UCONTEXT(2) | System Calls Manual | UCONTEXT(2) |
ucontext
—
#include <ucontext.h>
_UC_MACHINE_SP
(&uc);
_UC_MACHINE_FP
(&uc);
_UC_MACHINE_PC
(&uc);
_UC_MACHINE_INTRV
(&uc);
_UC_MACHINE_SET_PC
(&uc);
The ucontext_t structure includes the following members:
ucontext_t *uc_link sigset_t uc_sigmask stack_t uc_stack mcontext_t uc_mcontext
The uc_link member points to the context
that will be resumed after the function specified when modifying a context
using makecontext(3) has
returned. If uc_link is a NULL
pointer, then the context is the main context, and the process will exit
with an exit status of 0 upon return.
The uc_sigmask member is the set of signals that are blocked when the context is activated. Further information can be found in sigprocmask(2).
The uc_stack member defines the stack used by the context. Further information can be found in sigaltstack(2).
The uc_mcontext member defines the machine state associated with the context; it may consist of general registers, floating point registers and other machine-specific information. Its description is beyond the scope of this manual page; portable applications should not access this structure member.
The following auxiliary macros are available to access some of that machine-specific information:
_UC_MACHINE_SP
()_UC_MACHINE_FP
()_UC_MACHINE_PC
()_UC_MACHINE_INTRV
()_UC_MACHINE_SET_PC
()The frame pointer macro does not guarantee to retrieve a reliable
value and should not be used in a code unless no other debugging format is
easily accessible. A compiler might optimize the frame pointer register in a
function, reusing it as a general purpose register storage
(-fomit-frame-pointer
) or emit function prologues
only before parts that need them
(-fshrink-wrap
).
February 25, 2018 | NetBSD 9.0 |