rbj@uunet.UU.NET (Root Boy Jim) (03/08/91)
...do shmread & shmwrite exist? Was it too much trouble to create a variable whose size and location were fixed? ...given that we really do want shmread & shmwrite, why is the shared memory region repeatedly attached to & from? Does perl open & close files between I/O :-) ...is the length required on read, sysread, and syswrite? Use the length of the scalar by default. ...is the bits expression in vec required to be a power of two? ...can't waitpid be built from wait3? It is powerful enuf. ...is the sky blue? [I wanted to give you an easy one :-] -- [rbj@uunet 1] stty sane unknown mode: sane
chip@tct.uucp (Chip Salzenberg) (03/09/91)
According to rbj@uunet.UU.NET (Root Boy Jim): >...do shmread & shmwrite exist? Was it too much trouble to > create a variable whose size and location were fixed? > >...given that we really do want shmread & shmwrite, why is the > shared memory region repeatedly attached to & from? > Does perl open & close files between I/O :-) I did the System V IPC support, so let me answer. The reason was... laziness and impatience! (How appropriate for hacking Perl features...) I needed support for System V IPC, but I didn't need speed. I didn't (and still don't) understand Perl's internals well enough to hack in fixed-location and fixed-size variables. Ergo, shmread/shmwrite. As for the attach/detach, that's necessary to allow removed shared memory segments to disappear -- if you keep a segment attached, it will never disappear. -- Chip Salzenberg at Teltronics/TCT <chip@tct.uucp>, <uunet!pdn!tct!chip> "Most of my code is written by myself. That is why so little gets done." -- Herman "HLLs will never fly" Rubin