I am currently trying to locate a memory leak that was introduced in
version 0.4.0 of the SMPEG code, and has persisted into the current
0.4.5 pre-release code that is currently in the cvs archive. smpeg
0.3.5 was the last version of code in which plaympeg didn’t seem to be
leaking. Specifically if you run plaympeg -l , and watch either
top or ps -avx you can see that each time the mpeg loops it gains a bit
of memory. This is also true when an mpeg object is deleted after a
new. I tried using valgrind, it didn’t reveal anything useful. It
actually didn’t believe a leak existed. However, watching DRS and RSS
rise in value through ps -avx, I think proves it wrong.
I am grasping at straws here, and am in need of some direction. Can
anyone point me in the right direction.
Thank you,
Robert
Assuming that you run on Linux you may not actually have a memory leak
here. I have stumbled over a similar phenomenon a while back and it hit
me even worse (about 150kB every few seconds in a long-running program).
In fact the program did not have any memory leak I could find. Instead
it turned out that memory got fragmented. All the memory block that get
malloc()ed and free()d are junks out of a single big memory segment that
is grown/shrunk by the brk() syscall. The malloc library is just a very
complex and optimized wrapper around this syscall.
This all means that memory can’t always be given up in situations like that:
int *i, *j;
i=malloc(1000*sizeof(int));
j=malloc(sizeof(int));
free(i);
If j got allocated “behind” i it doesn’t matter whether i gets freed or
not, since the existance of j blocks the heap from shrinking. If j is
freed later on the memory consumed by i will be given back to the
system, too.
Hope that helps.
Gregor
Robert Diel wrote:> I am currently trying to locate a memory leak that was introduced in
version 0.4.0 of the SMPEG code, and has persisted into the current
0.4.5 pre-release code that is currently in the cvs archive. smpeg
0.3.5 was the last version of code in which plaympeg didn’t seem to be
leaking. Specifically if you run plaympeg -l , and watch either
top or ps -avx you can see that each time the mpeg loops it gains a bit
of memory. This is also true when an mpeg object is deleted after a
new. I tried using valgrind, it didn’t reveal anything useful. It
actually didn’t believe a leak existed. However, watching DRS and RSS
rise in value through ps -avx, I think proves it wrong.
I am grasping at straws here, and am in need of some direction. Can
anyone point me in the right direction.
Thank you,
Robert
SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl