bionic/tests/pthread_test.cpp
msg555 0f020d18b1 Handles spurious wake-ups in pthread_join()
Removed 'join_count' from pthread_internal_t and switched to using the flag
PTHREAD_ATTR_FLAG_JOINED to indicate if a thread is being joined. Combined with
a switch to a while loop in pthread_join, this fixes spurious wake-ups but
prevents a thread from being joined multiple times. This is fine for
two reasons:

1) The pthread_join specification allows for undefined behavior when multiple
   threads try to join a single thread.

2) There is no thread safe way to allow multiple threads to join a single
   thread with the pthread interface.  The second thread calling pthread_join
   could be pre-empted until the thread is destroyed and its handle reused for
   a different thread.  Therefore multi-join is always an error.

Bug: https://code.google.com/p/android/issues/detail?id=52255
Change-Id: I8b6784d47620ffdcdbfb14524e7402e21d46c5f7
2013-06-12 17:30:58 -07:00

342 lines
10 KiB
C++

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <gtest/gtest.h>
#include <errno.h>
#include <pthread.h>
#include <unistd.h>
TEST(pthread, pthread_key_create) {
pthread_key_t key;
ASSERT_EQ(0, pthread_key_create(&key, NULL));
ASSERT_EQ(0, pthread_key_delete(key));
// Can't delete a key that's already been deleted.
ASSERT_EQ(EINVAL, pthread_key_delete(key));
}
#if !defined(__GLIBC__) // glibc uses keys internally that its sysconf value doesn't account for.
TEST(pthread, pthread_key_create_lots) {
// We can allocate _SC_THREAD_KEYS_MAX keys.
std::vector<pthread_key_t> keys;
for (int i = 0; i < sysconf(_SC_THREAD_KEYS_MAX); ++i) {
pthread_key_t key;
// If this fails, it's likely that GLOBAL_INIT_THREAD_LOCAL_BUFFER_COUNT is wrong.
ASSERT_EQ(0, pthread_key_create(&key, NULL)) << i << " of " << sysconf(_SC_THREAD_KEYS_MAX);
keys.push_back(key);
}
// ...and that really is the maximum.
pthread_key_t key;
ASSERT_EQ(EAGAIN, pthread_key_create(&key, NULL));
// (Don't leak all those keys!)
for (size_t i = 0; i < keys.size(); ++i) {
ASSERT_EQ(0, pthread_key_delete(keys[i]));
}
}
#endif
static void* IdFn(void* arg) {
return arg;
}
static void* SleepFn(void* arg) {
sleep(reinterpret_cast<unsigned int>(arg));
return NULL;
}
static void* SpinFn(void* arg) {
volatile bool* b = reinterpret_cast<volatile bool*>(arg);
while (!*b) {
}
return NULL;
}
static void* JoinFn(void* arg) {
return reinterpret_cast<void*>(pthread_join(reinterpret_cast<pthread_t>(arg), NULL));
}
static void AssertDetached(pthread_t t, bool is_detached) {
pthread_attr_t attr;
ASSERT_EQ(0, pthread_getattr_np(t, &attr));
int detach_state;
ASSERT_EQ(0, pthread_attr_getdetachstate(&attr, &detach_state));
pthread_attr_destroy(&attr);
ASSERT_EQ(is_detached, (detach_state == PTHREAD_CREATE_DETACHED));
}
static void MakeDeadThread(pthread_t& t) {
ASSERT_EQ(0, pthread_create(&t, NULL, IdFn, NULL));
void* result;
ASSERT_EQ(0, pthread_join(t, &result));
}
TEST(pthread, pthread_create) {
void* expected_result = reinterpret_cast<void*>(123);
// Can we create a thread?
pthread_t t;
ASSERT_EQ(0, pthread_create(&t, NULL, IdFn, expected_result));
// If we join, do we get the expected value back?
void* result;
ASSERT_EQ(0, pthread_join(t, &result));
ASSERT_EQ(expected_result, result);
}
TEST(pthread, pthread_create_EAGAIN) {
pthread_attr_t attributes;
ASSERT_EQ(0, pthread_attr_init(&attributes));
ASSERT_EQ(0, pthread_attr_setstacksize(&attributes, static_cast<size_t>(-1) & ~(getpagesize() - 1)));
pthread_t t;
ASSERT_EQ(EAGAIN, pthread_create(&t, &attributes, IdFn, NULL));
}
TEST(pthread, pthread_no_join_after_detach) {
pthread_t t1;
ASSERT_EQ(0, pthread_create(&t1, NULL, SleepFn, reinterpret_cast<void*>(5)));
// After a pthread_detach...
ASSERT_EQ(0, pthread_detach(t1));
AssertDetached(t1, true);
// ...pthread_join should fail.
void* result;
ASSERT_EQ(EINVAL, pthread_join(t1, &result));
}
TEST(pthread, pthread_no_op_detach_after_join) {
bool done = false;
pthread_t t1;
ASSERT_EQ(0, pthread_create(&t1, NULL, SpinFn, &done));
// If thread 2 is already waiting to join thread 1...
pthread_t t2;
ASSERT_EQ(0, pthread_create(&t2, NULL, JoinFn, reinterpret_cast<void*>(t1)));
sleep(1); // (Give t2 a chance to call pthread_join.)
// ...a call to pthread_detach on thread 1 will "succeed" (silently fail)...
ASSERT_EQ(0, pthread_detach(t1));
AssertDetached(t1, false);
done = true;
// ...but t2's join on t1 still goes ahead (which we can tell because our join on t2 finishes).
void* join_result;
ASSERT_EQ(0, pthread_join(t2, &join_result));
ASSERT_EQ(0, reinterpret_cast<int>(join_result));
}
TEST(pthread, pthread_join_self) {
void* result;
ASSERT_EQ(EDEADLK, pthread_join(pthread_self(), &result));
}
#if __BIONIC__ // For some reason, gtest on bionic can cope with this but gtest on glibc can't.
static void TestBug37410() {
pthread_t t1;
ASSERT_EQ(0, pthread_create(&t1, NULL, JoinFn, reinterpret_cast<void*>(pthread_self())));
pthread_exit(NULL);
}
// Even though this isn't really a death test, we have to say "DeathTest" here so gtest knows to
// run this test (which exits normally) in its own process.
TEST(pthread_DeathTest, pthread_bug_37410) {
// http://code.google.com/p/android/issues/detail?id=37410
::testing::FLAGS_gtest_death_test_style = "threadsafe";
ASSERT_EXIT(TestBug37410(), ::testing::ExitedWithCode(0), "");
}
#endif
static void* SignalHandlerFn(void* arg) {
sigset_t wait_set;
sigfillset(&wait_set);
return reinterpret_cast<void*>(sigwait(&wait_set, reinterpret_cast<int*>(arg)));
}
TEST(pthread, pthread_sigmask) {
// Block SIGUSR1.
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGUSR1);
ASSERT_EQ(0, pthread_sigmask(SIG_BLOCK, &set, NULL));
// Spawn a thread that calls sigwait and tells us what it received.
pthread_t signal_thread;
int received_signal = -1;
ASSERT_EQ(0, pthread_create(&signal_thread, NULL, SignalHandlerFn, &received_signal));
// Send that thread SIGUSR1.
pthread_kill(signal_thread, SIGUSR1);
// See what it got.
void* join_result;
ASSERT_EQ(0, pthread_join(signal_thread, &join_result));
ASSERT_EQ(SIGUSR1, received_signal);
ASSERT_EQ(0, reinterpret_cast<int>(join_result));
}
#if __BIONIC__
extern "C" int __pthread_clone(void* (*fn)(void*), void* child_stack, int flags, void* arg);
TEST(pthread, __pthread_clone) {
uintptr_t fake_child_stack[16];
errno = 0;
ASSERT_EQ(-1, __pthread_clone(NULL, &fake_child_stack[0], CLONE_THREAD, NULL));
ASSERT_EQ(EINVAL, errno);
}
#endif
#if __BIONIC__ // Not all build servers have a new enough glibc? TODO: remove when they're on gprecise.
TEST(pthread, pthread_setname_np__too_long) {
ASSERT_EQ(ERANGE, pthread_setname_np(pthread_self(), "this name is far too long for linux"));
}
#endif
#if __BIONIC__ // Not all build servers have a new enough glibc? TODO: remove when they're on gprecise.
TEST(pthread, pthread_setname_np__self) {
ASSERT_EQ(0, pthread_setname_np(pthread_self(), "short 1"));
}
#endif
#if __BIONIC__ // Not all build servers have a new enough glibc? TODO: remove when they're on gprecise.
TEST(pthread, pthread_setname_np__other) {
// Emulator kernels don't currently support setting the name of other threads.
char* filename = NULL;
asprintf(&filename, "/proc/self/task/%d/comm", gettid());
struct stat sb;
bool has_comm = (stat(filename, &sb) != -1);
free(filename);
if (has_comm) {
pthread_t t1;
ASSERT_EQ(0, pthread_create(&t1, NULL, SleepFn, reinterpret_cast<void*>(5)));
ASSERT_EQ(0, pthread_setname_np(t1, "short 2"));
} else {
fprintf(stderr, "skipping test: this kernel doesn't have /proc/self/task/tid/comm files!\n");
}
}
#endif
#if __BIONIC__ // Not all build servers have a new enough glibc? TODO: remove when they're on gprecise.
TEST(pthread, pthread_setname_np__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
// Call pthread_setname_np after thread has already exited.
ASSERT_EQ(ESRCH, pthread_setname_np(dead_thread, "short 3"));
}
#endif
TEST(pthread, pthread_kill__0) {
// Signal 0 just tests that the thread exists, so it's safe to call on ourselves.
ASSERT_EQ(0, pthread_kill(pthread_self(), 0));
}
TEST(pthread, pthread_kill__invalid_signal) {
ASSERT_EQ(EINVAL, pthread_kill(pthread_self(), -1));
}
static void pthread_kill__in_signal_handler_helper(int signal_number) {
static int count = 0;
ASSERT_EQ(SIGALRM, signal_number);
if (++count == 1) {
// Can we call pthread_kill from a signal handler?
ASSERT_EQ(0, pthread_kill(pthread_self(), SIGALRM));
}
}
TEST(pthread, pthread_kill__in_signal_handler) {
struct sigaction action;
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
action.sa_handler = pthread_kill__in_signal_handler_helper;
sigaction(SIGALRM, &action, NULL);
ASSERT_EQ(0, pthread_kill(pthread_self(), SIGALRM));
}
TEST(pthread, pthread_detach__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
ASSERT_EQ(ESRCH, pthread_detach(dead_thread));
}
TEST(pthread, pthread_getcpuclockid__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
clockid_t c;
ASSERT_EQ(ESRCH, pthread_getcpuclockid(dead_thread, &c));
}
TEST(pthread, pthread_getschedparam__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
int policy;
sched_param param;
ASSERT_EQ(ESRCH, pthread_getschedparam(dead_thread, &policy, &param));
}
TEST(pthread, pthread_setschedparam__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
int policy = 0;
sched_param param;
ASSERT_EQ(ESRCH, pthread_setschedparam(dead_thread, policy, &param));
}
TEST(pthread, pthread_join__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
void* result;
ASSERT_EQ(ESRCH, pthread_join(dead_thread, &result));
}
TEST(pthread, pthread_kill__no_such_thread) {
pthread_t dead_thread;
MakeDeadThread(dead_thread);
ASSERT_EQ(ESRCH, pthread_kill(dead_thread, 0));
}
TEST(pthread, pthread_join__multijoin) {
bool done = false;
pthread_t t1;
ASSERT_EQ(0, pthread_create(&t1, NULL, SpinFn, &done));
pthread_t t2;
ASSERT_EQ(0, pthread_create(&t2, NULL, JoinFn, reinterpret_cast<void*>(t1)));
sleep(1); // (Give t2 a chance to call pthread_join.)
// Multiple joins to the same thread should fail.
ASSERT_EQ(EINVAL, pthread_join(t1, NULL));
done = true;
// ...but t2's join on t1 still goes ahead (which we can tell because our join on t2 finishes).
void* join_result;
ASSERT_EQ(0, pthread_join(t2, &join_result));
ASSERT_EQ(0, reinterpret_cast<int>(join_result));
}