How does makecontext work?

How does makecontext work?

The makecontext() function modifies the context pointed to by ucp (which was obtained from a call to getcontext(3)). Before invoking makecontext(), the caller must allocate a new stack for this context and assign its address to ucp->uc_stack, and define a successor context and assign its address to ucp->uc_link.

What does makecontext return?

makecontext() returns no values. The context being modified is using an alternate stack, and the target function entry point is not a valid Language Environment or C entry point. The argc argument specifies a value less than 0.

What is Ucontext_t?

DESCRIPTION. The ucontext_t type is a structure type suitable for holding the context for a user thread of execution. A thread’s context includes its stack, saved registers, and list of blocked signals. The ucontext_t structure contains at least these fields: ucontext_t *uc_link.

What does Makecontext do in C?

makecontext writes the function info into a context, and it will remain there until it is overwritten by something else. getcontext overwites the entire context, so would overwrite any function written there by a previous call to makecontext .

What is Ucontext in Linux?

ucontext. h defines functions ( setcontext , getcontext , makecontext , and swapcontext ) and structures ( ucontext_t and mcontext_t ) that allow the programmer to save and restore the program context.

What is Sigset_t?

The sigset_t data type is used to represent a signal set. Internally, it may be implemented as either an integer or structure type. For portability, use only the functions described in this section to initialize, change, and retrieve information from sigset_t objects—don’t try to manipulate them directly.

What is Sigwait?

The sigwait() function suspends execution of the calling thread until one of the signals specified in the signal set set becomes pending. The function accepts the signal (removes it from the pending list of signals), and returns the signal number in sig.

What is Sigchld signal?

The SIGCHLD signal is the only signal that the z/TPF system sends to a process. When a child process created by the tpf_fork function ends, the z/TPF system: Sends a SIGCHLD signal to the parent process to indicate that the child process has ended.

What signal is SIGQUIT?

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