From ead25f6c6bad5c65dbbe9c887b29a44dc3bf1bb8 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Tue, 29 Jul 2014 14:28:51 -0400 Subject: future: Fix race with two pausing threads. --- libdimension/future.c | 10 ++--- libdimension/tests/Makefile.am | 40 +++++++++-------- libdimension/tests/future.c | 98 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 124 insertions(+), 24 deletions(-) create mode 100644 libdimension/tests/future.c (limited to 'libdimension') diff --git a/libdimension/future.c b/libdimension/future.c index ef3f5e2..8133812 100644 --- a/libdimension/future.c +++ b/libdimension/future.c @@ -164,10 +164,9 @@ dmnsn_future_pause(dmnsn_future *future) while (future->nrunning < future->nthreads) { dmnsn_cond_wait_safely(&future->all_running_cond, &future->mutex); } - if (future->npaused++ == 0) { - while (future->nrunning > 0) { - dmnsn_cond_wait_safely(&future->none_running_cond, &future->mutex); - } + ++future->npaused; + while (future->nrunning > 0) { + dmnsn_cond_wait_safely(&future->none_running_cond, &future->mutex); } dmnsn_unlock_mutex(&future->mutex); } @@ -177,8 +176,7 @@ void dmnsn_future_resume(dmnsn_future *future) { dmnsn_lock_mutex(&future->mutex); - dmnsn_assert(future->npaused > 0, - "dmnsn_future_resume() without matching dmnsn_future_pause()"); + dmnsn_assert(future->npaused > 0, "dmnsn_future_resume() without matching dmnsn_future_pause()"); if (--future->npaused == 0) { dmnsn_cond_broadcast(&future->resume_cond); } diff --git a/libdimension/tests/Makefile.am b/libdimension/tests/Makefile.am index 0349850..0dc9a87 100644 --- a/libdimension/tests/Makefile.am +++ b/libdimension/tests/Makefile.am @@ -22,7 +22,10 @@ AM_CXXFLAGS = $(AM_CFLAGS) check_LTLIBRARIES = libdimension-tests.la \ libdimension-unit-test.la -check_PROGRAMS = warning.test \ +check_PROGRAMS = c89.test \ + c99.test \ + cxx.test \ + warning.test \ warning-as-error.test \ error.test \ custom-error-fn.test \ @@ -30,12 +33,10 @@ check_PROGRAMS = warning.test \ dictionary.test \ polynomial.test \ prtree.test \ + future.test \ png.test \ gl.test \ - render.test \ - c89.test \ - c99.test \ - cxx.test + render.test TESTS = $(check_PROGRAMS) XFAIL_TESTS = warning-as-error.test error.test @@ -64,6 +65,19 @@ libdimension_unit_test_la_SOURCES = unit-test.c libdimension_unit_test_la_CFLAGS = $(CHECK_CFLAGS) $(AM_CFLAGS) libdimension_unit_test_la_LIBADD = $(CHECK_LIBS) $(top_builddir)/libdimension/libdimension.la +c89_test_SOURCES = c89.c +c89_test_LDADD = libdimension-tests.la + +c89.o: CFLAGS += -std=c89 -Wpedantic + +c99_test_SOURCES = c99.c +c99_test_LDADD = libdimension-tests.la + +c99.o: CFLAGS += -std=c99 -Wpedantic + +cxx_test_SOURCES = cxx.cpp +cxx_test_LDADD = libdimension-tests.la + warning_test_SOURCES = warning.c warning_test_LDADD = libdimension-tests.la @@ -88,6 +102,9 @@ polynomial_test_LDADD = libdimension-unit-test.la prtree_test_SOURCES = prtree.c prtree_test_LDADD = libdimension-tests.la +future_test_SOURCES = future.c +future_test_LDADD = libdimension-unit-test.la + png_test_SOURCES = png.c png_test_LDADD = libdimension-tests.la @@ -97,18 +114,5 @@ gl_test_LDADD = libdimension-tests.la render_test_SOURCES = render.c render_test_LDADD = libdimension-tests.la -c89_test_SOURCES = c89.c -c89_test_LDADD = libdimension-tests.la - -c89.o: CFLAGS += -std=c89 -Wpedantic - -c99_test_SOURCES = c99.c -c99_test_LDADD = libdimension-tests.la - -c99.o: CFLAGS += -std=c99 -Wpedantic - -cxx_test_SOURCES = cxx.cpp -cxx_test_LDADD = libdimension-tests.la - clean-local: rm -f *.png diff --git a/libdimension/tests/future.c b/libdimension/tests/future.c new file mode 100644 index 0000000..ee2511a --- /dev/null +++ b/libdimension/tests/future.c @@ -0,0 +1,98 @@ +/************************************************************************* + * Copyright (C) 2014 Tavian Barnes * + * * + * This file is part of The Dimension Test Suite. * + * * + * The Dimension Test Suite is free software; you can redistribute it * + * and/or modify it under the terms of the GNU General Public License as * + * published by the Free Software Foundation; either version 3 of the * + * License, or (at your option) any later version. * + * * + * The Dimension Test Suite is distributed in the hope that it will be * + * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * + * General Public License for more details. * + * * + * You should have received a copy of the GNU General Public License * + * along with this program. If not, see . * + *************************************************************************/ + +/** + * @file + * Tests for dmnsn_future. + */ + +#include "../platform.c" +#include "../future.c" +#include "../threads.c" +#include "tests.h" +#include + +static dmnsn_future *future; +static atomic_int counter = ATOMIC_VAR_INIT(0); +static const int NTHREADS = 8; +static const int CHUNK = 100; + +static int +dmnsn_future_test_ccthread(void *ptr, unsigned int thread, unsigned int nthreads) +{ + for (int i = 0; i < CHUNK; ++i) { + for (int j = 0; j < CHUNK; ++j) { + atomic_fetch_add(&counter, 1); + } + dmnsn_future_increment(future); + } + return 0; +} + +static int +dmnsn_future_test_thread(void *ptr) +{ + dmnsn_future_set_total(future, NTHREADS*CHUNK); + return dmnsn_execute_concurrently(future, dmnsn_future_test_ccthread, ptr, NTHREADS); +} + +DMNSN_TEST_SETUP(future) +{ + future = dmnsn_new_future(); + dmnsn_new_thread(future, dmnsn_future_test_thread, NULL); +} + +DMNSN_TEST_TEARDOWN(future) +{ + int res = dmnsn_future_join(future); + ck_assert_int_eq(res, 0); +} + +void * +dmnsn_future_pause_and_check(void *ptr) +{ + for (int i = 0; i < CHUNK; ++i) { + dmnsn_future_pause(future); + + int value = atomic_load(&counter); + ck_assert_int_eq(value%CHUNK, 0); + + for (int j = 0; j < CHUNK; ++j) { + int new_value = atomic_load(&counter); + ck_assert_int_eq(new_value, value); + } + + dmnsn_future_resume(future); + } + + return NULL; +} + +DMNSN_TEST(future, pause_safely) +{ + // Check dmnsn_future_pause() behaviour from two concurrent threads + pthread_t thread; + if (pthread_create(&thread, NULL, dmnsn_future_pause_and_check, NULL) != 0) { + dmnsn_error("Couldn't start thread."); + } + + dmnsn_future_pause_and_check(NULL); + + dmnsn_join_thread(thread, NULL); +} -- cgit v1.2.3