forkable_test.cc

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// Copyright 2022 gRPC 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 <grpc/support/port_platform.h>
 
#ifndef GRPC_ENABLE_FORK_SUPPORT
 
// Test nothing, everything is fine
int main(int /* argc */, char** /* argv */) { return 0; }
 
#else  // GRPC_ENABLE_FORK_SUPPORT
 
#include <sys/wait.h>
#include <unistd.h>
 
#include <gtest/gtest.h>
 
#include "absl/time/clock.h"
 
#include <grpc/grpc.h>
#include <grpc/support/log.h>
 
#include "src/core/lib/event_engine/forkable.h"
 
namespace {
using ::grpc_event_engine::experimental::Forkable;
using ::grpc_event_engine::experimental::RegisterForkHandlers;
}  // namespace
 
class ForkableTest : public testing::Test {};
 
#ifdef GRPC_POSIX_FORK_ALLOW_PTHREAD_ATFORK
TEST_F(ForkableTest, BasicPthreadAtForkOperations) {
  class SomeForkable : public Forkable {
   public:
    void PrepareFork() override { prepare_called_ = true; }
    void PostforkParent() override { parent_called_ = true; }
    void PostforkChild() override { child_called_ = true; }
 
    void CheckParent() {
      EXPECT_TRUE(prepare_called_);
      EXPECT_TRUE(parent_called_);
      EXPECT_FALSE(child_called_);
    }
 
    void CheckChild() {
      EXPECT_TRUE(prepare_called_);
      EXPECT_FALSE(parent_called_);
      EXPECT_TRUE(child_called_);
    }
 
   private:
    bool prepare_called_ = false;
    bool parent_called_ = false;
    bool child_called_ = false;
  };
 
  SomeForkable forkable;
  int child_pid = fork();
  ASSERT_NE(child_pid, -1);
  if (child_pid == 0) {
    gpr_log(GPR_DEBUG, "I am child pid: %d", getpid());
    forkable.CheckChild();
    exit(testing::Test::HasFailure());
  } else {
    gpr_log(GPR_DEBUG, "I am parent pid: %d", getpid());
    forkable.CheckParent();
    int status;
    gpr_log(GPR_DEBUG, "Waiting for child pid: %d", child_pid);
    do {
      // retry on EINTR, and fail otherwise
      if (waitpid(child_pid, &status, 0) != -1) break;
      ASSERT_EQ(errno, EINTR);
    } while (true);
    if (WIFEXITED(status)) {
      ASSERT_EQ(WEXITSTATUS(status), 0);
    } else {
      // exited abnormally, fail and print the exit status
      ASSERT_EQ(-99, status);
    }
  }
}
#endif  // GRPC_POSIX_FORK_ALLOW_PTHREAD_ATFORK
 
int main(int argc, char** argv) {
  testing::InitGoogleTest(&argc, argv);
  RegisterForkHandlers();
  auto result = RUN_ALL_TESTS();
  return result;
}
 
#endif  // GRPC_ENABLE_FORK_SUPPORT