conformance/conformance_test_runner.cc - third_party/protobuf - Git at Google

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // This file contains a program for running the test suite in a separate
 // process.  The other alternative is to run the suite in-process.  See
 // conformance.proto for pros/cons of these two options.
 //
 // This program will fork the process under test and communicate with it over
 // its stdin/stdout:
 //
 //     +--------+   pipe   +----------+
 //     | tester | <------> | testee   |
 //     |        |          |          |
 //     |  C++   |          | any lang |
 //     +--------+          +----------+
 //
 // The tester contains all of the test cases and their expected output.
 // The testee is a simple program written in the target language that reads
 // each test case and attempts to produce acceptable output for it.
 //
 // Every test consists of a ConformanceRequest/ConformanceResponse
 // request/reply pair.  The protocol on the pipe is simply:
 //
 //   1. tester sends 4-byte length N (little endian)
 //   2. tester sends N bytes representing a ConformanceRequest proto
 //   3. testee sends 4-byte length M (little endian)
 //   4. testee sends M bytes representing a ConformanceResponse proto

 #include <errno.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>

 #include <algorithm>
 #include <cstdlib>
 #include <fstream>
 #include <future>
 #include <vector>

 #include "absl/strings/str_format.h"
 #include "conformance/conformance.pb.h"
 #include "conformance_test.h"

 using conformance::ConformanceResponse;
 using google::protobuf::ConformanceTestSuite;
 using std::string;
 using std::vector;

 #define STRINGIFY(x) #x
 #define TOSTRING(x) STRINGIFY(x)
 #define GOOGLE_CHECK_SYSCALL(call)                            \
   if (call < 0) {                                      \
     perror(#call " " __FILE__ ":" TOSTRING(__LINE__)); \
     exit(1);                                           \
   }

 namespace google {
 namespace protobuf {

 void ParseFailureList(const char *filename,
                       conformance::FailureSet *failure_list) {
   std::ifstream infile(filename);

   if (!infile.is_open()) {
     fprintf(stderr, "Couldn't open failure list file: %s\n", filename);
     exit(1);
   }

   for (string line; getline(infile, line);) {
     // Remove whitespace.
     line.erase(std::remove_if(line.begin(), line.end(), ::isspace), line.end());

     // Remove comments.
     line = line.substr(0, line.find("#"));

     if (!line.empty()) {
       failure_list->add_failure(line);
     }
   }
 }

 void UsageError() {
   fprintf(stderr, "Usage: conformance-test-runner [options] <test-program>\n");
   fprintf(stderr, "\n");
   fprintf(stderr, "Options:\n");
   fprintf(stderr,
           "  --failure_list <filename>   Use to specify list of tests\n");
   fprintf(stderr,
           "                              that are expected to fail.  File\n");
   fprintf(stderr,
           "                              should contain one test name per\n");
   fprintf(stderr,
           "                              line.  Use '#' for comments.\n");
   fprintf(stderr,
           "  --text_format_failure_list <filename>   Use to specify list \n");
   fprintf(stderr,
           "                              of tests that are expected to \n");
   fprintf(stderr, "                              fail in the \n");
   fprintf(stderr,
           "                              text_format_conformance_suite.  \n");
   fprintf(stderr,
           "                              File should contain one test name \n");
   fprintf(stderr,
           "                              per line.  Use '#' for comments.\n");

   fprintf(stderr,
           "  --enforce_recommended       Enforce that recommended test\n");
   fprintf(stderr,
           "                              cases are also passing. Specify\n");
   fprintf(stderr,
           "                              this flag if you want to be\n");
   fprintf(stderr,
           "                              strictly conforming to protobuf\n");
   fprintf(stderr, "                              spec.\n");
   fprintf(stderr,
           "  --output_dir                <dirname> Directory to write\n"
           "                              output files.\n");
   exit(1);
 }

 void ForkPipeRunner::RunTest(const std::string &test_name,
                              const std::string &request,
                              std::string *response) {
   if (child_pid_ < 0) {
     SpawnTestProgram();
   }
   current_test_name_ = test_name;

   uint32_t len = request.size();
   CheckedWrite(write_fd_, &len, sizeof(uint32_t));
   CheckedWrite(write_fd_, request.c_str(), request.size());

   if (!TryRead(read_fd_, &len, sizeof(uint32_t))) {
     // We failed to read from the child, assume a crash and try to reap.
     GOOGLE_LOG(INFO) << "Trying to reap child, pid=" << child_pid_;

     int status = 0;
     waitpid(child_pid_, &status, WEXITED);

     string error_msg;
     conformance::ConformanceResponse response_obj;
     if (WIFEXITED(status)) {
       if (WEXITSTATUS(status) == 0) {
         absl::StrAppendFormat(&error_msg,
                               "child timed out, killed by signal %d",
                               WTERMSIG(status));
         response_obj.set_timeout_error(error_msg);
       } else {
         absl::StrAppendFormat(&error_msg, "child exited, status=%d",
                               WEXITSTATUS(status));
         response_obj.set_runtime_error(error_msg);
       }
     } else if (WIFSIGNALED(status)) {
       absl::StrAppendFormat(&error_msg, "child killed by signal %d",
                             WTERMSIG(status));
     }
     GOOGLE_LOG(INFO) << error_msg;
     child_pid_ = -1;

     response_obj.SerializeToString(response);
     return;
   }

   response->resize(len);
   CheckedRead(read_fd_, (void *)response->c_str(), len);
 }

 int ForkPipeRunner::Run(int argc, char *argv[],
                         const std::vector<ConformanceTestSuite *> &suites) {
   if (suites.empty()) {
     fprintf(stderr, "No test suites found.\n");
     return EXIT_FAILURE;
   }
   bool all_ok = true;
   for (ConformanceTestSuite *suite : suites) {
     string program;
     std::vector<string> program_args;
     string failure_list_filename;
     conformance::FailureSet failure_list;

     bool performance = false;
     for (int arg = 1; arg < argc; ++arg) {
       if (strcmp(argv[arg], suite->GetFailureListFlagName().c_str()) == 0) {
         if (++arg == argc) UsageError();
         failure_list_filename = argv[arg];
         ParseFailureList(argv[arg], &failure_list);
       } else if (strcmp(argv[arg], "--performance") == 0) {
         performance = true;
         suite->SetPerformance(true);
       } else if (strcmp(argv[arg], "--verbose") == 0) {
         suite->SetVerbose(true);
       } else if (strcmp(argv[arg], "--enforce_recommended") == 0) {
         suite->SetEnforceRecommended(true);
       } else if (strcmp(argv[arg], "--output_dir") == 0) {
         if (++arg == argc) UsageError();
         suite->SetOutputDir(argv[arg]);
       } else if (argv[arg][0] == '-') {
         bool recognized_flag = false;
         for (ConformanceTestSuite *suite : suites) {
           if (strcmp(argv[arg], suite->GetFailureListFlagName().c_str()) == 0) {
             if (++arg == argc) UsageError();
             recognized_flag = true;
           }
         }
         if (!recognized_flag) {
           fprintf(stderr, "Unknown option: %s\n", argv[arg]);
           UsageError();
         }
       } else {
         program += argv[arg++];
         while (arg < argc) {
           program_args.push_back(argv[arg]);
           arg++;
         }
       }
     }

     ForkPipeRunner runner(program, program_args, performance);

     std::string output;
     all_ok = all_ok && suite->RunSuite(&runner, &output, failure_list_filename,
                                        &failure_list);

     fwrite(output.c_str(), 1, output.size(), stderr);
   }
   return all_ok ? EXIT_SUCCESS : EXIT_FAILURE;
 }

 // TODO(haberman): make this work on Windows, instead of using these
 // UNIX-specific APIs.
 //
 // There is a platform-agnostic API in
 //    src/google/protobuf/compiler/subprocess.h
 //
 // However that API only supports sending a single message to the subprocess.
 // We really want to be able to send messages and receive responses one at a
 // time:
 //
 // 1. Spawning a new process for each test would take way too long for thousands
 //    of tests and subprocesses like java that can take 100ms or more to start
 //    up.
 //
 // 2. Sending all the tests in one big message and receiving all results in one
 //    big message would take away our visibility about which test(s) caused a
 //    crash or other fatal error.  It would also give us only a single failure
 //    instead of all of them.
 void ForkPipeRunner::SpawnTestProgram() {
   int toproc_pipe_fd[2];
   int fromproc_pipe_fd[2];
   if (pipe(toproc_pipe_fd) < 0 || pipe(fromproc_pipe_fd) < 0) {
     perror("pipe");
     exit(1);
   }

   pid_t pid = fork();
   if (pid < 0) {
     perror("fork");
     exit(1);
   }

   if (pid) {
     // Parent.
     GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[0]));
     GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[1]));
     write_fd_ = toproc_pipe_fd[1];
     read_fd_ = fromproc_pipe_fd[0];
     child_pid_ = pid;
   } else {
     // Child.
     GOOGLE_CHECK_SYSCALL(close(STDIN_FILENO));
     GOOGLE_CHECK_SYSCALL(close(STDOUT_FILENO));
     GOOGLE_CHECK_SYSCALL(dup2(toproc_pipe_fd[0], STDIN_FILENO));
     GOOGLE_CHECK_SYSCALL(dup2(fromproc_pipe_fd[1], STDOUT_FILENO));

     GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[0]));
     GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[1]));
     GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[1]));
     GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[0]));

     std::unique_ptr<char[]> executable(new char[executable_.size() + 1]);
     memcpy(executable.get(), executable_.c_str(), executable_.size());
     executable[executable_.size()] = '\0';

     std::vector<const char *> argv;
     argv.push_back(executable.get());
     GOOGLE_LOG(INFO) << argv[0];
     for (size_t i = 0; i < executable_args_.size(); ++i) {
       argv.push_back(executable_args_[i].c_str());
       GOOGLE_LOG(INFO) << executable_args_[i];
     }
     argv.push_back(nullptr);
     // Never returns.
     GOOGLE_CHECK_SYSCALL(execv(executable.get(), const_cast<char **>(argv.data())));
   }
 }

 void ForkPipeRunner::CheckedWrite(int fd, const void *buf, size_t len) {
   if (static_cast<size_t>(write(fd, buf, len)) != len) {
     GOOGLE_LOG(FATAL) << current_test_name_
                << ": error writing to test program: " << strerror(errno);
   }
 }

 bool ForkPipeRunner::TryRead(int fd, void *buf, size_t len) {
   size_t ofs = 0;
   while (len > 0) {
     std::future<ssize_t> future = std::async(
         std::launch::async,
         [](int fd, void *buf, size_t ofs, size_t len) {
           return read(fd, (char *)buf + ofs, len);
         },
         fd, buf, ofs, len);
     std::future_status status;
     if (performance_) {
       status = future.wait_for(std::chrono::seconds(5));
       if (status == std::future_status::timeout) {
         GOOGLE_LOG(ERROR) << current_test_name_ << ": timeout from test program";
         kill(child_pid_, SIGQUIT);
         // TODO(sandyzhang): Only log in flag-guarded mode, since reading output
         // from SIGQUIT is slow and verbose.
         std::vector<char> err;
         err.resize(5000);
         ssize_t err_bytes_read;
         size_t err_ofs = 0;
         do {
           err_bytes_read =
               read(fd, (void *)&err[err_ofs], err.size() - err_ofs);
           err_ofs += err_bytes_read;
         } while (err_bytes_read > 0 && err_ofs < err.size());
         GOOGLE_LOG(ERROR) << "child_pid_=" << child_pid_ << " SIGQUIT: \n" << &err[0];
         return false;
       }
     } else {
       future.wait();
     }
     ssize_t bytes_read = future.get();
     if (bytes_read == 0) {
       GOOGLE_LOG(ERROR) << current_test_name_ << ": unexpected EOF from test program";
       return false;
     } else if (bytes_read < 0) {
       GOOGLE_LOG(ERROR) << current_test_name_
                  << ": error reading from test program: " << strerror(errno);
       return false;
     }

     len -= bytes_read;
     ofs += bytes_read;
   }

   return true;
 }

 void ForkPipeRunner::CheckedRead(int fd, void *buf, size_t len) {
   if (!TryRead(fd, buf, len)) {
     GOOGLE_LOG(FATAL) << current_test_name_
                << ": error reading from test program: " << strerror(errno);
   }
 }

 }  // namespace protobuf
 }  // namespace google
	// Protocol Buffers - Google's data interchange format
	// Copyright 2008 Google Inc. All rights reserved.
	// https://developers.google.com/protocol-buffers/
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	// This file contains a program for running the test suite in a separate
	// process. The other alternative is to run the suite in-process. See
	// conformance.proto for pros/cons of these two options.
	//
	// This program will fork the process under test and communicate with it over
	// its stdin/stdout:
	//
	// +--------+ pipe +----------+
	// \| tester \| <------> \| testee \|
	// \| \| \| \|
	// \| C++ \| \| any lang \|
	// +--------+ +----------+
	//
	// The tester contains all of the test cases and their expected output.
	// The testee is a simple program written in the target language that reads
	// each test case and attempts to produce acceptable output for it.
	//
	// Every test consists of a ConformanceRequest/ConformanceResponse
	// request/reply pair. The protocol on the pipe is simply:
	//
	// 1. tester sends 4-byte length N (little endian)
	// 2. tester sends N bytes representing a ConformanceRequest proto
	// 3. testee sends 4-byte length M (little endian)
	// 4. testee sends M bytes representing a ConformanceResponse proto

	#include <errno.h>
	#include <signal.h>
	#include <sys/types.h>
	#include <sys/wait.h>
	#include <unistd.h>

	#include <algorithm>
	#include <cstdlib>
	#include <fstream>
	#include <future>
	#include <vector>

	#include "absl/strings/str_format.h"
	#include "conformance/conformance.pb.h"
	#include "conformance_test.h"

	using conformance::ConformanceResponse;
	using google::protobuf::ConformanceTestSuite;
	using std::string;
	using std::vector;

	#define STRINGIFY(x) #x
	#define TOSTRING(x) STRINGIFY(x)
	#define GOOGLE_CHECK_SYSCALL(call) \
	if (call < 0) { \
	perror(#call " " __FILE__ ":" TOSTRING(__LINE__)); \
	exit(1); \
	}

	namespace google {
	namespace protobuf {

	void ParseFailureList(const char *filename,
	conformance::FailureSet *failure_list) {
	std::ifstream infile(filename);

	if (!infile.is_open()) {
	fprintf(stderr, "Couldn't open failure list file: %s\n", filename);
	exit(1);
	}

	for (string line; getline(infile, line);) {
	// Remove whitespace.
	line.erase(std::remove_if(line.begin(), line.end(), ::isspace), line.end());

	// Remove comments.
	line = line.substr(0, line.find("#"));

	if (!line.empty()) {
	failure_list->add_failure(line);
	}
	}
	}

	void UsageError() {
	fprintf(stderr, "Usage: conformance-test-runner [options] <test-program>\n");
	fprintf(stderr, "\n");
	fprintf(stderr, "Options:\n");
	fprintf(stderr,
	" --failure_list <filename> Use to specify list of tests\n");
	fprintf(stderr,
	" that are expected to fail. File\n");
	fprintf(stderr,
	" should contain one test name per\n");
	fprintf(stderr,
	" line. Use '#' for comments.\n");
	fprintf(stderr,
	" --text_format_failure_list <filename> Use to specify list \n");
	fprintf(stderr,
	" of tests that are expected to \n");
	fprintf(stderr, " fail in the \n");
	fprintf(stderr,
	" text_format_conformance_suite. \n");
	fprintf(stderr,
	" File should contain one test name \n");
	fprintf(stderr,
	" per line. Use '#' for comments.\n");

	fprintf(stderr,
	" --enforce_recommended Enforce that recommended test\n");
	fprintf(stderr,
	" cases are also passing. Specify\n");
	fprintf(stderr,
	" this flag if you want to be\n");
	fprintf(stderr,
	" strictly conforming to protobuf\n");
	fprintf(stderr, " spec.\n");
	fprintf(stderr,
	" --output_dir <dirname> Directory to write\n"
	" output files.\n");
	exit(1);
	}

	void ForkPipeRunner::RunTest(const std::string &test_name,
	const std::string &request,
	std::string *response) {
	if (child_pid_ < 0) {
	SpawnTestProgram();
	}
	current_test_name_ = test_name;

	uint32_t len = request.size();
	CheckedWrite(write_fd_, &len, sizeof(uint32_t));
	CheckedWrite(write_fd_, request.c_str(), request.size());

	if (!TryRead(read_fd_, &len, sizeof(uint32_t))) {
	// We failed to read from the child, assume a crash and try to reap.
	GOOGLE_LOG(INFO) << "Trying to reap child, pid=" << child_pid_;

	int status = 0;
	waitpid(child_pid_, &status, WEXITED);

	string error_msg;
	conformance::ConformanceResponse response_obj;
	if (WIFEXITED(status)) {
	if (WEXITSTATUS(status) == 0) {
	absl::StrAppendFormat(&error_msg,
	"child timed out, killed by signal %d",
	WTERMSIG(status));
	response_obj.set_timeout_error(error_msg);
	} else {
	absl::StrAppendFormat(&error_msg, "child exited, status=%d",
	WEXITSTATUS(status));
	response_obj.set_runtime_error(error_msg);
	}
	} else if (WIFSIGNALED(status)) {
	absl::StrAppendFormat(&error_msg, "child killed by signal %d",
	WTERMSIG(status));
	}
	GOOGLE_LOG(INFO) << error_msg;
	child_pid_ = -1;

	response_obj.SerializeToString(response);
	return;
	}

	response->resize(len);
	CheckedRead(read_fd_, (void *)response->c_str(), len);
	}

	int ForkPipeRunner::Run(int argc, char *argv[],
	const std::vector<ConformanceTestSuite *> &suites) {
	if (suites.empty()) {
	fprintf(stderr, "No test suites found.\n");
	return EXIT_FAILURE;
	}
	bool all_ok = true;
	for (ConformanceTestSuite *suite : suites) {
	string program;
	std::vector<string> program_args;
	string failure_list_filename;
	conformance::FailureSet failure_list;

	bool performance = false;
	for (int arg = 1; arg < argc; ++arg) {
	if (strcmp(argv[arg], suite->GetFailureListFlagName().c_str()) == 0) {
	if (++arg == argc) UsageError();
	failure_list_filename = argv[arg];
	ParseFailureList(argv[arg], &failure_list);
	} else if (strcmp(argv[arg], "--performance") == 0) {
	performance = true;
	suite->SetPerformance(true);
	} else if (strcmp(argv[arg], "--verbose") == 0) {
	suite->SetVerbose(true);
	} else if (strcmp(argv[arg], "--enforce_recommended") == 0) {
	suite->SetEnforceRecommended(true);
	} else if (strcmp(argv[arg], "--output_dir") == 0) {
	if (++arg == argc) UsageError();
	suite->SetOutputDir(argv[arg]);
	} else if (argv[arg][0] == '-') {
	bool recognized_flag = false;
	for (ConformanceTestSuite *suite : suites) {
	if (strcmp(argv[arg], suite->GetFailureListFlagName().c_str()) == 0) {
	if (++arg == argc) UsageError();
	recognized_flag = true;
	}
	}
	if (!recognized_flag) {
	fprintf(stderr, "Unknown option: %s\n", argv[arg]);
	UsageError();
	}
	} else {
	program += argv[arg++];
	while (arg < argc) {
	program_args.push_back(argv[arg]);
	arg++;
	}
	}
	}

	ForkPipeRunner runner(program, program_args, performance);

	std::string output;
	all_ok = all_ok && suite->RunSuite(&runner, &output, failure_list_filename,
	&failure_list);

	fwrite(output.c_str(), 1, output.size(), stderr);
	}
	return all_ok ? EXIT_SUCCESS : EXIT_FAILURE;
	}

	// TODO(haberman): make this work on Windows, instead of using these
	// UNIX-specific APIs.
	//
	// There is a platform-agnostic API in
	// src/google/protobuf/compiler/subprocess.h
	//
	// However that API only supports sending a single message to the subprocess.
	// We really want to be able to send messages and receive responses one at a
	// time:
	//
	// 1. Spawning a new process for each test would take way too long for thousands
	// of tests and subprocesses like java that can take 100ms or more to start
	// up.
	//
	// 2. Sending all the tests in one big message and receiving all results in one
	// big message would take away our visibility about which test(s) caused a
	// crash or other fatal error. It would also give us only a single failure
	// instead of all of them.
	void ForkPipeRunner::SpawnTestProgram() {
	int toproc_pipe_fd[2];
	int fromproc_pipe_fd[2];
	if (pipe(toproc_pipe_fd) < 0 \|\| pipe(fromproc_pipe_fd) < 0) {
	perror("pipe");
	exit(1);
	}

	pid_t pid = fork();
	if (pid < 0) {
	perror("fork");
	exit(1);
	}

	if (pid) {
	// Parent.
	GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[0]));
	GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[1]));
	write_fd_ = toproc_pipe_fd[1];
	read_fd_ = fromproc_pipe_fd[0];
	child_pid_ = pid;
	} else {
	// Child.
	GOOGLE_CHECK_SYSCALL(close(STDIN_FILENO));
	GOOGLE_CHECK_SYSCALL(close(STDOUT_FILENO));
	GOOGLE_CHECK_SYSCALL(dup2(toproc_pipe_fd[0], STDIN_FILENO));
	GOOGLE_CHECK_SYSCALL(dup2(fromproc_pipe_fd[1], STDOUT_FILENO));

	GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[0]));
	GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[1]));
	GOOGLE_CHECK_SYSCALL(close(toproc_pipe_fd[1]));
	GOOGLE_CHECK_SYSCALL(close(fromproc_pipe_fd[0]));

	std::unique_ptr<char[]> executable(new char[executable_.size() + 1]);
	memcpy(executable.get(), executable_.c_str(), executable_.size());
	executable[executable_.size()] = '\0';

	std::vector<const char *> argv;
	argv.push_back(executable.get());
	GOOGLE_LOG(INFO) << argv[0];
	for (size_t i = 0; i < executable_args_.size(); ++i) {
	argv.push_back(executable_args_[i].c_str());
	GOOGLE_LOG(INFO) << executable_args_[i];
	}
	argv.push_back(nullptr);
	// Never returns.
	GOOGLE_CHECK_SYSCALL(execv(executable.get(), const_cast<char **>(argv.data())));
	}
	}

	void ForkPipeRunner::CheckedWrite(int fd, const void *buf, size_t len) {
	if (static_cast<size_t>(write(fd, buf, len)) != len) {
	GOOGLE_LOG(FATAL) << current_test_name_
	<< ": error writing to test program: " << strerror(errno);
	}
	}

	bool ForkPipeRunner::TryRead(int fd, void *buf, size_t len) {
	size_t ofs = 0;
	while (len > 0) {
	std::future<ssize_t> future = std::async(
	std::launch::async,
	[](int fd, void *buf, size_t ofs, size_t len) {
	return read(fd, (char *)buf + ofs, len);
	},
	fd, buf, ofs, len);
	std::future_status status;
	if (performance_) {
	status = future.wait_for(std::chrono::seconds(5));
	if (status == std::future_status::timeout) {
	GOOGLE_LOG(ERROR) << current_test_name_ << ": timeout from test program";
	kill(child_pid_, SIGQUIT);
	// TODO(sandyzhang): Only log in flag-guarded mode, since reading output
	// from SIGQUIT is slow and verbose.
	std::vector<char> err;
	err.resize(5000);
	ssize_t err_bytes_read;
	size_t err_ofs = 0;
	do {
	err_bytes_read =
	read(fd, (void *)&err[err_ofs], err.size() - err_ofs);
	err_ofs += err_bytes_read;
	} while (err_bytes_read > 0 && err_ofs < err.size());
	GOOGLE_LOG(ERROR) << "child_pid_=" << child_pid_ << " SIGQUIT: \n" << &err[0];
	return false;
	}
	} else {
	future.wait();
	}
	ssize_t bytes_read = future.get();
	if (bytes_read == 0) {
	GOOGLE_LOG(ERROR) << current_test_name_ << ": unexpected EOF from test program";
	return false;
	} else if (bytes_read < 0) {
	GOOGLE_LOG(ERROR) << current_test_name_
	<< ": error reading from test program: " << strerror(errno);
	return false;
	}

	len -= bytes_read;
	ofs += bytes_read;
	}

	return true;
	}

	void ForkPipeRunner::CheckedRead(int fd, void *buf, size_t len) {
	if (!TryRead(fd, buf, len)) {
	GOOGLE_LOG(FATAL) << current_test_name_
	<< ": error reading from test program: " << strerror(errno);
	}
	}

	} // namespace protobuf
	} // namespace google