Windows Mobile Troubleshooting - How to log like a developer
After writing up my last blog article about Windows Mobile troubleshooting and logging utilities (see it again here), I was more closely at the lookout for other tools and tricks that might help assist in a similar fashion.. Of course I found some more good additional information and have included it in this round.. :-)
.NET Compact Framework Logging
On Steve Hegenderfer and Reed Robinson's excellent blog Reed posted a great article about how to enable .NET CF loader logs and what to look out for. Specifically referencing this MSDN information on how to enable the logging: http://msdn.microsoft.com/en-us/library/ms229650.aspx. It is all controlled in specific registry keys on the device to enable 6 different flavors of .NET CF logging: "Interop", "Error", "Loader", "Network", "Finalizer", or "Trace".
The Power Toys for .NET Compact Framework v3.5 download gives you additional tools to make this easier. One is the Remote Logging Configuration Tool:
So the most interesting for non-developers trying to troubleshoot .NET CF applications is probably the "Loader" logging. This is where you can see if the application even makes it off the ground and why. As Reed suggests in the article I mentioned it could be referencing a .NET assembly not present on the device for whatever reason..
Additional details on how to read the "Loader" logging can be found here: http://msdn.microsoft.com/en-us/library/ms229667.aspx.
File System Logging
This is a type of extreme logging that can really slow down a working operating system. But it can also show you exactly what is going on at the file I/O level. Specifically what files are being accessed or written to. This could be useful to trace back missing files or folders, or figuring out the last file access a specific application did before failing.
I only recently found a tool called MobileMon v0.5 by Brian Dunn. His website, http://www.mobilmon.com/, has more information and you can download the .CAB file there.
Basically you can install and run it in the background while it logs file activity.
Once you are done you can save it to a log file. Be aware however that the file name "mobilmon.log" may be hard to open on the device itself unless you install a tool (Like Voyager or Total Commander) to rename the file to mobilmon.txt. Then you can open it with the native Word Mobile.
Memory Management and Monitoring
Another important area of concern for current Windows Mobile troubleshooting is available memory on the device. Memory leaks, multiple running applications, and garbage heaps can all attribute to doing frequent soft-reboots to get a device functional again. A little known fact that I wasn’t fully aware of is that only 32 applications (actually processes) can run at the same time and each can at a maximum access 32mb of virtual memory..
An excellent resource of a virtual memory management overview is William Blanke’s article: http://www.codeproject.com/KB/mobile/VirtualMemory.aspx
In it he also has a small (12Kb) Virtual Memory tool (must register to download, the compiled .exe in included with the source code) you can run and visually see available memory (in red) for each of the 32 process slots.
Issue #1: One key thing apart from seeing how many of the slots are being used and if they are full, is finding the “device.exe” process. This process is responsible for loading up all the device drivers and William points out the potential issues if memory is low for this slot. Specific device features may simply not work.
Issue #2: Another area of concern could be applications that load up .DLL files. These can be loaded up in *any* processing slot and can be accessed by any process. This can be bad if your process or application running in the slot needs the memory and doesn’t use the particular DLL.
However William doesn’t address that in Windows Mobile 6.1 specific changes were made to better accommodate DLL files over 64Kb. These will now be loaded into specific slots higher and away from the process slots. Thus freeing up application space and reducing this potential worry. Please see more information on this 6.1 feature from Doug Boling here.
How sure if anything has/will change in Windows Mobile 6.5 as of yet. What we can look forward to is Windows Mobile 7.0 (which is based upon Windows CE 6.0) and it’s larger scale advanced memory management, explained in more detail here or here. But basically a little like Windows XP, and a limit of 32K processes and 2GB per process, compared to 32 and 32Mb per process. :-)
Issue #3: Careful on the usage of storage cards to install or run applications from. If the device goes into hibernation or sleep mode, it could power down the storage card and render any application housed there non-functional. See more tips here.
Some older reference links on Windows Mobile memory management:
- RAM, ROM and Task Managers
- How WM 5.0 Shell Handles Low Memory Situations
- Memory Management on WM 6.x
- MSDN Webcast: Memory Management for Windows Mobile
- DumpMem Utility
- NETCF: Memory leak... now what??
Update March 20, 2009: If you are using a Motorola/Symbol ruggedized device you also may want to ask your Motorola rep about their “Private SDK” and a tool called the “Remote Memory Viewer”. It may also be beneficial as Raffaele Limosani states here..
Hope this article further assists in troubleshooting Windows Mobile issues you might run into!
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