Table of Contents
What is Linux Eventfd?
eventfd() creates an “eventfd object” that can be used as an event wait/notify mechanism by user-space applications, and by the kernel to notify user-space applications of events. The object contains an unsigned 64-bit integer (uint64_t) counter that is maintained by the kernel.
Is Eventfd thread safe?
1 Answer. Writing to an eventfd is thread safe, i.e., two threads (or even processes) are allowed to write to the same fd at the same time, and they will be properly serialized.
What is Epoll_ctl?
DESCRIPTION top. This system call is used to add, modify, or remove entries in the interest list of the epoll(7) instance referred to by the file descriptor epfd. It requests that the operation op be performed for the target file descriptor, fd.
What is pipes in IPC?
A Pipe is a technique used for inter process communication. A pipe is a mechanism by which the output of one process is directed into the input of another process. Thus it provides one way flow of data between two related processes.
What are different IPC mechanism in Linux?
Linux supports three types of interprocess communication mechanisms which first appeared in Unix System V (1983). These are message queues, semaphores and shared memory. These System V IPC mechanisms all share common authentication methods.
What is Epollhup?
EPOLLHUP is UNMASKABLE event (…). It means that after we received EOF , poll always returns immediately, making impossible poll() on write() in state CLOSE_WAIT .
What causes Epollerr?
What makes EPOLLERR and EPOLLHUP happen? EPOLLERR Error condition happened on the associated file descriptor. epoll_wait(2) will always wait for this event; it is not necessary to set it in events. EPOLLHUP Hang up happened on the associated file descriptor.
Is pipe an IPC mechanism?
A Pipe is a technique used for inter process communication. A pipe is a mechanism by which the output of one process is directed into the input of another process.
What is pipe Linux?
A pipe is a form of redirection (transfer of standard output to some other destination) that is used in Linux and other Unix-like operating systems to send the output of one command/program/process to another command/program/process for further processing. You can make it do so by using the pipe character ‘|’.
What are the IPC mechanisms in Linux?
This is the first article in a series about interprocess communication (IPC) in Linux. The series uses code examples in C to clarify the following IPC mechanisms: This article reviews some core concepts before moving on to the first two of these mechanisms: shared files and shared memory.
Are named pipes faster than sockets IPC?
Everyone seems to say named pipes are faster than sockets IPC. How much faster are they? I would prefer to use sockets because they can do two-way communication and are very flexible but will choose speed over flexibility if it is by considerable amount. Best results you’ll get with Shared Memory solution.
What is an example of an IPC file?
In this first code example, the data shared through IPC is text: two lines from Shakespeare’s play Richard III. Yet, the shared file’s contents could be voluminous, arbitrary bytes (e.g., a digitized movie), which makes file sharing an impressively flexible IPC mechanism.
What is inter-process communication in Linux?
Inter-process communication in Linux: Shared storage 1 Core concepts. A process is a program in execution, and each process has its own address space, which comprises the memory locations that the process is allowed to access. 2 Shared files. 3 Shared memory. 4 Wrapping up.