/*******************************************************************************
 *
 * Copyright (c) 2000-2003 Intel Corporation 
 * 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 name of Intel Corporation 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 INTEL 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.
 *
 ******************************************************************************/

#ifndef THREADPOOL_H
#define THREADPOOL_H

#ifdef UPNP_USE_MSVCPP
	#define UPNP_INLINE
#else
	#define UPNP_INLINE inline
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* Size of job free list */
#define JOBFREELISTSIZE 100

#define INFINITE_THREADS -1

#define EMAXTHREADS (-8 & 1<<29)

/* Invalid Policy */
#define INVALID_POLICY (-9 & 1<<29)

/* Invalid JOB Id */
#define INVALID_JOB_ID (-2 & 1<<29)

typedef enum duration {SHORT_TERM,PERSISTENT} Duration;

typedef enum priority {LOW_PRIORITY,
		       MED_PRIORITY,
		       HIGH_PRIORITY} ThreadPriority;

#define DEFAULT_PRIORITY MED_PRIORITY /* default priority used by TPJobInit */
#define DEFAULT_MIN_THREADS 1	      /* default minimum used by TPAttrInit */
#define DEFAULT_MAX_THREADS 10	      /* default max used by TPAttrInit	*/
#define DEFAULT_JOBS_PER_THREAD 10    /* default jobs per thread used by TPAttrInit */
#define DEFAULT_STARVATION_TIME	500   /* default starvation time used by TPAttrInit */
#define DEFAULT_IDLE_TIME 10 * 1000   /* default idle time used by TPAttrInit */
#define DEFAULT_FREE_ROUTINE NULL     /* default free routine used TPJobInit */
#define DEFAULT_MAX_JOBS_TOTAL 100    /* default max jobs used TPAttrInit */

/* Statistics */
/* always include stats because code change is minimal */
#define STATS 1

#ifdef _DEBUG
	#define DEBUG 1
#endif

#include "LinkedList.h"

#ifdef WIN32
    #include <time.h>
    #include <winsock2.h>
    struct timezone 
    {
        int  tz_minuteswest; /* minutes W of Greenwich */
        int  tz_dsttime;     /* type of dst correction */
    };
    int gettimeofday(struct timeval *tv, struct timezone *tz);
#else /* WIN32 */
    #include <sys/time.h> /* for gettimeofday() */
#endif

#include "FreeList.h"

#include "ithread.h"
#include <errno.h>

#define EXPORT

typedef int PolicyType;
#define DEFAULT_POLICY SCHED_OTHER
#define DEFAULT_SCHED_PARAM 0 /* default priority */

/****************************************************************************
 * Name: free_routine
 *
 *  Description:
 *     Function for freeing a thread argument
 *****************************************************************************/
typedef void (*free_routine)(void *arg);

/****************************************************************************
 * Name: ThreadPoolAttr
 *
 *  Description:
 *     Attributes for thread pool. Used to set and change parameters of
 *     thread pool
 *****************************************************************************/
typedef struct THREADPOOLATTR
{
	/* minThreads, ThreadPool will always maintain at least this many threads */
	int minThreads;

	/* maxThreads, ThreadPool will never have more than this number of threads */
	int maxThreads;

	/* maxIdleTime (in milliseconds) this is the maximum time a thread will
	 * remain idle before dying */
	int maxIdleTime;

	/* jobs per thread to maintain */
	int jobsPerThread;

	/* maximum number of jobs that can be queued totally. */
	int maxJobsTotal;

	/* the time a low priority or med priority job waits before getting bumped
	 * up a priority (in milliseconds) */
	int starvationTime;

	/* scheduling policy to use */
	PolicyType schedPolicy;
} ThreadPoolAttr;

/****************************************************************************
 * Name: ThreadPool
 *
 *  Description:
 *     Internal ThreadPool Job
 *****************************************************************************/
typedef struct THREADPOOLJOB
{
	start_routine func;
	void *arg;
	free_routine free_func;
	struct timeval requestTime;
	int priority;
	int jobId;
} ThreadPoolJob;

/****************************************************************************
 * Name: ThreadPoolStats
 *
 *  Description:
 *     Structure to hold statistics
 *****************************************************************************/

typedef struct TPOOLSTATS
{
	double totalTimeHQ;
	int totalJobsHQ;
	double avgWaitHQ;
	double totalTimeMQ;
	int totalJobsMQ;
	double avgWaitMQ;
	double totalTimeLQ;
	int totalJobsLQ;
	double avgWaitLQ;
	double totalWorkTime;
	double totalIdleTime;
	int workerThreads;
	int idleThreads;
	int persistentThreads;
	int totalThreads;
	int maxThreads;
	int currentJobsHQ;
	int currentJobsLQ;
	int currentJobsMQ;
} ThreadPoolStats;


/****************************************************************************
 * Name: ThreadPool
 *
 *  Description:
 *     A thread pool similar to the thread pool in the UPnP SDK.
 *     Allows jobs to be scheduled for running by threads in a 
 *     thread pool. The thread pool is initialized with a 
 *     minimum and maximum thread number as well as a 
 *	   max idle time
 *     and a jobs per thread ratio. If a worker thread waits the whole
 *     max idle time without receiving a job and the thread pool
 *     currently has more threads running than the minimum
 *     then the worker thread will exit. If when 
 *     scheduling a job the current job to thread ratio
 *     becomes greater than the set ratio and the thread pool currently has
 *     less than the maximum threads then a new thread will
 *     be created.
 *
 *****************************************************************************/

typedef struct THREADPOOL
{
	ithread_mutex_t mutex; /* mutex to protect job qs */
	ithread_cond_t condition; /* condition variable to signal Q */
	ithread_cond_t start_and_shutdown; /* condition variable for start 
					and stop */
	int lastJobId; /* ids for jobs */
	int shutdown;  /* whether or not we are shutting down */
	int totalThreads;      /* total number of threads */
	int persistentThreads; /* number of persistent threads */
	FreeList jobFreeList;  /* free list of jobs */
	LinkedList lowJobQ;    /* low priority job Q */
	LinkedList medJobQ;    /* med priority job Q */
	LinkedList highJobQ;   /* high priority job Q */
	ThreadPoolJob *persistentJob; /* persistent job */

	ThreadPoolAttr attr; /* thread pool attributes */

	/* statistics */
	ThreadPoolStats stats;
} ThreadPool;



/****************************************************************************
 * Function: ThreadPoolInit
 *
 *  Description:
 *      Initializes and starts ThreadPool. Must be called first.
 *      And only once for ThreadPool.
 *  Parameters:
 *      tp  - must be valid, non null, pointer to ThreadPool.
 *      attr - can be null
 *
 *       if not null then attr contains the following fields:
 *
 *      minWorkerThreads - minimum number of worker threads
 *                                 thread pool will never have less than this
 *                                  number of threads.
 *      maxWorkerThreads - maximum number of worker threads
 *                         thread pool will never have more than this
 *                         number of threads.
 *      maxIdleTime      - maximum time that a worker thread will spend
 *                         idle. If a worker is idle longer than this
 *                         time and there are more than the min
 *                         number of workers running, than the
 *                         worker thread exits.
 *      jobsPerThread    - ratio of jobs to thread to try and maintain
 *                         if a job is scheduled and the number of jobs per
 *                         thread is greater than this number,and  
 *                         if less than the maximum number of
 *                         workers are running then a new thread is 
 *                         started to help out with efficiency.
 *      schedPolicy      - scheduling policy to try and set (OS dependent)
 *  Returns:
 *      0 on success, nonzero on failure.
 *      EAGAIN if not enough system resources to create minimum threads.
 *      INVALID_POLICY if schedPolicy can't be set
 *      EMAXTHREADS if minimum threads is greater than maximum threads
 *****************************************************************************/
int ThreadPoolInit(ThreadPool *tp, ThreadPoolAttr *attr);

/****************************************************************************
 * Function: ThreadPoolAddPersistent
 *
 *  Description:
 *      Adds a persistent job to the thread pool.
 *      Job will be run as soon as possible.
 *      Call will block until job is scheduled.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      ThreadPoolJob - valid thread pool job with the following fields:
 *
 *        func - ThreadFunction to run
 *        arg - argument to function.
 *        priority - priority of job.
 * 
 *  Returns:
 *      0 on success, nonzero on failure
 *      EOUTOFMEM not enough memory to add job.
 *      EMAXTHREADS not enough threads to add persistent job.
 *****************************************************************************/
int ThreadPoolAddPersistent(ThreadPool*tp, ThreadPoolJob *job, int *jobId);

/****************************************************************************
 * Function: ThreadPoolGetAttr
 *
 *  Description:
 *      Gets the current set of attributes
 *      associated with the thread pool.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      out - non null pointer to store attributes
 *  Returns:
 *      0 on success, nonzero on failure
 *      Always returns 0.
 *****************************************************************************/
int ThreadPoolGetAttr(ThreadPool *tp, ThreadPoolAttr *out);
/****************************************************************************
 * Function: ThreadPoolSetAttr
 *
 *  Description:
 *      Sets the attributes for the thread pool.
 *      Only affects future calculations. 
 *  Parameters:
 *      tp - valid thread pool pointer
 *      attr - pointer to attributes, null sets attributes to default.
 *  Returns:
 *      0 on success, nonzero on failure
 *      Returns INVALID_POLICY if policy can not be set.
 *****************************************************************************/
int ThreadPoolSetAttr(ThreadPool *tp, ThreadPoolAttr *attr);

/****************************************************************************
 * Function: ThreadPoolAdd
 *
 *  Description:
 *      Adds a job to the thread pool.
 *      Job will be run as soon as possible.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      func - ThreadFunction to run
 *      arg - argument to function.
 *      priority - priority of job.
 *      poolid - id of job
 *      free_function - function to use when freeing argument 
 *  Returns:
 *      0 on success, nonzero on failure
 *      EOUTOFMEM if not enough memory to add job.
 *****************************************************************************/
int ThreadPoolAdd (ThreadPool*tp, ThreadPoolJob *job, int *jobId);

/****************************************************************************
 * Function: ThreadPoolRemove
 *
 *  Description:
 *      Removes a job from the thread pool.
 *      Can only remove jobs which are not
 *      currently running.
 *  Parameters:
 *      tp - valid thread pool pointer
 *      jobid - id of job
 *      out - space for removed job.
 *  Returns:
 *      0 on success, nonzero on failure.
 *      INVALID_JOB_ID if job not found. 
 *****************************************************************************/
int ThreadPoolRemove(ThreadPool *tp, int jobId, ThreadPoolJob *out);



/****************************************************************************
 * Function: ThreadPoolShutdown
 *
 *  Description:
 *      Shuts the thread pool down.
 *      Waits for all threads to finish. 
 *      May block indefinitely if jobs do not
 *      exit.
 *  Parameters:
 *      tp - must be valid tp     
 *  Returns:
 *      0 on success, nonzero on failure
 *      Always returns 0.
 *****************************************************************************/
int ThreadPoolShutdown(ThreadPool *tp);


/****************************************************************************
 * Function: TPJobInit
 *
 *  Description:
 *      Initializes thread pool job.
 *      Sets the priority to default defined in ThreadPool.h.
 *      Sets the free_routine to default defined in ThreadPool.h
 *  Parameters:
 *      ThreadPoolJob *job - must be valid thread pool attributes.    
 *      start_routine func - function to run, must be valid
 *      void * arg - argument to pass to function.
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobInit(ThreadPoolJob *job, start_routine func, void *arg);

/****************************************************************************
 * Function: TPJobSetPriority
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobSetPriority(ThreadPoolJob *job, ThreadPriority priority);

/****************************************************************************
 * Function: TPJobSetFreeFunction
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPJobSetFreeFunction(ThreadPoolJob *job, free_routine func);

/****************************************************************************
 * Function: TPAttrInit
 *
 *  Description:
 *      Initializes thread pool attributes.
 *      Sets values to defaults defined in ThreadPool.h.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrInit(ThreadPoolAttr *attr);

/****************************************************************************
 * Function: TPAttrSetMaxThreads
 *
 *  Description:
 *      Sets the max threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      maxThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMaxThreads(ThreadPoolAttr *attr, int maxThreads);

/****************************************************************************
 * Function: TPAttrSetMinThreads
 *
 *  Description:
 *      Sets the min threads for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes. 
 *      minThreads - value to set
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMinThreads(ThreadPoolAttr *attr, int minThreads);

/****************************************************************************
 * Function: TPAttrSetIdleTime
 *
 *  Description:
 *      Sets the idle time for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetIdleTime(ThreadPoolAttr *attr, int idleTime);

/****************************************************************************
 * Function: TPAttrSetJobsPerThread
 *
 *  Description:
 *      Sets the jobs per thread ratio
 *  Parameters:
 *      attr - must be valid thread pool attributes.
 *      jobsPerThread - number of jobs per thread to maintain
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetJobsPerThread(ThreadPoolAttr *attr, int jobsPerThread);

/****************************************************************************
 * Function: TPAttrSetStarvationTime
 *
 *  Description:
 *      Sets the starvation time for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *      int starvationTime - milliseconds
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetStarvationTime(ThreadPoolAttr *attr, int starvationTime);

/****************************************************************************
 * Function: TPAttrSetSchedPolicy
 *
 *  Description:
 *      Sets the scheduling policy for the thread pool attributes.
 *  Parameters:
 *      attr - must be valid thread pool attributes.    
 *      PolicyType schedPolicy - must be a valid policy type.
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetSchedPolicy(ThreadPoolAttr *attr, PolicyType schedPolicy);


/****************************************************************************
 * Function: TPAttrSetMaxJobsTotal
 *
 *  Description:
 *      Sets the maximum number jobs that can be qeued totally.
 *  Parameters:
 *      attr - must be valid thread pool attributes.
 *      maxJobsTotal - maximum number of jobs
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
int TPAttrSetMaxJobsTotal(ThreadPoolAttr *attr, int maxJobsTotal);

/****************************************************************************
 * Function: ThreadPoolGetStats
 *
 *  Description:
 *      Returns various statistics about the
 *      thread pool.
 *      Only valid if STATS has been defined.
 *  Parameters:
 *      ThreadPool *tp - valid initialized threadpool    
 *      ThreadPoolStats *stats - valid stats, out parameter
 *  Returns:
 *      Always returns 0.
 *****************************************************************************/
#ifdef STATS
	EXPORT int ThreadPoolGetStats(ThreadPool *tp, ThreadPoolStats *stats);

	EXPORT void ThreadPoolPrintStats(ThreadPoolStats *stats);
#else
	static UPNP_INLINE int ThreadPoolGetStats(ThreadPool *tp, ThreadPoolStats *stats) {}

	static UPNP_INLINE void ThreadPoolPrintStats(ThreadPoolStats *stats) {}
#endif

#ifdef __cplusplus
}
#endif

#endif /* ThreadPool */

