acourtny@unix1.tcd.ie (Antony A. Courtney) writes:
>I wrote the following short program to test whether or not signals are reliable
>on our particular SVR4 implementation (A Siemens-Nixdorf RM600 running Sinix).
>The particular implementation of signal() is from Stevens' "Advanced Programming
>in the UNIX environment".
>What's the word? Are signals "reliable" or aren't they?
Signals in SVR4 and BSD are more reliable than the signalingmechnismens in
older SVR Versions. So if the same Signal is send twice or more to a process
the second delivery ist blocked until the first is handled. But there is no stacking of signals, so they get lost, if there is more than one Signal pending.
SVR4 signal handling also supports Blocking and Masking of Signals. For more Information, please refer to Stevens, and M.J.Bach "The Design of the UNIX OS" or
Leffler et.al. "The Design of BSD OS". Don't be frustated, a better Idea would be to use Messagequeues to serialize events.
