From 8c2ae6e3ed072b06fc3cbc34fa8a14b2acbb49d5 Mon Sep 17 00:00:00 2001 From: normal Date: Thu, 2 Aug 2018 21:13:50 +0000 Subject: thread_pthread.c (gvl_acquire_common): persist timeout across calls Reuse old expiration time if the previous native_cond_timedwait did not return ETIMEDOUT. This should improve timeslice accuracy for Timeout.timeout rubyspec without causing excessive wakeups on uncontended GVL acquisition. cf. http://ci.rvm.jp/results/trunk-gc-asserts@silicon-docker/1180486 http://ci.rvm.jp/results/trunk-gc-asserts@silicon-docker/1184623 git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64165 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- thread_pthread.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'thread_pthread.c') diff --git a/thread_pthread.c b/thread_pthread.c index c8487e55f1..b095c2ef1c 100644 --- a/thread_pthread.c +++ b/thread_pthread.c @@ -95,14 +95,20 @@ gvl_acquire_common(rb_vm_t *vm, rb_thread_t *th) list_add_tail(&vm->gvl.waitq, &nd->ubf_list); do { if (!vm->gvl.timer) { - struct timespec ts = { 0, TIME_QUANTUM_USEC * 1000 }; + static struct timespec ts; + static int err = ETIMEDOUT; + /* * become designated timer thread to kick vm->gvl.acquired - * periodically + * periodically. Continue on old timeout if it expired: */ - ts = native_cond_timeout(&nd->cond.gvlq, ts); + if (err == ETIMEDOUT) { + ts.tv_sec = 0; + ts.tv_nsec = TIME_QUANTUM_USEC * 1000; + ts = native_cond_timeout(&nd->cond.gvlq, ts); + } vm->gvl.timer = th; - native_cond_timedwait(&nd->cond.gvlq, &vm->gvl.lock, &ts); + err = native_cond_timedwait(&nd->cond.gvlq, &vm->gvl.lock, &ts); vm->gvl.timer = 0; ubf_wakeup_all_threads(); -- cgit v1.2.3