ian@0: //
ian@0: // Boost.Process
ian@0: // ~~~~~~~~~~~~~
ian@0: //
ian@0: // Copyright (c) 2006, 2007 Julio M. Merino Vidal
ian@0: // Copyright (c) 2008 Ilya Sokolov, Boris Schaeling
ian@0: // Copyright (c) 2009 Boris Schaeling
ian@0: // Copyright (c) 2010 Felipe Tanus, Boris Schaeling
ian@0: //
ian@0: // Distributed under the Boost Software License, Version 1.0. (See accompanying
ian@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
ian@0: //
ian@0: 
ian@0: /**
ian@0:  * \file boost/process/detail/basic_status_service.hpp
ian@0:  *
ian@0:  * Includes the declaration of the basic status service class.
ian@0:  */
ian@0: 
ian@0: #ifndef BOOST_PROCESS_DETAIL_BASIC_STATUS_SERVICE_HPP
ian@0: #define BOOST_PROCESS_DETAIL_BASIC_STATUS_SERVICE_HPP
ian@0: 
ian@0: #include <boost/process/config.hpp>
ian@0: 
ian@0: #if defined(BOOST_POSIX_API)
ian@0: #   include <boost/process/operations.hpp>
ian@0: #   include <string>
ian@0: #   include <sys/types.h>
ian@0: #   include <sys/wait.h>
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0: #   include <windows.h>
ian@0: #else
ian@0: #   error "Unsupported platform."
ian@0: #endif
ian@0: 
ian@0: #include <boost/process/pid_type.hpp>
ian@0: #include <boost/process/detail/status_impl.hpp>
ian@0: #include <boost/asio.hpp>
ian@0: #include <boost/thread.hpp>
ian@0: #include <boost/shared_ptr.hpp>
ian@0: #include <boost/make_shared.hpp>
ian@0: #include <boost/scoped_ptr.hpp>
ian@0: #include <boost/system/error_code.hpp>
ian@0: #include <boost/unordered_map.hpp>
ian@0: #include <vector>
ian@0: #include <algorithm>
ian@0: 
ian@0: namespace boost {
ian@0: namespace process {
ian@0: namespace detail {
ian@0: 
ian@0: /**
ian@0:  * The basic_status_service class provides the service to wait for processes
ian@0:  * synchronously and asynchronously.
ian@0:  */
ian@0: template <typename StatusImplementation = status_impl>
ian@0: class basic_status_service
ian@0:     : public boost::asio::detail::service_base<StatusImplementation>
ian@0: {
ian@0: public:
ian@0:     explicit basic_status_service(boost::asio::io_service &io_service)
ian@0:         : boost::asio::detail::service_base<StatusImplementation>(io_service),
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         interrupt_pid_(-1),
ian@0:         pids_(0)
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:         run_(true)
ian@0: #endif
ian@0:     {
ian@0: #if defined(BOOST_WINDOWS_API)
ian@0:         handles_.push_back(CreateEvent(NULL, FALSE, FALSE, NULL));
ian@0:         if (handles_[0] == NULL)
ian@0:             BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR("CreateEvent() failed");
ian@0:         work_thread_ = boost::thread(
ian@0:             &basic_status_service<StatusImplementation>::work_thread, this);
ian@0: #endif
ian@0:     }
ian@0: 
ian@0:     ~basic_status_service()
ian@0:     {
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         bool worker_thread_active = (pids_ != 0);
ian@0:         lock.unlock();
ian@0:         if (worker_thread_active)
ian@0:         {
ian@0:             stop_work_thread();
ian@0:             work_thread_.join();
ian@0:         }
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:         stop_work_thread();
ian@0:         work_thread_.join();
ian@0:         CloseHandle(handles_[0]);
ian@0: #endif
ian@0:     }
ian@0: 
ian@0:     typedef boost::shared_ptr<StatusImplementation> implementation_type;
ian@0: 
ian@0:     void construct(implementation_type &impl)
ian@0:     {
ian@0:         impl = boost::make_shared<StatusImplementation>();
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         impls_.push_back(impl);
ian@0:     }
ian@0: 
ian@0:     void destroy(implementation_type &impl)
ian@0:     {
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         typename std::vector<implementation_type>::iterator it =
ian@0:             std::find(impls_.begin(), impls_.end(), impl);
ian@0:         if (it != impls_.end())
ian@0:             impls_.erase(it);
ian@0: #if defined(BOOST_WINDOWS_API)
ian@0:         interrupt_work_thread();
ian@0:         work_thread_cond_.wait(work_thread_mutex_);
ian@0:         impl->clear(handles_);
ian@0:         work_thread_cond_.notify_all();
ian@0: #endif
ian@0:         impl.reset();
ian@0:     }
ian@0: 
ian@0:     int wait(implementation_type &impl, pid_type pid)
ian@0:     {
ian@0:         boost::system::error_code ec;
ian@0:         int status = impl->wait(pid, ec);
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         if (ec.value() == ECHILD)
ian@0:         {
ian@0:             boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:             boost::unordered_map<pid_t, int>::iterator it = statuses_.find(pid);
ian@0:             if (it == statuses_.end())
ian@0:             {
ian@0:                 work_thread_cond_.wait(work_thread_mutex_);
ian@0:                 it = statuses_.find(pid);
ian@0:             }
ian@0:             if (it != statuses_.end())
ian@0:             {
ian@0:                 status = it->second;
ian@0:                 statuses_.erase(it);
ian@0:                 ec.clear();
ian@0:             }
ian@0:         }
ian@0: #endif
ian@0:         boost::asio::detail::throw_error(ec);
ian@0:         return status;
ian@0:     }
ian@0: 
ian@0:     template <typename Handler>
ian@0:     void async_wait(implementation_type &impl, pid_type pid, Handler handler)
ian@0:     {
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         if (++pids_ == 1)
ian@0:         {
ian@0:             work_.reset(new boost::asio::io_service::work(
ian@0:                 this->get_io_service()));
ian@0:             work_thread_ = boost::thread(
ian@0:                 &basic_status_service<StatusImplementation>::work_thread,
ian@0:                 this);
ian@0:         }
ian@0:         impl->async_wait(pid, this->get_io_service().wrap(handler));
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:         HANDLE handle = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION,
ian@0:             FALSE, pid);
ian@0:         if (handle == NULL)
ian@0:             BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR("OpenProcess() failed");
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         if (!work_)
ian@0:             work_.reset(new boost::asio::io_service::work(
ian@0:                 this->get_io_service()));
ian@0:         interrupt_work_thread();
ian@0:         work_thread_cond_.wait(work_thread_mutex_);
ian@0:         handles_.push_back(handle);
ian@0:         impl->async_wait(handle, this->get_io_service().wrap(handler));
ian@0:         work_thread_cond_.notify_all();
ian@0: #endif
ian@0:     }
ian@0: 
ian@0: private:
ian@0:     void shutdown_service()
ian@0:     {
ian@0: #if defined(BOOST_WINDOWS_API)
ian@0:         boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:         work_.reset();
ian@0: #endif
ian@0:     }
ian@0: 
ian@0:     void work_thread()
ian@0:     {
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         for (;;)
ian@0:         {
ian@0:             int status;
ian@0:             pid_t pid = ::wait(&status);
ian@0:             if (pid == -1)
ian@0:             {
ian@0:                 if (errno != EINTR)
ian@0:                     BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR("wait(2) failed");
ian@0:             }
ian@0:             else if (interrupted(pid))
ian@0:             {
ian@0:                 // On POSIX the only reason to interrupt is to break out.
ian@0:                 break;
ian@0:             }
ian@0:             else
ian@0:             {
ian@0:                 boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:                 bool regchild = false;
ian@0:                 for (typename std::vector<implementation_type>::iterator it =
ian@0:                     impls_.begin(); it != impls_.end(); ++it)
ian@0:                     regchild |= (*it)->complete(pid, status);
ian@0:                 if (regchild && --pids_ == 0)
ian@0:                 {
ian@0:                     work_.reset();
ian@0:                     break;
ian@0:                 }
ian@0:                 else if (!regchild)
ian@0:                 {
ian@0:                     statuses_.insert(boost::unordered_map<pid_t, int>::
ian@0:                         value_type(pid, status));
ian@0:                     work_thread_cond_.notify_all();
ian@0:                 }
ian@0:             }
ian@0:         }
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:         for (;;)
ian@0:         {
ian@0:             DWORD res = WaitForMultipleObjects(handles_.size(), &handles_[0],
ian@0:                 FALSE, INFINITE);
ian@0:             if (res == WAIT_FAILED)
ian@0:                 BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR(
ian@0:                     "WaitForMultipleObjects() failed");
ian@0:             else if (res - WAIT_OBJECT_0 == 0)
ian@0:             {
ian@0:                 boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:                 if (!run_)
ian@0:                     break;
ian@0:                 work_thread_cond_.notify_all();
ian@0:                 work_thread_cond_.wait(work_thread_mutex_);
ian@0:             }
ian@0:             else if (res - WAIT_OBJECT_0 > 0)
ian@0:             {
ian@0:                 HANDLE handle = handles_[res - WAIT_OBJECT_0];
ian@0:                 DWORD exit_code;
ian@0:                 if (!GetExitCodeProcess(handle, &exit_code))
ian@0:                     BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR(
ian@0:                         "GetExitCodeProcess() failed");
ian@0:                 boost::unique_lock<boost::mutex> lock(work_thread_mutex_);
ian@0:                 for (typename std::vector<implementation_type>::iterator it =
ian@0:                     impls_.begin(); it != impls_.end(); ++it)
ian@0:                     (*it)->complete(handle, exit_code);
ian@0:                 std::vector<HANDLE>::iterator it = handles_.begin();
ian@0:                 std::advance(it, res - WAIT_OBJECT_0);
ian@0:                 handles_.erase(it);
ian@0:                 if (handles_.size() == 1)
ian@0:                     work_.reset();
ian@0:             }
ian@0:         }
ian@0: #endif
ian@0:     }
ian@0: 
ian@0:     void interrupt_work_thread()
ian@0:     {
ian@0: #if defined(BOOST_POSIX_API)
ian@0:         // By creating a child process which immediately exits
ian@0:         // we interrupt wait().
ian@0:         std::vector<std::string> args;
ian@0:         args.push_back("-c");
ian@0:         args.push_back("'exit'");
ian@0:         interrupt_pid_ = create_child("/bin/sh", args).get_id();
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:         // By signaling the event in the first slot WaitForMultipleObjects()
ian@0:         // will return. The work thread won't do anything except checking if
ian@0:         // it should continue to run.
ian@0:         if (!SetEvent(handles_[0]))
ian@0:             BOOST_PROCESS_THROW_LAST_SYSTEM_ERROR("SetEvent() failed");
ian@0: #endif
ian@0:     }
ian@0: 
ian@0: #if defined(BOOST_POSIX_API)
ian@0:     bool interrupted(pid_t pid)
ian@0:     {
ian@0:         boost::mutex::scoped_lock lock(work_thread_mutex_);
ian@0:         return interrupt_pid_ == pid;
ian@0:     }
ian@0: #endif
ian@0: 
ian@0:     void stop_work_thread()
ian@0:     {
ian@0:         boost::mutex::scoped_lock lock(work_thread_mutex_);
ian@0: #if defined(BOOST_WINDOWS_API)
ian@0:         // Access to run_ must be sychronized with running().
ian@0:         run_ = false;
ian@0: #endif
ian@0:         // Access to interrupt_pid_ must be sychronized with interrupted().
ian@0:         interrupt_work_thread();
ian@0:     }
ian@0: 
ian@0:     boost::scoped_ptr<boost::asio::io_service::work> work_;
ian@0:     std::vector<implementation_type> impls_;
ian@0:     boost::mutex work_thread_mutex_;
ian@0:     boost::thread work_thread_;
ian@0:     boost::condition_variable_any work_thread_cond_;
ian@0: #if defined(BOOST_POSIX_API)
ian@0:     pid_t interrupt_pid_;
ian@0:     int pids_;
ian@0:     boost::unordered_map<pid_t, int> statuses_;
ian@0: #elif defined(BOOST_WINDOWS_API)
ian@0:     bool run_;
ian@0:     std::vector<HANDLE> handles_;
ian@0: #endif
ian@0: };
ian@0: 
ian@0: }
ian@0: }
ian@0: }
ian@0: 
ian@0: #endif