Release 7.1.1 new features

New library functions and related changes

The following library calls have been added for Release 7.1.1:

   getxcontext
   swapxcontext
   makexcontext

These call are identical to their getcontext(2), swapcontext(3C), and makecontext(3C) counterparts, except they use the extended user context structure uxcontext_t.

Applications should use the getxcontext function to determine if the operating system and CPU support saving and restoring the extended floating point register state. On systems that do not support the extended floating point state, getxcontext will return ``-1'' with errno set to EINVAL.

The setcontext system call has been modified to accept either a ucontext_t user context structure or a uxcontext_t extended user context structure (see ``Signal Handling Changes'').

NOTE: Applications should not mix calls that use ucontext_t and uxcontext_t. If an application uses the Pentium III extended floating point registers and subsequently restores the floating state with a ucontext_t, the contents of the extended floating point registers will be undefined and the extended floating point status register (mxcsr) will be reset after the next floating point or Pentium III Streaming SIMD extended floating point instruction is executed.