/* BEGIN_ICS_COPYRIGHT5 ****************************************

Copyright (c) 2015-2020, Intel Corporation

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    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
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      documentation and/or other materials provided with the distribution.
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** END_ICS_COPYRIGHT5   ****************************************/


#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "datatypes.h"
#include "ithread.h"
#include "idebug.h"

//----------------------------------------------------------------
//Globals
//----------------------------------------------------------------
// threadNameKey is global to all threads which is used to access
// the thread's name from its thread local storage.
static pthread_key_t  threadNameKey;
static pthread_once_t key_once = PTHREAD_ONCE_INIT;	// ensures key is only set once
static int isNameKeySet = 0;	// to ensure key has been created before it is used.
//----------------------------------------------------------------
//Init function to set the threadNameKey once.
//Invoked via the pthread_once interface in __UserThreadStartup.
//----------------------------------------------------------------
static void
__ThreadMakeKey()
{
	int rc;

	if ((rc = pthread_key_create(&threadNameKey, NULL)) == 0)
		isNameKeySet = 1;
	else
		MsgOut("Failed to create thread name key, rc: %d.\n",rc);
}
//----------------------------------------------------------------
// Internal function to initialize the thread data structure. This
// function is typically called before a call to kernel_thread().
//----------------------------------------------------------------
static boolean
__InitializeThreadData(IN THREAD *pThread, IN THREAD_CALLBACK Callback, 
                       IN void *Context, IN char *Name)
{
	if (pThread == NULL)
	{
		return FALSE;
	}
	pThread->m_Private.m_Osd.tr_flags 	= 0;
	pThread->m_Private.m_Callback 		= Callback;
	pThread->m_Private.m_Context 		= Context;
	memcpy(pThread->m_Private.m_Osd.tr_name, Name, THREAD_NAME_SIZE);
	return EventInit( &pThread->m_Private.m_Osd.tr_RunningEvent );
}

//
//----------------------------------------------------------------
// Internal function to run a new user mode thread.
// This function is always run as a result of creation a new user mode thread.
// Its main job is to synchronize the creation and running of the new thread.
//----------------------------------------------------------------
// 


static int
__UserThreadStartup(void * arg)
{
	THREAD *pThread = (THREAD *) arg;
	//
	// Trigger the thread running event.
	// The creating thread waits on this event.
	//
#if DEBUG_THREAD
	DbgOut ("__UserThreadStartup( %p )[\n",pThread );
#endif
	// create thread name_key
	(void)pthread_once(&key_once, __ThreadMakeKey);
	// set thread name
	if (isNameKeySet)
		ThreadSetName(pThread->m_Private.m_Osd.tr_name);

	EventTrigger(&pThread->m_Private.m_Osd.tr_RunningEvent);
		if (pThread->m_Private.m_Callback)
	{
		pThread->m_Private.m_Callback(pThread->m_Private.m_Context);
	}

#if DEBUG_THREAD
	DbgOut("__UserThreadStartup( %p )]\n",pThread );
#endif

	return (0) ;
		
}
//----------------------------------------------------------------
//
// Indicate that there was an intent to use a thread 
//----------------------------------------------------------------
//
void 
ThreadInitState ( IN THREAD *pThread )
{
  	pThread->m_Private.m_Osd.tr_state = Constructed;
	EventInitState( &pThread->m_Private.m_Osd.tr_RunningEvent);
}

// 
//----------------------------------------------------------------
// Create a new thread. This thread will execute supplied "Callback"
// with the user supplied "Context"
//----------------------------------------------------------------
//
boolean
ThreadCreate( IN THREAD *pThread, IN char* Name, IN THREAD_CALLBACK Callback, IN void *Context )
{
	int ret;

	//
	// Initialize the thread structure 
	//
	if (!__InitializeThreadData(pThread, Callback, Context, Name)) {
		return FALSE;
	}

#if DEBUG_THREAD
	DbgOut("__ThreadCreate( %p )[\n",pThread );
#endif
	
	ret = pthread_create(&pThread->m_Private.m_Osd.tr_id,
				 NULL,
				(void *)__UserThreadStartup,
				(void *)pThread);

	if (ret != 0)	// pthread_create returns a "0" for success
	{
		return FALSE;
	}
	
	// TBD - any way to set name of thread?
	
	//
	// Wait for the "child" thread to indicate that it is up and running
	// It assumes that the spawned thread will signal Running Event when it starts up
	//
	EventWaitOn( &pThread->m_Private.m_Osd.tr_RunningEvent, EVENT_NO_TIMEOUT);
	
	pThread->m_Private.m_Osd.tr_state = Started;
	
#if DEBUG_THREAD
	DbgOut("__ThreadCreate( %p )]\n",pThread );
#endif

	return TRUE;
}

//
//----------------------------------------------------------------
// Destroy the thread.
// If this function is called after the callback function terminated causing
// the thread to terminate, this function returns immediately.
// If this function is called before the callback function returns, the
// caller will wait for the kill event forever.
//----------------------------------------------------------------
//
void
ThreadDestroy( IN THREAD *pThread )
{
  	if ( pThread->m_Private.m_Osd.tr_state != Started )
  	{
		// thread was never Started 
    		return;
  	}
	// If more than one threads are wating on a thread
	// the outcome may not be deterministic
	// Might want to try waiting on the thread kill event

#if DEBUG_THREAD
	DbgOut ("__ThreadDestroy( %p )[\n",pThread );
#endif
	pthread_join( pThread->m_Private.m_Osd.tr_id, NULL );
  	EventDestroy( &pThread->m_Private.m_Osd.tr_RunningEvent );

	// clear all the thread state data
  	pThread->m_Private.m_Osd.tr_state 	= Destroyed;
  	pThread->m_Private.m_Osd.tr_id 		= 0;
  	pThread->m_Private.m_Callback 		= NULL;
  	pThread->m_Private.m_Context 		= NULL;
#if DEBUG_THREAD
	DbgOut ("__ThreadDestroy( %p )]\n",pThread );
#endif
}

// 
//----------------------------------------------------------------
// Suspend a thread execution for "pause_ms" milliseconds
//----------------------------------------------------------------
//
void
ThreadSuspend( IN uint32 pause_ms )
{
	// Convert to micro seconds
	usleep(pause_ms * 1000);
	
}

//
//----------------------------------------------------------------
// Delay execution of thread for some number of microseconds.
// This uses Linuxs' udelay() function. Remember, suggested maximum
// value of microseconds is 1000, ie, 1 milliseconds.
//----------------------------------------------------------------
//
void
ThreadStall( IN uint32 pause_us )
{
	usleep(pause_us);
}


//----------------------------------------------------------------
// Number of processors on this system 
//----------------------------------------------------------------
uint32
ProcCount(void)
{
	//********************************
	//*********** FOR NOW!! **********
	//********************************
  return 0;
}

uint32
CurrentProc(void)
{
	return 0; 	// for now
}

//----------------------------------------------------------------
// set priority for current thread
//----------------------------------------------------------------
void ThreadSetPriority(IN THREAD_PRI pri)
{
	if (nice(pri) < 0) {
		MsgOut("Failed to set thread priority.\n");
	}
}

//----------------------------------------------------------------
//set thread name. using a thread specific key
//----------------------------------------------------------------
void ThreadSetName(IN char *name)
{

	if( pthread_setspecific(threadNameKey, name)!= 0)
	{
		MsgOut("Failed to Set Thread Name.\n");
	}

}

//------------------------------------------------------------------
// get thread name. returns the name which was set by
// ThreadSetName().
// -----------------------------------------------------------------
char* ThreadGetName(void)
{
	char* name;

	name = (char*)pthread_getspecific(threadNameKey);

	return (name != NULL)?name:"null";
}

