procs | A modern replacement for ps written in Rust | Command Line Interface library

Your solution looks fine, as you are doing these using stored procedures. Also, your history table looks very simple. Maybe you can add, what kind of operation(INSERT, UPDATE) and who made the change.

So why the random number of fails?

The MD4 code presented is not thread safe, and you are adding a bit of thread-unsafety of your own.

Observe in particular variables A, B, C, and D in file md4.c. These are declared at file scope and without the _Thread_local qualifier, so they have static storage duration and are shared by all threads in the process. These are modified during the computation, so you have data races involving all of these. The resulting behavior is undefined, and it shouldn't be hard to imagine how it might mess things up if multiple threads were clobbering the values that each other had written in those variables.

As for your own code, with each call to runprocs(), the main thread and each new one created all share the same struct data object, which the threads read and modify and the main thread reads, all without synchronization. This also causes undefined behavior, though it looks like this could be rescued by engaging a mutex or other synchronization mechanism.

Additionally, the MD4 code appears to be deterministic -- given the same input, it will always (if run single-threaded to avoid undefined behavior) produce the same output. It is therefore unclear what you seek to accomplish by running it in multiple threads on the same input.

Also, the while(!d.done) loop is pointless and poor form. You should be joining each thread via pthread_join() to clean up its resources after it, and since that has the (primary) effect of waiting for the thread to terminate, you don't need to also roll your own wait for termination.

You seem to be confused as to what $(shell ...) does. If you want this to happen when the target is run, not when the Makefile is parsed, you want to take out the $(shell ...).

Also, don't use ls in scripts.

If I'm able to guess what you are trying to do, probably something like

Update your add_customer function to send a notification to the channel. To send the notification use the NOTIFY command or the pg_notify(text, text) function.

You can use when for doing the equivalent of update:

Use sys.all_objects:

I'm just worried that the code may not be precompiled or something.

This is not to worry about, besides, there is no precompilation or similar in Tcl. Once executed for the first time, the generated proc's body will be byte-compiled (however the body script was assembled).

However, your proc generator is not robust. Variable substitution under quotes will break your body script when someData contains a string which renders the body script or one of its commands incomplete, e.g.:

This should be fairly simple.

I first recreated your dataset with the following...

Yes, those expressions will produce the same results.

This assumes context: