SOAP in PHP

See: http://www.perl.com/pub/2001/01/soap.html
SOAP server: server.cgi

#!/usr/bin/perl -w
use SOAP::Transport::HTTP;

SOAP::Transport::HTTP::CGI     
    -> dispatch_to('Demo')       
    -> handle;

package Demo;

sub hi {                       
    return "hello, world\n";       
}

sub languages {                
    return ("Perl", "C", "sh");  
}

SOAP client: client.pl

#!/usr/bin/perl -w
use SOAP::Lite;

$s = SOAP::Lite
    -> uri('http://localhost/Demo')
    -> proxy('http://localhost/DFetch_stamp/tmp/hibye.cgi')
    -> hi()
    -> result; # can use result() too.

print $s;

Now run: perl client.pl, you can see the output.

Other notes:
- multiple line comments in perl: start with "=pod", end with "=cut".

MSSQL management

- Log file size can grow very large. So its max size should be set at the beginning.
- If a log file is already too large, need to shrink/trunk it: 1) right click -> properties -> options (set recovery mode to simple), 2) Tasks > Shrink > Database (specify size to shrink to, and do it), 3) right click -> properties -> options (set recovery mode to full).
- Set default memory usage: right click on instance, choose memory.
- Get size of tables. See here for example. Below command will show size of data, index, reserved and free.

  EXEC sp_spaceused [table name]

Gordon Moore - An inspiration

Gordon Moore co-funded Intel, is the author of the Moore's law, and with his wife endowed the Gordon and Betty Moore Foundation to support many higher education and research projects, including $3M to the one I'm working for right now.

He is an inspiration. This post is dedicated to him.

Monitor process memory and CPU usage in C#

There are relevant libraries to monitor process memory and CPU usage.

[1] Process Class
[2] How to get CPU usage of processes and threads
[3] Pushing the Limits of Windows: Physical Memory

It's a little confusing with multiple functions on memory usage, but WorkingSet64() is one that can be used.

Multi-threading with C#

Ok, I worked on multi-threaded applications in C# in the past. Now I'm back to do something again.

Some notes:

1. Below 2 are the same for C# 2.0 and after, ThreadStart can be omitted (but can be useful say when you want to start a group of functions):

    1) Thread newThread = new Thread(new ThreadStart(this.checkProcesses)); 
    2) Thread newThread = new Thread(this.checkProcesses); 

2. The new thread by default is not a background process, which means when the GUI exits, it continues to run in the background. If you set it as a background process, then GUI exit will cause it to exit as well (usually this is desired):

    newThread.IsBackground = true; // usually desired.

3. Access of GUI control needs special handling using Invoke() method:

    delegate void SetTextCallback(string a, string b);
    private void setMsg(string a, string b) {
        if (this.textBox1.InvokeRequired) {
            SetTextCallback d = new SetTextCallback(setMsg);
            this.Invoke(d, new object[] { s, b });
        }
        else { this.textBox1.Text = a + b; }
    }

Then call the setMsg method in the thread method: this.setMsg("hello, ", "world");

Ways of using multi-threading:

    // Method 1. basic method.
    Thread newThread = new Thread(this.checkProcesses); 
    newThread.IsBackground = true; 
    newThread.Start();

    // Method 2. use BackgroundWorker. 

References:

[1] Multi-process: http://msdn.microsoft.com/en-us/library/6x4c42hc.aspx
[2] Multiple process, access form control: http://msdn.microsoft.com/en-us/library/ms171728%28v=vs.80%29.aspx
[3] Background worker: http://stackoverflow.com/questions/363377/c-sharp-how-do-i-run-a-simple-bit-of-code-in-a-new-thread

Recover from winlogon failure

Ok, I got this blue screen error when booting my Dell/XP Professional computer after a shutdown with error with message:

STOP:  c000021a {Fatal System Error}
The Windows Logon Process system process terminated unexpectedly with a status of 
0xc0000005 (0x00000000 0x00000000).
THe system has been shut down.

There is no way to log in no matter what I do: not in safe mode, not in previous good configuration, not using the original XP Professional installation disk from Dell.

A good suggestion I received after searching on line is here.

It says my c:\windows\system32\winlogon.exe file is corrupted and I need to replace it with a good one.

Since I was not able to get in the system even with the original Dell installation CD, I tried to use Hiren's BootCD and it worked! I was able to back up my important files on C drive now.

I followed instruction by replacing c:\windows\system32\winlogon.exe with c:\windows\system32\dllcache\winlogon.exe, but it got the same error. I searched my computer and found C:\WINDOWS\SoftwareDistribution\Download\9866fb57abdc0ea2f5d4e132d055ba4e\winlogon.exe, then used this for replacement. It worked and now I can log in!

But I still see nothing after logging in, which means c:\windows\explorer.exe is also corrupted. Again, replace it with c:\windows\system32\dllcache\winlogon.exe did not work, but C:\WINDOWS\SoftwareDistribution\Download\9866fb57abdc0ea2f5d4e132d055ba4e\explorer.exe worked!

So now, one day later, my computer is recovered. I'm glad I didn't have to reinstall it.

DOS command

[1] Remove a non-empty folder (see Remove a Directory and All Subdirectories): RMDIR c:\blah /s /q
/s - remove directory when it's not empty.
/q - quiet mode, no prompt for yes/no.

[2] in vbs file, call a dos command, may have error "file not found", adding "CMD /C" before the command will remove the error: objShell.Exec("cmd /C rmdir folder_to_remove /S /Q")