From b72b0b14d0da0b506fbddf755cc8c7d0cd813287 Mon Sep 17 00:00:00 2001
From: "Peter S. Mazinger" <ps.m@gmx.net>
Date: Fri, 22 Apr 2011 00:33:48 +0200
Subject: rework cancellation for sigwait, sigtimedwait and sigwaitinfo

sigtimedwait:
- provide __sigtimedwait_nocancel
- use __SYSCALL_SIGSET_T_SIZE instead of _NSIG / 8
- do not provide __sigtimedwait
- guard a section to avoid failure on archs if SI_TKILL/SI_USER are not defined
sigwaitinfo:
- simply use sigtimedwait since that handles cancellation already
sigwait:
- use non-cancellable functions (sigtimedwait, sigsuspend)
- get rid of code already done in __sigtimedwait_nocancel

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
---
 libc/signal/sigwait.c | 91 ++++++++++-----------------------------------------
 1 file changed, 18 insertions(+), 73 deletions(-)

(limited to 'libc/signal')

diff --git a/libc/signal/sigwait.c b/libc/signal/sigwait.c
index 5e9c4275f..7d47f99de 100644
--- a/libc/signal/sigwait.c
+++ b/libc/signal/sigwait.c
@@ -21,92 +21,36 @@
 
 #define __need_NULL
 #include <stddef.h>
+#include <sys/syscall.h>
 #include <signal.h>
+#include <cancel.h>
 
-#ifdef __UCLIBC_HAS_THREADS_NATIVE__
-# include <sysdep-cancel.h>
+#if defined __NR_rt_sigtimedwait && defined __UCLIBC_HAS_REALTIME__
 
-# ifdef __NR_rt_sigtimedwait
-#  include <string.h>
+#include <string.h>
 
 /* Return any pending signal or wait for one for the given time.  */
-static int do_sigwait(const sigset_t *set, int *sig)
+static int __NC(sigwait)(const sigset_t *set, int *sig)
 {
 	int ret;
 
-#  ifdef SIGCANCEL
-	sigset_t tmpset;
-	if (set != NULL
-		&& (__builtin_expect (__sigismember (set, SIGCANCEL), 0)
-#   ifdef SIGSETXID
-		|| __builtin_expect (__sigismember (set, SIGSETXID), 0)
-#   endif
-		))
-	{
-		/* Create a temporary mask without the bit for SIGCANCEL set.  */
-		// We are not copying more than we have to.
-		memcpy(&tmpset, set, _NSIG / 8);
-		__sigdelset(&tmpset, SIGCANCEL);
-#   ifdef SIGSETXID
-		__sigdelset(&tmpset, SIGSETXID);
-#   endif
-		set = &tmpset;
-	}
-#  endif
-
-	/* XXX The size argument hopefully will have to be changed to the
-	   real size of the user-level sigset_t.  */
-	INTERNAL_SYSCALL_DECL(err);
 	do
-		ret = INTERNAL_SYSCALL (rt_sigtimedwait, err, 4, set, NULL,
-			NULL, _NSIG / 8);
-	while (INTERNAL_SYSCALL_ERROR_P (ret, err)
-		&& INTERNAL_SYSCALL_ERRNO (ret, err) == EINTR);
-	if (! INTERNAL_SYSCALL_ERROR_P (ret, err))
-	{
+		/* we might as well use sigtimedwait and do not care about cancellation */
+		ret = __NC(sigtimedwait)(set, NULL, NULL);
+	while (ret == -1 && errno == EINTR);
+	if (ret != -1) {
 		*sig = ret;
 		ret = 0;
-	}
-else
-	ret = INTERNAL_SYSCALL_ERRNO (ret, err);
+	} else
+		ret = errno;
 
 	return ret;
 }
 
-int sigwait (const sigset_t *set, int *sig)
-{
-	if(SINGLE_THREAD_P)
-		return do_sigwait(set, sig);
-
-	int oldtype = LIBC_CANCEL_ASYNC();
-
-	int result = do_sigwait(set, sig);
-
-	LIBC_CANCEL_RESET(oldtype);
-
-	return result;
-}
-# else /* __NR_rt_sigtimedwait */
-#  error We must have rt_sigtimedwait defined!!!
-# endif
-#else /* __UCLIBC_HAS_THREADS_NATIVE__ */
+#else /* __NR_rt_sigtimedwait */
 
-# if defined __UCLIBC_HAS_REALTIME__
-
-int sigwait (const sigset_t *set, int *sig)
-{
-	int ret = 1;
-	if ((ret = __sigwaitinfo(set, NULL)) != -1) {
-		*sig = ret;
-		return 0;
-	}
-	return 1;
-}
-
-# else /* __UCLIBC_HAS_REALTIME__ */
-# include <errno.h>
-# include <unistd.h>	/* smallint */
 /* variant without REALTIME extensions */
+#include <unistd.h>	/* smallint */
 
 static smallint was_sig; /* obviously not thread-safe */
 
@@ -115,7 +59,7 @@ static void ignore_signal(int sig)
 	was_sig = sig;
 }
 
-int sigwait (const sigset_t *set, int *sig)
+static int __NC(sigwait)(const sigset_t *set, int *sig)
 {
   sigset_t tmp_mask;
   struct sigaction saved[NSIG];
@@ -149,7 +93,7 @@ int sigwait (const sigset_t *set, int *sig)
       }
 
   /* Now we can wait for signals.  */
-  sigsuspend (&tmp_mask);
+  __NC(sigsuspend)(&tmp_mask);
 
  restore_handler:
   save_errno = errno;
@@ -165,5 +109,6 @@ int sigwait (const sigset_t *set, int *sig)
   *sig = was_sig;
   return was_sig == -1 ? -1 : 0;
 }
-# endif /* __UCLIBC_HAS_REALTIME__ */
-#endif /* __UCLIBC_HAS_THREADS_NATIVE__ */
+#endif /* __NR_rt_sigtimedwait */
+
+CANCELLABLE_SYSCALL(int, sigwait, (const sigset_t *set, int *sig), (set, sig))
-- 
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