diff options
author | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-08-24 19:19:01 +0000 |
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committer | normal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-08-24 19:19:01 +0000 |
commit | 0a77fd04b7ee902d3542b12986731a5b4d3e6d51 (patch) | |
tree | 12b05fc37d63dc66e5bb54304c106eac0b191a19 /thread_pthread.c | |
parent | 5bd4283f77ba1bbaf72b365e9d9e24b7abd7bd49 (diff) |
thread_pthread.c: use eventfd instead of pipe on Linux
Based on r64478, any regular user creating more than 1024 pipes
on Linux will end up with tiny pipes with only a single page
capacity. So avoid wasting user resources and use lighter
eventfd on Linux.
[ruby-core:88563] [Misc #15011]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64527 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'thread_pthread.c')
-rw-r--r-- | thread_pthread.c | 50 |
1 files changed, 42 insertions, 8 deletions
diff --git a/thread_pthread.c b/thread_pthread.c index 64b2684c22..52e2a049f1 100644 --- a/thread_pthread.c +++ b/thread_pthread.c @@ -37,6 +37,13 @@ #include <time.h> #include <signal.h> +#if defined(HAVE_SYS_EVENTFD_H) && defined(HAVE_EVENTFD) +# define USE_EVENTFD (1) +# include <sys/eventfd.h> +#else +# define USE_EVENTFD (0) +#endif + #if defined(SIGVTALRM) && !defined(__CYGWIN__) # define USE_UBF_LIST 1 #endif @@ -1386,13 +1393,17 @@ static struct { static void rb_thread_wakeup_timer_thread_fd(int fd) { +#if USE_EVENTFD + const uint64_t buff = 1; +#else + const char buff = '!'; +#endif ssize_t result; /* already opened */ if (fd >= 0) { - static const char buff[1] = {'!'}; retry: - if ((result = write(fd, buff, 1)) <= 0) { + if ((result = write(fd, &buff, sizeof(buff))) <= 0) { int e = errno; switch (e) { case EINTR: goto retry; @@ -1505,8 +1516,8 @@ rb_thread_wakeup_timer_thread(int sig) } } -#define CLOSE_INVALIDATE(expr) \ - close_invalidate(&expr,"close_invalidate: "#expr) +#define CLOSE_INVALIDATE_PAIR(expr) \ + close_invalidate_pair(expr,"close_invalidate: "#expr) static void close_invalidate(int *fdp, const char *msg) { @@ -1519,6 +1530,19 @@ close_invalidate(int *fdp, const char *msg) } static void +close_invalidate_pair(int fds[2], const char *msg) +{ + if (USE_EVENTFD && fds[0] == fds[1]) { + close_invalidate(&fds[0], msg); + fds[1] = -1; + } + else { + close_invalidate(&fds[0], msg); + close_invalidate(&fds[1], msg); + } +} + +static void set_nonblock(int fd) { int oflags; @@ -1545,6 +1569,18 @@ setup_communication_pipe_internal(int pipes[2]) return 0; } + /* + * Don't bother with eventfd on ancient Linux 2.6.22..2.6.26 which were + * missing EFD_* flags, they can fall back to pipe + */ +#if USE_EVENTFD && defined(EFD_NONBLOCK) && defined(EFD_CLOEXEC) + pipes[0] = pipes[1] = eventfd(0, EFD_NONBLOCK|EFD_CLOEXEC); + if (pipes[0] >= 0) { + rb_update_max_fd(pipes[0]); + return 0; + } +#endif + err = rb_cloexec_pipe(pipes); if (err != 0) { rb_warn("pipe creation failed for timer: %s, scheduling broken", @@ -1612,8 +1648,7 @@ static void ubf_timer_invalidate(void) { #if UBF_TIMER == UBF_TIMER_PTHREAD - CLOSE_INVALIDATE(timer_pthread.low[0]); - CLOSE_INVALIDATE(timer_pthread.low[1]); + CLOSE_INVALIDATE_PAIR(timer_pthread.low); #endif } @@ -1669,8 +1704,7 @@ rb_thread_create_timer_thread(void) rb_pid_t owner = signal_self_pipe.owner_process; if (owner && owner != current) { - CLOSE_INVALIDATE(signal_self_pipe.normal[0]); - CLOSE_INVALIDATE(signal_self_pipe.normal[1]); + CLOSE_INVALIDATE_PAIR(signal_self_pipe.normal); ubf_timer_invalidate(); } |