the thread kernel into a garbage collector thread which is started when
the fisrt thread is created (other than the initial thread). This
removes the window of opportunity where a context switch will cause a
thread that has locked the malloc spinlock, to enter the thread kernel,
find there is a dead thread and try to free memory, therefore trying
to lock the malloc spinlock against itself.
The garbage collector thread acts just like any other thread, so
instead of having a spinlock to control accesses to the dead thread
list, it uses a mutex and a condition variable so that it can happily
wait to be signalled when a thread exists.
launching an application into space when someone tries to debug it.
The dead thread list now has it's own link pointer, so use that when
reporting the grateful dead.
- Add support of a thread being listed in the dead thread list as well
as the thread list.
- Add a new thread state to make sigwait work properly. (Submitted by
Daniel M. Eischen <eischen@vigrid.com>)
- Add global variable for the garbage collector mutex and condition
variable.
- Delete a couple of prototypes that are no longer required.
- Add a prototype for the garbage collector thread.
realloc functions check for recursion within the malloc code itself. In
a thread-safe library, the single spinlock ensures that no two threads
go inside the protected code at the same time. The thread implementation
is responsible for ensuring that the spinlock does in fact protect malloc.
There was a window of opportunity in which this was not the case. I'll fix
that with a commit RSN.
disks.
* Fix a whole raft of warnings, printf and otherwise.
* Make zalloc work for alpha (just a case of using the right typedef).
* Add some (disabled) malloc debug printing to stand.h.
compact and much better one donated by Matt Dillon. Implement a simple
sbrk() which uses the existing setheap() api.
Remove the custom allocator from the UFS code. It wasn't working quite
right, and it shouldn't be needed with the new allocator.
Fix a serious problem with changing the value of already-existent
environment variables. Don't attempt to modify the supposedly-const
argument to putenv()
Fix an off-by-one sizing error in the zipfs code detected by the new
allocator.
Submitted by: zmalloc from Matt Dillon <dillon@backplane.com>
string. From the submitted patch:
Credit for patch: Chris Torek <torek@bsdi.com>
Tod Miller <millert@openbsd.org>
This makes us in line with SunOS 4.1.3_U1, Solaris 2.6, OpenBSD 2.3,
HP-UX 10.20, Irix 5.3. The previous behavior was in line with Ultrix 4.4.
PR: bin/7970
Submitted by: Niall Smart nialls@euristix.ie
Our spinlock implementation allows a particular thread to obtain a lock
multiple times, but release the lock with a single unlock call. Since
we're detecting recursion, we know the lock is already owned by the
current thread in a previous call and must not be released in the
current call. This is really far too dependent on this particular
spinlock implementation, so I've added commented out calls to
THREAD_UNLOCK in the appropriate places. We can activate this code when
spinlock is taught to count each lock operation.
generation was causing unaligned access faults on the Alpha.
I have incremented the devstat version number, since this is an interface
change. You'll need to recompile libdevstat, systat, iostat, vmstat and
rpc.rstatd along with your kernel.
Partially Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
The functions that were being compiled into the library have been moved to
scsi_all.c.
One warning: Any programs using scsi_start_stop() or scsi_read_write()
that included scsi_da.h but not scsi_all.h will need to be
changed to include scsi_all.h. This doesn't affect
camcontrol, and I don't think it affects any ports, but you
never know.
PR: kern/7969
Reviewed by: gibbs
In some cases replace if (a == null) a = malloc(x); else a =
realloc(a, x); with simple reallocf(a, x). Per ANSI-C, this is
guaranteed to be the same thing.
I've been running these on my system here w/o ill effects for some
time. However, the CTM-express is at part 6 of 34 for the CAM
changes, so I've not been able to do a build world with the CAM in the
tree with these changes. Shouldn't impact anything, but...
