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 *); -
ucontext_t *
getcontextx(void); -
int
setcontext(const ucontext_t *); -
void
makecontext(ucontext_t *, void *void, int, ...); -
int
swapcontext(ucontext_t *, const ucontext_t *);
Releases
61 releases since FreeBSD 4.7-RELEASE; the text changed 34 times.