GETCONTEXT(2) | System Calls Manual | GETCONTEXT(2) |
getcontext
, setcontext
—
#include <ucontext.h>
int
getcontext
(ucontext_t
*ucp);
int
setcontext
(const
ucontext_t *ucp);
getcontext
() function initializes the object pointed
to by ucp to the current user context of the calling
thread. The user context defines a thread's execution environment and includes
the contents of its machine registers, its signal mask, and its current
execution stack.
The setcontext
() function restores the
user context defined in the object pointed to by ucp
as most recently initialized by a previous call to either
getcontext
() or
makecontext(3). If
successful, execution of the program resumes as defined in the
ucp argument, and setcontext
()
will not return. If ucp was initialized by the
getcontext
() function, program execution continues
as if the corresponding invocation of getcontext
()
had just returned (successfully). If ucp was
initialized by the
makecontext(3) function,
program execution continues with the function (and function arguments)
passed to
makecontext(3).
getcontext
() returns 0 and
setcontext
() does not return. Otherwise a value of -1
is returned and errno is set to indicate the error.
getcontext
() and
setcontext
() functions will fail if:
EFAULT
]The setcontext
() function will fail
if:
EINVAL
]getcontext
() and
setcontext
() functions conform to
X/Open System Interfaces and Headers Issue 5
(“XSH5”) and IEEE Std 1003.1-2001
(“POSIX.1”). The errno indications
are an extension to the standard.
The IEEE Std 1003.1-2004
(“POSIX.1”) revision marked the functions
getcontext
() and
setcontext
() as obsolete, citing portability issues
and recommending the use of POSIX threads instead. The IEEE
Std 1003.1-2008 (“POSIX.1”) revision removed the
functions from the specification.
getcontext
() and
setcontext
() functions first appeared in
AT&T System V Release 4 UNIX.
April 28, 2010 | NetBSD 9.0 |