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epoll_pwait2

Intro

epoll_pwait2 - wait for an I/O event on an epoll file descriptor with optional behavior for handling signals

Description

The epoll_pwait2 system call provides a wait for an I/O event on an epoll file descriptor. It is an extension to the epoll_pwait system call, which allows for the specification of an optional signal set for atomically unblocked signals. This is particularly useful for applications that need to ensure the correctness of behavior in a multithread environment where multiple threads might be blocked using the same epoll file descriptor, and one thread might unblock a signal that should eventually be handled by a different thread.

The advantages of using this system call include allowing signals to be handled atomically (without being interrupted by other signals), and allowing multiple threads to wait on the same epoll file descriptor.

However, one drawback to using this system call is that it requires a single set of signals to be specified for all threads, as opposed to the epoll_wait system call which allows for signals to be specified on a per-thread basis.

Arguments

  • fd:int[K] - epoll instance file descriptor
  • events:struct epoll_event*[K] - a memory region where epoll_event structures are featured
  • maxevents:int[K] - the maximum number of events to be returned
  • timeout:const struct timespec*[K] - a timeout interval, or NULL for no timeout
  • sigset:const sigset_t*[K] - a signal set mask, or NULL for the current set

Available Tags

  • K - Originated from kernel-space.

Hooks

sys_epoll_pwait2

Type

Kprobes + Uprobes

Purpose

To capture the entrance and exit of the epoll_pwait2 system call.

Example Use Case

An application that needs to ensure the correctness of its behavior in a multithread environment where multiple threads might be blocked using the same epoll file descriptor and where one thread might unblock a signal that should eventually be handled by a different thread could use this system call to ensure that signals are handled atomically without being interrupted by other signals, and that multiple threads can wait on the same epoll file descriptor.

Issues

None.

epoll_wait, epoll_pwait

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.