This is an interesting perspective. I think of signals the other way around -- that they came out of people realizing how useful hardware interrupts could be i

This is an interesting perspective. I think of signals the other way around -- that they came out of people realizing how useful hardware interrupts could be in allowing devices to talk to the kernel, so they engineered a similar affordance (signals) to allow the kernel to talk to processes. In the case of hardware interrupts (like for old keyboards), if you didn't grab that character off the hardware right away, it would vanish, or another one would take its place. As long as you were fast, it worked. Same with signals. As long as you don't try to do too much in the handler, it works. In other words, it was designed to be "good enough" if used properly (just like all hardware).