File based process synchronization

[Ulrich Sprick]

Hi all,

I have a problem that should be quite common, but I'm not (yet) familiar with process synchronization in .NET:
There are several applications that write to a single file on disk. The apps open a FileStream with FileShare.None to prevent others
from reading garbage.

Now if a second process wants to open the file, it will fail. Currently I put the thread in a short Sleep and retry loop, but I'd
rather like to WaitForSingleObject() or so: The process 2 should be blocked until the first one closes the file and the file
(handle?) gets "signaled".

I came across the W32 Read/WriteFileEx(), which performs overlapped I/O, but I have a feeling that's a number too big...
Can anyone point me in the right direction?

Thanks a lot,
ulrich

[Jon Skeet [C# MVP]]

Ulrich Sprick <no******************@gmx.de> wrote:

I have a problem that should be quite common, but I'm not (yet)
familiar with process synchronization in .NET: There are several applications that write to a single file on disk.
The apps open a FileStream with FileShare.None to prevent others from
reading garbage.

Now if a second process wants to open the file, it will fail.
Currently I put the thread in a short Sleep and retry loop, but I'd
rather like to WaitForSingleObject() or so: The process 2 should be
blocked until the first one closes the file and the file (handle?)
gets "signaled".

I came across the W32 Read/WriteFileEx(), which performs overlapped
I/O, but I have a feeling that's a number too big... Can anyone point
me in the right direction?

I'd suggest using a Mutex which you wait for and signal.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too

[Ulrich Sprick]

Thanks Jon, I'll give it a try.
ulrich

"Jon Skeet [C# MVP]" <sk***@pobox.com> schrieb im Newsbeitrag news:MP************************@msnews.microsoft.c om...

Ulrich Sprick <no******************@gmx.de> wrote:

I have a problem that should be quite common, but I'm not (yet)
familiar with process synchronization in .NET:

There are several applications that write to a single file on disk.
The apps open a FileStream with FileShare.None to prevent others from
reading garbage.

Now if a second process wants to open the file, it will fail.
Currently I put the thread in a short Sleep and retry loop, but I'd
rather like to WaitForSingleObject() or so: The process 2 should be
blocked until the first one closes the file and the file (handle?)
gets "signaled".

I came across the W32 Read/WriteFileEx(), which performs overlapped
I/O, but I have a feeling that's a number too big... Can anyone point
me in the right direction?

I'd suggest using a Mutex which you wait for and signal.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too