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D-Bus Tutorial

  • by kjohri

1.0 D-Bus

D-Bus is a mechanism for interprocess communication under Linux and other Unix-like systems. D-Bus has a layered architecture. At the lowest level is the D-Bus wire protocol described in the D-Bus Specification. The libdbus library is an implementation of the wire protocol.… Read more

POSIX Shared Memory in Linux

  • by kjohri

1.0 Shared Memory

Shared memory is the fastest method of interprocess communication (IPC) under Linux and other Unix-like systems. The system provides a shared memory segment which the calling process can map to its address space. After that, it behaves just like any other part of the process's address space.… Read more

System V Shared Memory in Linux

  • by kjohri

1.0 Shared Memory

Shared memory is one of the three interprocess communication (IPC) mechanisms available under Linux and other Unix-like systems. The other two IPC mechanisms are the message queues and semaphores. In case of shared memory, a shared memory segment is created by the kernel and mapped to the data segment of the address space of a requesting process.… Read more

Queue implementation in C using linked list

  • by kjohri

1.0 Queue

A queue is something we see often in our daily lives. People stand in a queue to get into a bus, to get food in a buffet, buy tickets from the ticket counter, etc. Queues are a fair solution of ordering people to get a resource; people are served in the chronological order of their arrival leading to the coinage of the phrase, first come, first served (FCFS).… Read more

POSIX Threads Synchronization in C

  • by kjohri

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 process they belong to.… Read more

POSIX Threads Programming in C

  • by kjohri

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.… Read more

POSIX Semaphores in Linux

  • by kjohri

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.… Read more

System V Semaphores in Linux

1.0 Semaphores

A semaphore is a mechanism for synchronizing processes and threads. Semaphore, in Unix-like systems, are provided under interprocess communication (IPC) facilities along with message queues and shared memory. While message queues can be used by themselves for interprocess communication, semaphores are needed for implementing shared memory based interprocess communication systems.… Read more

POSIX message queues in Linux

  • by kjohri

1.0 POSIX Message queues

POSIX interprocess comunication (IPC) was introduced in the POSIX.1b standard (IEEE Std 1003.1b-1993) for real time extensions. POSIX message queues have been made available in Linux since the version 2.6.6 (May 2004). POSIX IPC calls are as per the standard but may not be available on older Unix-like systems.… Read more

System V message queues in Linux

  • by kjohri

1.0 Message queues

Message queues are one of the interprocess communication mechanisms available under Linux. Message queues, shared memory and semaphores are normally listed as the three interprocess communication mechanisms under Linux. Semaphores, though, are really for process synchronization. In practice, shared memory, aided by semaphores, makes an interprocess communication mechanism.… Read more