tree 2e4c8c4568f19cbffe2933066e42a0c7ce937404
parent 69bfc89770152033d4aa0bc5673fc46e65d89838
author Dmitry V. Levin <ldv@altlinux.org> 1454368499 +0000
committer Dmitry V. Levin <ldv@altlinux.org> 1454503402 +0000

Implement caching of print_sockaddr_by_inode

As -yy parser, compared to -y, needs to do at least 5 extra syscalls
(getxattr, socket, sendmsg, recvmsg, close) to print socket details,
caching results of netlink conversations between strace and kernel
noticeably reduces amount of system time spent by strace.

The caching is safe since sockets do not change their addresses after
successful bind or connect syscall.

* defs.h (string_quote, print_sockaddr_by_inode_cached): New prototypes.
* socketutils.c (cache_entry): New type.
(CACHE_SIZE, CACHE_MASK): New macros.
(cache): New static array.
(cache_and_print_inode_details): New static function.
(print_sockaddr_by_inode_cached): New function.
(inet_parse_response, unix_parse_response): Use
cache_and_print_inode_details.
* util.c (printfd): Use string_quote and print_sockaddr_by_inode_cached.
(string_quote): Remove static qualifier.
* NEWS: Mention this improvement.
* tests/unix-yy.c (main): Update.