//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// kernel --
//
// Author           : Thierry Delisle
// Created On       : Tue Jan 17 12:27:26 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Tue Apr 10 14:46:49 2018
// Update Count     : 10
//

#pragma once

#include <stdbool.h>

#include "invoke.h"
#include "time_t.h"

extern "C" {
#include <pthread.h>
}

//-----------------------------------------------------------------------------
// Locks
struct semaphore {
	__spinlock_t lock;
	int count;
	__queue_t(thread_desc) waiting;
};

void  ?{}(semaphore & this, int count = 1);
void ^?{}(semaphore & this);
void   P (semaphore & this);
void   V (semaphore & this);


//-----------------------------------------------------------------------------
// Cluster
struct cluster {
	// Ready queue locks
	__spinlock_t ready_queue_lock;

	// Ready queue for threads
	__queue_t(thread_desc) ready_queue;

	// Name of the cluster
	const char * name;

	// Preemption rate on this cluster
	Duration preemption_rate;

	// List of idle processors
	// __dllist_t(struct processor) idles;
};

extern struct cluster * mainCluster;
extern Duration default_preemption();

void ?{} (cluster & this, const char * name, Duration preemption_rate);
void ^?{}(cluster & this);

static inline void ?{} (cluster & this)                           { this{"Anonymous Cluster", default_preemption()}; }
static inline void ?{} (cluster & this, Duration preemption_rate) { this{"Anonymous Cluster", preemption_rate}; }
static inline void ?{} (cluster & this, const char * name)        { this{name, default_preemption()}; }

//-----------------------------------------------------------------------------
// Processor
enum FinishOpCode { No_Action, Release, Schedule, Release_Schedule, Release_Multi, Release_Multi_Schedule };

//TODO use union, many of these fields are mutually exclusive (i.e. MULTI vs NOMULTI)
struct FinishAction {
	FinishOpCode action_code;
	thread_desc * thrd;
	__spinlock_t * lock;
	__spinlock_t ** locks;
	unsigned short lock_count;
	thread_desc ** thrds;
	unsigned short thrd_count;
};
static inline void ?{}(FinishAction & this) {
	this.action_code = No_Action;
	this.thrd = NULL;
	this.lock = NULL;
}
static inline void ^?{}(FinishAction & this) {}

// Processor
coroutine processorCtx_t {
	struct processor * proc;
};

// Wrapper around kernel threads
struct processor {
	// Main state
	// Coroutine ctx who does keeps the state of the processor
	struct processorCtx_t runner;

	// Cluster from which to get threads
	cluster * cltr;

	// Name of the processor
	const char * name;

	// Handle to pthreads
	pthread_t kernel_thread;

	// Termination
	// Set to true to notify the processor should terminate
	volatile bool do_terminate;

	// Termination synchronisation
	semaphore terminated;

	// RunThread data
	// Action to do after a thread is ran
	struct FinishAction finish;

	// Preemption data
	// Node which is added in the discrete event simulaiton
	struct alarm_node_t * preemption_alarm;

	// If true, a preemption was triggered in an unsafe region, the processor must preempt as soon as possible
	bool pending_preemption;

	struct {
		pthread_mutex_t lock;
		pthread_cond_t  cond;
	} idle;

#ifdef __CFA_DEBUG__
	// Last function to enable preemption on this processor
	const char * last_enable;
#endif
};

void  ?{}(processor & this, const char * name, cluster & cltr);
void ^?{}(processor & this);

static inline void  ?{}(processor & this)                    { this{ "Anonymous Processor", *mainCluster}; }
static inline void  ?{}(processor & this, cluster & cltr)    { this{ "Anonymous Processor", cltr}; }
static inline void  ?{}(processor & this, const char * name) { this{name, *mainCluster }; }

// Local Variables: //
// mode: c //
// tab-width: 4 //
// End: //