GETCONTEXT(2) Linux Programmer's Manual GETCONTEXT(2)
getcontext, setcontext - get or set the user context
int getcontext(ucontext_t *ucp);
int setcontext(const ucontext_t *ucp);
ucp points to a structure defined in <ucontext.h> containing the
signal mask, execution stack, and machine registers.
getcontext(2) gets the current context of the calling process, storing
it in the ucontext struct pointed to by ucp.
setcontext(2) sets the context of the calling process to the state
stored in the ucontext struct pointed to by ucp. The struct must either
have been created by getcontext(2) or have been passed as the third
parameter of the sigaction(2) signal handler.
The ucontext struct created by getcontext(2) is defined in <ucontext.h>
typedef struct ucontext
unsigned long int uc_flags;
struct ucontext *uc_link;
struct _fpstate __fpregs_mem;
getcontext(2) returns 0 on success and -1 on failure. setcontext(2)
does not return a value on success and returns -1 on failure.
These functions comform to: XPG4-UNIX.
When a signal handler executes, the current user context is saved and a
new context is created by the kernel. If the calling process leaves
the signal handler using longjmp(2), the original context cannot be
restored, and the result of future calls to getcontext(2) are unpre-
dictable. To avoid this problem, use siglongjmp(2) or setcontext(2) in
signal handlers instead of longjmp(2).
sigaction(2), sigaltstack(2), sigprocmask(2), sigsetjmp(3), setjmp(3).
Red Hat Linux 6.1 20 September 1999 GETCONTEXT(2)