
-#endif
-
-int
-rb_grantpt(int masterfd)
-{
-    if (RUBY_SIGCHLD) {
-        rb_vm_t *vm = GET_VM();
-        int ret, e;
-
-        /*
-         * Prevent waitpid calls from Ruby by taking waitpid_lock.
-         * Pedantically, grantpt(3) is undefined if a non-default
-         * SIGCHLD handler is defined, but preventing conflicting
-         * waitpid calls ought to be sufficient.
-         *
-         * We could install the default sighandler temporarily, but that
-         * could cause SIGCHLD to be missed by other threads.  Blocking
-         * SIGCHLD won't work here, either, unless we stop and restart
-         * timer-thread (as only timer-thread sees SIGCHLD), but that
-         * seems like overkill.
-         */
-        rb_nativethread_lock_lock(&vm->waitpid_lock);
-        {
-            ret = grantpt(masterfd); /* may spawn `pt_chown' and wait on it */
-            if (ret < 0) e = errno;
-        }
-        rb_nativethread_lock_unlock(&vm->waitpid_lock);
-
-        if (ret < 0) errno = e;
-        return ret;
-    }
-    else {
-        return grantpt(masterfd);
-    }
-}