457 lines
15 KiB
C++
457 lines
15 KiB
C++
// Copyright 2010 Google Inc.
|
|
// All rights reserved.
|
|
//
|
|
// 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.
|
|
|
|
#include "utils/process/child.ipp"
|
|
|
|
extern "C" {
|
|
#include <sys/stat.h>
|
|
#include <sys/wait.h>
|
|
|
|
#include <fcntl.h>
|
|
#include <signal.h>
|
|
#include <unistd.h>
|
|
}
|
|
|
|
#include <cassert>
|
|
#include <cerrno>
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <iostream>
|
|
#include <memory>
|
|
|
|
#include "utils/defs.hpp"
|
|
#include "utils/format/macros.hpp"
|
|
#include "utils/logging/macros.hpp"
|
|
#include "utils/process/exceptions.hpp"
|
|
#include "utils/process/fdstream.hpp"
|
|
#include "utils/process/system.hpp"
|
|
#include "utils/process/status.hpp"
|
|
#include "utils/sanity.hpp"
|
|
#include "utils/signals/interrupts.hpp"
|
|
|
|
|
|
namespace utils {
|
|
namespace process {
|
|
|
|
|
|
/// Private implementation fields for child objects.
|
|
struct child::impl {
|
|
/// The process identifier.
|
|
pid_t _pid;
|
|
|
|
/// The input stream for the process' stdout and stderr. May be NULL.
|
|
std::auto_ptr< process::ifdstream > _output;
|
|
|
|
/// Initializes private implementation data.
|
|
///
|
|
/// \param pid The process identifier.
|
|
/// \param output The input stream. Grabs ownership of the pointer.
|
|
impl(const pid_t pid, process::ifdstream* output) :
|
|
_pid(pid), _output(output) {}
|
|
};
|
|
|
|
|
|
} // namespace process
|
|
} // namespace utils
|
|
|
|
|
|
namespace fs = utils::fs;
|
|
namespace process = utils::process;
|
|
namespace signals = utils::signals;
|
|
|
|
|
|
namespace {
|
|
|
|
|
|
/// Exception-based version of dup(2).
|
|
///
|
|
/// \param old_fd The file descriptor to duplicate.
|
|
/// \param new_fd The file descriptor to use as the duplicate. This is
|
|
/// closed if it was open before the copy happens.
|
|
///
|
|
/// \throw process::system_error If the call to dup2(2) fails.
|
|
static void
|
|
safe_dup(const int old_fd, const int new_fd)
|
|
{
|
|
if (process::detail::syscall_dup2(old_fd, new_fd) == -1) {
|
|
const int original_errno = errno;
|
|
throw process::system_error(F("dup2(%s, %s) failed") % old_fd % new_fd,
|
|
original_errno);
|
|
}
|
|
}
|
|
|
|
|
|
/// Exception-based version of open(2) to open (or create) a file for append.
|
|
///
|
|
/// \param filename The file to open in append mode.
|
|
///
|
|
/// \return The file descriptor for the opened or created file.
|
|
///
|
|
/// \throw process::system_error If the call to open(2) fails.
|
|
static int
|
|
open_for_append(const fs::path& filename)
|
|
{
|
|
const int fd = process::detail::syscall_open(
|
|
filename.c_str(), O_CREAT | O_WRONLY | O_APPEND,
|
|
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
|
|
if (fd == -1) {
|
|
const int original_errno = errno;
|
|
throw process::system_error(F("Failed to create %s because open(2) "
|
|
"failed") % filename, original_errno);
|
|
}
|
|
return fd;
|
|
}
|
|
|
|
|
|
/// Exception-based, type-improved version of wait(2).
|
|
///
|
|
/// Because we are waiting for the termination of a process, and because this is
|
|
/// the canonical way to call wait(2) for this module, we ensure from here that
|
|
/// any subprocess of the process we are killing is terminated.
|
|
///
|
|
/// \param pid The identifier of the process to wait for.
|
|
///
|
|
/// \return The termination status of the process.
|
|
///
|
|
/// \throw process::system_error If the call to waitpid(2) fails.
|
|
static process::status
|
|
safe_wait(const pid_t pid)
|
|
{
|
|
LD(F("Waiting for pid=%s") % pid);
|
|
int stat_loc;
|
|
if (process::detail::syscall_waitpid(pid, &stat_loc, 0) == -1) {
|
|
const int original_errno = errno;
|
|
throw process::system_error(F("Failed to wait for PID %s") % pid,
|
|
original_errno);
|
|
}
|
|
return process::status(pid, stat_loc);
|
|
}
|
|
|
|
|
|
/// Logs the execution of another program.
|
|
///
|
|
/// \param program The binary to execute.
|
|
/// \param args The arguments to pass to the binary, without the program name.
|
|
static void
|
|
log_exec(const fs::path& program, const process::args_vector& args)
|
|
{
|
|
std::string plain_command = program.str();
|
|
for (process::args_vector::const_iterator iter = args.begin();
|
|
iter != args.end(); ++iter)
|
|
plain_command += F(" %s") % *iter;
|
|
LD(F("Executing %s") % plain_command);
|
|
}
|
|
|
|
|
|
/// Maximum number of arguments supported by cxx_exec.
|
|
///
|
|
/// We need this limit to avoid having to allocate dynamic memory in the child
|
|
/// process to construct the arguments list, which would have side-effects in
|
|
/// the parent's memory if we use vfork().
|
|
#define MAX_ARGS 128
|
|
|
|
|
|
static void cxx_exec(const fs::path& program, const process::args_vector& args)
|
|
throw() UTILS_NORETURN;
|
|
|
|
|
|
/// Executes an external binary and replaces the current process.
|
|
///
|
|
/// This function must not use any of the logging features, so that the output
|
|
/// of the subprocess is not "polluted" by our own messages.
|
|
///
|
|
/// This function must also not affect the global state of the current process
|
|
/// as otherwise we would not be able to use vfork(). Only state stored in the
|
|
/// stack can be touched.
|
|
///
|
|
/// \param program The binary to execute.
|
|
/// \param args The arguments to pass to the binary, without the program name.
|
|
static void
|
|
cxx_exec(const fs::path& program, const process::args_vector& args) throw()
|
|
{
|
|
assert(args.size() < MAX_ARGS);
|
|
try {
|
|
const char* argv[MAX_ARGS + 1];
|
|
|
|
argv[0] = program.c_str();
|
|
for (process::args_vector::size_type i = 0; i < args.size(); i++)
|
|
argv[1 + i] = args[i].c_str();
|
|
argv[1 + args.size()] = NULL;
|
|
|
|
#if defined(__minix) && !defined(NDEBUG)
|
|
const int ret =
|
|
#endif /* defined(__minix) && !defined(NDEBUG) */
|
|
::execv(program.c_str(),
|
|
(char* const*)(unsigned long)(const void*)argv);
|
|
const int original_errno = errno;
|
|
assert(ret == -1);
|
|
|
|
std::cerr << "Failed to execute " << program << ": "
|
|
<< std::strerror(original_errno) << "\n";
|
|
std::abort();
|
|
} catch (const std::runtime_error& error) {
|
|
std::cerr << "Failed to execute " << program << ": "
|
|
<< error.what() << "\n";
|
|
std::abort();
|
|
} catch (...) {
|
|
std::cerr << "Failed to execute " << program << "; got unexpected "
|
|
"exception during exec\n";
|
|
std::abort();
|
|
}
|
|
}
|
|
|
|
|
|
} // anonymous namespace
|
|
|
|
|
|
/// Creates a new child.
|
|
///
|
|
/// \param implptr A dynamically-allocated impl object with the contents of the
|
|
/// new child.
|
|
process::child::child(impl *implptr) :
|
|
_pimpl(implptr)
|
|
{
|
|
}
|
|
|
|
|
|
/// Destructor for child.
|
|
process::child::~child(void)
|
|
{
|
|
}
|
|
|
|
|
|
/// Helper function for fork().
|
|
///
|
|
/// Please note: if you update this function to change the return type or to
|
|
/// raise different errors, do not forget to update fork() accordingly.
|
|
///
|
|
/// \return In the case of the parent, a new child object returned as a
|
|
/// dynamically-allocated object because children classes are unique and thus
|
|
/// noncopyable. In the case of the child, a NULL pointer.
|
|
///
|
|
/// \throw process::system_error If the calls to pipe(2) or fork(2) fail.
|
|
std::auto_ptr< process::child >
|
|
process::child::fork_capture_aux(void)
|
|
{
|
|
std::cout.flush();
|
|
std::cerr.flush();
|
|
|
|
int fds[2];
|
|
if (detail::syscall_pipe(fds) == -1)
|
|
throw process::system_error("pipe(2) failed", errno);
|
|
|
|
std::auto_ptr< signals::interrupts_inhibiter > inhibiter(
|
|
new signals::interrupts_inhibiter);
|
|
pid_t pid = detail::syscall_fork();
|
|
if (pid == -1) {
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
::close(fds[0]);
|
|
::close(fds[1]);
|
|
throw process::system_error("fork(2) failed", errno);
|
|
} else if (pid == 0) {
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
#if !defined(__minix)
|
|
::setpgid(::getpid(), ::getpid());
|
|
#endif /* !defined(__minix) */
|
|
|
|
try {
|
|
::close(fds[0]);
|
|
safe_dup(fds[1], STDOUT_FILENO);
|
|
safe_dup(fds[1], STDERR_FILENO);
|
|
::close(fds[1]);
|
|
} catch (const system_error& e) {
|
|
std::cerr << F("Failed to set up subprocess: %s\n") % e.what();
|
|
std::abort();
|
|
}
|
|
return std::auto_ptr< process::child >(NULL);
|
|
} else {
|
|
::close(fds[1]);
|
|
LD(F("Spawned process %s: stdout and stderr inherited") % pid);
|
|
signals::add_pid_to_kill(pid);
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
return std::auto_ptr< process::child >(
|
|
new process::child(new impl(pid, new process::ifdstream(fds[0]))));
|
|
}
|
|
}
|
|
|
|
|
|
/// Helper function for fork().
|
|
///
|
|
/// Please note: if you update this function to change the return type or to
|
|
/// raise different errors, do not forget to update fork() accordingly.
|
|
///
|
|
/// \param stdout_file The name of the file in which to store the stdout.
|
|
/// If this has the magic value /dev/stdout, then the parent's stdout is
|
|
/// reused without applying any redirection.
|
|
/// \param stderr_file The name of the file in which to store the stderr.
|
|
/// If this has the magic value /dev/stderr, then the parent's stderr is
|
|
/// reused without applying any redirection.
|
|
///
|
|
/// \return In the case of the parent, a new child object returned as a
|
|
/// dynamically-allocated object because children classes are unique and thus
|
|
/// noncopyable. In the case of the child, a NULL pointer.
|
|
///
|
|
/// \throw process::system_error If the call to fork(2) fails.
|
|
std::auto_ptr< process::child >
|
|
process::child::fork_files_aux(const fs::path& stdout_file,
|
|
const fs::path& stderr_file)
|
|
{
|
|
std::cout.flush();
|
|
std::cerr.flush();
|
|
|
|
std::auto_ptr< signals::interrupts_inhibiter > inhibiter(
|
|
new signals::interrupts_inhibiter);
|
|
pid_t pid = detail::syscall_fork();
|
|
if (pid == -1) {
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
throw process::system_error("fork(2) failed", errno);
|
|
} else if (pid == 0) {
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
#if !defined(__minix)
|
|
::setpgid(::getpid(), ::getpid());
|
|
#endif /* !defined(__minix) */
|
|
|
|
try {
|
|
if (stdout_file != fs::path("/dev/stdout")) {
|
|
const int stdout_fd = open_for_append(stdout_file);
|
|
safe_dup(stdout_fd, STDOUT_FILENO);
|
|
::close(stdout_fd);
|
|
}
|
|
if (stderr_file != fs::path("/dev/stderr")) {
|
|
const int stderr_fd = open_for_append(stderr_file);
|
|
safe_dup(stderr_fd, STDERR_FILENO);
|
|
::close(stderr_fd);
|
|
}
|
|
} catch (const system_error& e) {
|
|
std::cerr << F("Failed to set up subprocess: %s\n") % e.what();
|
|
std::abort();
|
|
}
|
|
return std::auto_ptr< process::child >(NULL);
|
|
} else {
|
|
LD(F("Spawned process %s: stdout=%s, stderr=%s") % pid % stdout_file %
|
|
stderr_file);
|
|
signals::add_pid_to_kill(pid);
|
|
inhibiter.reset(NULL); // Unblock signals.
|
|
return std::auto_ptr< process::child >(
|
|
new process::child(new impl(pid, NULL)));
|
|
}
|
|
}
|
|
|
|
|
|
/// Spawns a new binary and multiplexes and captures its stdout and stderr.
|
|
///
|
|
/// If the subprocess cannot be completely set up for any reason, it attempts to
|
|
/// dump an error message to its stderr channel and it then calls std::abort().
|
|
///
|
|
/// \param program The binary to execute.
|
|
/// \param args The arguments to pass to the binary, without the program name.
|
|
///
|
|
/// \return A new child object, returned as a dynamically-allocated object
|
|
/// because children classes are unique and thus noncopyable.
|
|
///
|
|
/// \throw process::system_error If the process cannot be spawned due to a
|
|
/// system call error.
|
|
std::auto_ptr< process::child >
|
|
process::child::spawn_capture(const fs::path& program, const args_vector& args)
|
|
{
|
|
std::auto_ptr< child > child = fork_capture_aux();
|
|
if (child.get() == NULL)
|
|
cxx_exec(program, args);
|
|
log_exec(program, args);
|
|
return child;
|
|
}
|
|
|
|
|
|
/// Spawns a new binary and redirects its stdout and stderr to files.
|
|
///
|
|
/// If the subprocess cannot be completely set up for any reason, it attempts to
|
|
/// dump an error message to its stderr channel and it then calls std::abort().
|
|
///
|
|
/// \param program The binary to execute.
|
|
/// \param args The arguments to pass to the binary, without the program name.
|
|
/// \param stdout_file The name of the file in which to store the stdout.
|
|
/// \param stderr_file The name of the file in which to store the stderr.
|
|
///
|
|
/// \return A new child object, returned as a dynamically-allocated object
|
|
/// because children classes are unique and thus noncopyable.
|
|
///
|
|
/// \throw process::system_error If the process cannot be spawned due to a
|
|
/// system call error.
|
|
std::auto_ptr< process::child >
|
|
process::child::spawn_files(const fs::path& program,
|
|
const args_vector& args,
|
|
const fs::path& stdout_file,
|
|
const fs::path& stderr_file)
|
|
{
|
|
std::auto_ptr< child > child = fork_files_aux(stdout_file, stderr_file);
|
|
if (child.get() == NULL)
|
|
cxx_exec(program, args);
|
|
log_exec(program, args);
|
|
return child;
|
|
}
|
|
|
|
|
|
/// Returns the process identifier of this child.
|
|
///
|
|
/// \return A process identifier.
|
|
int
|
|
process::child::pid(void) const
|
|
{
|
|
return _pimpl->_pid;
|
|
}
|
|
|
|
|
|
/// Gets the input stream corresponding to the stdout and stderr of the child.
|
|
///
|
|
/// \pre The child must have been started by fork_capture().
|
|
///
|
|
/// \return A reference to the input stream connected to the output of the test
|
|
/// case.
|
|
std::istream&
|
|
process::child::output(void)
|
|
{
|
|
PRE(_pimpl->_output.get() != NULL);
|
|
return *_pimpl->_output;
|
|
}
|
|
|
|
|
|
/// Blocks to wait for completion.
|
|
///
|
|
/// \return The termination status of the child process.
|
|
///
|
|
/// \throw process::system_error If the call to waitpid(2) fails.
|
|
process::status
|
|
process::child::wait(void)
|
|
{
|
|
const process::status status = safe_wait(_pimpl->_pid);
|
|
{
|
|
signals::interrupts_inhibiter inhibiter;
|
|
signals::remove_pid_to_kill(_pimpl->_pid);
|
|
}
|
|
return status;
|
|
}
|