//
// 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_private.hfa --
//
// Author           : Thierry Delisle
// Created On       : Mon Feb 13 12:27:26 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Nov 30 19:25:02 2019
// Update Count     : 8
//

#pragma once

#include "kernel.hfa"
#include "thread.hfa"

#include "alarm.hfa"


//-----------------------------------------------------------------------------
// Scheduler

extern "C" {
	void disable_interrupts() OPTIONAL_THREAD;
	void enable_interrupts_noPoll();
	void enable_interrupts( __cfaabi_dbg_ctx_param );
}

void ScheduleThread( thread_desc * ) __attribute__((nonnull (1)));
static inline void WakeThread( thread_desc * thrd, bool must_yield ) {
	if( !thrd ) return;

	enum coroutine_state new_state = must_yield ? Reschedule : Rerun;

	disable_interrupts();
	static_assert(sizeof(thrd->state) == sizeof(int));
	enum coroutine_state old_state = (enum coroutine_state)__atomic_exchange_n((volatile int *)&thrd->state, (int)new_state, __ATOMIC_SEQ_CST);
	switch(old_state) {
		case Active:
			// Wake won the race, the thread will reschedule/rerun itself
			break;
		case Inactive:
			// Wake lost the race,
			thrd->state = Inactive;
			ScheduleThread( thrd );
			break;
		case Rerun:
		case Reschedule:
			abort("More than one thread attempted to schedule thread %p\n", thrd);
			break;
		case Halted:
		case Start:
		case Primed:
		default:
			// This makes no sense, something is wrong abort
			abort();
	}
	enable_interrupts( __cfaabi_dbg_ctx );
}
thread_desc * nextThread(cluster * this);

//Block current thread and release/wake-up the following resources
void BlockInternal(void);
void BlockInternal(__spinlock_t * lock);
void BlockInternal(thread_desc * thrd);
void BlockInternal(__spinlock_t * lock, thread_desc * thrd);
void BlockInternal(__spinlock_t * locks [], unsigned short count);
void BlockInternal(__spinlock_t * locks [], unsigned short count, thread_desc * thrds [], unsigned short thrd_count);
void BlockInternal(__finish_callback_fptr_t callback);
void LeaveThread(__spinlock_t * lock, thread_desc * thrd);

//-----------------------------------------------------------------------------
// Processor
void main(processorCtx_t *);

void * create_pthread( pthread_t *, void * (*)(void *), void * );

static inline void wake_fast(processor * this) {
	__cfaabi_dbg_print_safe("Kernel : Waking up processor %p\n", this);
	post( this->idleLock );
}

static inline void wake(processor * this) {
	disable_interrupts();
	wake_fast(this);
	enable_interrupts( __cfaabi_dbg_ctx );
}

struct event_kernel_t {
	alarm_list_t alarms;
	__spinlock_t lock;
};

extern event_kernel_t * event_kernel;

struct __cfa_kernel_preemption_state_t {
	bool enabled;
	bool in_progress;
	unsigned short disable_count;
};

extern volatile thread_local __cfa_kernel_preemption_state_t preemption_state __attribute__ ((tls_model ( "initial-exec" )));

//-----------------------------------------------------------------------------
// Threads
extern "C" {
      void CtxInvokeThread(void (*main)(void *), void * this);
}

extern void ThreadCtxSwitch(coroutine_desc * src, coroutine_desc * dst);

__cfaabi_dbg_debug_do(
	extern void __cfaabi_dbg_thread_register  ( thread_desc * thrd );
	extern void __cfaabi_dbg_thread_unregister( thread_desc * thrd );
)

//-----------------------------------------------------------------------------
// Utils
#define KERNEL_STORAGE(T,X) static char storage_##X[sizeof(T)]

static inline uint32_t tls_rand() {
	kernelTLS.rand_seed ^= kernelTLS.rand_seed << 6;
	kernelTLS.rand_seed ^= kernelTLS.rand_seed >> 21;
	kernelTLS.rand_seed ^= kernelTLS.rand_seed << 7;
	return kernelTLS.rand_seed;
}


void doregister( struct cluster & cltr );
void unregister( struct cluster & cltr );

void doregister( struct cluster * cltr, struct thread_desc & thrd );
void unregister( struct cluster * cltr, struct thread_desc & thrd );

void doregister( struct cluster * cltr, struct processor * proc );
void unregister( struct cluster * cltr, struct processor * proc );

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