blob: 253df0dd516a845eb7c0f6e84c42f435b56f4291 [file] [log] [blame]
// Copyright 2017 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT
#include <err.h>
#include <inttypes.h>
#include <lib/unittest/unittest.h>
#include <platform.h>
#include <pow2.h>
#include <stdio.h>
#include <stdlib.h>
#include <zircon/time.h>
#include <zircon/types.h>
#include <fbl/algorithm.h>
#include <fbl/auto_call.h>
#include <kernel/auto_lock.h>
#include <kernel/cpu.h>
#include <kernel/event.h>
#include <kernel/mp.h>
#include <kernel/spinlock.h>
#include <kernel/thread.h>
#include <kernel/timer.h>
#include <ktl/atomic.h>
#include <ktl/iterator.h>
#include <ktl/optional.h>
#include <ktl/unique_ptr.h>
#include "tests.h"
static void timer_diag_cb(Timer* timer, zx_time_t now, void* arg) {
Event* event = (Event*)arg;
event->Signal();
}
static int timer_do_one_thread(void* arg) {
Event event;
Timer timer;
const Deadline deadline = Deadline::after(ZX_MSEC(10));
timer.Set(deadline, timer_diag_cb, &event);
event.Wait();
printf("got timer on cpu %u\n", arch_curr_cpu_num());
return 0;
}
static void timer_diag_all_cpus(void) {
Thread* timer_threads[SMP_MAX_CPUS];
uint max = arch_max_num_cpus();
uint i;
for (i = 0; i < max; i++) {
char name[16];
snprintf(name, sizeof(name), "timer %u\n", i);
timer_threads[i] =
Thread::CreateEtc(NULL, name, timer_do_one_thread, NULL, DEFAULT_PRIORITY, NULL);
DEBUG_ASSERT_MSG(timer_threads[i] != NULL, "failed to create thread for cpu %u\n", i);
timer_threads[i]->SetCpuAffinity(cpu_num_to_mask(i));
timer_threads[i]->Resume();
}
for (i = 0; i < max; i++) {
zx_status_t status = timer_threads[i]->Join(NULL, ZX_TIME_INFINITE);
DEBUG_ASSERT_MSG(status == ZX_OK, "failed to join thread for cpu %u: %d\n", i, status);
}
}
static void timer_diag_cb2(Timer* timer, zx_time_t now, void* arg) {
auto timer_count = static_cast<ktl::atomic<size_t>*>(arg);
timer_count->fetch_add(1);
Thread::Current::preemption_state().PreemptSetPending();
}
static void timer_diag_coalescing(TimerSlack slack, const zx_time_t* deadline,
const zx_duration_t* expected_adj, size_t count) {
printf("testing coalsecing mode %u\n", slack.mode());
ktl::atomic<size_t> timer_count(0);
fbl::AllocChecker ac;
auto timers = ktl::unique_ptr<Timer[]>(new (&ac) Timer[count]);
if (!ac.check()) {
printf("\n!! failed to allocate %zu timers\n", count);
return;
}
printf(" orig new adjustment\n");
for (size_t ix = 0; ix != count; ++ix) {
const Deadline dl(deadline[ix], slack);
timers[ix].Set(dl, timer_diag_cb2, &timer_count);
printf("[%zu] %" PRIi64 " -> %" PRIi64 ", %" PRIi64 "\n", ix, dl.when(),
timers[ix].scheduled_time_for_test(), timers[ix].slack_for_test());
if (timers[ix].slack_for_test() != expected_adj[ix]) {
printf("\n!! unexpected adjustment! expected %" PRIi64 "\n", expected_adj[ix]);
}
}
// Wait for the timers to fire.
while (timer_count.load() != count) {
Thread::Current::Sleep(current_time() + ZX_MSEC(5));
}
}
static void timer_diag_coalescing_center(void) {
zx_time_t when = current_time() + ZX_MSEC(1);
zx_duration_t off = ZX_USEC(10);
TimerSlack slack = {2u * off, TIMER_SLACK_CENTER};
const zx_time_t deadline[] = {
when + (6u * off), // non-coalesced, adjustment = 0
when, // non-coalesced, adjustment = 0
when - off, // coalesced with [1], adjustment = 10u
when - (3u * off), // non-coalesced, adjustment = 0
when + off, // coalesced with [1], adjustment = -10u
when + (3u * off), // non-coalesced, adjustment = 0
when + (5u * off), // coalesced with [0], adjustment = 10u
when - (3u * off), // non-coalesced, same as [3], adjustment = 0
};
const zx_duration_t expected_adj[ktl::size(deadline)] = {
0, 0, ZX_USEC(10), 0, -ZX_USEC(10), 0, ZX_USEC(10), 0};
timer_diag_coalescing(slack, deadline, expected_adj, ktl::size(deadline));
}
static void timer_diag_coalescing_late(void) {
zx_time_t when = current_time() + ZX_MSEC(1);
zx_duration_t off = ZX_USEC(10);
TimerSlack slack = {3u * off, TIMER_SLACK_LATE};
const zx_time_t deadline[] = {
when + off, // non-coalesced, adjustment = 0
when + (2u * off), // non-coalesced, adjustment = 0
when - off, // coalesced with [0], adjustment = 20u
when - (3u * off), // non-coalesced, adjustment = 0
when + (3u * off), // non-coalesced, adjustment = 0
when + (2u * off), // non-coalesced, same as [1]
when - (4u * off), // coalesced with [3], adjustment = 10u
};
const zx_duration_t expected_adj[ktl::size(deadline)] = {0, 0, ZX_USEC(20), 0, 0, 0, ZX_USEC(10)};
timer_diag_coalescing(slack, deadline, expected_adj, ktl::size(deadline));
}
static void timer_diag_coalescing_early(void) {
zx_time_t when = current_time() + ZX_MSEC(1);
zx_duration_t off = ZX_USEC(10);
TimerSlack slack = {3u * off, TIMER_SLACK_EARLY};
const zx_time_t deadline[] = {
when, // non-coalesced, adjustment = 0
when + (2u * off), // coalesced with [0], adjustment = -20u
when - off, // non-coalesced, adjustment = 0
when - (3u * off), // non-coalesced, adjustment = 0
when + (4u * off), // non-coalesced, adjustment = 0
when + (5u * off), // coalesced with [4], adjustment = -10u
when - (2u * off), // coalesced with [3], adjustment = -10u
};
const zx_duration_t expected_adj[ktl::size(deadline)] = {0, -ZX_USEC(20), 0, 0,
0, -ZX_USEC(10), -ZX_USEC(10)};
timer_diag_coalescing(slack, deadline, expected_adj, ktl::size(deadline));
}
static void timer_far_deadline(void) {
Event event;
Timer timer;
const Deadline deadline = Deadline::no_slack(ZX_TIME_INFINITE - 5);
timer.Set(deadline, timer_diag_cb, &event);
zx_status_t st = event.WaitDeadline(current_time() + ZX_MSEC(100), Interruptible::No);
if (st != ZX_ERR_TIMED_OUT) {
printf("error: unexpected timer fired!\n");
} else {
timer.Cancel();
}
}
// Print timer diagnostics for manual review.
int timer_diag(int, const cmd_args*, uint32_t) {
timer_diag_coalescing_center();
timer_diag_coalescing_late();
timer_diag_coalescing_early();
timer_diag_all_cpus();
timer_far_deadline();
return 0;
}
struct timer_stress_args {
ktl::atomic<int> timer_stress_done;
ktl::atomic<uint64_t> num_set;
ktl::atomic<uint64_t> num_fired;
};
static void timer_stress_cb(Timer* t, zx_time_t now, void* void_arg) {
timer_stress_args* args = reinterpret_cast<timer_stress_args*>(void_arg);
args->num_fired++;
}
// Returns a random duration between 0 and max (inclusive).
static zx_duration_t rand_duration(zx_duration_t max) {
return (zx_duration_mul_int64(max, rand())) / RAND_MAX;
}
static int timer_stress_worker(void* void_arg) {
timer_stress_args* args = reinterpret_cast<timer_stress_args*>(void_arg);
while (!args->timer_stress_done.load()) {
Timer t;
zx_duration_t timer_duration = rand_duration(ZX_MSEC(5));
// Set a timer, then switch to a different CPU to ensure we race with it.
interrupt_saved_state_t int_state = arch_interrupt_save();
cpu_num_t timer_cpu = arch_curr_cpu_num();
const Deadline deadline = Deadline::after(timer_duration);
t.Set(deadline, timer_stress_cb, void_arg);
Thread::Current::Get()->SetCpuAffinity(~cpu_num_to_mask(timer_cpu));
DEBUG_ASSERT(arch_curr_cpu_num() != timer_cpu);
arch_interrupt_restore(int_state);
// We're now running on something other than timer_cpu.
args->num_set++;
// Sleep for the timer duration so that this thread's timer_cancel races with the timer
// callback. We want to race to ensure there are no synchronization or memory visibility
// issues.
Thread::Current::SleepRelative(timer_duration);
t.Cancel();
}
return 0;
}
static unsigned get_num_cpus_online() {
unsigned count = 0;
cpu_mask_t online = mp_get_online_mask();
while (online) {
online >>= 1;
++count;
}
return count;
}
// timer_stress is a simple stress test intended to flush out bugs in kernel timers.
int timer_stress(int argc, const cmd_args* argv, uint32_t) {
if (argc < 2) {
printf("not enough args\n");
printf("usage: %s <num seconds>\n", argv[0].str);
return ZX_ERR_INTERNAL;
}
// We need 2 or more CPUs for this test.
if (get_num_cpus_online() < 2) {
printf("not enough online cpus\n");
return ZX_ERR_INTERNAL;
}
timer_stress_args args{};
Thread* threads[256];
for (auto& thread : threads) {
thread = Thread::Create("timer-stress-worker", &timer_stress_worker, &args, DEFAULT_PRIORITY);
}
printf("running for %zu seconds\n", argv[1].u);
for (const auto& thread : threads) {
thread->Resume();
}
Thread::Current::SleepRelative(ZX_SEC(argv[1].u));
args.timer_stress_done.store(1);
for (const auto& thread : threads) {
thread->Join(nullptr, ZX_TIME_INFINITE);
}
printf("timer stress done; timer set %zu, timer fired %zu\n", args.num_set.load(),
args.num_fired.load());
return 0;
}
struct timer_args {
ktl::atomic<int> result;
ktl::atomic<int> timer_fired;
ktl::atomic<int> remaining;
ktl::atomic<int> wait;
SpinLock* lock;
};
static void timer_cb(Timer*, zx_time_t now, void* void_arg) {
timer_args* arg = reinterpret_cast<timer_args*>(void_arg);
arg->timer_fired.store(1);
}
// Set a timer and cancel it before the deadline has elapsed.
static bool cancel_before_deadline() {
BEGIN_TEST;
timer_args arg{};
Timer t;
const Deadline deadline = Deadline::after(ZX_HOUR(5));
t.Set(deadline, timer_cb, &arg);
ASSERT_TRUE(t.Cancel());
ASSERT_FALSE(arg.timer_fired.load());
END_TEST;
}
// Set a timer and cancel it after it has fired.
static bool cancel_after_fired() {
BEGIN_TEST;
timer_args arg{};
Timer t;
const Deadline deadline = Deadline::no_slack(current_time());
t.Set(deadline, timer_cb, &arg);
while (!arg.timer_fired.load()) {
}
ASSERT_FALSE(t.Cancel());
END_TEST;
}
static void timer_cancel_cb(Timer* t, zx_time_t now, void* void_arg) {
timer_args* arg = reinterpret_cast<timer_args*>(void_arg);
arg->result.store(t->Cancel());
arg->timer_fired.store(1);
}
// Set a timer and cancel it from its own callback.
static bool cancel_from_callback() {
BEGIN_TEST;
timer_args arg{};
arg.result = 1;
Timer t;
const Deadline deadline = Deadline::no_slack(current_time());
t.Set(deadline, timer_cancel_cb, &arg);
while (!arg.timer_fired.load()) {
}
ASSERT_FALSE(arg.result);
ASSERT_FALSE(t.Cancel());
END_TEST;
}
static void timer_set_cb(Timer* t, zx_time_t now, void* void_arg) {
timer_args* arg = reinterpret_cast<timer_args*>(void_arg);
if (arg->remaining.fetch_sub(1) >= 1) {
const Deadline deadline = Deadline::after(ZX_USEC(10));
t->Set(deadline, timer_set_cb, void_arg);
}
}
// Set a timer that re-sets itself from its own callback.
static bool set_from_callback() {
BEGIN_TEST;
timer_args arg{};
arg.remaining = 5;
Timer t;
const Deadline deadline = Deadline::no_slack(current_time());
t.Set(deadline, timer_set_cb, &arg);
while (arg.remaining.load() > 0) {
}
// We cannot assert the return value below because we don't know if the last timer has fired.
t.Cancel();
END_TEST;
}
static void timer_trylock_cb(Timer* t, zx_time_t now, void* void_arg) {
timer_args* arg = reinterpret_cast<timer_args*>(void_arg);
arg->timer_fired.store(1);
while (arg->wait.load()) {
}
int result = t->TrylockOrCancel(arg->lock);
if (!result) {
arg->lock->Release();
}
arg->result.store(result);
}
// See that timer_trylock_or_cancel spins until the timer is canceled.
static bool trylock_or_cancel_canceled() {
BEGIN_TEST;
// We need 2 or more CPUs for this test.
if (get_num_cpus_online() < 2) {
printf("skipping test trylock_or_cancel_canceled, not enough online cpus\n");
return true;
}
timer_args arg{};
Timer t;
SpinLock lock;
arg.lock = &lock;
arg.wait = 1;
interrupt_saved_state_t int_state = arch_interrupt_save();
cpu_num_t timer_cpu = arch_curr_cpu_num();
const Deadline deadline = Deadline::after(ZX_USEC(100));
t.Set(deadline, timer_trylock_cb, &arg);
// The timer is set to run on timer_cpu, switch to a different CPU, acquire the spinlock then
// signal the callback to proceed.
Thread::Current::Get()->SetCpuAffinity(~cpu_num_to_mask(timer_cpu));
DEBUG_ASSERT(arch_curr_cpu_num() != timer_cpu);
arch_interrupt_restore(int_state);
{
AutoSpinLock guard(&lock);
while (!arg.timer_fired.load()) {
}
// Callback should now be running. Tell it to stop waiting and start trylocking.
arg.wait.store(0);
// See that timer_cancel returns false indicating that the timer ran.
ASSERT_FALSE(t.Cancel());
}
// See that the timer failed to acquire the lock.
ASSERT_TRUE(arg.result);
END_TEST;
}
// See that timer_trylock_or_cancel acquires the lock when the holder releases it.
static bool trylock_or_cancel_get_lock() {
BEGIN_TEST;
// We need 2 or more CPUs for this test.
if (get_num_cpus_online() < 2) {
printf("skipping test trylock_or_cancel_get_lock, not enough online cpus\n");
return true;
}
timer_args arg{};
Timer t;
SpinLock lock;
arg.lock = &lock;
arg.wait = 1;
interrupt_saved_state_t int_state = arch_interrupt_save();
cpu_num_t timer_cpu = arch_curr_cpu_num();
const Deadline deadline = Deadline::after(ZX_USEC(100));
t.Set(deadline, timer_trylock_cb, &arg);
// The timer is set to run on timer_cpu, switch to a different CPU, acquire the spinlock then
// signal the callback to proceed.
Thread::Current::Get()->SetCpuAffinity(~cpu_num_to_mask(timer_cpu));
DEBUG_ASSERT(arch_curr_cpu_num() != timer_cpu);
arch_interrupt_restore(int_state);
{
AutoSpinLock guard(&lock);
while (!arg.timer_fired.load()) {
}
// Callback should now be running. Tell it to stop waiting and start trylocking.
arg.wait.store(0);
}
// See that timer_cancel returns false indicating that the timer ran.
ASSERT_FALSE(t.Cancel());
// Note, we cannot assert the value of arg.result. We have both released the lock and canceled
// the timer, but we don't know which of these events the timer observed first.
END_TEST;
}
static bool print_timer_queues() {
BEGIN_TEST;
// Allocate a bunch of timers and a small buffer. Set the timers then see that |PrintTimerQueues|
// doesn't overflow the buffer.
constexpr size_t kNumTimers = 1000;
fbl::AllocChecker ac;
auto timers = ktl::unique_ptr<Timer[]>(new (&ac) Timer[kNumTimers]);
ASSERT_TRUE(ac.check());
constexpr size_t kBufferSize = 4096;
auto buffer = ktl::unique_ptr<char[]>(new (&ac) char[kBufferSize]);
ASSERT_TRUE(ac.check());
// Fill the buffer with a pattern so we can detect overflow.
memset(buffer.get(), 'X', kBufferSize);
for (size_t i = 0; i < kNumTimers; ++i) {
timers[i].Set(
Deadline::infinite(), [](Timer*, zx_time_t, void*) {}, nullptr);
}
auto cleanup = fbl::MakeAutoCall([&]() {
for (size_t i = 0; i < kNumTimers; ++i) {
timers[i].Cancel();
}
});
// Tell |PrintTimerQueues| the buffer is one less than it really is.
TimerQueue::PrintTimerQueues(buffer.get(), kBufferSize - 1);
// See that our sentinel was not overwritten.
ASSERT_EQ('X', buffer[kBufferSize - 1]);
// See that a null terminator was written to the last available position.
ASSERT_EQ(0, buffer[kBufferSize - 2]);
END_TEST;
}
static bool deadline_after() {
BEGIN_TEST;
ktl::array<ktl::optional<TimerSlack>, 5> kSlackModes{
ktl::nullopt, // nullopt is used for testing the default mode (should be "none").
TimerSlack::none(), // an explicit test of "none"
TimerSlack(ZX_USEC(100), TIMER_SLACK_CENTER),
TimerSlack(ZX_USEC(200), TIMER_SLACK_EARLY),
TimerSlack(ZX_USEC(200), TIMER_SLACK_LATE),
};
// Test to make sure that a relative timeout which is an infinite amount of
// time from now produces an infinite deadline.
for (const auto& slack : kSlackModes) {
Deadline deadline = slack.has_value() ? Deadline::after(ZX_TIME_INFINITE, slack.value())
: Deadline::after(ZX_TIME_INFINITE);
ASSERT_EQ(ZX_TIME_INFINITE, deadline.when());
// Default slack should be "none"
const TimerSlack& expected = slack.has_value() ? slack.value() : TimerSlack::none();
ASSERT_EQ(expected.amount(), deadline.slack().amount());
ASSERT_EQ(expected.mode(), deadline.slack().mode());
}
// While we cannot control the precise deadline which will be produced from
// our call to Deadline::after, we _can_ bound the range it might exist in.
// Test for this as well.
for (const auto& slack : kSlackModes) {
constexpr zx_duration_t kTimeout = ZX_MSEC(10);
zx_time_t before = zx_time_add_duration(current_time(), kTimeout);
Deadline deadline =
slack.has_value() ? Deadline::after(kTimeout, slack.value()) : Deadline::after(kTimeout);
zx_time_t after = zx_time_add_duration(current_time(), kTimeout);
ASSERT_LE(before, deadline.when());
ASSERT_GE(after, deadline.when());
// Default slack should be "none"
const TimerSlack& expected = slack.has_value() ? slack.value() : TimerSlack::none();
ASSERT_EQ(expected.amount(), deadline.slack().amount());
ASSERT_EQ(expected.mode(), deadline.slack().mode());
}
END_TEST;
}
UNITTEST_START_TESTCASE(timer_tests)
UNITTEST("cancel_before_deadline", cancel_before_deadline)
UNITTEST("cancel_after_fired", cancel_after_fired)
UNITTEST("cancel_from_callback", cancel_from_callback)
UNITTEST("set_from_callback", set_from_callback)
UNITTEST("trylock_or_cancel_canceled", trylock_or_cancel_canceled)
UNITTEST("trylock_or_cancel_get_lock", trylock_or_cancel_get_lock)
UNITTEST("print_timer_queue", print_timer_queues)
UNITTEST("Deadline::after", deadline_after)
UNITTEST_END_TESTCASE(timer_tests, "timer", "timer tests")