susumu.yata
null+****@clear*****
Thu Jul 11 18:12:21 JST 2013
susumu.yata 2013-07-11 18:12:21 +0900 (Thu, 11 Jul 2013) New Revision: e603869b4b5020bb617e1f349ff84daef42afec3 https://github.com/groonga/grnxx/commit/e603869b4b5020bb617e1f349ff84daef42afec3 Message: Fix a bug of grnxx::PeriodicClock. Modified files: lib/grnxx/periodic_clock.cpp lib/grnxx/periodic_clock.hpp test/test_time.cpp Modified: lib/grnxx/periodic_clock.cpp (+22 -15) =================================================================== --- lib/grnxx/periodic_clock.cpp 2013-07-11 16:37:31 +0900 (96a5615) +++ lib/grnxx/periodic_clock.cpp 2013-07-11 18:12:21 +0900 (2f10d49) @@ -17,10 +17,13 @@ */ #include "grnxx/periodic_clock.hpp" -#include "grnxx/thread.hpp" +#include <memory> + +#include "grnxx/intrinsic.hpp" #include "grnxx/lock.hpp" #include "grnxx/logger.hpp" #include "grnxx/mutex.hpp" +#include "grnxx/thread.hpp" namespace grnxx { namespace { @@ -29,8 +32,10 @@ namespace { // busy-wait loop, which exhausts CPU resources. constexpr Duration UPDATE_INTERVAL = Duration::milliseconds(100); +// The number of PeriodicClock objects. volatile uint32_t ref_count = 0; -grnxx::Thread *thread = nullptr; +// The current thread ID. +volatile uint32_t thread_id = 0; Mutex mutex; } // namespace @@ -38,10 +43,12 @@ Mutex mutex; Time PeriodicClock::now_ = Time::min(); PeriodicClock::PeriodicClock() { - // Start the internal thread iff this is the first object. Lock lock(&mutex); if (++ref_count == 1) try { - thread = grnxx::Thread::create(routine); + // Start an internal thread that updates "now_" periodically. + std::unique_ptr<grnxx::Thread> thread(grnxx::Thread::create(routine)); + thread->detach(); + // Immediately update "now_". now_ = SystemClock::now(); } catch (...) { GRNXX_WARNING() << "failed to create thread for PeriodicClock"; @@ -49,25 +56,25 @@ PeriodicClock::PeriodicClock() { } PeriodicClock::~PeriodicClock() { - // Stop the running thread iff this is the last object. Lock lock(&mutex); if (--ref_count == 0) { - try { - thread->detach(); - } catch (...) { - GRNXX_WARNING() << "failed to detach thread for PeriodicClock"; - } - delete thread; - thread = nullptr; now_ = Time::min(); + // Increment "thread_id" so that an internal thread will stop. + atomic_fetch_and_add(1, &thread_id); } } -// Periodically update the internal time variable. void PeriodicClock::routine() { - while (ref_count != 0) { + // Increment "thread_id" to generate the ID of this thread. + const uint64_t this_thread_id = atomic_fetch_and_add(1, &thread_id) + 1; + // This thread terminates if there are no PeriodicClock objects or another + // thread is running. + while ((ref_count != 0) && (this_thread_id == thread_id)) { Thread::sleep_for(UPDATE_INTERVAL); - now_ = SystemClock::now(); + Lock lock(&mutex); + if ((ref_count != 0) && (this_thread_id == thread_id)) { + now_ = SystemClock::now(); + } } } Modified: lib/grnxx/periodic_clock.hpp (+1 -0) =================================================================== --- lib/grnxx/periodic_clock.hpp 2013-07-11 16:37:31 +0900 (68f9a95) +++ lib/grnxx/periodic_clock.hpp 2013-07-11 18:12:21 +0900 (074fdf1) @@ -42,6 +42,7 @@ class PeriodicClock { private: static Time now_; + // Update "now_" periodically. static void routine(); }; Modified: test/test_time.cpp (+12 -14) =================================================================== --- test/test_time.cpp 2013-07-11 16:37:31 +0900 (555d04f) +++ test/test_time.cpp 2013-07-11 18:12:21 +0900 (c6e9b45) @@ -26,6 +26,9 @@ #include "grnxx/time.hpp" void test_time() { + GRNXX_NOTICE() << "grnxx::SystemClock::now() = " + << grnxx::SystemClock::now(); + assert(grnxx::Time::max().count() == std::numeric_limits<std::int64_t>::max()); assert(grnxx::Time::min().count() == @@ -33,9 +36,9 @@ void test_time() { } void test_broken_down_time() { - GRNXX_NOTICE() << "grnxx::SystemClock::now().universal_time(): " + GRNXX_NOTICE() << "grnxx::SystemClock::now().universal_time() = " << grnxx::SystemClock::now().universal_time(); - GRNXX_NOTICE() << "grnxx::SystemClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::SystemClock::now().local_time() = " << grnxx::SystemClock::now().local_time(); enum { LOOP_COUNT = 1 << 16 }; @@ -61,8 +64,7 @@ void test_broken_down_time() { void test_system_clock() { grnxx::Time time = grnxx::SystemClock::now(); - GRNXX_NOTICE() << "grnxx::SystemClock::now(): " << time; - GRNXX_NOTICE() << "grnxx::SystemClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::SystemClock::now().local_time() = " << time.local_time(); enum { LOOP_COUNT = 1 << 16 }; @@ -80,27 +82,23 @@ void test_periodic_clock() { grnxx::PeriodicClock clock; grnxx::Time time = grnxx::PeriodicClock::now(); - GRNXX_NOTICE() << "grnxx::PeriodicClock::now(): " << time; - GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time() = " << time.local_time(); time = grnxx::PeriodicClock::now(); - GRNXX_NOTICE() << "grnxx::PeriodicClock::now(): " << time; - GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time() = " << time.local_time(); - grnxx::Thread::sleep_for(grnxx::Duration::milliseconds(310)); + grnxx::Thread::sleep_for(grnxx::Duration::milliseconds(110)); time = grnxx::PeriodicClock::now(); - GRNXX_NOTICE() << "grnxx::PeriodicClock::now(): " << time; - GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time() = " << time.local_time(); - grnxx::Thread::sleep_for(grnxx::Duration::milliseconds(310)); + grnxx::Thread::sleep_for(grnxx::Duration::milliseconds(110)); time = grnxx::PeriodicClock::now(); - GRNXX_NOTICE() << "grnxx::PeriodicClock::now(): " << time; - GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time(): " + GRNXX_NOTICE() << "grnxx::PeriodicClock::now().local_time() = " << time.local_time(); enum { LOOP_COUNT = 1 << 20 }; -------------- next part -------------- HTML����������������������������...ダウンロード
