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| author | Kaz Kylheku <kaz@kylheku.com> | 2013-12-20 06:57:13 -0800 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2013-12-20 06:57:13 -0800 |
| commit | 6e8aaedc1f3be2c9c7c3031499ad2b4bce05dfbc (patch) | |
| tree | a972a7ce0467da3e666c4f841b9970971c5c211e /ChangeLog | |
| parent | 0231fc1659ea0a75e058b38c3085d7631162f1b1 (diff) | |
| download | txr-6e8aaedc1f3be2c9c7c3031499ad2b4bce05dfbc.tar.gz txr-6e8aaedc1f3be2c9c7c3031499ad2b4bce05dfbc.tar.bz2 txr-6e8aaedc1f3be2c9c7c3031499ad2b4bce05dfbc.zip | |
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.
Diffstat (limited to 'ChangeLog')
| -rw-r--r-- | ChangeLog | 23 |
1 files changed, 23 insertions, 0 deletions
@@ -1,3 +1,26 @@ +2013-12-20 Kaz Kylheku <kaz@kylheku.com> + + 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. + 2013-12-17 Kaz Kylheku <kaz@kylheku.com> Version 72 |