1.0 Signals Signals are notifications delivered asynchronously to a process by the kernel. Signals are grouped in two categories. First, there are standard signals, which have been there since the early days of Unix. Second, there are POSIX real-time signals which are specified in POSIX.1b, or, IEEE Std 1003.1b-1993, for Real-time Extensions for POSIX compliant …
1.0 Shared Memory Shared memory is an inter process communication (IPC) mechanism in Linux and other UNIX-like systems. Based on input parameters, the kernel provides a (shared) memory segment to the calling process. The calling process maps the shared memory segment to its address space. This way, the same shared memory segment can be mapped …
1.0 POSIX Threads Synchronization POSIX Threads provide multiple flows of execution within a process. The threads have their own stacks but share the global data and the heap. So the global variables are visible to multiple threads. Also, the threads need to synchronize their actions so that they jointly realize the overall objectives of the …
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 …
1.0 Semaphores Semaphores are used for process and thread synchronization. Semaphores are clubbed with message queues and shared memory under the Interprocess Communication (IPC) facilities in Unix-like systems such as Linux. There are two varieties of semaphores, the traditional System V semaphores and the newer POSIX semaphores. In this post we will look at the …
POSIX message queue calls for interprocess communication (IPC) between processes are explained with an example of server and client programs in C under Linux.
