[Dovecot] test program #2: mmaping

[Jim Maenpaa]

> Attached another test program. I don't expect it to print any errors
> with any OS, but I'd like to confirm it for non-Linux SMP kernels.
>
> (Except for OpenBSD, it doesn't work correctly in it anyway because it
> doesn't support mixing write()s and mmap())
>
> <concurrency.c>

Mac OS X for Intel 10.4.9: SMP (Core Duo)

$ ./concurrency
writing, page size = 4096
0: reading, page size = 4096
open(): No such file or directory
4: reading, page size = 4096
3: reading, page size = 4096
1: reading, page size = 4096
$ 2: reading, page size = 4096
open(): No such file or directory
open(): No such file or directory
open(): No such file or directory
open(): No such file or directory

With all of the reader processes dying almost immediately.


Mac OS X for PowerPC 10.4.9: non-SMP (G4)

$ ./concurrency
writing, page size = 4096
4: reading, page size = 4096
3: reading, page size = 4096
2: reading, page size = 4096
1: reading, page size = 4096
0: reading, page size = 4096
open(): No such file or directory

With one reader process dying after about two minutes. Nothing else  
after another 20 minutes.

-jim