Click here to Skip to main content
15,867,765 members
Articles / Desktop Programming / Win32

Full-Featured Task Manager for Windows Mobile

Rate me:
Please Sign up or sign in to vote.
5.00/5 (11 votes)
17 Feb 2008CPOL2 min read 70.4K   1.2K   53   11
A full-featured Task Manager for Windows Mobile.

Introduction

There are many task managers for Windows Mobile out there, but I've never seen one that shows how much memory is being used by each process. I found this odd until I started digging into why. Microsoft hasn't provided the standard APIs for querying for a process' memory usage because memory works differently on WM. Fortunately, they did provide the Toolhelp32 APIs. This article implements a Task Manager for Windows Mobile that utilizes the Toolhelp32 library to take a snapshot of the heap and tally the memory usage for every process.

Background

The company I work for recently implemented a new mobile email solution. I found my phone/PPC's memory was frequently around 1MB even though the Task Manager that comes with WM didn't list any running processes. I decided to write a quick utility to walk active processes, and found the built-in task manager was only displaying processes which had a main window. I turned that utility into version 0.5 which displayed all processes, let me kill them, etc. I still hadn't answered my question about which process was chewing up my memory and if it was associated with the new email solution. I was frustrated by the lack of APIs for finding memory usage statistics. I needed to know how much memory the processes associated with my company's email solution was using, so I dug deeper. What I've published here is my final solution.

Using the Code

I won't spend much time describing how the application as a whole works, it's pretty standard. There is a file named Toolhelp32.cs which contains all the P/Invoke signatures needed to use the Toolhelp32 library. Below is the block of code that does the grunt work.

C#
uint GetMemUsage(uint ProcId)
{
  uint MemUsage = 0;
  IntPtr hHeapSnapshot = 
   Toolhelp32.CreateToolhelp32Snapshot(Toolhelp32.TH32CS_SNAPHEAPLIST, ProcId);
  if (hHeapSnapshot != INVALID_HANDLE_VALUE)
  {
    Toolhelp32.HEAPLIST32 HeapList = new Toolhelp32.HEAPLIST32();
    HeapList.dwSize = (uint)Marshal.SizeOf(HeapList);
    if (Toolhelp32.Heap32ListFirst(hHeapSnapshot, ref HeapList))
    {
      do 
      {
        Toolhelp32.HEAPENTRY32 HeapEntry = new Toolhelp32.HEAPENTRY32();
        HeapEntry.dwSize = (uint)Marshal.SizeOf(HeapEntry);
        if (Toolhelp32.Heap32First(hHeapSnapshot, ref HeapEntry, 
                    HeapList.th32ProcessID, HeapList.th32HeapID))
        {
          do
          {
            MemUsage += HeapEntry.dwBlockSize;
          } while (Toolhelp32.Heap32Next(hHeapSnapshot, ref HeapEntry));
        }
      } while (Toolhelp32.Heap32ListNext(hHeapSnapshot, ref HeapList));
    } 
    Toolhelp32.CloseToolhelp32Snapshot(hHeapSnapshot);
  }
  return MemUsage;
}

CreateToolhelp32Snapshot creates a snapshot of processes, threads, heaps, and modules of a process. I pass in the TH32CS_SNAPHEAPLIST, telling it I want information about the heap list. Once I have the snapshot, I walk the heaplists with the Heap32ListFirst and Heap32ListNext calls. For each list, I walk the heap with Heap32First and Heap32Next, and add up the block sizes for each entry in each list. Voila, the total allocated blocks for a process.

Points of Interest

There are lots of great articles out there on memory management for WM. I wish I had saved them so I could post the links here. All I can say is memory management on WM, while not nearly as robust as for a desktop OS, is much more complicated. Read-up before attempting anything more than Hello World for WM. And yes, the new email solution was the culprit.

History

  • Initial version posted 02/14/2008 8:50PM (EST).

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
United States United States
This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Comments and Discussions

 
QuestionReal memory usage ? Pin
sir_zealot@go2.pl19-Aug-09 3:12
sir_zealot@go2.pl19-Aug-09 3:12 
Hello. I found this article very interesting but is it real memory ussage. I have downloaded MobileTaskManager for WidnowsCE and it shows different values. I think there should be some substraction from this memory ussage? Further more I am not able to see memory usage of NK.EXE process. I found that I may not have rights to see it. Is it possible ?

Thanks.
QuestionKill a process ?? Pin
GamePlanner17-Jul-09 5:57
GamePlanner17-Jul-09 5:57 
GeneralError Pin
PavanPareta22-Nov-08 0:07
PavanPareta22-Nov-08 0:07 
GeneralRe: Error Pin
Brian P. Adams1-Jun-09 6:19
Brian P. Adams1-Jun-09 6:19 
GeneralRe: regarding code Pin
User 226147410-Jul-08 13:39
User 226147410-Jul-08 13:39 
GeneralBuilding the project with VS2005 and removing OpenNETCF Pin
Jeoffman15-May-08 2:55
Jeoffman15-May-08 2:55 
GeneralRe: Building the project with VS2005 and removing OpenNETCF Pin
Gary Dobbins6-Jun-08 4:54
Gary Dobbins6-Jun-08 4:54 
GeneralRe: Building the project with VS2005 and removing OpenNETCF Pin
Jeoffman9-Jun-08 3:13
Jeoffman9-Jun-08 3:13 
GeneralVS2005 version Pin
fbausch10-Mar-08 6:10
fbausch10-Mar-08 6:10 
GeneralNice one Pin
gore0118-Feb-08 0:22
gore0118-Feb-08 0:22 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.