Commit Graph

10 Commits

Author SHA1 Message Date
Daniel Eischen
45d8008748 Hide the definition of struct __sFILEX and add the needed
lock definitions to it.  flockfile state is now allocated
along with the rest of FILE.  This eliminates the need for a
separate allocation of flockfile state as well as eliminating
the mutex/lock used to serialize its allocation.
2001-03-01 05:22:14 +00:00
Brian Feldman
75d4fd11cb Correctly handle the race itself, too (don't leave it locked).
This is about to be replaced anyway by initialization explicitly
instead of lazily, and reducing the complexity of it.  As it is
now, this will work fine, however.
2001-02-23 17:55:01 +00:00
Brian Feldman
93f9377a7c Use the right names to call pthread_mutex_{,un}lock so that things
work in both the libc only and libc/libc_r case.
2001-02-23 06:26:22 +00:00
Brian Feldman
4524204190 Fix the problems I (and others, undoubtedly) have been having for a
while with threaded software in -CURRENT acting very "weird".  It has
seemed, for example, in Mozilla that threads attempting to do host
lookups have been locking up.  That's exactly the case.

There was a race condition in the implementation of the initialization
of the mutex used to protect FILE operations, first of all: multiple
instances of FLOCKFILE() in libc could occur on the same FILE at
the same time and cause strange behavior by overwriting eachothers'
creation of the mutex and the rest of the file lock.

Secondly, it's not appropriate to test the "validity" of the file
descriptor referenced by the FILE; if the code is calling FLOCKFILE()
or FUNLOCKFILE(), it wants the FILE to be locked or unlocked, not
to be locked or unlocked on the condition that _file is >= 0.  This
also could quite easily cause leaks by failing to perform the lock or
unlock operation when it actually is needed.

Mozilla now works again on -CURRENT when linked to libc_r.so.5 and
libc.so.5.
2001-02-23 04:59:12 +00:00
Warner Losh
91e1be28dc 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.
2001-02-16 06:11:22 +00:00
Daniel Eischen
29ac6bd228 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
2001-02-11 22:06:43 +00:00
Daniel Eischen
d201fe46e3 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
2001-01-24 13:01:12 +00:00
Peter Wemm
7f3dea244c $Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00
John Birrell
4c717fd74d Remove leading underscores for the functions (weak symbols here) that
POSIX defines.
1998-05-05 21:56:42 +00:00
John Birrell
ec216c2634 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.
1998-04-11 07:40:47 +00:00