1.0 Problem Suppose there are n concurrent peer processes, where n > 1. All these processes have a checkpoint, which is an important point in the execution trace of the process. These processes need to be synchronized such that no process crosses its checkpoint before the others have reached their individual checkpoints. For example, a …
D-Bus is a mechanism for interprocess communication for Linux systems. D-Bus concepts along with example client-server programs are explained.
1.0 POSIX threads A process is an execution environment in an operating system. A process has code and data segments which are initialized from a program during an exec system call. A process has a thread of execution, wherein instructions are executed as per the value of the program counter register. Associated with a process …
POSIX message queue calls for interprocess communication (IPC) between processes are explained with an example of server and client programs in C under Linux.
1.0 FIFO FIFOs are pipes with a name and are also commonly referred to as named pipes. Pipes are common on Linux command lines but do not have a system-wide name. So, any two processes that wish to communicate using a pipe need to be related, either parent and child or, sharing a common parent, …
1.0 Interprocess communication A process is an active operating system entity which executes programs. Normally, a process, like a specialist, does one particular job (well). In real life, there are complex workflows and we, often, have multiple processes collaborating to accomplish certain objectives. In order to work together, processes need to exchange data. So we …
File Permissions In Linux, each files has nine permission bits. There are three basic permissions, read (r), write (w) and execute (x), for a file. These three permissions are there for the owner (o) of the file, the group (g) set for the file and the “others” (o). The ls -l command displays the permission …
htop is a ncurses based program for viewing processes in a Linux system. htop gives visual indications about processor, memory and swap usage.
The best way to use pidstat is to pass a list of process ids with the -p parameter. The -u option reports CPU utilization. The -l parameter displays the process command name and its arguments. And we can optionally put time interval in seconds for the interval between reports and again, optionally, a count for …
Execution time A process has an execution time associated with it. The execution time comprises of two parts, the user time and the system time. The user time is the time spent by the CPU in executing instructions in user mode. The system time is the time spent by the CPU in executing instructions on …
