For a project I have made several message flows in Websphere Message Broker 7.
One of these flows is quite a complicated flow with lots of database calls and transformations. However, it performs correctly and rather quickly given what it needs to do.
The problem is that while it is active, it consumes more and more resources, until the broker runs out of memory. Even if I use a small test case and it is able to complete before it crashes anything, the resources are not released. In this case, I can confirm the output of the flow (which is fine), but operations reported that it keeps consuming memory.
So, I guess a memory leak. I have no idea how and where to find it. Could anyone point me in a direction where to look?
If additional information is necessary, just ask. I would prefer not to put the entire compute node in this thread due to its size.
That you are having high memory consumption even after the processing is done makes me think that your message flow has some kind of state, that is stored in memory via shared or static variables.
You might be saving a lot of data in shared variables in ESQL, or static variables in Java in your flow.
Or if you are using JavaComputes, you might leak resources like ResultSets.
Or it could be some bug, you should check for known and fixed leaks in the fix packs issued for V7:
http://www-01.ibm.com/support/docview.wss?&uid=swg27019145
As stated in my comment above, a DataFlowEngine never releases its resources after completion.
This is the thread of IBM explaining the matter (bullet 8):
http://www-01.ibm.com/support/docview.wss?uid=swg21665926#8
Apart from that, the real issue seemed to be the use of Environment-variables inside a loop, which consumed a lot of memory. Deleting the variables after use is a good practice I can recommend.
Related
Sometimes, I want to use lua_pushstring in places after I allocated some resources which I would need to cleanup in case of failure. However, as the documentation seems to imply, lua_push* functions can always end up with an out of memory exception. But that exception instant-quits my C scope and doesn't allow me to cleanup whatever I might have temporarily allocated that might have to be freed in case of error.
Example code to illustrate the situation:
void* blubb = malloc(20);
...some other things happening here...
lua_pushstring(L, "test"); //how to do this call safely so I can still take care of blubb?
...possibly more things going on here...
free(blubb);
Is there a way I can check beforehand if such an exception would happen and then avoid pushing and doing my own error triggering as soon as I safely cleaned up my own resources? Or can I somehow simply deactivate the setjmp, and then check some "magic variable" after doing the push to see if it actually worked or triggered an error?
I considered pcall'ing my own function, but even just pushing the function on the stack I want to call safely through pcall can possibly give me an out of memory, can't it?
To clear things up, I am specifically asking this for combined use with custom memory allocators that will prevent Lua from allocating too much memory, so assume this is not a case where the whole system has run out of memory.
Unless you have registered a user-defined memory handler with Lua when you created your Lua state, getting an out of memory error means that your entire application has run out of memory. Recovery from this state is generally not possible. Or at least, not feasible in a lot of cases. It could be depending on your application, but probably not.
In short, if it ever comes up, you've got bigger things to be concerned about ;)
The only kind of cleanup that should affect you is for things external to your application. If you have some process global memory that you need to free or set some state in. You're doing interprocess communication and you have some memory mapped file you're talking though. Or something like that.
Otherwise, it's probably better to just kill your process.
You could build Lua as a C++ library. When you do that, errors become actual exceptions, which you can either catch or just use RAII objects to handle.
If you're stuck with C... well, there's not much you can do.
I am specifically interested in a custom allocator that will out of memory much earlier to avoid Lua eating too much memory.
Then you should handle it another way. To signal an out-of-memory error is basically to say, "I want Lua to terminate right now."
The way to stop Lua from eating memory is to periodically check the Lua state's memory, and garbage collect it if it's using too much. And if that doesn't free up enough memory, then you should terminate the Lua state manually, but only when it is safe to do so.
lua_atpanic() may be one solution for you, depending on the kind of cleanup you need to do. It will never throw an error.
In your specific example you could also create blubb as a userdata. Then Lua would free it automatically when it left the stack.
I have recently gotten into some more Lua sandboxing again, and now I think the answer I accepted previously is a bad idea. I have given this some more thought:
Why periodic checking is not enough
Periodically checking for large memory consumption and terminating Lua "only when it is safe to do so" seems like a bad idea if you consider that a single huge table can eat up a lot of your memory with one single VM instruction about which you'll only find out after it happened - where your program might already be dying from it, and then you indeed have much bigger problems which you could have avoided entirely if you had stopped that allocation in time in the first place.
Since Lua has a nice out of memory exception already built-in, I would just like to use that one since this allows me to do the minimal required thing (preventing the script from allocating more stuff, while possibly allowing it to recover) without my C code breaking from it.
Therefore my current plan for Lua sandboxing with memory limit is:
Use custom allocator that returns NULL with limit
Design all C functions to be able to handle this without memory leak or other breakage
But how to design the C functions safely?
How to do that, since lua_pushstring and others can always setjmp away with an error without me knowing whether that is gonna happen in advance? (this was originally my question)
I think I found a working approach:
I added a facility to register pointers when I allocate them, and where I unregister them after I am done with them. This means if Lua suddenly setjmp's me out of my C code without me getting a chance to clean up, I have everything in a global list I need to clean up that mess later when I'm back in control.
Is that ugly or what?
Yes, it is quite the hack. But, it will most likely work, and unlike 'periodic checking' it will actually allow me to have a true hard limit and avoid getting the application itself trouble because of an aggressive attack.
Is there a way to access (read or free) memory chunks that are outside the memory that is allocated for the program without getting access violation exceptions.
Well what I actually would like to understand apart from this, is how a memory cleaner (system garbage collector) works. I've always wanted to write such a program. (The language isn't an issue)
Thanks in advance :)
No.
Any modern operating system will prevent one process from accessing memory that belongs to another process.
In fact, it you understood virtual memory, you'd understand that this is impossible. Each process has its own virtual address space.
The simple answer (less I'm mistaken), no. Generally it's not a good idea for 2 reasons. First is because it causes a trust problem between your program and other programs (not to mention us humans won't trust your application either). second is if you were able to access another applications memory and make a change without the application knowing about it, you will cause the application to crash (also viruses do this).
A garbage collector is called from a runtime. The runtime "owns" the memory space and allows other applications to "live" within that memory space. This is why the garbage collector can exist. You will have to create a runtime that the OS allocates memory to, have the runtime execute the application under it's authority and use the GC under it's authority as well. You will need to allow some instrumentation or API that allows the application developer to "request" memory from your runtime (not the OS) and your runtime have a way to not only response to such a request but also keep track of the memory space it's allocating to that application. You will probably need to have a framework (set of DLL's) that makes these calls available to the application (the developer would use them to form the request inside their application).
You have to be sure that your garbage collector does not remove memory other then the memory that is used by the application being executed, as you may have more then 1 application running within your runtime at the same time.
Hope this helps.
Actually the right answer is YES.. there are some programs that does it (and if they exists.. it means it is possible...)
maybe you need to write a kernel drive to accomplish this, but it is possible.
Oh - and I have another example... Debugger attach command... here is one program that interacts with another program memory even though both started as a different process....
of course - messing with another program memory.. if you don't know what you're doing will probably make it crush...
Question:
Is there an easy way to get a list of types of resources that leak in a running application? IOW by connecting to an application ?
I know memproof can do it, but it slows down so much that the application won't even last a minute. Most taskmanager likes can show the number, but not the type.
It is not a problem that the check itself is catastrophic (halts the app process), since I can check with a taskmgr if I'm getting close (or at least I hope)
Any other insights on resource leak hunting (so not memory) is also welcomed.
Background:
I've an Delphi 7/2006/2009 app (compiles with all three) and after about a few week it starts acting funny. However only on one of the places it runs, on several other systems it runs till the power goes out.
I've tried to put in some debug code to narrow the problem down. and found out that the exception is EOutofResources on a save of a file. (the file save can happen thousands of times a day).
I have tried to reason out memory leaks (with fastmm), but since the dataflow is quite high (60MByte/s from gigabit industrial camera's), I can only rule out "creeping" memory leaks with fastmm, not quick flashes of memoryleaks that exhaust memory around the time it happens. If something goes wrong, the app fills memory in under half a minute.,
Main suspects are filehandles that are somehow left on some error and TMetafiles (which are streamed to these files). Minor suspects are VST, popupmenu and tframes
Updates:
Another possible tip: It ran fine for two years with D7, and now the problems are with Turbo Explorer (which I use for stable projects not converted to D2009 ).
Paul-Jan: Since it only happens once a week (and that can happen at night), information acquisition is slow. Which is why I ask this question, need to combine stuff for when I'm there thursday. In short: no I don't know 100% sure. I intend to bring the entire Systemtools collection to see if I can find something (because then it will be running for days). There is also a chance that I see open files. (maybe should try to find some mingw lsof and schedule it)
But the app sees very little GUI action (it is an machine vision inspection app), except screen refresh +/- 15/s which is tbitmap stretchdraw + tmetafile, but I get this error when saving to disk (TFileStream) handles are probably really exhausted. However in the same stream, TMetafile is also savetostreamed, something which later apps don't have anymore, and they can run from months.
------------------- UPDATE
I've searched and searched and searched, and managed to reproduce the problems in-vitro two or three times. The problems happened when memusage was +/- 256MB (the systems have 2GB), user objects 200, gdi objects 500, not one file more open than expected ).
This is not really exceptional. I do notice that I leak small amounts of handles, probably due to reparenting frames (something in the VCL seems to leak HPalette's), but I suspect the core cause is a different problem. I reuse TMetafile, and .clear it inbetween. I think clearing the metafile doesn't really (always?) resize the resource, eventually each metafile in the entire pool of tmetafile at maximum size, and with 20-40+ tmetafiles (which can be several 100ks each) this will hit the desktop heap limit.
That's theory, but I'll try to verify this by setting the desktop limit to 10MB at the customers, but it will be several weeks before I have confirmation if this changes anything. This theory also confirms why this machine is special (it's possible that this machine naturally has slightly larger metafiles on average). Occasionally freeing and recreating a tmetafile in the pool might also help.
Luckily all these problems (both tmetafile and reparenting) have already been designed out in newer generations of the apps.
Due to the special circumstances (and the fact that I have very limited test windows), this is going to be a while, but I decided to accept the desktop heap as an example for now (though the GDILeaks stuff was also somewhat useful).
Another thing that the audit revealed GDI-types usage in a thread (though only saving tmetafiles (that weren't used or connected otherwise) to streams.
------------- Update 2.
Increasing the desktop limit only seemed to minorly increase the time till the problem occurred.
Unfortunately, I won't be able to follow up on this further, since the machines were updated to a newer version of the framework that doesn't have the problem.
In summary I can only state what the three core modifications were going from the old to the new framework:
I no longer change screens by reparenting frames. I now work with forms that I hide and show. I changed this since I also had very rare crashes or exceptions (that could be clicked away) due to this. The crashes were all while operating the GUI though, not spontaneously like the main problem
The routine where the crash happened dealt with TMetafile. TMetafile has been designed out, and replace by a simpler own made format. (basically arrays with Opengl vertices)
Drawing no longer happened with tbitmap with a tmetafile overlay strechdrawn over it, but using OpenGL.
Of course it could be something else too, that got changed in the rewrite of the above parts, fixing some very nasty detail bug. It would have to be an extremely bad one, since I analysed the above system as much as I could.
Updated nov 2012 after some private mail discussion: In retrospect, the next step would have been adding a counter to the metafiles objects, and simply reinstantiate them every x * 1000 uses or so, and see if that changes anything. If you have similar problems, try to see if you can somewhat regularly destroy and reinitialize long living resources that are dynamically allocated.
There is a slim chance that the error is misleading. The VCL naively reports EOutOfResources if it is unable to obtain a DC for a window (see TWinControl.GetDeviceContext in Controls.pas).
I say "naively" because there are other reasons why GetDC() might return a NULL handle and the VCL should report the OS error, not assume an out of resources condition (there is a Windows version check required for this to be reliably possible, but the VCL could and should take of that too).
I had a situation where I was getting the EOutOfResources error as the result of a window handle becoming invalid. Once I'd discovered the true problem, finding the cause and fixing it was simple, but I wasted many, many hours trying to find a non-existent resource leak.
If possible I would examine the stack trace leading to this exception - if it is coming from TWinControl.GetDeviceContext then the problem may not be what you think (it's impossible to say what it might be of course, but eliminating the impossible is always the first step toward discovering the solution, no matter how improbable).
If they are GDI handle leaks you can have a look at MSDN Magazine January 2003 which uses the tool GDILeaks. Other tools are GDIObj or GDIView. Also see here.
Another source of EOutOfResources could be that the Desktop Heap is full. I've had that issue on busy terminal servers with large screens.
If there are lots of file handles you are leaking you could check out Process Explorer and have a look at the open file handles of your process and see any out of the ordinary. Or use WinDbg with the !htrace command.
I've run into this problem before. From what I've been able to tell, Delphi may throw an EOutOfResources any time the Windows API returns ERROR_NOT_ENOUGH_MEMORY, and (as the other answers here discuss) Windows may return ERROR_NOT_ENOUGH_MEMORY for a variety of conditions.
In my case, EOutOfResources was being caused by a TBitmap - in particular, TBitmap's call to CreateCompatibleBitmap, which it uses with its default PixelFormat of pfDevice. Apparently Windows may enforce fairly strict systemwide limits on the memory available for device-dependent bitmaps (see, e.g, this discussion), even if your system otherwise has plenty of memory and plenty of GDI resources. (These systemwide limits are apparently because Windows may allocate device-dependent bitmaps in the video card's memory.)
The solution is simply to use device-independent bitmaps (DIBs) instead (although these may not offer quite as good of a performance). To do this in Delphi, set TBitmap.PixelFormat to anything other than pfDevice. This KB article describes how to pick the optimal DIB format for a device, although I generally just use pf32Bit instead of trying to determine the optimal format for each of the monitors the application is displayed on.
Most of the times I saw EOutOfResources, it was some sort of handle leak.
Did you try something like MadExcept?
--jeroen
"I've tried to put in some debug code to narrow the problem down. and found out that the exception is EOutofResources on a save of a file. (the file save can happen thousands of times a day)."
I'm shooting in the dark here, but could it be that you're using the Windows API to (GetTempFileName) create a temp file and you're blowing out some file system indexes or forgetting to close a file handle?
Either way, I do agree that with your supposition about it being a file handle problem. That seems to be the most likely thing given your symptoms and diagnosis.
Also try to check handle count for the application with Process Explorer from SysInternals. Handle leaks can be very dangerous and they build slowly through time.
I am currently having this problem, in software that is clearly not leaking any handles in my own code, so if there are leaks they could be happening in a component's source code or the VCL sourcecode itself.
The handle count and GDI and user object counts are not increasing, nor is anything being created. Deltic's answer shows corner cases where the message is kind of a red-herring, and Allen suggests that even a file write can cause this error.
So far, The best strategy I have found for hunting them down is to use either JCL JCLDEBUG stack tracebacks, or the exception report save features in MadExcept to generate the context information to find out what is actually failing.
Secondly, AQTime contains many tools to help you, including a resource profiler that can keep the links between where the code that created the resources is, and how it was called, along with counts of the total numbers of handles. It can grab results MID RUN and so it is not limited to detecting unfreed resources after you exit. So, run AQTime, do a results capture in mid run, wait several hours, and capture again, and you should have two points in time to compare handle counts. Just in case it is the obvious thing. But as Deltics wisely points out, this exception class is raised in cases where it probably shouldn't have been.
I spent all of today chasing this issue down. I found plenty of helpful resources pointing me in the direction of GDI, with the fact that I'm using GDI+ to produce high-speed animations directly onto the main form via timer/invalidate/onpaint (animation performed in separate thread). I also have a panel in this form with some dynamically created controls for the user to make changes to the animation.
It was extremely random and spontaneous. It wouldn't break anywhere in my code, and when the error dialog appeared, the animation on the main form would continue to work. At one point, two of these errors popped up at the same time (as opposed to sequential).
I carefully observed my code and made sure I wasn't leaking any handles related to GDI. In fact, my entire application tends to keep less than 300 handles, according to Task Manager. Regardless, this error would randomly pop up. And it would always correspond with the simplest UI related action, such as just moving the mouse over a standard VCL control.
Solution
I believe I have solved it by changing the logic to performing the drawing within a custom control, rather than directly to the main form as I had been doing before. I think the fact that I was rapidly drawing on the same form canvas which shared other controls, somehow they interfered. Now that it has its own dedicated canvas to draw on, it seems to be perfectly fixed.
That is with about 1 hour of vigorous testing at least.
[Fingers crossed]
I have detected a memory corruption in my embedded environment (my program is running on a set top box with a proprietary OS ). but I couldn't get the root cause of it.
the memory corruption , itself, is detected after a stress test of launching and exiting an application multiple times. giving that I couldn't set a memory break point because the corruptued variable is changing it's address every time that the application is launched, is there any idea to catch the root cause of this corruption?
(A memory break point is break point launched when the environment change the value of a giving memory address)
note also that all my software is developed using C language.
Thanks for your help.
These are always difficult problems on embedded systems and there is no easy answer. Some tips:
Look at the value the memory gets corrupted with. This can give a clear hint.
Look at datastructures next to your memory corruption.
See if there is a pattern in the memory corruption. Is it always at a similar address?
See if you can set up the memory breakpoint at run-time.
Does the embedded system allow memory areas to be sandboxed? Set-up sandboxes to safeguard your data memory.
Good luck!
Where is the data stored and how is it accessed by the two processes involved?
If the structure was allocated off the heap, try allocating a much larger block and putting large guard areas before and after the structure. This should give you an idea of whether it is one of the surrounding heap allocations which has overrun into the same allocation as your structure. If you find that the memory surrounding your structure is untouched, and only the structure itself is corrupted then this indicates that the corruption is being caused by something which has some knowledge of your structure's location rather than a random memory stomp.
If the structure is in a data section, check your linker map output to determine what other data exists in the vicinity of your structure. Check whether those have also been corrupted, introduce guard areas, and check whether the problem follows the structure if you force it to move to a different location. Again this indicates whether the corruption is caused by something with knowledge of your structure's location.
You can also test this by switching data from the heap into a data section or visa versa.
If you find that the structure is no longer corrupted after moving it elsewhere or introducing guard areas, you should check the linker map or track the heap to determine what other data is in the vicinity, and check accesses to those areas for buffer overflows.
You may find, though, that the problem does follow the structure wherever it is located. If this is the case then audit all of the code surrounding references to the structure. Check the contents before and after every access.
To check whether the corruption is being caused by another process or interrupt handler, add hooks to each task switch and before and after each ISR is called. The hook should check whether the contents have been corrupted. If they have, you will be able to identify which process or ISR was responsible.
If the structure is ever read onto a local process stack, try increasing the process stack and check that no array overruns etc have occurred. Even if not read onto the stack, it's likely that you will have a pointer to it on the stack at some point. Check all sub-functions called in the vicinity for stack issues or similar that could result in the pointer being used erroneously by unrelated blocks of code.
Also consider whether the compiler or RTOS may be at fault. Try turning off compiler optimisation, and failing that inspect the code generated. Similarly consider whether it could be due to a faulty context switch in your proprietary RTOS.
Finally, if you are sharing the memory with another hardware device or CPU and you have data cache enabled, make sure you take care of this through using uncached accesses or similar strategies.
Yes these problems can be tough to track down with a debugger.
A few ideas:
Do regular code reviews (not fast at tracking down a specific bug, but valuable for catching such problems in general)
Comment-out or #if 0 out sections of code, then run the cut-down application. Try commenting-out different sections to try to narrow down in which section of the code the bug occurs.
If your architecture allows you to easily disable certain processes/tasks from running, by the process of elimination perhaps you can narrow down which process is causing the bug.
If your OS is a cooperative multitasking e.g. round robin (this would be too hard I think for preemptive multitasking): Add code to the end of the task that "owns" the structure, to save a "check" of the structure. That check could be a memcpy (if you have the time and space), or a CRC. Then after every other task runs, add some code to verify the structure compared to the saved check. This will detect any changes.
I'm assuming by your question you mean that you suspect some part of the proprietary code is causing the problem.
I have dealt with a similar issue in the past using what a colleague so tastefully calls a "suicide note". I would allocate a buffer capable of storing a number of copies of the structure that is being corrupted. I would use this buffer like a circular list, storing a copy of the current state of the structure at regular intervals. If corruption was detected, the "suicide note" would be dumped to a file or to serial output. This would give me a good picture of what was changed and how, and by increasing the logging frequency I was able to narrow down the corrupting action.
Depending on your OS, you may be able to react to detected corruption by looking at all running processes and seeing which ones are currently holding a semaphore (you are using some kind of access control mechanism with shared memory, right?). By taking snapshots of this data too, you perhaps can log the culprit grabbing the lock before corrupting your data. Along the same lines, try holding the lock to the shared memory region for an absurd length of time and see if the offending program complains. Sometimes they will give an error message that has important information that can help your investigation (for example, line numbers, function names, or code offsets for the offending program).
If you feel up to doing a little linker kung fu, you can most likely specify the address of any statically-allocated data with respect to the program's starting address. This might give you a consistent-enough memory address to set a memory breakpoint.
Unfortunately, this sort of problem is not easy to debug, especially if you don't have the source for one or more of the programs involved. If you can get enough information to understand just how your data is being corrupted, you may be able to adjust your structure to anticipate and expect the corruption (sometimes needed when working with code that doesn't fully comply with a specification or a standard).
You detect memory corruption. Could you be more specific how? Is it a crash with a core dump, for example?
Normally the OS will completely free all resources and handles your program has when the program exits, gracefully or otherwise. Even proprietary OSes manage to get this right, although its not a given.
So an intermittent problem could seem to be triggered after stress but just be chance, or could be in the initialisation of drivers or other processes the program communicates with, or could be bad error handling around say memory allocations that fail when the OS itself is under stress e.g. lazy tidying up of the closed programs.
Printfs in custom malloc/realloc/free proxy functions, or even an Electric Fence -style custom allocator might help if its as simple as a buffer overflow.
Use memory-allocation debugging tools like ElectricFence, dmalloc, etc - at minimum they can catch simple errors and most moderately-complex ones (overruns, underruns, even in some cases write (or read) after free), etc. My personal favorite is dmalloc.
A proprietary OS might limit your options a bit. One thing you might be able to do is run the problem code on a desktop machine (assuming you can stub out the hardware-specific code), and use the more-sophisticated tools available there (i.e. guardmalloc, electric fence).
The C library that you're using may include some routines for detecting heap corruption (glibc does, for instance). Turn those on, along with whatever tracing facilities you have, so you can see what was happening when the heap was corrupted.
First I am assuming you are on a baremetal chip that isn't running Linux or some other POSIX-capable OS (if you are there are much better techniques such as Valgrind and ASan).
Here's a couple tips for tracking down embedded memory corruption:
Use JTAG or similar to set a memory watchpoint on the area of memory that is being corrupted, you might be able to catch the moment when memory being is accidentally being written there vs a correct write, many JTAG debuggers include plugins for IDEs that allow you to get stack traces as well
In your hard fault handler try to generate a call stack that you can print so you can get a rough idea of where the code is crashing, note that since memory corruption can occur some time before the crash actually occurs the stack traces you get are unlikely to be helpful now but with better techniques mentioned below the stack traces will help, generating a backtrace on baremetal can be a very difficult task though, if you so happen to be using a Cortex-M line processor check this out https://github.com/armink/CmBacktrace or try searching the web for advice on generating a back/stack trace for your particular chip
If your compiler supports it use stack canaries to detect and immediately crash if something writes over the stack, for details search the web for "Stack Protector" for GCC or Clang
If you are running on a chip that has an MPU such as an ARM Cortex-M3 then you can use the MPU to write-protect the region of memory that is being corrupted or a small region of memory right before the region being corrupted, this will cause the chip to crash at the moment of the corruption rather than much later
We have an application with hundreds of possible user actions, and think about how enhancing memory leak testing.
Currently, here's the way it happens: When manually testing the software, if it appears that our application consumes too much memory, we use a memory tool, find the cause and fix it. It's a rather slow and not efficient process: the problems are discovered late and it relies on the good will of one developer.
How can we improve that?
Internally check that some actions (like "close file") do recover some memory and log it?
Assert on memory state inside our unit tests (but it seems this would be a tedious task) ?
Manually regularly check it from time to time?
Include that check each time a new user story is implemented?
Which language?
I'd use a tool such as Valgrind, try to fully exercise the program and see what it reports.
first line of defense:
check list with common memory
allocation related errors for
developers
coding guidelines
second line of defense:
code reviews
static code analyis (as a part of build process)
memory profiling tools
If you work with unmanaged language (like C/C++) you can efficiently discover most of the memory leaks by hijacking memory management functions. For example you can track all memory allocations/deallocations.
It seems to me that the core of the problem is not so much finding memory leaks as knowing when to test for them. You say you have lots of user actions, but you don't say what sequences of user actions are meaningful. If you can generate meaningful sequences at random, I'd argue hard for random testing. On random tests you would measure
Code coverage (with gcov or valgrind)
Memory usage (with valgrind)
Coverage of the user actions themselves
By "coverage of user actions" I mean statements like the following:
For every pair of actions A and B, if there is a meaningful sequence of actions in which A is immediately followed by B, then we have tested such a sequence.
If that's not true, then you can ask for what fraction of pairs A and B it is true.
If you have the CPU cycles to afford it, you would probably also benefit from running valgrind or another memory-checking tool either before every commit to your source-code repository or during a nightly build.
Automate!
In my company we have programmed an endless action path for our application. The java garbage collector should clean all unused maps and list and something like that. So we let the application start with the endless action path and look, whether the memory use size is growing.
The check which fields are not deleted you can use JProfiler for Java.
Replace new and delete with your custom versions and log every act of allocation/deallocation.
Speaking generally (not about testing, rather to fight the issue in its origin), smartpointers help to avoid this problem. Fortunately, C++11 standard provides new convenient smart pointer classes (shared_ptr, unique_ptr).