Error running concurrent process and storing results in array

[drug]

06.05.2020 09:24, data pulverizer пишет:
> On Wednesday, 6 May 2020 at 05:44:47 UTC, drug wrote:
>>
>> proc is already a delegate, so &proc is a pointer to the delegate, 
>> just pass a `proc` itself
> 
> Thanks done that but getting a range violation on z which was not there 
> before.
> 
> ```
> core.exception.RangeError at onlineapp.d(3): Range violation
> ----------------
> ??:? _d_arrayboundsp [0x55de2d83a6b5]
> onlineapp.d:3 void onlineapp.process(double, double, long, 
> shared(double[])) [0x55de2d8234fd]
> onlineapp.d:16 void onlineapp.main().__lambda1() [0x55de2d823658]
> ??:? void core.thread.osthread.Thread.run() [0x55de2d83bdf9]
> ??:? thread_entryPoint [0x55de2d85303d]
> ??:? [0x7fc1d6088668]
> ```
> 

confirmed. I think that's because `proc` delegates captures `i` variable 
of `for` loop. I managed to get rid of range violation by using `foreach`:
```
foreach(i; 0..n) // instead of for(long i = 0; i < n;)
```
I guess that `proc` delegate cant capture `i` var of `foreach` loop so 
the range violation doesn't happen.

you use `proc` delegate to pass arguments to `process` function. I would 
recommend for this purpose to derive a class from class Thread. Then you 
can pass the arguments in ctor of the derived class like:
```
foreach(long i; 0..n)
     new DerivedThread(double)(i), cast(double)(i + 1), i, z).start(); 
thread_joinAll();
```

not tested example of derived thread
```
class DerivedThread
{
     this(double x, double y, long i, shared(double[]) z)
     {
         this.x = x;
	this.y = y;
	this.i = i;
	this.z = z;
         super(&run);
     }
private:
     void run()
     {
          process(x, y, i, z);
     }
	double x, y;
	long i;
	shared(double[]) z;
}
```