// **********************************************************************
//
// Copyright (c) 2003-2006 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************

#include <IceUtil/DisableWarnings.h>
#include <Ice/Ice.h>
#include <IceGrid/Activator.h>
#include <IceGrid/Admin.h>
#include <IceGrid/Internal.h>
#include <IceGrid/TraceLevels.h>
#include <IceGrid/Util.h>
#include <IceGrid/ServerI.h>

#include <IcePatch2/Util.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#ifndef _WIN32
#   include <sys/wait.h>
#   include <signal.h>
#endif

using namespace std;
using namespace Ice;
using namespace IceGrid;

namespace IceGrid
{

class TerminationListenerThread : public IceUtil::Thread
{
public:

    TerminationListenerThread(Activator& activator) :
	_activator(activator)
    {
    }

    virtual 
    void run()
    {
	_activator.runTerminationListener();
    }

private:
    
    Activator& _activator;
};

}

#define ICE_STRING(X) #X

namespace IceGrid
{

#ifndef _WIN32
//
// Helper function for async-signal safe error reporting
//
void
reportChildError(int err, int fd, const char* cannot, const char* name)
{
    //
    // Send any errors to the parent process, using the write
    // end of the pipe.
    //
    char msg[500];
    strcpy(msg, cannot);
    strcat(msg, " `");
    strcat(msg, name);
    strcat(msg, "':  ");
    strcat(msg, strerror(err));
    write(fd, msg, strlen(msg));
    close(fd);

    //
    // _exit instead of exit to avoid interferences with the parent
    // process.
    //
    _exit(EXIT_FAILURE);
}

#endif

#ifndef _WIN32
string
signalToString(int signal)
{
    switch(signal)
    {
	case SIGHUP:
	{
	    return ICE_STRING(SIGHUP);
	}
	case SIGINT:
	{
	    return ICE_STRING(SIGINT);
	}
	case SIGQUIT:
	{
	    return ICE_STRING(SIGQUIT);
	}
	case SIGILL:
	{
	    return ICE_STRING(SIGILL);
	}
	case SIGTRAP:
	{
	    return ICE_STRING(SIGTRAP);
	}
	case SIGABRT:
	{
	    return ICE_STRING(SIGABRT);
	}
	case SIGBUS:
	{
	    return ICE_STRING(SIGBUS);
	}
	case SIGFPE:
	{
	    return ICE_STRING(SIGFPE);
	}
	case SIGKILL:
	{
	    return ICE_STRING(SIGKILL);
	}
	case SIGUSR1:
	{
	    return ICE_STRING(SIGUSR1);
	}
	case SIGSEGV:
	{
	    return ICE_STRING(SIGSEGV);
	}
	case SIGPIPE:
	{
	    return ICE_STRING(SIGPIPE);
	}
	case SIGALRM:
	{
	    return ICE_STRING(SIGALRM);
	}
	case SIGTERM:
	{
	    return ICE_STRING(SIGTERM);
	}
	default:
	{
	    ostringstream os;
	    os << "signal " << signal;
	    return os.str();
	}
    }
#endif
}

int
stringToSignal(const string& str)
{
#ifdef _WIN32
    throw BadSignalException();
#else

    if(str == ICE_STRING(SIGHUP))
    {
	return SIGHUP;
    }
    else if(str ==  ICE_STRING(SIGINT))
    {
	return SIGINT;
    }
    else if(str == ICE_STRING(SIGQUIT))
    {
	return SIGQUIT;
    }
    else if(str == ICE_STRING(SIGILL))
    {
	return SIGILL;
    }
    else if(str == ICE_STRING(SIGTRAP))
    {
	return SIGTRAP;
    }
    else if(str == ICE_STRING(SIGABRT))
    {
	return SIGABRT;
    }
    else if(str == ICE_STRING(SIGBUS))
    {
	return SIGBUS;
    }
    else if(str == ICE_STRING(SIGFPE))
    {
	return SIGFPE;
    }
    else if(str == ICE_STRING(SIGKILL))
    {
	return SIGKILL;
    }
    else if(str == ICE_STRING(SIGUSR1))
    {
	return SIGUSR1;
    }
    else if(str == ICE_STRING(SIGSEGV))
    {
	return SIGSEGV;
    }
    else if(str == ICE_STRING(SIGUSR2))
    {
	return SIGUSR2;
    }
    else if(str == ICE_STRING(SIGPIPE))
    {
	return SIGPIPE;
    }
    else if(str == ICE_STRING(SIGALRM))
    {
	return SIGALRM;
    }
    else if(str == ICE_STRING(SIGTERM))
    {
	return SIGTERM;
    }
    else
    {
	if(str != "")
	{
	    char* end;
	    long int signal = strtol(str.c_str(), &end, 10);
	    if(*end == '\0' && signal > 0 && signal < 64)
	    {
		return static_cast<int>(signal);
	    }
	}
	throw BadSignalException();
    }
}
#endif

}

Activator::Activator(const TraceLevelsPtr& traceLevels, const PropertiesPtr& properties) :
    _traceLevels(traceLevels),
    _properties(properties),
    _deactivating(false)
{
#ifdef _WIN32
    _hIntr = CreateEvent(
        NULL,  // Security attributes
        TRUE,  // Manual reset
        FALSE, // Initial state is nonsignaled
        NULL   // Unnamed
    );

    if(_hIntr == NULL)
    {
	SyscallException ex(__FILE__, __LINE__);
	ex.error = getSystemErrno();
	throw ex;
    }
#else
    int fds[2];
    if(pipe(fds) != 0)
    {
	SyscallException ex(__FILE__, __LINE__);
	ex.error = getSystemErrno();
	throw ex;
    }
    _fdIntrRead = fds[0];
    _fdIntrWrite = fds[1];
    int flags = fcntl(_fdIntrRead, F_GETFL);
    flags |= O_NONBLOCK;
    fcntl(_fdIntrRead, F_SETFL, flags);
#endif

    _outputDir = _properties->getProperty("IceGrid.Node.Output");
    _redirectErrToOut = (_properties->getPropertyAsInt("IceGrid.Node.RedirectErrToOut") > 0);

    //
    // Parse the properties override property.
    //
    string props = _properties->getProperty("IceGrid.Node.PropertiesOverride");
    if(!props.empty())
    {
	string::size_type end = 0;
	while(end != string::npos)
	{
	    const string delim = " \t\r\n";
		
	    string::size_type beg = props.find_first_not_of(delim, end);
	    if(beg == string::npos)
	    {
		break;
	    }
		
	    end = props.find_first_of(delim, beg);
	    string arg;
	    if(end == string::npos)
	    {
		arg = props.substr(beg);
	    }
	    else
	    {
		arg = props.substr(beg, end - beg);
	    }
	    if(arg.find("--") != 0)
	    {
		arg = "--" + arg;
	    }
	    _propertiesOverride.push_back(arg);
	}
    }    
}

Activator::~Activator()
{
    assert(!_thread);
    
#ifdef _WIN32
    if(_hIntr != NULL)
    {
        CloseHandle(_hIntr);
    }
#else
    close(_fdIntrRead);
    close(_fdIntrWrite);
#endif
}

int
Activator::activate(const string& name,
		    const string& exePath,
		    const string& pwdPath,
		    const Ice::StringSeq& options,
		    const Ice::StringSeq& envs,
		    const ServerIPtr& server)
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);

    if(_deactivating)
    {
	throw string("The node is being shutdown.");
    }

    string path = exePath;
    if(path.empty())
    {
	throw string("The server executable path is empty.");
    }

    string pwd = IcePatch2::simplify(pwdPath);
#ifdef _WIN32
    if(!IcePatch2::isAbsolute(path))
    {
	if(path.find('/') == string::npos)
	{
	    //
	    // Get the absolute pathname of the executable.
	    //
	    char absbuf[_MAX_PATH];
	    char* filePart;
	    string ext = path.size() <= 4 || path[path.size() - 4] != '.' ? ".exe" : "";
	    if(SearchPath(NULL, path.c_str(), ext.c_str(), _MAX_PATH, absbuf, &filePart) == 0)
	    {
		if(_traceLevels->activator > 0)
		{
		    Trace out(_traceLevels->logger, _traceLevels->activatorCat);
		    out << "cannot convert `" << path << "' into an absolute path";
		}
		throw string("The server executable path `" + path + "' can't be converted into an absolute path.");
	    }
	    path = absbuf;
	}
   	else if(!pwd.empty())
	{
	    path = pwd + "/" + path;
	}
    }

    //
    // Get the absolute pathname of the working directory.
    //
    if(!pwd.empty())
    {
	char absbuf[_MAX_PATH];
	if(_fullpath(absbuf, pwd.c_str(), _MAX_PATH) == NULL)
	{
	    if(_traceLevels->activator > 0)
	    {
		Trace out(_traceLevels->logger, _traceLevels->activatorCat);
		out << "cannot convert `" << pwd << "' into an absolute path";
	    }
	    throw string("The server working directory path `" + pwd + "' can't be converted into an absolute path.");
	}
	pwd = absbuf;
    }
#endif

    //
    // Setup arguments.
    //
    StringSeq args;
    args.push_back(path);
    args.insert(args.end(), options.begin(), options.end());
    args.insert(args.end(), _propertiesOverride.begin(), _propertiesOverride.end());
    args.push_back("--Ice.Default.Locator=" + _properties->getProperty("Ice.Default.Locator"));
    args.push_back("--Ice.ServerId=" + name);
    
    if(_outputDir.size() > 0)
    {
	string outFile = _outputDir + "/" + name + ".out";
	string errFile = _redirectErrToOut ? outFile : _outputDir + "/" + name + ".err";
	args.push_back("--Ice.StdOut=" + outFile);
	args.push_back("--Ice.StdErr=" + errFile);
    }


    if(_traceLevels->activator > 1)
    {
	Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
	out << "activating server `" << name << "'";
	if(_traceLevels->activator > 2)
	{
	    out << "\n";
	    out << "path = " << path << "\n";
	    out << "pwd = " << pwd << "\n";
	    if(!envs.empty())
	    {
		out << "envs = " << toString(envs, ", ") << "\n";
	    }
	    if(!args.empty())
	    {
		out << "args = " << toString(args);
	    }
	}
    }

    //
    // Activate and create.
    //
#ifdef _WIN32
    //
    // Compose command line.
    //
    string cmd;
    StringSeq::const_iterator p;
    for(p = args.begin(); p != args.end(); ++p)
    {
        if(p != args.begin())
        {
            cmd.push_back(' ');
        }
        //
        // Enclose arguments containing spaces in double quotes.
        //
        if((*p).find(' ') != string::npos)
        {
            cmd.push_back('"');
            cmd.append(*p);
            cmd.push_back('"');
        }
        else
        {
            cmd.append(*p);
        }
    }

    const char* dir;
    if(!pwd.empty())
    {
        dir = pwd.c_str();
    }
    else
    {
        dir = NULL;
    }

    //
    // Make a copy of the command line.
    //
    char* cmdbuf = strdup(cmd.c_str());

    //
    // Create the environment block for the child process. We start with the environment
    // of this process, and then merge environment variables from the server description.
    // Since Windows is case insensitive wrt environment variables we convert the keys to
    // uppercase to ensure matches are found.
    //
    const char* env = NULL;
    string envbuf;
    if(!envs.empty())
    {
        map<string, string> envMap;
        LPVOID parentEnv = GetEnvironmentStrings();
        const char* var = reinterpret_cast<const char*>(parentEnv);
        if(*var == '=')
        {
            //
            // The environment block may start with some information about the
            // current drive and working directory. This is indicated by a leading
            // '=' character, so we skip to the first '\0' byte.
            //
            while(*var)
                var++;
            var++;
        }
        while(*var)
        {
            string s(var);
            string::size_type pos = s.find('=');
            if(pos != string::npos)
            {
	    	string key = s.substr(0, pos);
		std::transform(key.begin(), key.end(), key.begin(), toupper);
                envMap.insert(map<string, string>::value_type(key, s.substr(pos + 1)));
            }
            var += s.size();
            var++; // Skip the '\0' byte
        }
        FreeEnvironmentStrings(static_cast<char*>(parentEnv));
        for(p = envs.begin(); p != envs.end(); ++p)
        {
            string s = *p;
            string::size_type pos = s.find('=');
            if(pos != string::npos)
            {
	        string key = s.substr(0, pos);
		std::transform(key.begin(), key.end(), key.begin(), toupper);
		envMap.erase(key);
                envMap.insert(map<string, string>::value_type(key, s.substr(pos + 1)));
            }
        }
        for(map<string, string>::const_iterator q = envMap.begin(); q != envMap.end(); ++q)
        {
            envbuf.append(q->first);
            envbuf.push_back('=');
            envbuf.append(q->second);
            envbuf.push_back('\0');
        }
        envbuf.push_back('\0');
        env = envbuf.c_str();
    }

    Process process;

    STARTUPINFO si;
    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    
    PROCESS_INFORMATION pi;
    ZeroMemory(&pi, sizeof(pi));

    BOOL b = CreateProcess(
        NULL,                     // Executable
        cmdbuf,                   // Command line
        NULL,                     // Process attributes
        NULL,                     // Thread attributes
        FALSE,                    // Do NOT inherit handles
        CREATE_NEW_PROCESS_GROUP, // Process creation flags
        (LPVOID)env,              // Process environment
        dir,                      // Current directory
        &si,                      // Startup info
        &pi                       // Process info
    );

    free(cmdbuf);

    if(!b)
    {
        SyscallException ex(__FILE__, __LINE__);
        ex.error = getSystemErrno();
        throw ex;
    }

    //
    // Caller is responsible for closing handles in PROCESS_INFORMATION. We don't need to
    // keep the thread handle, so we close it now. The process handle will be closed later.
    //
    CloseHandle(pi.hThread);

    
    process.pid = pi.dwProcessId;
    process.hnd = pi.hProcess;
    process.server = server;
    _processes.insert(make_pair(name, process));
    
    setInterrupt();

    if(_traceLevels->activator > 0)
    {
        Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
        out << "activated server `" << name << "' (pid = " << pi.dwProcessId << ")";
    }

    return static_cast<Ice::Int>(process.pid);
#else
    int fds[2];
    if(pipe(fds) != 0)
    {
	SyscallException ex(__FILE__, __LINE__);
	ex.error = getSystemErrno();
	throw ex;
    }

    //
    // Convert to standard argc/argv.
    //
    int argc = static_cast<int>(args.size());
    char** argv = static_cast<char**>(malloc((argc + 1) * sizeof(char*)));
    int i = 0;
    for(StringSeq::const_iterator p = args.begin(); p != args.end(); ++p, ++i)
    {
	assert(i < argc);
	argv[i] = strdup(p->c_str());
    }
    assert(i == argc);
    argv[argc] = 0;
    
    int envCount = static_cast<int>(envs.size());
    char** envArray = new char*[envCount];
    i = 0;
    for(StringSeq::const_iterator q = envs.begin(); q != envs.end(); ++q)
    {
	envArray[i++] = strdup(q->c_str());
    }

    //
    // Current directory
    //
    const char* pwdCStr = pwd.c_str();

    pid_t pid = fork();
    if(pid == -1)
    {
	SyscallException ex(__FILE__, __LINE__);
	ex.error = getSystemErrno();
	throw ex;
    }

    if(pid == 0) // Child process.
    {
	//
	// Until exec, we can only use async-signal safe functions
	//

	//
	// Assign a new process group for this process. 
	//
	setpgid(0, 0);

	//
	// Close all file descriptors, except for standard input,
	// standard output, standard error, and the write side
	// of the newly created pipe.
	//
	int maxFd = static_cast<int>(sysconf(_SC_OPEN_MAX));
	for(int fd = 3; fd < maxFd; ++fd)
	{
	    if(fd != fds[1])
	    {
		close(fd);
	    }
	}

	for(i = 0; i < envCount; i++)
	{
	    if(putenv(envArray[i]) != 0)
	    {
		reportChildError(errno, fds[1], "cannot set environment variable",  envArray[i]); 
	    }
	}
	//
	// Each env is leaked on purpose ... see man putenv().
	//
	delete[] envArray;

	//
	// Change working directory.
	//
	if(strlen(pwdCStr) != 0)
	{
	    if(chdir(pwdCStr) == -1)
	    {
		reportChildError(errno, fds[1], "cannot change working directory to",  pwdCStr);
	    }
	}	

	if(execvp(argv[0], argv) == -1)
	{
	    reportChildError(errno, fds[1], "cannot execute",  argv[0]);
	}
    }
    else // Parent process.
    {
	close(fds[1]);

	for(i = 0; argv[i]; i++)
	{
	    free(argv[i]);
	}
	free(argv);

	for(i = 0; i < envCount; ++i)
	{
	    free(envArray[i]);
	}
	delete[] envArray;

	Process process;
	process.pid = pid;
	process.pipeFd = fds[0];
	process.server = server;
	_processes.insert(make_pair(name, process));
	
	int flags = fcntl(process.pipeFd, F_GETFL);
	flags |= O_NONBLOCK;
	fcntl(process.pipeFd, F_SETFL, flags);

	setInterrupt();

	if(_traceLevels->activator > 0)
	{
	    Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
	    out << "activated server `" << name << "' (pid = " << pid << ")";
	}
    }

    return pid;
#endif
}

void
Activator::deactivate(const string& name, const Ice::ProcessPrx& process)
{
#ifdef _WIN32
    Ice::Int pid = getServerPid(name);
    if(pid == 0)
    {
	//
	// Server is already deactivated.
	//
	return;
    }
#endif

    //
    // Try to shut down the server gracefully using the process proxy.
    //
    if(process)
    {
	if(_traceLevels->activator > 1)
	{
	    Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
	    out << "deactivating `" << name << "' using process proxy";
	}
	try
	{
	    process->shutdown();
	    return;
	}
	catch(const Ice::LocalException& ex)
	{
	    Ice::Warning out(_traceLevels->logger);
	    out << "exception occurred while deactivating `" << name << "' using process proxy:\n" << ex;
	}
    }

    if(_traceLevels->activator > 1)
    {
        Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
        out << "no process proxy, deactivating `" << name << "' using signal";
    }

#ifdef _WIN32
    //
    // Generate a Ctrl+Break event on the child.
    //
    if(GenerateConsoleCtrlEvent(CTRL_BREAK_EVENT, pid))
    {
        if(_traceLevels->activator > 1)
        {
            Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
            out << "sent Ctrl+Break to server `" << name << "' (pid = " << pid << ")";
        }
    }
    else if(GetLastError() != ERROR_INVALID_PARAMETER) // Process with pid doesn't exist anymore.
    {
        SyscallException ex(__FILE__, __LINE__);
        ex.error = getSystemErrno();
        throw ex;
    }
#else
    //
    // Send a SIGTERM to the process.
    //
    sendSignal(name, SIGTERM);
    
#endif
}

void
Activator::kill(const string& name)
{
#ifdef _WIN32
    Ice::Int pid = getServerPid(name);
    if(pid == 0)
    {
	//
	// Server is already deactivated.
	//
	return;
    }

    HANDLE hnd = OpenProcess(PROCESS_TERMINATE, FALSE, pid);
    if(hnd == NULL)
    {
        SyscallException ex(__FILE__, __LINE__);
        ex.error = getSystemErrno();
        throw ex;
    }

    BOOL b = TerminateProcess(hnd, 0); // We use 0 for the exit code to make sure it's not considered as a crash.

    CloseHandle(hnd);

    if(_traceLevels->activator > 1)
    {
	Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
	out << "terminating server `" << name << "' (pid = " << pid << ")";
    }

#else
    sendSignal(name, SIGKILL);
#endif
}


void
Activator::sendSignal(const string& name, const string& signal)
{
    sendSignal(name, stringToSignal(signal));
}

void
Activator::sendSignal(const string& name, int signal)
{
#ifdef _WIN32
    //
    // TODO: Win32 implementation?
    //
    throw BadSignalException();

#else
    Ice::Int pid = getServerPid(name);
    if(pid == 0)
    {
	//
	// Server is already deactivated.
	//
	return;
    }

    int ret = ::kill(static_cast<pid_t>(pid), signal);
    if(ret != 0 && getSystemErrno() != ESRCH)
    {
	SyscallException ex(__FILE__, __LINE__);
	ex.error = getSystemErrno();
	throw ex;
    }

    if(_traceLevels->activator > 1)
    {
	Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
	out << "sent " << signalToString(signal) << " to server `" << name << "' (pid = " << pid << ")";
    }
#endif
}

Ice::Int
Activator::getServerPid(const string& name)
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);

    map<string, Process>::const_iterator p = _processes.find(name);
    if(p == _processes.end())
    {
	return 0;
    }

    return static_cast<Ice::Int>(p->second.pid);
}

void
Activator::start()
{
    //
    // Create and start the termination listener thread.
    //
    _thread = new TerminationListenerThread(*this);
    _thread->start();
}

void
Activator::waitForShutdown()
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
    while(!_deactivating)
    {
	wait();
    }
}

void
Activator::shutdown()
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
    //
    // Deactivation has been initiated. Set _deactivating to true to 
    // prevent activation of new processes. This will also cause the
    // termination listener thread to stop when there are no more
    // active processes.
    //
    _deactivating = true;
    setInterrupt();
    notifyAll();
}

void
Activator::destroy()
{
    {
	IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
	assert(_deactivating);
    }

    //
    // Deactivate all the processes.
    //
    deactivateAll();

    //
    // Join the termination listener thread. This thread terminates
    // when there's no more processes and when _deactivating is set to
    // true.
    //
    _thread->getThreadControl().join();
    _thread = 0;
}

void
Activator::runTerminationListener()
{
    while(true)
    {
	try
	{
	    terminationListener();
	    break;
	}
	catch(const Exception& ex)
	{
	    Error out(_traceLevels->logger);
	    out << "exception in process termination listener:\n" << ex;
	}
	catch(...)
	{
	    Error out(_traceLevels->logger);
	    out << "unknown exception in process termination listener";
	}
    }
}

void
Activator::deactivateAll()
{
    //
    // Stop all active processes.
    //
    map<string, Process> processes;
    {
	IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
	processes = _processes;
    }

    for(map<string, Process>::iterator p = processes.begin(); p != processes.end(); ++p)
    {
	//
	// Stop the server. The listener thread should detect the
	// process deactivation and remove it from the activator's
	// list of active processes.
	//
	try
	{
	    p->second.server->stop_async(0);
	}
	catch(const ObjectNotExistException&)
	{
	    //
	    // Expected if the server was in the process of being destroyed.
	    //
	}
	catch(const Ice::LocalException& ex)
	{
	    Ice::Warning out(_traceLevels->logger);
	    out << "unexpected exception raised by server `" << p->first << "' stop:\n" << ex;
	}
    }
}

void
Activator::terminationListener()
{
#ifdef _WIN32
    while(true)
    {
        vector<HANDLE> handles;

        //
        // Lock while we collect the process handles.
        //
        {
            IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);

            for(map<string, Process>::iterator p = _processes.begin(); p != _processes.end(); ++p)
            {
                handles.push_back(p->second.hnd);
            }
        }

        handles.push_back(_hIntr);

        //
        // Wait for a child to terminate, or the interrupt event to be signaled.
        //
        DWORD ret = WaitForMultipleObjects(static_cast<DWORD>(handles.size()), &handles[0], FALSE, INFINITE);
        if(ret == WAIT_FAILED)
        {
            SyscallException ex(__FILE__, __LINE__);
            ex.error = getSystemErrno();
            throw ex;
        }

        vector<HANDLE>::size_type pos = ret - WAIT_OBJECT_0;
        assert(pos < handles.size());
        HANDLE hnd = handles[pos];

	vector<Process> terminated;
	bool deactivated = false;
	{
	    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
	    
	    if(hnd == _hIntr)
	    {
		clearInterrupt();
	    }
	    else
	    {
		for(map<string, Process>::iterator p = _processes.begin(); p != _processes.end(); ++p)
		{
		    if(p->second.hnd == hnd)
		    {
			terminated.push_back(p->second);
			_processes.erase(p);
			break;
		    }
		}
            }

	    deactivated = _deactivating && _processes.empty();
	}
	
	for(vector<Process>::const_iterator p = terminated.begin(); p != terminated.end(); ++p)
	{
	    DWORD status;
	    BOOL b = GetExitCodeProcess(p->hnd, &status);
	    CloseHandle(p->hnd);
	    assert(status != STILL_ACTIVE);

	    if(_traceLevels->activator > 0)
	    {
		Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
		out << "detected termination of server `" << p->server->getId() << "'";
		if(status != 0)
		{
		    out << "\nexit code = " << status;
		}
	    }

	    try
	    {
		p->server->terminated("", status);
	    }
	    catch(const Ice::LocalException& ex)
	    {
		Ice::Warning out(_traceLevels->logger);
		out << "unexpected exception raised by server `" << p->server->getId() << "' termination:\n" << ex;
	    }
	}

	if(deactivated)
        {
            return;
        }
    }
#else
    while(true)
    {
	fd_set fdSet;
	int maxFd = _fdIntrRead;
	FD_ZERO(&fdSet);
	FD_SET(_fdIntrRead, &fdSet);
	
	{
	    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);

	    for(map<string, Process>::iterator p = _processes.begin(); p != _processes.end(); ++p)
	    {
		int fd = p->second.pipeFd;
		FD_SET(fd, &fdSet);
		if(maxFd < fd)
		{
		    maxFd = fd;
		}
	    }
	}
	
    repeatSelect:
	int ret = ::select(maxFd + 1, &fdSet, 0, 0, 0);
	assert(ret != 0);
	
	if(ret == -1)
	{
#ifdef EPROTO
	    if(errno == EINTR || errno == EPROTO)
	    {
		goto repeatSelect;
	    }
#else
	    if(errno == EINTR)
	    {
		goto repeatSelect;
	    }
#endif
	    
	    SyscallException ex(__FILE__, __LINE__);
	    ex.error = getSystemErrno();
	    throw ex;
	}
	
	vector<Process> terminated;
	bool deactivated = false;
	{
	    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
	    
	    if(FD_ISSET(_fdIntrRead, &fdSet))
	    {
		clearInterrupt();

		if(_deactivating && _processes.empty())
                {
                    return;
                }
	    }
	    
	    map<string, Process>::iterator p = _processes.begin();
	    while(p != _processes.end())
	    {
		int fd = p->second.pipeFd;
		if(!FD_ISSET(fd, &fdSet))   
		{
		    ++p;
		    continue;
		}

		char s[16];
		ssize_t rs;
		string message;

		//
		// Read the message over the pipe.
		//
		while((rs = read(fd, &s, 16)) > 0)
		{
		    message.append(s, rs);
		}

		//
		// Keep the received message.
		//
		if(!message.empty())
		{
		    p->second.msg += message;
		}

		if(rs == -1)
		{
		    if(errno != EAGAIN || message.empty())
		    {
			SyscallException ex(__FILE__, __LINE__);
			ex.error = getSystemErrno();
			throw ex;
		    }

		    ++p;
		}
		else if(rs == 0)
		{    
		    //
		    // If the pipe was closed, the process has terminated.
		    //

		    terminated.push_back(p->second);
    
		    close(p->second.pipeFd);
		    _processes.erase(p++);
		}
	    }

	    //
	    // We are deactivating and there's no more active processes.
	    //
	    deactivated = _deactivating && _processes.empty();
	}
	
	for(vector<Process>::const_iterator p = terminated.begin(); p != terminated.end(); ++p)
	{
	    int status;
#if defined(__linux)
	    int nRetry = 0;
	    while(true) // The while loop is necessary for the linux workaround.
	    {
		pid_t pid = waitpid(p->pid, &status, 0);
		if(pid < 0)
		{
		    //
		    // Some Linux distribution have a bogus waitpid() (e.g.: CentOS 4.x). It doesn't 
		    // block and reports an incorrect ECHILD error on the first call. We sleep a 
		    // little and retry to work around this issue (it appears from testing that a
		    // single retry is enough but to make sure we retry up to 10 times before to throw.)
		    //
		    if(errno == ECHILD && nRetry < 10)
		    {
			// Wait 1ms, 11ms, 21ms, etc.
			IceUtil::ThreadControl::sleep(IceUtil::Time::milliSeconds(nRetry * 10 + 1)); 
			++nRetry;
			continue;
		    }
		    SyscallException ex(__FILE__, __LINE__);
		    ex.error = getSystemErrno();
		    throw ex;
		}
		assert(pid == p->pid);
		break;
	    }
#else
	    pid_t pid = waitpid(p->pid, &status, 0);
	    if(pid < 0)
	    {
		SyscallException ex(__FILE__, __LINE__);
		ex.error = getSystemErrno();
		throw ex;
	    }
	    assert(pid == p->pid);
#endif

	    if(_traceLevels->activator > 0)
	    {
		Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
		out << "detected termination of server `" << p->server->getId() << "'";
		if(!p->msg.empty())
		{
		    out << "\nreason = " << p->msg;
		}
		if(WIFEXITED(status) && status != 0)
		{
		    out << "\nexit code = " << WEXITSTATUS(status);
		}
		else if(WIFSIGNALED(status))
		{
		    out << "\nsignal = " << signalToString(WTERMSIG(status));
		}
	    }

	    try
	    {
		p->server->terminated(p->msg, status);
	    }
	    catch(const Ice::LocalException& ex)
	    {
		Ice::Warning out(_traceLevels->logger);
		out << "unexpected exception raised by server `" << p->server->getId() << "' termination:\n" << ex;
	    }
	}

	if(deactivated)
	{
	    return;
	}
    }
#endif
}

void
Activator::clearInterrupt()
{
#ifdef _WIN32
    ResetEvent(_hIntr);
#else
    char c;
    while(read(_fdIntrRead, &c, 1) == 1)
        ;
#endif
}

void
Activator::setInterrupt()
{
#ifdef _WIN32
    SetEvent(_hIntr);
#else
    char c = 0;
    write(_fdIntrWrite, &c, 1);
#endif
}