Using an async buffer

[Ali Çehreli]

On 11/07/2019 07:07 AM, bioinfornatics wrote:
 > Dear,
 >
 > I try to use the async buffer describe into std.parallelism
 > documentation but my test code core dump!

I admit I don't fully understand the lifetime issues but removing the 
"code smell" of the modul-level File object solved the issue for me, 
which requires four changes:

// (1) Comment out the module-level variable
// File file;

// ...

@system
void next(File file, ref ubyte[] buf)
{
   // (2.a) Use the parameter 'file'
   // (2.b) Adjust the length of the buffer
   //       (rawRead may read less than the requested size)
     buf = file.rawRead(buf);
}

// ...

     // (3) Define a local variable
     auto file = File(filePath, "rb");

// ...

     // (4) Use "callables" that use the local 'file':
     auto asyncReader = taskPool.asyncBuf((ref ubyte[] buf) => 
next(file, buf),
                                          () => file.eof,
                                          bufferSize);

Ali