/*##############################################################################

    Copyright (C) 2011 HPCC Systems.

    All rights reserved. This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
############################################################################## */



#ifndef __JTHREAD__
#define __JTHREAD__

#include "jexpdef.hpp"
#include "jiface.hpp"
#include "jmutex.hpp"
#include "jexcept.hpp"
#include "jhash.hpp"

#ifdef _WIN32
#define DEFAULT_THREAD_PRIORITY THREAD_PRIORITY_NORMAL
#else
// no thread priority handling?
#endif

interface jlib_decl IThread : public IInterface
{
    virtual void start() = 0;
    virtual int run() = 0;
};

interface jlib_decl IThreadName 
{
    virtual const char *get()=0;
};



extern jlib_decl void addThreadExceptionHandler(IExceptionHandler *handler);
extern jlib_decl void removeThreadExceptionHandler(IExceptionHandler *handler);
extern jlib_decl void enableThreadSEH();
extern jlib_decl void disableThreadSEH();

extern jlib_decl unsigned threadLogID();  // for use in logging

class jlib_decl Thread : public CInterface, public IThread
{
private:
    ThreadId threadid;
    unsigned short stacksize; // in 4K blocks
    char prioritydelta;
    char nicelevel;

    bool alive;
    unsigned tidlog;
#ifdef _WIN32
    HANDLE hThread;
    static unsigned WINAPI _threadmain(LPVOID v);
#else
    static void *_threadmain(void *v);
#endif
    virtual int begin();
    void init(const char *name);
    void handleException(IException *e);
    void adjustNiceLevel();

protected:
    struct cThreadName: implements IThreadName
    {
        char *threadname;
        const char *get() { return threadname; }
    } cthreadname;
    IThreadName *ithreadname;
public:
#ifndef _WIN32
    Semaphore suspend;
    Semaphore starting;
#endif
    Semaphore stopped;

    IMPLEMENT_IINTERFACE;

    Thread(const char *_name) { init(_name); }
    Thread() { init(NULL); }
    ~Thread();

    void adjustPriority(char delta);
    void setNice(char nicelevel);
    void setStackSize(size32_t size);               // required stack size in bytes - called before start() (obviously)
    const char *getName() { const char *ret = ithreadname?ithreadname->get():NULL; return ret?ret:"unknown"; }
    bool isAlive() { return alive; }
    bool join(unsigned timeout=INFINITE);

    virtual void start();
    virtual void startRelease();        

    StringBuffer &getInfo(StringBuffer &str) { str.appendf("%8"I64F"X %6"I64F"d %u: %s",(__int64)threadid,(__int64)threadid,tidlog,getName()); return str; } 
    const char *getLogInfo(int &thandle,unsigned &tid) { 
#ifdef _WIN32
        thandle = (int)(memsize_t)hThread;
#elif defined __FreeBSD__
        thandle = (int)(memsize_t)threadid;
#else
        thandle = threadid; 
#endif
        tid = tidlog;
        return getName(); 
    }

    // run method not implemented - concrete derived classes must do so
    static  void setDefaultStackSize(size32_t size);    // NB under windows requires linker setting (/stack:)

    IThreadName *queryThreadName() { return ithreadname; }
    void setThreadName(IThreadName *name) { ithreadname = name; }

};

interface IThreaded
{
    virtual void main() = 0;
};

// utility class, useful for containing a thread
class CThreaded : public Thread
{
    IThreaded *owner;
public:
    CThreaded(const char *name) : Thread(name) { }
    void init(IThreaded *_owner) { owner = _owner; start(); }
    virtual int run() { owner->main(); return 1; }
};

// Asynchronous 'for' utility class
// see HRPCUTIL.CPP for example of usage

class jlib_decl CAsyncFor
{
public:
    void For(unsigned num,unsigned maxatonce,bool abortFollowingException=false,bool shuffled=false);
    virtual void Do(unsigned idx=0)=0;
};

// Thread local storage - use MAKETHREADLOCALIINTERFACE macro to get a thread local type

template <class CLASS, class CLASSINIT = CLASS, class MAP = MapBetween<ThreadId, ThreadId, CLASS, CLASSINIT> >
class ThreadLocalOf : public MAP
{
public:
    CLASS * query()
    {
        CLASS * find = threadMap.getValue(GetCurrentThreadId());
        if(find) return find;
        threadMap.setValue(GetCurrentThreadId(), CLASSINIT());
        return threadMap.getValue(GetCurrentThreadId());
    }
    operator CLASS & ()
    {
        return *query();
    }
private:
    MAP threadMap;
};

#define MAKETHREADLOCALIINTERFACE(C, CI, NAME)                                                      \
typedef ThreadLocalOf<C, CI> NAME


// ---------------------------------------------------------------------------
// Thread Pools
// ---------------------------------------------------------------------------

interface IPooledThread: extends IInterface                 // base class for deriving pooled thread (alternative to Thread)
{
public:
       virtual void init(void *param)=0;                    // called before main started (from within start)
       virtual void main()=0;                               // where threads code goes (param is passed from start)
       virtual bool stop()=0;                               // called to cause main to return, returns false if request rejected
       virtual bool canReuse()=0;                           // return true if object can be re-used (after stopped), otherwise released
};

interface IThreadFactory: extends IInterface                // factory for creating new pooled instances (called when pool empty)
{
       virtual IPooledThread *createNew()=0;
};

typedef IIteratorOf<IPooledThread> IPooledThreadIterator;
typedef unsigned PooledThreadHandle;

interface IThreadPool : extends IInterface
{
        virtual PooledThreadHandle start(void *param)=0;    // starts a new thread reuses stopped pool entries
        virtual PooledThreadHandle start(void *param,const char *name)=0;   // starts a new thread reuses stopped pool entries 
        virtual PooledThreadHandle start(void *param,const char *name,unsigned timeout)=0;  // starts a new thread reuses stopped pool entries, throws exception if can't start within timeout 
        virtual bool stop(PooledThreadHandle handle)=0;     // initiates stop on specified thread (may return false)
        virtual bool stopAll(bool tryall=false)=0;          // initiates stop on all threads, if tryall continues even if one or more fails
        virtual bool join(PooledThreadHandle handle,unsigned timeout=INFINITE)=0;
                                                            // waits for a single thread to terminate
        virtual bool joinAll(bool del=true,unsigned timeout=INFINITE)=0;    // waits for all threads in thread pool to terminate
                                                                            // if del true frees all pooled threads
        virtual IPooledThreadIterator *running()=0;                 // return an iterator for all currently running threads
        virtual unsigned runningCount()=0;                  // number of currently running threads
        virtual PooledThreadHandle startNoBlock(void *param)=0; // starts a new thread if it can do so without blocking, else throws exception
        virtual PooledThreadHandle startNoBlock(void *param,const char *name)=0;    // starts a new thread if it can do so without blocking, else throws exception
};

extern jlib_decl IThreadPool *createThreadPool(
                                const char *poolname,       // trace name of pool
                                IThreadFactory *factory,    // factory for creating new thread instances
                                IExceptionHandler *exceptionHandler=NULL, // optional exception handler
                                unsigned defaultmax=50,     // maximum number of threads before starts blocking
                                unsigned delay=1000,        // maximum delay on each block
                                unsigned stacksize=0,       // stack size (bytes) 0 is default
                                unsigned timeoutOnRelease=INFINITE, // maximum time waited for thread to terminate on releasing pool
                                unsigned targetpoolsize=0           // target maximum size of pool (default same as defaultmax)   
                             );

extern jlib_decl StringBuffer &getThreadList(StringBuffer &str);
extern jlib_decl unsigned getThreadCount();
extern jlib_decl StringBuffer &getThreadName(int thandle,unsigned logtid,StringBuffer &name); // either thandle or tid should be 0

// Simple pipe process support
interface ISimpleReadStream;

interface IPipeProcess: extends IInterface
{
    virtual bool run(const char *title,const char *prog, const char *dir,
                       bool hasinput,bool hasoutput,bool haserror=false,
                       size32_t stderrbufsize=0) = 0;               // set to non-zero to automatically buffer stderror output
    virtual bool hasInput() = 0;                                    // i.e. can write to pipe
    virtual size32_t write(size32_t sz, const void *buffer) = 0;    // write pipe process standard output
    virtual bool hasOutput() = 0;                                   // i.e. can read from pipe
    virtual size32_t read(size32_t sz, void *buffer) = 0;           // read from pipe process standard output
    virtual ISimpleReadStream *getOutputStream() = 0;               // read from pipe process standard output
    virtual bool hasError() = 0;                                    // i.e. can read from pipe stderr
    virtual size32_t readError(size32_t sz, void *buffer) = 0;      // read from pipe process standard error
    virtual ISimpleReadStream *getErrorStream() = 0;                // read from pipe process standard error

    virtual unsigned wait() = 0;                                    // returns return code
    virtual unsigned wait(unsigned timeoutms, bool &timedout) = 0;  // sets timedout to true if times out
    virtual void closeInput() = 0;                                  // indicate finished input to pipe
    virtual void closeOutput() = 0;                                 // indicate finished reading from pipe (generally called automatically)
    virtual void closeError() = 0;                                  // indicate finished reading from pipe stderr
    virtual void abort() = 0;
    virtual void notifyTerminated(HANDLE pid,unsigned retcode) = 0; // internal
    virtual HANDLE getProcessHandle() = 0;                          // used to auto kill
};

extern jlib_decl IPipeProcess *createPipeProcess(const char *allowedprograms=NULL);

//--------------------------------------------------------

interface IWorkQueueItem: extends IInterface
{
    virtual void execute()=0;
};

interface IWorkQueueThread: extends IInterface
{
    virtual void post(IWorkQueueItem *item)=0;  // takes ownership of item
    virtual void wait()=0;
    virtual unsigned pending()=0;
};

// Simple lightweight async worker queue
// internally thread persists for specified time waiting before self destroying
extern jlib_decl IWorkQueueThread *createWorkQueueThread(unsigned persisttime=1000*60);


#endif