Archive for February 19th, 2007

InstantDump (JIT Process Dumper)

Monday, February 19th, 2007

Techniques utilizing user mode process dumpers and debuggers like Microsoft userdump.exe, NTSD or WinDbg and CDB from Debugging Tools for Windows are too slow to pick up a process and dump it. You need either to attach a debugger manually, run the command line prompt or switch to Task Manager. This deficiency was the primary motivation for me to use JIT (just-in-time) technology for process dumpers. The new tool, InstantDump, will dump a process instantly and non-invasively in a moment when you need it. How does it work? You point to any window and press hot key.

InstantDump could be useful to study hang GUI processes or to get several dumps of the same process during some period of time (CPU spiking case or memory leak, for example) or just dump the process for the sake of dumping it (for curiosity). The tool uses the same tooltip technology introduced in WindowHistory 4.0 to dynamically display window information.

Short user guide:

1. The program will run only on XP/W2K3/Vista (in fact it will not load on W2K).

2. Run InstantDump.exe on 32-bit system or InstantDump64.exe on x64 Windows. If you attempt to run InstantDump.exe on x64 Windows it will show this message box and quit:


3. InstantDump puts itself into task bar icon notification area:

4. By default when you move the mouse pointer over windows the tooltip follows the cursor describing the process and thread id and process image path (you can disable tips in Options dialog box):

5. If you hold Ctrl-RightShift-Break for less than a second then the process (which window is under the cursor) will be dumped according to the settings for external process dumper in options dialog (accessible via task bar icon right mouse click):


The saved dump name will be (in our Calculator window case): calc.exe_9f8(2552)_22-17-56_18-Feb-2007.dmp

Looks like there is no NTSD in Vista so you have to use another user mode dumper, for example, install MS userdump.exe and specify the following command line in Options dialog:

userdump.exe %d %s

or resort to WinDbg or CDB command line.

The tool can be downloaded from here.

The new version of this tool is under development that will automatically pick up a process name from Task Manager, Process Explorer or Process Monitor (in fact, from any tool that displays the list of processes) and then instantly dump it.

- Dmitry Vostokov -