Is there a minimum number of instruction guaranteed to be executed by a thread during any given time slot. The Wikipedia page for Execution Model says "The addition operation is an indivisible unit of work in many languages"
I would like to learn more about the execution model of POSIX Thread used with C/C++ and minimum number of indivisible instruction or statements guaranteed to be executed in a single time slot. Can someone give a pointer from where I can learn more on this. Thanks is advance
No, there are no guarantees on the number of instructions per time. The way things work is more complicated than executing a set number of instructions anyway.
Executed instructions depends more on the processor architecture than the language. The "traditional" MIPS architecture taught in many introductory design courses would execute one instruction per clock cycle; a processor designed like this running at 1MHz would execute one million operations per second. Real-world processors use techniques such as pipelines, branch prediction, "hyper-threading", etc. and do not have a set number of operations per clock cycle.
Beyond that, real-world processors will generally function under an operating system with multi-tasking capabilities. This means that a thread can be interrupted by the kernel at unknown points, and not execute any code at all as other threads are given processor time. There are "real-time" operating systems that are designed to give more guarantees about how long it takes to execute the code running on the processor.
You have already done some research on Wikipedia; some of the keywords above should help track down more articles on the subject, and from there you should be able to find plenty of primary sources to learn more on the subject.