// **********************************************************************
//
// Copyright (c) 2003-2016 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/ArgVector.h>
#include <IceUtil/FileUtil.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 <IcePatch2Lib/Util.h>

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

#ifndef _WIN32
#   include <sys/wait.h>
#   include <signal.h>
#   include <pwd.h> // for getpwuid
#else
#ifndef SIGKILL
#   define SIGKILL 9
#endif
#ifndef SIGTERM
#   define SIGTERM 15
#endif
#endif

#if defined(__linux) || defined(__sun) || defined(_AIX) || defined(__GLIBC__)
#   include <grp.h> // for initgroups
#endif

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

#define ICE_STRING(X) #X

namespace IceGrid
{

class TerminationListenerThread : public IceUtil::Thread
{
public:

    TerminationListenerThread(Activator& activator) :
        IceUtil::Thread("IceGrid termination listener thread"),
        _activator(activator)
    {
    }

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

private:

    Activator& _activator;
};

#ifndef _WIN32
//
// Helper function for async-signal safe error reporting
//
void
reportChildError(int err, int fd, const char* cannot, const char* name, const TraceLevelsPtr& traceLevels)
{
    //
    // 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, "'");
    if(err)
    {
        strcat(msg, ": ");
        strcat(msg, strerror(err));
    }
    ssize_t sz = write(fd, msg, strlen(msg));
    if(sz == -1)
    {
        Ice::Warning out(traceLevels->logger);
        out << "error rerporting child error msg: `" << msg << "'";
    }
    close(fd);

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

#endif

string
signalToString(int signal)
{
    switch(signal)
    {
#ifndef _WIN32
        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 SIGUSR1:
        {
            return ICE_STRING(SIGUSR1);
        }
        case SIGSEGV:
        {
            return ICE_STRING(SIGSEGV);
        }
        case SIGPIPE:
        {
            return ICE_STRING(SIGPIPE);
        }
        case SIGALRM:
        {
            return ICE_STRING(SIGALRM);
        }
#endif
        case SIGKILL:
        {
            return ICE_STRING(SIGKILL);
        }
        case SIGTERM:
        {
            return ICE_STRING(SIGTERM);
        }
        default:
        {
            ostringstream os;
            os << "signal " << signal;
            return os.str();
        }
    }
}

int
stringToSignal(const string& str)
{
#ifndef _WIN32
    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(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
#endif
        if(str == ICE_STRING(SIGKILL))
    {
        return SIGKILL;
    }
    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)
            {
#ifdef _WIN32
                if(signal == SIGKILL || signal == SIGTERM)
                {
                    return static_cast<int>(signal);
                }
#else
                return static_cast<int>(signal);
#endif
            }
        }
        throw BadSignalException("unknown signal `" + str + "'");
        return SIGTERM; // Keep the compiler happy.
    }
}

#ifdef _WIN32
struct UnicodeStringLess
{

bool
operator()(const wstring& lhs, const wstring& rhs) const
{
    int r = CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, lhs.c_str(), -1, rhs.c_str(), -1);
    assert(r > 0);
    return r == CSTR_LESS_THAN;
}

};
#endif

}

#ifdef _WIN32
extern "C" void CALLBACK activatorWaitCallback(PVOID data, BOOLEAN)
{
    Activator::Process* process = reinterpret_cast<Activator::Process*>(data);
    process->activator->processTerminated(process);
}
#endif

Activator::Activator(const TraceLevelsPtr& traceLevels) :
    _traceLevels(traceLevels),
    _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


}

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,
#ifndef _WIN32
                    uid_t uid,
                    gid_t gid,
#endif
                    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 = IcePatch2Internal::simplify(pwdPath);
#ifdef _WIN32
    if(!IceUtilInternal::isAbsolutePath(path))
    {
        if(path.find('/') == string::npos)
        {
            //
            // Get the absolute pathname of the executable.
            //
            wchar_t absbuf[_MAX_PATH];
            wchar_t* fPart;
            wstring ext = path.size() <= 4 || path[path.size() - 4] != '.' ? L".exe" : L"";

            //
            // IceGrid doesn't support to use string converters, so don't need to use
            // any string converter in wstringToString conversions.
            //
            if(SearchPathW(NULL, IceUtil::stringToWstring(path).c_str(), ext.c_str(), _MAX_PATH, absbuf, &fPart) == 0)
            {
                if(_traceLevels->activator > 0)
                {
                    Trace out(_traceLevels->logger, _traceLevels->activatorCat);
                    out << "couldn't find `" << path << "' executable.";
                }
                throw string("Couldn't find `" + path + "' executable.");
            }
            path = IceUtil::wstringToString(absbuf);
        }
        else if(!pwd.empty())
        {
            path = pwd + "/" + path;
        }
    }

    //
    // Get the absolute pathname of the working directory.
    //
    // IceGrid doesn't support to use string converters, so
    // don't need to use any string converter in stringToWstring
    // conversions.
    //
    if(!pwd.empty())
    {
        wchar_t absbuf[_MAX_PATH];
        if(_wfullpath(absbuf, IceUtil::stringToWstring(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 = IceUtil::wstringToString(absbuf);
    }
#endif

    //
    // Setup arguments.
    //
    StringSeq args;
    args.push_back(path);
    args.insert(args.end(), options.begin(), options.end());

    if(_traceLevels->activator > 0)
    {
        Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
        out << "activating server `" << name << "'";
        if(_traceLevels->activator > 1)
        {
            out << "\n";
            out << "path = " << path << "\n";
            if(pwd.empty())
            {
                string cwd;
                if(IceUtilInternal::getcwd(cwd) == 0)
                {
                    out << "pwd = " << cwd << "\n";
                }
            }
            else
            {
                out << "pwd = " << pwd << "\n";
            }
#ifndef _WIN32
            out << "uid/gid = " << uid << "/" << gid << "\n";
#endif
            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;
    for(StringSeq::const_iterator 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);
        }
    }

    //
    // IceGrid doesn't support to use string converters, so don't need to use
    // any string converter in stringToWstring conversions.
    //
    wstring wpwd = IceUtil::stringToWstring(pwd);
    const wchar_t* dir = !wpwd.empty() ? wpwd.c_str() : NULL;

    //
    // Make a copy of the command line.
    //
    wchar_t* cmdbuf = _wcsdup(IceUtil::stringToWstring(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 wchar_t* env = NULL;
    wstring envbuf;
    if(!envs.empty())
    {
        map<wstring, wstring, UnicodeStringLess> envMap;
        LPVOID parentEnv = GetEnvironmentStringsW();
        const wchar_t* var = reinterpret_cast<const wchar_t*>(parentEnv);
        if(*var == L'=')
        {
            //
            // 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 != L'\0')
                var++;
            var++;
        }
        while(*var != L'\0')
        {
            wstring s(var);
            wstring::size_type pos = s.find(L'=');
            if(pos != wstring::npos)
            {
                envMap[s.substr(0, pos)] = s.substr(pos + 1);
            }
            var += s.size();
            var++; // Skip the '\0' byte
        }
        FreeEnvironmentStringsW(static_cast<wchar_t*>(parentEnv));
        for(StringSeq::const_iterator p = envs.begin(); p != envs.end(); ++p)
        {
            //
            // IceGrid doesn't support to use string converters, so don't need to use
            // any string converter in stringToWstring conversions.
            //
            wstring s = IceUtil::stringToWstring(*p);
            wstring::size_type pos = s.find(L'=');
            if(pos != wstring::npos)
            {
                envMap[s.substr(0, pos)] = s.substr(pos + 1);
            }
        }

        for(map<wstring, wstring, UnicodeStringLess>::const_iterator q = envMap.begin(); q != envMap.end(); ++q)
        {
            envbuf.append(q->first);
            envbuf.push_back(L'=');
            envbuf.append(q->second);
            envbuf.push_back(L'\0');
        }
        envbuf.push_back(L'\0');
        env = envbuf.c_str();
    }

    Process process;

    STARTUPINFOW si;
    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);

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

    free(cmdbuf);

    if(!b)
    {
        throw IceUtilInternal::lastErrorToString();
    }

    //
    // 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.activator = this;
    process.pid = pi.dwProcessId;
    process.hnd = pi.hProcess;
    process.server = server;
    map<string, Process>::iterator it = _processes.insert(make_pair(name, process)).first;

    Process* pp = &it->second;
    if(!RegisterWaitForSingleObject(&pp->waithnd, pp->hnd, activatorWaitCallback, pp, INFINITE,
                                    WT_EXECUTEDEFAULT | WT_EXECUTEONLYONCE))
    {
        throw IceUtilInternal::lastErrorToString();
    }

    //
    // Don't print the following trace, this might interfer with the
    // output of the started process if it fails with an error message.
    //
//     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;
    }

    int errorFds[2];
    if(pipe(errorFds) != 0)
    {
        SyscallException ex(__FILE__, __LINE__);
        ex.error = getSystemErrno();
        throw ex;
    }


    //
    // Convert to standard argc/argv.
    //
    IceUtilInternal::ArgVector av(args);
    IceUtilInternal::ArgVector env(envs);

    //
    // 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
        //

        //
        // Unblock signals blocked by IceUtil::CtrlCHandler.
        //
        sigset_t sigs;
        sigemptyset(&sigs);
        sigaddset(&sigs, SIGHUP);
        sigaddset(&sigs, SIGINT);
        sigaddset(&sigs, SIGTERM);
        sigprocmask(SIG_UNBLOCK, &sigs, 0);

        //
        // Change the uid/gid under which the process will run.
        //
        if(setgid(gid) == -1)
        {
            ostringstream os;
            os << gid;
            reportChildError(getSystemErrno(), errorFds[1], "cannot set process group id", os.str().c_str(),
                             _traceLevels);
        }

        errno = 0;
        struct passwd* pw = getpwuid(uid);
        if(!pw)
        {
            if(errno)
            {
                reportChildError(getSystemErrno(), errorFds[1], "cannot read the password database", "",
                                 _traceLevels);
            }
            else
            {
                ostringstream os;
                os << uid;
                reportChildError(getSystemErrno(), errorFds[1], "unknown user uid"  , os.str().c_str(),
                                 _traceLevels);
            }
        }

        //
        // Don't initialize supplementary groups if we are not running as root.
        //
        if(getuid() == 0 && initgroups(pw->pw_name, gid) == -1)
        {
            ostringstream os;
            os << pw->pw_name;
            reportChildError(getSystemErrno(), errorFds[1], "cannot initialize process supplementary group access list for user",
                             os.str().c_str(), _traceLevels);
        }

        if(setuid(uid) == -1)
        {
            ostringstream os;
            os << uid;
            reportChildError(getSystemErrno(), errorFds[1], "cannot set process user id", os.str().c_str(),
                             _traceLevels);
        }

        //
        // 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] && fd != errorFds[1])
            {
                close(fd);
            }
        }

        for(int i = 0; i < env.argc; i++)
        {
            //
            // Each env is leaked on purpose ... see man putenv().
            //
            if(putenv(strdup(env.argv[i])) != 0)
            {
                reportChildError(errno, errorFds[1], "cannot set environment variable",  env.argv[i],
                                 _traceLevels);
            }
        }

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

        //
        // Close on exec the error message file descriptor.
        //
        int flags = fcntl(errorFds[1], F_GETFD);
        flags |= 1; // FD_CLOEXEC
        if(fcntl(errorFds[1], F_SETFD, flags) == -1)
        {
            close(errorFds[1]);
            errorFds[1] = -1;
        }

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

        //
        // Read a potential error message over the error message pipe.
        //
        char s[16];
        ssize_t rs;
        string message;
        while((rs = read(errorFds[0], &s, 16)) > 0)
        {
            message.append(s, rs);
        }

        //
        // If an error occured before the exec() we do some cleanup and throw.
        //
        if(!message.empty())
        {
            close(fds[0]);
            close(errorFds[0]);
            waitPid(pid);
            throw message;
        }

        //
        // Otherwise, the exec() was successfull and we don't need the error message
        // pipe anymore.
        //
        close(errorFds[0]);

        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();

    //
    // Don't print the following trace, this might interfere with the
    // output of the started process if it fails with an error message.
    //
//      if(_traceLevels->activator > 0)
//      {
//          Ice::Trace out(_traceLevels->logger, _traceLevels->activatorCat);
//          out << "activated server `" << name << "' (pid = " << pid << ")";
//      }
    }

    return pid;
#endif
}

namespace
{

class ShutdownCallback : public IceUtil::Shared
{
public:

    ShutdownCallback(const ActivatorPtr& activator, const string& name, const TraceLevelsPtr& traceLevels) :
        _activator(activator), _name(name), _traceLevels(traceLevels)
    {

    }

    virtual void
    exception(const Ice::Exception& ex)
    {
        Ice::Warning out(_traceLevels->logger);
        out << "exception occurred while deactivating `" << _name << "' using process proxy:\n" << ex;

        //
        // Send a SIGTERM to the process.
        //
        _activator->sendSignal(_name, SIGTERM);
    }

private:

    const ActivatorPtr _activator;
    const string _name;
    const TraceLevelsPtr _traceLevels;
};

}

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";
        }
        process->begin_shutdown(Ice::newCallback_Process_shutdown(new ShutdownCallback(this, name, _traceLevels),
                                                                  &ShutdownCallback::exception));
        return;
    }

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

    //
    // Send a SIGTERM to the process.
    //
    sendSignal(name, SIGTERM);
}

void
Activator::kill(const string& name)
{
    sendSignal(name, SIGKILL);
}


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

void
Activator::sendSignal(const string& name, int signal)
{
    Ice::Int pid = getServerPid(name);
    if(pid == 0)
    {
        //
        // Server is already deactivated.
        //
        return;
    }

#ifdef _WIN32
    if(signal == SIGTERM)
    {
        //
        // 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 if(signal == SIGKILL)
    {
        HANDLE hnd = OpenProcess(PROCESS_TERMINATE, FALSE, pid);
        if(hnd == NULL)
        {
            SyscallException ex(__FILE__, __LINE__);
            ex.error = getSystemErrno();
            throw ex;
        }

        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 << "terminated server `" << name << "' (pid = " << pid << ")";
        }
    }
    else
    {
        throw BadSignalException("signal not supported on Windows");
    }
#else
    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()
{
    map<string, Process> processes;
    {
        IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
        assert(_deactivating);
        processes = _processes;
    }

    //
    // Stop all active 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 ServerStopException&)
        {
            // Server already stopped or destroyed.
        }
        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;
        }
    }

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

bool
Activator::isActive()
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
    return !_deactivating;
}

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::terminationListener()
{
#ifdef _WIN32
    while(true)
    {
        //
        // Wait for the interrupt event to be signaled.
        //
        DWORD ret = WaitForSingleObject(_hIntr, INFINITE);
        if(ret == WAIT_FAILED)
        {
            SyscallException ex(__FILE__, __LINE__);
            ex.error = getSystemErrno();
            throw ex;
        }
		clearInterrupt();

        //
        // Collect terminated processes
        //
        vector<Process> terminated;
        bool deactivated = false;
        {
            IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
            for(vector<Process*>::const_iterator q = _terminated.begin(); q != _terminated.end(); ++q)
            {
                for(map<string, Process>::iterator p = _processes.begin(); p != _processes.end(); ++p)
                {
                    if(&p->second == *q)
                    {
                        terminated.push_back(p->second);
                        _processes.erase(p);
                        break;
                    }
                }
            }
            _terminated.clear();
            deactivated = _deactivating && _processes.empty();
        }

        for(vector<Process>::const_iterator p = terminated.begin(); p != terminated.end(); ++p)
        {
            UnregisterWait(p->waithnd);

            DWORD status;
            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 = waitPid(p->pid);
            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;
    ssize_t sz = write(_fdIntrWrite, &c, 1);
    if(sz == -1)
    {
        SyscallException ex(__FILE__, __LINE__);
        ex.error = IceInternal::getSystemErrno();
        throw ex;
    }
#endif
}

#ifndef _WIN32
int
Activator::waitPid(pid_t processPid)
{
    try
    {
        int status;
#if defined(__linux)
        int nRetry = 0;
        while(true) // The while loop is necessary for the linux workaround.
        {
            pid_t pid = waitpid(processPid, &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 == processPid);
            break;
        }
#else
        pid_t pid = waitpid(processPid, &status, 0);
        if(pid < 0)
        {
            SyscallException ex(__FILE__, __LINE__);
            ex.error = getSystemErrno();
            throw ex;
        }
        assert(pid == processPid);
#endif
        return status;
    }
    catch(const Ice::LocalException& ex)
    {
        Error out(_traceLevels->logger);
        out << "unable to get process status:\n" << ex;
        return -1;
    }
}
#else
void
Activator::processTerminated(Activator::Process* process)
{
    IceUtil::Monitor< IceUtil::Mutex>::Lock sync(*this);
    setInterrupt();
    _terminated.push_back(process);
}
#endif