fork() in C
Fork system call is used for creating a new process, which is called child process, which runs concurrently with the process that makes the fork() call (parent process). After a new child process is created, both processes will execute the next instruction following the fork() system call.
wait() in linux
wait is a built-in command of Linux that waits for completing any running process. wait command is used with a particular process id or job id. If no process id or job id is given with wait command then it will wait for all current child processes to complete and returns exit status.
execlp() in linux
function replaces the current process image with a new process image specified by file. The new image is constructed from a regular, executable file called the new process image file. No return is made because the calling process image is replaced by the new process image.
Inter Process Communication (IPC)
a mechanism which allows processes to communicate with each other and synchronize their actions. The communication between these processes can be seen as a method of co-operation between them.
Process States
The process, from its creation to completion, passes through various states. The minimum number of states is five. The names of the states are not standardized although the process may be in one of the following states during execution.
Process Control Block (PCB)
a data structure that contains information of the process related to it. The process control block is also known as a task control block, entry of the process table, etc.
Process Scheduling
the activity of the process manager that handles the removal of the running process from the CPU and the selection of another process on the basis of a particular strategy.
Thread
There is a way of thread execution inside the process of any operating system. Apart from this, there can be more than one thread inside a process. Thread is often referred to as a lightweight process.
Multithreading
Multithreading models are three types: Many to many relationship, Many to one relationship, One to one relationship.
Concurrency
the execution of the multiple instruction sequences at the same time. It happens in the operating system when there are several process threads running in parallel. The running process threads always communicate with each other through shared memory or message passing.