From 971ef822679dfa6ee63ff83a47b4e4d1aa60d146 Mon Sep 17 00:00:00 2001 From: akr Date: Sat, 18 Jan 2014 14:13:22 +0000 Subject: * ext/socket: Avoid unnecessary ppoll/select on Linux. Patch by Eric Wong. [ruby-core:57950] [Bug #9039] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44643 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ext/socket/rubysocket.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'ext/socket/rubysocket.h') diff --git a/ext/socket/rubysocket.h b/ext/socket/rubysocket.h index c74fb326ec..2f8ce9d084 100644 --- a/ext/socket/rubysocket.h +++ b/ext/socket/rubysocket.h @@ -386,4 +386,20 @@ NORETURN(void rsock_sys_fail_sockaddr(const char *, struct sockaddr *addr, sockl NORETURN(void rsock_sys_fail_raddrinfo(const char *, VALUE rai)); NORETURN(void rsock_sys_fail_raddrinfo_or_sockaddr(const char *, VALUE addr, VALUE rai)); +/* + * It is safe on Linux to attempt using a socket without waiting on it in + * all cases. For some syscalls (e.g. accept/accept4), blocking on the + * syscall instead of relying on select/poll allows the kernel to use + * "wake-one" behavior and avoid the thundering herd problem. + * This is likely safe on all other *nix-like systems, so this whitelist + * can be expanded by interested parties. + */ +#if defined(__linux__) +static inline int rsock_maybe_fd_writable(int fd) { return 1; } +static inline void rsock_maybe_wait_fd(int fd) { } +#else /* some systems (mswin/mingw) need these. ref: r36946 */ +# define rsock_maybe_fd_writable(fd) rb_thread_fd_writable((fd)) +# define rsock_maybe_wait_fd(fd) rb_thread_wait_fd((fd)) +#endif + #endif -- cgit v1.2.3