Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
If used with fopen(3)/fdopen(3)-ed FILEs, stdio accurately uses
non-cancellable internal versions of the functions, i.e. it seems to
be fine with regard to cancellation. But if the funopen(3) and
f{r,w}open(3) functions were used to open the FILE, and corresponding
user functions create cancellation points (they typically have no
other choice), then stdio code at least leaks FILE' lock.
The change installs cleanup handler which unlocks FILE. Some minimal
restructuring of the code was required to make it use common return
place to satisfy hand-rolled pthread_cleanup_pop() requirements.
Noted by: eugen
Reviewed by: eugen, vangyzen
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D11246
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
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
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.
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.
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).
