Imagine a processor with no interrupts. We can do a lot better and get rid of most exceptions (e.g. system calls, page faults etc.), most peripheral devices/buses, and even cache misses, but let’s start with interrupts. Modern micro-processors are bloated
IEEE 1588 PTP is a mess
IEEE 1588 was not designed for modern enterprise computer networks and contains many hacks to make it sort of work. The standard also suffers from being overly explicit on some things and overly unspecific on others. One marker of the
MiFID II Clock Sync – talk at Bank of England April 12 2016
download
Operations and maps on finite sequences
A lot of what I’m trying to do with mathematical models of computer systems involves operations on finite sequences. Define a “finite sequence of length n>0” to be any total map f: {1 … n} → X for some set X.
The difference between unspecified, undefined, and non-deterministic
There is too much confusion in the “formal methods” computer science literature between these three different terms. Let me start with what this means for a state machine and then move on to engineering objects such as threads. Suppose we
Software quality at toyota
The good stuff starts on page 36 Koopman.
A mathematical basis for understanding software modularity
Download.
one way queues
Here’s some code for lock free queues for a single producer and single consumer. The code is designed for Intel multiprocessors with strong memory model. I don’t know what ARM offers these days. But the strong memory model for x86
The Auragen file system.
This article on the interesting Wave Transactional File System inspired me to look up an earlier file system that also used copy on write semantics. From: Anita Borg, Wolfgang Blau, Wolfgang Graetsch, Ferdinand Herrmann, and Wolfgang Oberle. 1989. Fault tolerance
Paxos and other consensus algorithms and the unaccountable love for asynchrony
I’ve been looking at Paxos and Raft and Zab and other algorithms that can loosely be called “consensus” algorithms because we want to see where we can improve distributed system operation with precision time synchronization or where we can offer novel features