TEST(sfrlock, contended_reads_writes_sanity_cpp) {
volatile unsigned cnt = 0;
const unsigned thread_count = 10;
const unsigned inc = 100;
SFRLock sfrlock;
measure_time_concurrent(thread_count, [&] (unsigned idx) {
if (idx < thread_count / 2) {
for (unsigned j = repeat / 5; j; j--) {
{
std::lock_guard<SFRWriteLock> lg(sfrlock.writeLock());
for (unsigned k = inc; k; k--) {
cnt++;
}
}
usleep(1);
}
} else {
for (unsigned j = repeat; j; j--) {
{
std::lock_guard<SFRReadLock> lg(sfrlock.readLock());
EXPECT_EQ(cnt % inc, 0);
}
}
}
});
EXPECT_EQ(cnt, inc * (repeat / 5) * (thread_count / 2));
}
TEST(sfrlock, contended_reads_write_sanity) {
volatile unsigned cnt = 0;
const unsigned thread_count = 5;
const unsigned inc = 100;
sfrlock_t sfrlock;
sfrlock_init(&sfrlock);
measure_time_concurrent(thread_count, [&] (unsigned idx) {
if (!idx) {
for (unsigned j = repeat / 5; j; j--) {
sfrlock_wrlock(&sfrlock);
for (unsigned k = inc; k; k--) {
cnt++;
}
sfrlock_wrunlock(&sfrlock);
usleep(1);
}
} else {
for (unsigned j = repeat; j; j--) {
sfrlock_rdlock(&sfrlock);
EXPECT_EQ(cnt % inc, 0);
sfrlock_rdunlock(&sfrlock);
}
}
});
EXPECT_EQ(cnt, inc * repeat / 5);
}
TEST(sfrlock, contended_write_cost) {
double t;
double r;
const unsigned thread_count = 5;
sfrlock_t sfrlock;
pthread_rwlock_t rwlock;
pthread_mutex_t mutex;
sfrlock_init(&sfrlock);
pthread_rwlock_init(&rwlock, nullptr);
pthread_mutex_init(&mutex, nullptr);
r = measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
sfrlock_wrlock(&sfrlock);
sfrlock_wrunlock(&sfrlock);
}
});
printf("sfrlock_t time: %lf ms\n", r / 1e6);
t = measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
pthread_rwlock_wrlock(&rwlock);
pthread_rwlock_unlock(&rwlock);
}
});
printf("pthread_rwlock_t time: %lf ms (%+.2lf%%)\n", t / 1e6,
-(1 - (t / r)) * 100);
t = measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
pthread_mutex_lock(&mutex);
pthread_mutex_unlock(&mutex);
}
});
printf("pthread_mutex_t time: %lf ms (%+.2lf%%)\n", t / 1e6,
-(1 - (t / r)) * 100);
pthread_rwlock_destroy(&rwlock);
pthread_mutex_destroy(&mutex);
}
TEST(sfrlock, concurrent_reads_sanity_cpp) {
const unsigned thread_count = 20;
SFRLock sfrlock;
measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
std::lock_guard<SFRReadLock> lg(sfrlock.readLock());
}
sfrlock.readLock().lock();
});
}
TEST(sfrlock, contended_writes_sanity_cpp) {
unsigned cnt = 0;
const unsigned thread_count = 5;
SFRLock sfrlock;
measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
{
std::lock_guard<SFRWriteLock> lg(sfrlock.writeLock());
cnt++;
}
}
});
EXPECT_EQ(cnt, thread_count * repeat);
}
TEST(sfrlock, concurrent_reads_sanity) {
const unsigned thread_count = 20;
sfrlock_t sfrlock;
sfrlock_init(&sfrlock);
measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
sfrlock_rdlock(&sfrlock);
sfrlock_rdunlock(&sfrlock);
}
sfrlock_rdlock(&sfrlock);
});
}
TEST(sfrlock, contended_writes_sanity) {
unsigned cnt = 0;
const unsigned thread_count = 5;
sfrlock_t sfrlock;
sfrlock_init(&sfrlock);
measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
sfrlock_wrlock(&sfrlock);
cnt++;
sfrlock_wrunlock(&sfrlock);
}
});
EXPECT_EQ(cnt, thread_count * repeat);
}
TEST(cwlock, contended_single_acquirer) {
const unsigned thread_count = 30;
cwlock_t cwlock;
unsigned owners = 0;
cwlock_init(&cwlock);
measure_time_concurrent(thread_count, [&] (unsigned) {
for (unsigned j = repeat; j; j--) {
if (cwlock_lock(&cwlock)) {
EXPECT_EQ(__sync_fetch_and_add(&owners, 1), 0);
EXPECT_EQ(__sync_sub_and_fetch(&owners, 1), 0);
cwlock_unlock(&cwlock);
}
}
});
}
TEST(cwlock, contended_release_only_once_done) {
const unsigned thread_count = 30;
cwlock_t cwlock;
unsigned inside = 0;
unsigned owners = 0;
cwlock_init(&cwlock);
measure_time_concurrent(thread_count, [&] (unsigned) {
if (cwlock_lock(&cwlock)) {
EXPECT_EQ(__sync_fetch_and_add(&owners, 1), 0);
/*
* Sleep for half a second so that all threads will block before we
* increment the inside count and release the other threads.
*/
usleep(500000);
__sync_fetch_and_add(&inside, 1);
EXPECT_EQ(__sync_sub_and_fetch(&owners, 1), 0);
cwlock_unlock(&cwlock);
}
EXPECT_EQ(inside, 1);
});
}
