Merge "debuggerd_client_test: less racy test setup"

#include <fcntl.h>

#include <stdio.h>

#include <sys/eventfd.h>

#include <unistd.h>

#include <chrono>

TEST(debuggerd_client, race) {

  static int THREAD_COUNT = getThreadCount();

  pid_t forkpid = fork();

  ASSERT_NE(-1, forkpid);

  // Semaphore incremented once per thread started.

  unique_fd barrier(eventfd(0, EFD_SEMAPHORE));

  ASSERT_NE(-1, barrier.get());

  pid_t forkpid = fork();

  ASSERT_NE(-1, forkpid);

  if (forkpid == 0) {

    // Spawn a bunch of threads, to make crash_dump take longer.

    std::vector<std::thread> threads;

    threads.reserve(THREAD_COUNT);

    for (int i = 0; i < THREAD_COUNT; ++i) {

      threads.emplace_back([]() {

        while (true) {

          std::this_thread::sleep_for(60s);

      threads.emplace_back([&barrier]() {

        uint64_t count = 1;

        ASSERT_NE(-1, write(barrier.get(), &count, sizeof(count)));

        for (;;) {

          pause();

        }

      });

    }

    for (;;) {

      pause();

    }

  }

    std::this_thread::sleep_for(60s);

    exit(0);

  // Wait for the child to spawn all of its threads.

  for (int i = 0; i < THREAD_COUNT; ++i) {

    uint64_t count;

    ASSERT_NE(-1, read(barrier.get(), &count, sizeof(count)));

  }

  unique_fd pipe_read, pipe_write;

  constexpr int PIPE_SIZE = 16 * 1024 * 1024;

  ASSERT_EQ(PIPE_SIZE, fcntl(pipe_read.get(), F_SETPIPE_SZ, PIPE_SIZE));

  // Wait for a bit to let the child spawn all of its threads.

  std::this_thread::sleep_for(1s);

  ASSERT_TRUE(

      debuggerd_trigger_dump(forkpid, kDebuggerdNativeBacktrace, 60000, std::move(pipe_write)));

  // Immediately kill the forked child, to make sure that the dump didn't return early.