libc MT-safety, part 2.

Add a lock to FILE.  flockfile and friends are now implemented
(for the most part) in libc.  flockfile_debug is implemented in
libc_r; I suppose it's about time to kill it but will do it in
a future commit.

Fix a potential deadlock in _fwalk in a threaded environment.
A file flag (__SIGN) was added to stdio.h that, when set, tells
_fwalk to ignore it in its walk.  This seemed to be needed in
refill.c because each file needs to be locked when flushing.

Add a stub for pthread_self in libc.  This is needed by flockfile
which is allowed by POSIX to be recursive.

Make fgetpos() error return value (-1) match man page.

Remove recursive calls to locked functions (stdio); I think I've
got them all, but I may have missed a couple.

A few K&R -> ANSI conversions along with removal of a few instances
of "register".

$Id$ -> $FreeBSD$ in libc/stdio/rget.c

Not objected to:	-arch, a few months ago

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/libc/gen/_pthread_stubs.c b/lib/libc/gen/_pthread_stubs.c
index 87b0ad2..be6dab7 100644
--- a/lib/libc/gen/_pthread_stubs.c
+++ b/lib/libc/gen/_pthread_stubs.c
@@ -49,8 +49,14 @@
 #pragma weak	_pthread_mutexattr_destroy=_pthread_mutexattr_destroy_stub
 #pragma weak	_pthread_mutexattr_settype=_pthread_mutexattr_settype_stub
 #pragma weak	_pthread_once=_pthread_once_stub
+#pragma weak	_pthread_self=_pthread_self_stub
 #pragma weak	_pthread_setspecific=_pthread_setspecific_stub
 
+struct pthread {
+};
+
+static struct pthread	main_thread;
+
 
 void *
 _pthread_getspecific_stub(pthread_key_t key)
@@ -124,6 +130,12 @@ _pthread_once_stub(pthread_once_t *once_control, void (*init_routine) (void))
 	return (0);
 }
 
+pthread_t
+_pthread_self_stub(void)
+{
+	return (&main_thread);
+}
+
 int
 _pthread_setspecific_stub(pthread_key_t key, const void *value)
 {