// Copyright 2018 The gVisor Authors. // // 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 <errno.h> #include <limits.h> #include <pthread.h> #include <signal.h> #include <stdint.h> #include <stdio.h> #include <string.h> #include <sys/epoll.h> #include <sys/eventfd.h> #include <time.h> #include <unistd.h> #include "gtest/gtest.h" #include "test/util/epoll_util.h" #include "test/util/eventfd_util.h" #include "test/util/file_descriptor.h" #include "test/util/posix_error.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { constexpr int kFDsPerEpoll = 3; constexpr uint64_t kMagicConstant = 0x0102030405060708; uint64_t ms_elapsed(const struct timespec* begin, const struct timespec* end) { return (end->tv_sec - begin->tv_sec) * 1000 + (end->tv_nsec - begin->tv_nsec) / 1000000; } TEST(EpollTest, AllWritable) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN | EPOLLOUT, kMagicConstant + i)); } struct epoll_event result[kFDsPerEpoll]; ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(kFDsPerEpoll)); for (int i = 0; i < kFDsPerEpoll; i++) { ASSERT_EQ(result[i].events, EPOLLOUT); } } TEST(EpollTest, LastReadable) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN | EPOLLOUT, kMagicConstant + i)); } uint64_t tmp = 1; ASSERT_THAT(WriteFd(eventfds[kFDsPerEpoll - 1].get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); struct epoll_event result[kFDsPerEpoll]; ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(kFDsPerEpoll)); int i; for (i = 0; i < kFDsPerEpoll - 1; i++) { EXPECT_EQ(result[i].events, EPOLLOUT); } EXPECT_EQ(result[i].events, EPOLLOUT | EPOLLIN); EXPECT_EQ(result[i].data.u64, kMagicConstant + i); } TEST(EpollTest, LastNonWritable) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN | EPOLLOUT, kMagicConstant + i)); } // Write the maximum value to the event fd so that writing to it again would // block. uint64_t tmp = ULLONG_MAX - 1; ASSERT_THAT(WriteFd(eventfds[kFDsPerEpoll - 1].get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); struct epoll_event result[kFDsPerEpoll]; ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(kFDsPerEpoll)); int i; for (i = 0; i < kFDsPerEpoll - 1; i++) { EXPECT_EQ(result[i].events, EPOLLOUT); } EXPECT_EQ(result[i].events, EPOLLIN); EXPECT_THAT(ReadFd(eventfds[kFDsPerEpoll - 1].get(), &tmp, sizeof(tmp)), sizeof(tmp)); EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(kFDsPerEpoll)); for (i = 0; i < kFDsPerEpoll; i++) { EXPECT_EQ(result[i].events, EPOLLOUT); } } TEST(EpollTest, Timeout_NoRandomSave) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN, kMagicConstant + i)); } constexpr int kTimeoutMs = 200; struct timespec begin; struct timespec end; struct epoll_event result[kFDsPerEpoll]; { const DisableSave ds; // Timing-related. EXPECT_THAT(clock_gettime(CLOCK_MONOTONIC, &begin), SyscallSucceeds()); ASSERT_THAT( RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, kTimeoutMs), SyscallSucceedsWithValue(0)); EXPECT_THAT(clock_gettime(CLOCK_MONOTONIC, &end), SyscallSucceeds()); } // Check the lower bound on the timeout. Checking for an upper bound is // fragile because Linux can overrun the timeout due to scheduling delays. EXPECT_GT(ms_elapsed(&begin, &end), kTimeoutMs - 1); } void* writer(void* arg) { int fd = *reinterpret_cast<int*>(arg); uint64_t tmp = 1; usleep(200000); if (WriteFd(fd, &tmp, sizeof(tmp)) != sizeof(tmp)) { fprintf(stderr, "writer failed: errno %s\n", strerror(errno)); } return nullptr; } TEST(EpollTest, WaitThenUnblock) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN, kMagicConstant + i)); } // Fire off a thread that will make at least one of the event fds readable. pthread_t thread; int make_readable = eventfds[0].get(); ASSERT_THAT(pthread_create(&thread, nullptr, writer, &make_readable), SyscallSucceedsWithValue(0)); struct epoll_event result[kFDsPerEpoll]; EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_THAT(pthread_detach(thread), SyscallSucceeds()); } void sighandler(int s) {} void* signaler(void* arg) { pthread_t* t = reinterpret_cast<pthread_t*>(arg); // Repeatedly send the real-time signal until we are detached, because it's // difficult to know exactly when epoll_wait on another thread (which this // is intending to interrupt) has started blocking. while (1) { usleep(200000); pthread_kill(*t, SIGRTMIN); } return nullptr; } TEST(EpollTest, UnblockWithSignal) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN, kMagicConstant + i)); } signal(SIGRTMIN, sighandler); // Unblock the real time signals that InitGoogle blocks :( sigset_t unblock; sigemptyset(&unblock); sigaddset(&unblock, SIGRTMIN); ASSERT_THAT(sigprocmask(SIG_UNBLOCK, &unblock, nullptr), SyscallSucceeds()); pthread_t thread; pthread_t cur = pthread_self(); ASSERT_THAT(pthread_create(&thread, nullptr, signaler, &cur), SyscallSucceedsWithValue(0)); struct epoll_event result[kFDsPerEpoll]; EXPECT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, -1), SyscallFailsWithErrno(EINTR)); EXPECT_THAT(pthread_cancel(thread), SyscallSucceeds()); EXPECT_THAT(pthread_detach(thread), SyscallSucceeds()); } TEST(EpollTest, TimeoutNoFds) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); struct epoll_event result[kFDsPerEpoll]; EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } struct addr_ctx { int epollfd; int eventfd; }; void* fd_adder(void* arg) { struct addr_ctx* actx = reinterpret_cast<struct addr_ctx*>(arg); struct epoll_event event; event.events = EPOLLIN | EPOLLOUT; event.data.u64 = 0xdeadbeeffacefeed; usleep(200000); if (epoll_ctl(actx->epollfd, EPOLL_CTL_ADD, actx->eventfd, &event) == -1) { fprintf(stderr, "epoll_ctl failed: %s\n", strerror(errno)); } return nullptr; } TEST(EpollTest, UnblockWithNewFD) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto eventfd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD()); pthread_t thread; struct addr_ctx actx = {epollfd.get(), eventfd.get()}; ASSERT_THAT(pthread_create(&thread, nullptr, fd_adder, &actx), SyscallSucceedsWithValue(0)); struct epoll_event result[kFDsPerEpoll]; // Wait while no FDs are ready, but after 200ms fd_adder will add a ready FD // to epoll which will wake us up. EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_THAT(pthread_detach(thread), SyscallSucceeds()); EXPECT_EQ(result[0].data.u64, 0xdeadbeeffacefeed); } TEST(EpollTest, Oneshot) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); std::vector<FileDescriptor> eventfds; for (int i = 0; i < kFDsPerEpoll; i++) { eventfds.push_back(ASSERT_NO_ERRNO_AND_VALUE(NewEventFD())); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfds[i].get(), EPOLLIN, kMagicConstant + i)); } struct epoll_event event; event.events = EPOLLOUT | EPOLLONESHOT; event.data.u64 = kMagicConstant; ASSERT_THAT( epoll_ctl(epollfd.get(), EPOLL_CTL_MOD, eventfds[0].get(), &event), SyscallSucceeds()); struct epoll_event result[kFDsPerEpoll]; // One-shot entry means that the first epoll_wait should succeed. ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].data.u64, kMagicConstant); // One-shot entry means that the second epoll_wait should timeout. EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } TEST(EpollTest, EdgeTriggered_NoRandomSave) { // Test edge-triggered entry: make it edge-triggered, first wait should // return it, second one should time out, make it writable again, third wait // should return it, fourth wait should timeout. auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto eventfd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD()); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfd.get(), EPOLLOUT | EPOLLET, kMagicConstant)); struct epoll_event result[kFDsPerEpoll]; { const DisableSave ds; // May trigger spurious event. // Edge-triggered entry means that the first epoll_wait should return the // event. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].data.u64, kMagicConstant); // Edge-triggered entry means that the second epoll_wait should time out. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } uint64_t tmp = ULLONG_MAX - 1; // Make an fd non-writable. ASSERT_THAT(WriteFd(eventfd.get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); // Make the same fd non-writable to trigger a change, which will trigger an // edge-triggered event. ASSERT_THAT(ReadFd(eventfd.get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); { const DisableSave ds; // May trigger spurious event. // An edge-triggered event should now be returned. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].data.u64, kMagicConstant); // The edge-triggered event had been consumed above, we don't expect to // get it again. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } } TEST(EpollTest, OneshotAndEdgeTriggered) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto eventfd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD()); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), eventfd.get(), EPOLLOUT | EPOLLET | EPOLLONESHOT, kMagicConstant)); struct epoll_event result[kFDsPerEpoll]; // First time one shot edge-triggered entry means that epoll_wait should // return the event. ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].data.u64, kMagicConstant); // Edge-triggered entry means that the second epoll_wait should time out. ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); uint64_t tmp = ULLONG_MAX - 1; // Make an fd non-writable. ASSERT_THAT(WriteFd(eventfd.get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); // Make the same fd non-writable to trigger a change, which will not trigger // an edge-triggered event because we've also included EPOLLONESHOT. ASSERT_THAT(ReadFd(eventfd.get(), &tmp, sizeof(tmp)), SyscallSucceedsWithValue(sizeof(tmp))); ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } TEST(EpollTest, CycleOfOneDisallowed) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); struct epoll_event event; event.events = EPOLLOUT; event.data.u64 = kMagicConstant; ASSERT_THAT(epoll_ctl(epollfd.get(), EPOLL_CTL_ADD, epollfd.get(), &event), SyscallFailsWithErrno(EINVAL)); } TEST(EpollTest, CycleOfThreeDisallowed) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto epollfd1 = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto epollfd2 = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); ASSERT_NO_ERRNO( RegisterEpollFD(epollfd.get(), epollfd1.get(), EPOLLIN, kMagicConstant)); ASSERT_NO_ERRNO( RegisterEpollFD(epollfd1.get(), epollfd2.get(), EPOLLIN, kMagicConstant)); struct epoll_event event; event.events = EPOLLIN; event.data.u64 = kMagicConstant; EXPECT_THAT(epoll_ctl(epollfd2.get(), EPOLL_CTL_ADD, epollfd.get(), &event), SyscallFailsWithErrno(ELOOP)); } TEST(EpollTest, CloseFile) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); auto eventfd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD()); ASSERT_NO_ERRNO( RegisterEpollFD(epollfd.get(), eventfd.get(), EPOLLOUT, kMagicConstant)); struct epoll_event result[kFDsPerEpoll]; ASSERT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, -1), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].data.u64, kMagicConstant); // Close the event fd early. eventfd.reset(); EXPECT_THAT(RetryEINTR(epoll_wait)(epollfd.get(), result, kFDsPerEpoll, 100), SyscallSucceedsWithValue(0)); } TEST(EpollTest, PipeReaderHupAfterWriterClosed) { auto epollfd = ASSERT_NO_ERRNO_AND_VALUE(NewEpollFD()); int pipefds[2]; ASSERT_THAT(pipe(pipefds), SyscallSucceeds()); FileDescriptor rfd(pipefds[0]); FileDescriptor wfd(pipefds[1]); ASSERT_NO_ERRNO(RegisterEpollFD(epollfd.get(), rfd.get(), 0, kMagicConstant)); struct epoll_event result[kFDsPerEpoll]; // Initially, rfd should not generate any events of interest. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, 0), SyscallSucceedsWithValue(0)); // Close the write end of the pipe. wfd.reset(); // rfd should now generate EPOLLHUP, which EPOLL_CTL_ADD unconditionally adds // to the set of events of interest. ASSERT_THAT(epoll_wait(epollfd.get(), result, kFDsPerEpoll, 0), SyscallSucceedsWithValue(1)); EXPECT_EQ(result[0].events, EPOLLHUP); EXPECT_EQ(result[0].data.u64, kMagicConstant); } } // namespace } // namespace testing } // namespace gvisor