ucontext(3)

ucontext3

User thread context

Usage

#include <ucontext.h>

Library

Standard C Library (libc, -lc)

Overview

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

context to assume when this one returns

sigset_t uc_sigmask

signals being blocked

stack_t uc_stack

stack area

mcontext_t uc_mcontext

saved registers

The uc_link field points to the context to resume when this context's entry point function returns. If uc_link is equal to NULL, then the process exits when this context returns.

The uc_mcontext field is machine-dependent and should be treated as opaque by portable applications.

The following functions are defined to manipulate ucontext_t structures:

int getcontext(ucontext_t *);

int setcontext(const ucontext_t *);

void makecontext(ucontext_t *, void *void, int, ...);

int swapcontext(ucontext_t *, const ucontext_t *);

Releases

Unchanged in 96 releases since Mac OS X 10.5.

  1. 10.5–26.5

From libplatform 375.120.2 in macOS 26.5. Parsed by carta from the page's mdoc source.