What is sigaction in C?
What is sigaction in C?
DESCRIPTION. The sigaction() function allows the calling process to examine and/or specify the action to be associated with a specific signal.
What does sigaction do in Linux?
The sigaction() system call is used to change the action taken by a process on receipt of a specific signal. (See signal(7) for an overview of signals.) signum specifies the signal and can be any valid signal except SIGKILL and SIGSTOP.
What is the difference between signal and sigaction?
The signal() function does not (necessarily) block other signals from arriving while the current handler is executing; sigaction() can block other signals until the current handler returns. The signal() function (usually) resets the signal action back to SIG_DFL (default) for almost all signals.
What is Rt_sigreturn?
According to sigreturn man page, rt_sigreturn is advanced variant of sigreturn which supports enlarged signal type: The original Linux system call was named sigreturn(). However, with the addition of real-time signals in Linux 2.2, a new system call, rt_sigreturn() was added to support an enlarged sigset_t type.
What is Sigemptyset in C?
sigemptyset() is part of a family of functions that manipulate signal sets. Signal sets are data objects that let a process keep track of groups of signals. For example, a process can create one signal set to record which signals it is blocking, and another signal set to record which signals are pending.
How do signals work in C?
A signal is a software generated interrupt that is sent to a process by the OS because of when user press ctrl-c or another process tell something to this process. There are fix set of signals that can be sent to a process. signal are identified by integers.
Which sigaction flag is used to prevent a system call from being interrupted?
You can set sa_mask in your sigaction call to block certain signals while a particular signal handler runs. This way, the signal handler can run without being interrupted itself by signals.
What is vDSO Linux?
The “vDSO” (virtual dynamic shared object) is a small shared library that the kernel automatically maps into the address space of all user-space applications. Applications usually do not need to concern themselves with these details as the vDSO is most commonly called by the C library.
What is Futex in Linux?
In computing, a futex (short for “fast userspace mutex”) is a kernel system call that programmers can use to implement basic locking, or as a building block for higher-level locking abstractions such as semaphores and POSIX mutexes or condition variables.
Can SIGQUIT be blocked?
The SIGKILL signal is used to cause immediate program termination. It cannot be handled or ignored, and is therefore always fatal. It is also not possible to block this signal.
