[Lazarus] thread safe

[Michael Schnell]

On 06/27/2011 08:01 PM, Andrew Brunner wrote:
>
> That all changed with the introduction of multi-core systems.  But in
> those days everything  was inline.  Now a days everything is running
> in parallel.
>
Yep. But the user application code just sees threads.

Since ages, the user code needs to consider threads to work concurrently 
and any instruction of each active thread can be executed at exactly the 
same time, exactly as if each thread has it's own CPU. So any possible 
concurrent access needs to be protected by the means that are offered by 
the appropriate libraries (e.g. critical section).

Thus regarding the user code there is no difference at all. The dirty 
details need to be handled by the infrastructure (compiler, libraries, OS).

If the user code needs more performance that this simple paradigm can 
offer it might introduce low level stuff (such as interlocked 
instructions). But I would not consider such programs "user code" any more.

-Michael