asked on

Threading Process Has Multiple Openings?

I have a thread that starts a backup.bat process.

Problem: Multiple .bat are opened instead of just ONE.

Help............ here's the code...........

private void startBackupThread()
{
if ((thread1 == null) || ((thread1.ThreadState & (System.Threading.ThreadState.Unstarted | System.Threading.ThreadState.Stopped)) != 0))
{
thread1 = new Thread(new ThreadStart(backupBat));
thread1.IsBackground = true;
thread1.Priority = ThreadPriority.Normal;
thread1.Start();
}
}

private void backupBat()
{
Process proc = new Process();
proc.StartInfo.FileName = txtBackupBatPath.Text.ToString();
proc.Start();
}

dfu23

can you use a static boolean variable or some other flag (in a DB or whatever) to indicate that the backup batch process has already been kicked off ... and maybe add a date/time so you can conditionally know when to run it again?

kvnsdr

ASKER

I've since added ''proc.WaitForExit();'' which helps some, but not all. Still two .bat DOS cmd widows open consecutively..... It's getting better though......

Process proc = new Process();
proc.StartInfo.FileName = txtBackupBatPath.Text.ToString();
proc.WaitForExit();
proc.Start();

AlexNek

It looks strange. What happends with this code?
Process proc = new Process();
proc.StartInfo.FileName = txtBackupBatPath.Text.ToString();
proc.WaitForExit();

Kate12

you have to syncronize the block of code:
private static object syncLock = new object();

private void backupBat()
{
lock(syncLock)
{
Process proc = new Process();
proc.StartInfo.FileName = txtBackupBatPath.Text.ToString();
proc.Start();
proc.WaitForExit();
}
}
This way only one thread will touch the .bat file at one time.

AlexNek

I would suggest in addition rewrite you code
if (thread1 == null)
{
thread1 = new Thread(new ThreadStart(backupBat));
thread1.IsBackground = true;
thread1.Priority = ThreadPriority.Normal;
thread1.Start();
}
and test if startBackupThread() called more that once.

2 Kate12
If thread started more that once we can't prevent to start the second copy when the first is finished.

gregoryyoung

well that code is backwards try this ...

Process proc = new Process();
proc.StartInfo.FileName = txtBackupBatPath.Text.ToString();
proc.Start();
proc.WaitForExit();
thread1 = null;

then in your starting code ...

lock(SomeLockObject) {
if ((thread1 == null))
{
thread1 = new Thread(new ThreadStart(backupBat));
thread1.IsBackground = true;
thread1.Priority = ThreadPriority.Normal;
thread1.Start();
}

gregoryyoung

sry didnt see other posts on the first bit ... the main thing you need to protect is the *creation* of the thread ... not the execution portion of the thread ... I might also make the code set thread1 = null when it is complete and only check thread1==null ...

Cheers,

Greg

ASKER CERTIFIED SOLUTION

kvnsdr

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