diff mbox

[libgo] Replace wait4 by waitpid (PR go/47515)

Message ID mcrei5ous4c.fsf@google.com
State New
Headers show

Commit Message

Ian Lance Taylor March 30, 2011, 11:05 p.m. UTC 
Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE> writes:

> Currently, libgo uses wait4 unconditionally, which is missing on IRIX
> 6.5.  Fortunately, the rusage * arg is used nowhere, so I've decide to
> replace wait4 by waitpid, which seems to be considerably more portable.

Thanks for the patch, but I wasn't entirely happy with the approach
because it removes the os.Waitmsg.Rusage field.  That field is
inherently system dependent but I would rather not get rid of it.  I
wrote this patch instead, which I hope will also solve the problem.
Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
Committed to mainline.

Ian

Comments

Rainer Orth March 31, 2011, 3:54 p.m. UTC | #1 
Ian Lance Taylor <iant@google.com> writes:

> Thanks for the patch, but I wasn't entirely happy with the approach
> because it removes the os.Waitmsg.Rusage field.  That field is
> inherently system dependent but I would rather not get rid of it.  I
> wrote this patch instead, which I hope will also solve the problem.
> Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
> Committed to mainline.

I'll give it a try on IRIX, but the machine is slow (full
bootstrap/regtest takes ca. 44 hours) and I can't yet include Go in the
regular bootstraps over the weekend since the 64-bit libgo doesn't build
due to an additional field in struct timeval:

	http://gcc.gnu.org/ml/gcc-patches/2011-03/msg02146.html

	Rainer
diff mbox

Patch

diff -r a602eae61cf4 libgo/Makefile.am
--- a/libgo/Makefile.am	Wed Mar 30 15:33:32 2011 -0700
+++ b/libgo/Makefile.am	Wed Mar 30 16:01:55 2011 -0700
@@ -1246,13 +1246,20 @@ 
 endif # !LIBGO_IS_LINUX
 
 
-# Define ForkExec, PtraceForkExec, Exec, and Wait4.
+# Define ForkExec, PtraceForkExec, and Exec.
 if LIBGO_IS_RTEMS
 syscall_exec_os_file = syscalls/exec_stubs.go
 else
 syscall_exec_os_file = syscalls/exec.go
 endif
 
+# Define Wait4.
+if HAVE_WAIT4
+syscall_wait_file = syscalls/wait4.go
+else
+syscall_wait_file = syscalls/waitpid.go
+endif
+
 # Define Sleep.
 if LIBGO_IS_RTEMS
 syscall_sleep_file = syscalls/sleep_rtems.go
@@ -1329,6 +1336,7 @@ 
 	$(syscall_errstr_decl_file) \
 	syscalls/exec_helpers.go \
 	$(syscall_exec_os_file) \
+	$(syscall_wait_file) \
 	$(syscall_filesize_file) \
 	$(syscall_stat_file) \
 	$(syscall_sleep_file) \
diff -r a602eae61cf4 libgo/configure.ac
--- a/libgo/configure.ac	Wed Mar 30 15:33:32 2011 -0700
+++ b/libgo/configure.ac	Wed Mar 30 16:01:55 2011 -0700
@@ -381,8 +381,9 @@ 
 AC_CHECK_HEADERS(sys/mman.h syscall.h sys/epoll.h sys/ptrace.h sys/syscall.h sys/user.h sys/utsname.h)
 AM_CONDITIONAL(HAVE_SYS_MMAN_H, test "$ac_cv_header_sys_mman_h" = yes)
 
-AC_CHECK_FUNCS(srandom random strerror_r strsignal)
+AC_CHECK_FUNCS(srandom random strerror_r strsignal wait4)
 AM_CONDITIONAL(HAVE_STRERROR_R, test "$ac_cv_func_strerror_r" = yes)
+AM_CONDITIONAL(HAVE_WAIT4, test "$ac_cv_func_wait4" = yes)
 
 AC_CACHE_CHECK([for __sync_bool_compare_and_swap_4],
 [libgo_cv_func___sync_bool_compare_and_swap_4],
diff -r a602eae61cf4 libgo/mksysinfo.sh
--- a/libgo/mksysinfo.sh	Wed Mar 30 15:33:32 2011 -0700
+++ b/libgo/mksysinfo.sh	Wed Mar 30 16:01:55 2011 -0700
@@ -377,6 +377,8 @@ 
     nrusage="$nrusage $field;"
   done
   echo "type Rusage struct {$nrusage }" >> ${OUT}
+else
+  echo "type Rusage struct {}" >> ${OUT}
 fi
 
 # The utsname struct.
diff -r a602eae61cf4 libgo/syscalls/exec.go
--- a/libgo/syscalls/exec.go	Wed Mar 30 15:33:32 2011 -0700
+++ b/libgo/syscalls/exec.go	Wed Mar 30 16:01:55 2011 -0700
@@ -17,7 +17,6 @@ 
 func libc_dup2(int, int) int __asm__ ("dup2")
 func libc_execve(*byte, **byte, **byte) int __asm__ ("execve")
 func libc_sysexit(int) __asm__ ("_exit")
-func libc_wait4(Pid_t, *int, int, *Rusage) Pid_t __asm__ ("wait4")
 
 // Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
 // If a dup or exec fails, write the errno int to pipe.
@@ -263,16 +262,3 @@ 
 	libc_execve(StringBytePtr(argv0), &argv_arg[0], &envv_arg[0])
 	return GetErrno()
 }
-
-func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
-	var status int
-	r := libc_wait4(Pid_t(pid), &status, options, rusage)
-	wpid = int(r)
-	if r < 0 {
-		errno = GetErrno()
-	}
-	if wstatus != nil {
-		*wstatus = WaitStatus(status)
-	}
-	return
-}
diff -r a602eae61cf4 libgo/syscalls/wait4.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgo/syscalls/wait4.go	Wed Mar 30 16:01:55 2011 -0700
@@ -0,0 +1,22 @@ 
+// wait4.go -- Wait4 for systems with wait4.
+
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package syscall
+
+func libc_wait4(Pid_t, *int, int, *Rusage) Pid_t __asm__ ("wait4")
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
+	var status int
+	r := libc_wait4(Pid_t(pid), &status, options, rusage)
+	wpid = int(r)
+	if r < 0 {
+		errno = GetErrno()
+	}
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}
diff -r a602eae61cf4 libgo/syscalls/waitpid.go
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgo/syscalls/waitpid.go	Wed Mar 30 16:01:55 2011 -0700
@@ -0,0 +1,22 @@ 
+// waitpid.go -- Wait4 for systems without wait4, but with waitpid.
+
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package syscall
+
+func libc_waitpid(Pid_t, *int, int) Pid_t __asm__ ("waitpid")
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
+	var status int
+	r := libc_waitpid(Pid_t(pid), &status, options)
+	wpid = int(r)
+	if r < 0 {
+		errno = GetErrno()
+	}
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}