[Lazarus] semaphores

[Lukasz Sokol]

On 14/02/2012 09:48, Antonio Fortuny wrote:

>> System-wide solutions for Linux is the *Unix-way*, is to create a
>> lock-file;
> Got it.
>> If you create one on a tmpfs mounted directory,
> What do you call a "tmpfs mounted directory" ? I'm only a pascal
> programmer not a system guy
Usually in /tmp, or by examining the output of 'mount'.

>> it will all happen in memory, hence no hard-drive storage access
>> will happen (unless moved to swap, but in your case it won't ever
>> happen) so all you need to do is check for lock file existence.
> Does it mean that every process will have to create the file ? An
> open-close sequence checking the IOResult would be enough ?

No, only the process that uses the resource, creates the file, that
/i think/ should be enough, others only see if file exists.

Also, for other examples of inter-process communication, you may
want to read about DBUS maybe ?

L.

>> (IMHO) There is also futex (Fast Userspace muTEX) but I don't know
>> much about that one; http://en.wikipedia.org/wiki/Futex
>> 
>> HTH. L.
>> 
>>