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.
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.
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...
when it returns NULL to indicate failure, it will also free the memory
that was passed to it, if that was non-null.
This does not change the semantics of realloc.
A second commit will be done to commit the conversion of those places in
the code that can safely use this to avoid memory leaks when confronted
with low memory situations.
Beaten-to-death-but-finally-approved-in: -current
but also assumes that they are 32-bits. This is one place where I don't
think it is appropriate to change 'long' to 'int'. I don't see why the
code couldn't be fixed so that using natural long variables does the
right thing. It's spaggetti code so it'll take some effort. Obviously
NetBSD thought so too because they change 'long' to 'int32_t' etc
and left it at that. As a temporary measure FreeBSD/Alpha can use the
NetBSD code and put this on the list of things to fix.
libc to determine if locking is required. This is needed in libc
for use with kernel threads, but until a thread is created, we don't
really want to bother locking things. The variable was added here
because the crt code calls exit(main()) so all programs will get the
variable.
a malloc. The signal handler creates a thread which requires a malloc...
For now, the only thing to do is to block signals. When we move user
pthreads to use the kernel threads, mutexes will be implemented in kernel
space and then malloc can revert.
This fixes bugs in the manual handling. abs.[cS] was handled too
specially and the wrong (.c) variant for each of div.[cS], labs.[cS]
and ldiv.[cS] was added to SRCS. This caused the .c variant to be
used if `depend' was made and the .S version to be used otherwise.
Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru>
Various cleanup from Keith Bostic
Reinstate calloc() as a separate funtion, in its own source/object file.
leave the manpage integrated with malloc.3 and friends. Too many things
were broken in this respect.
PR: 4002
Reviewed by: phk
Submitted by: Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru>
Submitted by: Keith Bostic <bostic@bostic.com>
Various portability and stylistic cleanups.
Kill MALLOC_STATS & the 'D' option.
Fix the 'V' option.
Major overhaul of the man-page.
You milage should not vary.
Reviewed by: Keith Bostic <bostic@bostic.com>
Submitted by: Keith Bostic <bostic@bostic.com>
implement (better) falback code inside srandomdev() itself.
Change return type from int to void (binary compatibility surprisely
achieved). Userland code will be changed soon.
