//
// 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 Feb  4 12:29:26 2020
// Update Count     : 22
//

#pragma once

#include <stdbool.h>

#include "invoke.h"
#include "time_t.hfa"
#include "coroutine.hfa"

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

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

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


//-----------------------------------------------------------------------------
// Processor
extern struct cluster * mainCluster;

// 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
	struct cluster * cltr;

	// Name of the processor
	const char * name;

	// Handle to pthreads
	pthread_t kernel_thread;

	// RunThread data
	// Action to do after a thread is ran
	$thread * destroyer;

	// 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;

	// Idle lock (kernel semaphore)
	__bin_sem_t idle;

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

	// Termination synchronisation (user semaphore)
	semaphore terminated;

	// pthread Stack
	void * stack;

	// Link lists fields
	struct __dbg_node_proc {
		struct processor * next;
		struct processor * prev;
	} node;

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

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

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

static inline [processor *&, processor *& ] __get( processor & this ) __attribute__((const)) { return this.node.[next, prev]; }

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

	// Ready queue for threads
	__queue_t($thread) ready_queue;

	// Name of the cluster
	const char * name;

	// Preemption rate on this cluster
	Duration preemption_rate;

	// List of processors
	__spinlock_t idle_lock;
	__dllist_t(struct processor) procs;
	__dllist_t(struct processor) idles;
	unsigned int nprocessors;

	// List of threads
	__spinlock_t thread_list_lock;
	__dllist_t(struct $thread) threads;
	unsigned int nthreads;

	// Link lists fields
	struct __dbg_node_cltr {
		cluster * next;
		cluster * prev;
	} node;
};
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()}; }

static inline [cluster *&, cluster *& ] __get( cluster & this ) __attribute__((const)) { return this.node.[next, prev]; }

static inline struct processor * active_processor() { return TL_GET( this_processor ); } // UNSAFE
static inline struct cluster   * active_cluster  () { return TL_GET( this_processor )->cltr; }

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