On 01/01/11 20:30, Brandon S Allbery KF8NH wrote:
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On 1/1/11 20:21 , Maciej Piechotka wrote:
On Sat, 2011-01-01 at 13:59 -0500, Brandon S Allbery KF8NH wrote:
On 12/23/10 20:57 , Thomas Schilling wrote:
I also find the name 'forkOnIO' extremely confusing. Without reading the docs it seems to imply that a thread is created on IO, i.e., if I/O happens. This makes no sense, and is of course not what's happening. However, I assume you chose it because forkIOOn looks a bit weird. In that case, why not use forkThreadOn, and in a separate proposal change forkIO to forkThread (or just fork).
+1 The name "forkIO" always seemed a bit odd to me; aren't threads pretty much constrained to IO anyway?
Depends on what you understand by thread:
Implicit threading in the runtime doesn't actually count, no; if that isn't referentially transparent then by definition it is broken.
Kernel threads are an implementation detail, unless you need one for Thread-Local State or the like (using the poorly-named forkOS). GHC threads are created by both forkIO and (usually) `par`. `par` is referentially transparent because you can't observe GHC threads outside of IO, not because GHC threads aren't created by `par`. (The "usually" is because the compiler and runtime is free to make a thread or not, since it *is* referentially transparent regardless of this choice.) For a programmer, it's useful to understand the difference between concurrency and parallelism. But for an amateur understanding of the implementation, both programming-concepts use the same sort of GHC-threads. I like the name "forkIO" because it says pretty much what it does: it creates ("forks") a second running IO. It doesn't fork a process (Unix fork()), and it doesn't necessarily fork a kernel thread. It does fork a Haskell thread (although it is not the only basic function that forks Haskell threads). (Correct me if I'm wrong about the implementation.) IMHO whether "threads [are] pretty much constrained to IO" does "depend on what you understand by thread". I don't mind either name "forkIO" or "forkThread". -Isaac