NAME

ucontext — user thread context

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include < ucontext.h>

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

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 *);

SEE ALSO

sigaltstack(2), getcontext(3), getcontextx(3), makecontext(3)