MFC r320472,r320508,r320509:
Make stdio deferred cancel-safe.

Requested by: eugen

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic all number the clauses 1 through 3,
so follow suit to make comparison easier.

Acked-by: imp@

Next stage of stdio cleanup: Retire __sFILEX and merge the fields back into
__sFILE. This was supposed to be done in 6.0. Some notes:
- Where possible I restored the various lines to their pre-__sFILEX state.
- Retire INITEXTRA() and just initialize the wchar bits (orientation and
mbstate) explicitly instead. The various places that used INITEXTRA
didn't need the locking fields or _up initialized. (Some places needed
_up to exist and not be off the end of a NULL or garbage pointer, but
they didn't require it to be initialized to a specific value.)
- For now, stdio.h "knows" that pthread_t is a 'struct pthread *' to
avoid namespace pollution of including all the pthread types in stdio.h.
Once we remove all the inlines and make __sFILE private it can go back
to using pthread_t, etc.
- This does not remove any of the inlines currently and does not change
any of the public ABI of 'FILE'.

MFC after: 1 month
Reviewed by: peter

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Set stream orientation in ungetc() instead of __ungetc(). This avoids
setting it redundantly when called from ungetwc(), vfscanf() etc.,
which already set the orientation.

Remove duplicate check for EOF from ungetc(); __ungetc() already checks.

Basic support for wide character I/O: getwc(), fgetwc(), getwchar(),
putwc(), fputwc(), putwchar(), ungetwc(), fwide().

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove __P() usage.

Back out disabling ungetc() at 0, use different solution:
keep negative offset internally, but return 0 externally in ftell*()
I.e. use 0 now as 'unspecified value' per POSIX ungetc() description.

Disallow ungetc at offset 0 (to prevent negative offset happens), so simplify
checks in ftell.

Fix the current libc breakage in current:
o Back out the __std* stuff. Can't figure out how to do this right now,
so we'll save it for late.
o use _up as a pointer for extra fields that we need to access.
o back out the libc major version bump.

Submitted by: green
reviewed by: peter, imp, green, obrien (to varying degrees).

We'll fix the "how do we stop encoding sizeof(FILE) in binaries" part
later.

Remove _THREAD_SAFE and make libc thread-safe by default by
adding (weak definitions to) stubs for some of the pthread
functions. If the threads library is linked in, the real
pthread functions will pulled in.

Use the following convention for system calls wrapped by the
threads library:
__sys_foo - actual system call
_foo - weak definition to __sys_foo
foo - weak definition to __sys_foo

Change all libc uses of system calls wrapped by the threads
library from foo to _foo. In order to define the prototypes
for _foo(), we introduce namespace.h and un-namespace.h
(suggested by bde). All files that need to reference these
system calls, should include namespace.h before any standard
includes, then include un-namespace.h after the standard
includes and before any local includes. <db.h> is an exception
and shouldn't be included in between namespace.h and
un-namespace.h namespace.h will define foo to _foo, and
un-namespace.h will undefine foo.

Try to eliminate some of the recursive calls to MT-safe
functions in libc/stdio in preparation for adding a mutex
to FILE. We have recursive mutexes, but would like to avoid
using them if possible.

Remove uneeded includes of <errno.h> from a few files.

Add $FreeBSD$ to a few files in order to pass commitprep.

Approved by: -arch

$Id$ -> $FreeBSD$

Add FILE locking stubs for libc.

Change the FILE locking to support kernel threads when linked with
libpthread (which you haven't see yet). This requires that libc become
thread-safe and thread-aware, testing __isthreaded before attempting
to do lock/unlock calls. The impact on non-threaded programs is minor.
This change works with libc_r, so it's the best compromise.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Suggested by: Bruce Evans, Jeffrey Hsu, Gary Palmer

Added $Id$'s to files that were lacking them (gpalmer), made some
cosmetic changes to conform to style guidelines (bde) and checked
against NetBSD and Lite2 to remove unnecessary divergences (hsu, bde)

One last code cleanup:-

Removed spurious casts in fseek.c and stdio.c.
Added missing function argument in fwalk.c.
Added missing header include in flags.c and rget.c.
Put in casts where int's were being passed as size_t's.
Put in missing prototypes for static functions.
Changed second args of __sflags() inflags.c and writehook() in vasprintf.c
from char * to const char * to conform to prototypes.

This directory now compiles with no warnings with -Wall under
gcc-2.6.3 and with considerably less warnings than before with the
ultra-pedantic script I used for testing. (Most of the remaining ones
are due to const poisoning).

Reviewed by: julian and (hsu?)
Submitted by: John Birrel(L?)

changes for threadsafe operations

This commit was generated by cvs2svn to compensate for changes in r1573,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Lib Sources