Fixing a bug and performance issue.

Problem: we are using sigsetjmp but with a jmp_buf structure;
it requires sigjmp_buf!

Performance issue: sigsetjmp is a dog which makes system calls.
Solution: let's roll our own cached version of sigprocmask which
only calls the real sigprocmask when the mask changes. Then
our extended_setjmp will just use regular setjmp, plus our own
custom signal saving and restoring based on the cached version.

* signal.c (sig_blocked_cache): New variable.
(set_sig_handler): Use our sig_mask instead of sigprocmask.
(mem_set_bits, mem_clr_bits): New static functions.
(sig_mask): New function.

* signal.h (extended_jmp_buf): New member, blocked.
(extended_setjmp): save blocked signals by peeking into
sig_blocked_cache, and restore using sig_mask.
(sig_blocked_cache, sig_mask): Declared.

0 files changed, 0 insertions, 0 deletions