Because POSIX does not allow EINTR to be returned from sigwait(),

add a wrapper for it in libc and rework the code in libthr, the
system call still can return EINTR, we keep this feature.

Discussed on: thread
Reviewed by:  jilles

lib/libc/stdlib/Makefile.inc

@@ -9,7 +9,7 @@ MISRCS+=_Exit.c a64l.c abort.c abs.c atexit.c atof.c atoi.c atol.c atoll.c \
 	getsubopt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c \
 	insque.c l64a.c labs.c ldiv.c llabs.c lldiv.c lsearch.c malloc.c \
 	merge.c ptsname.c qsort.c qsort_r.c radixsort.c rand.c random.c \
-	reallocf.c realpath.c remque.c strfmon.c strtoimax.c \
+	reallocf.c realpath.c remque.c sigwait.c strfmon.c strtoimax.c \
 	strtol.c strtoll.c strtoq.c strtoul.c strtonum.c strtoull.c \
         strtoumax.c strtouq.c system.c tdelete.c tfind.c tsearch.c twalk.c
 

lib/libc/sys/Makefile.inc

@@ -21,6 +21,9 @@ SRCS+=	stack_protector.c stack_protector_compat.c __error.c
 SRCS+=	fcntl.c ftruncate.c lseek.c mmap.c pread.c pwrite.c truncate.c
 PSEUDO+= _fcntl.o
 .endif
+SRCS+= sigwait.c
+NOASM+= sigwait.o
+PSEUDO+= _sigwait.o
 
 # Add machine dependent asm sources:
 SRCS+=${MDASM}

lib/libc/sys/Symbol.map

@@ -919,6 +919,7 @@ FBSDprivate_1.0 {
 	_sigtimedwait;
 	__sys_sigtimedwait;
 	_sigwait;
+	__sigwait;
 	__sys_sigwait;
 	_sigwaitinfo;
 	__sys_sigwaitinfo;

lib/libc/sys/sigwait.c

@@ -0,0 +1,46 @@
+/*-
+ * Copyright (c) 2010 davidxu@freebsd.org
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <errno.h>
+#include <signal.h>
+
+int __sys_sigwait(const sigset_t * restrict, int * restrict);
+
+__weak_reference(__sigwait, sigwait);
+
+int
+__sigwait(const sigset_t * restrict set, int * restrict sig)
+{
+	int ret;
+
+	/* POSIX does not allow EINTR to be returned */
+	do  {
+		ret = __sys_sigwait(set, sig);
+	} while (ret == EINTR);
+	return (ret);
+}

lib/libthr/thread/thr_sig.c

@@ -67,7 +67,7 @@ int	_sigtimedwait(const sigset_t *set, siginfo_t *info,
 	const struct timespec * timeout);
 int	__sigwaitinfo(const sigset_t *set, siginfo_t *info);
 int	_sigwaitinfo(const sigset_t *set, siginfo_t *info);
-int	__sigwait(const sigset_t *set, int *sig);
+int	___sigwait(const sigset_t *set, int *sig);
 int	_sigwait(const sigset_t *set, int *sig);
 int	__sigsuspend(const sigset_t *sigmask);
 int	_sigaction(int, const struct sigaction *, struct sigaction *);
@@ -634,7 +634,7 @@ __sigsuspend(const sigset_t * set)
 	return (ret);
 }
 
-__weak_reference(__sigwait, sigwait);
+__weak_reference(___sigwait, sigwait);
 __weak_reference(__sigtimedwait, sigtimedwait);
 __weak_reference(__sigwaitinfo, sigwaitinfo);
 
@@ -708,15 +708,17 @@ _sigwait(const sigset_t *set, int *sig)
  *   it is not canceled.
  */ 
 int
-__sigwait(const sigset_t *set, int *sig)
+___sigwait(const sigset_t *set, int *sig)
 {
 	struct pthread	*curthread = _get_curthread();
 	sigset_t newset;
 	int ret;
 
-	_thr_cancel_enter(curthread);
+	do {
-	ret = __sys_sigwait(thr_remove_thr_signals(set, &newset), sig);
+		_thr_cancel_enter(curthread);
-	_thr_cancel_leave(curthread, (ret != 0));
+		ret = __sys_sigwait(thr_remove_thr_signals(set, &newset), sig);
+		_thr_cancel_leave(curthread, (ret != 0));
+	} while (ret == EINTR);
 	return (ret);
 }