//
// 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.
//
// monitor_desc.c --
//
// Author           : Thierry Delisle
// Created On       : Thd Feb 23 12:27:26 2017
// Last Modified By : Peter A. Buhr
// Last Modified On : Mon Jul 31 14:59:05 2017
// Update Count     : 3
//

#include "monitor"

#include <stdlib>
#include <inttypes.h>

#include "libhdr.h"
#include "kernel_private.h"

#include "bits/algorithms.h"

//-----------------------------------------------------------------------------
// Forward declarations
static inline void set_owner ( monitor_desc * this, thread_desc * owner );
static inline void set_owner ( monitor_desc * storage [], __lock_size_t count, thread_desc * owner );
static inline void set_mask  ( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
static inline void reset_mask( monitor_desc * this );

static inline thread_desc * next_thread( monitor_desc * this );
static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & monitors );

static inline void lock_all  ( __spinlock_t * locks [], __lock_size_t count );
static inline void lock_all  ( monitor_desc * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count );
static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count );
static inline void unlock_all( monitor_desc * locks [], __lock_size_t count );

static inline void save   ( monitor_desc * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
static inline void restore( monitor_desc * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*in */ recursions [], __waitfor_mask_t /*in */ masks [] );

static inline void init     ( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );

static inline thread_desc *        check_condition   ( __condition_criterion_t * );
static inline void                 brand_condition   ( condition & );
static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t &, monitor_desc * monitors [], __lock_size_t count );

forall(dtype T | sized( T ))
static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
static inline __lock_size_t count_max    ( const __waitfor_mask_t & mask );
static inline __lock_size_t aggregate    ( monitor_desc * storage [], const __waitfor_mask_t & mask );

#ifndef __CFA_LOCK_NO_YIELD
#define DO_LOCK lock_yield
#else
#define DO_LOCK lock
#endif

//-----------------------------------------------------------------------------
// Useful defines
#define wait_ctx(thrd, user_info)                               /* Create the necessary information to use the signaller stack                         */ \
	__condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
	__condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
	init( count, monitors, waiter, criteria );                /* Link everything together                                                            */ \

#define wait_ctx_primed(thrd, user_info)                        /* Create the necessary information to use the signaller stack                         */ \
	__condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
	__condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
	init_push( count, monitors, waiter, criteria );           /* Link everything together and push it to the AS-Stack                                */ \

#define monitor_ctx( mons, cnt )                                /* Define that create the necessary struct for internal/external scheduling operations */ \
	monitor_desc ** monitors = mons;                          /* Save the targeted monitors                                                          */ \
	__lock_size_t count = cnt;                                /* Save the count to a local variable                                                  */ \
	unsigned int recursions[ count ];                         /* Save the current recursion levels to restore them later                             */ \
	__waitfor_mask_t masks [ count ];                         /* Save the current waitfor masks to restore them later                                */ \
	__spinlock_t *   locks [ count ];                         /* We need to pass-in an array of locks to BlockInternal                               */ \

#define monitor_save    save   ( monitors, count, locks, recursions, masks )
#define monitor_restore restore( monitors, count, locks, recursions, masks )


//-----------------------------------------------------------------------------
// Enter/Leave routines


extern "C" {
	// Enter single monitor
	static void __enter_monitor_desc( monitor_desc * this, const __monitor_group_t & group ) {
		// Lock the monitor spinlock
		DO_LOCK( this->lock DEBUG_CTX2 );
		thread_desc * thrd = this_thread;

		LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);

		if( !this->owner ) {
			// No one has the monitor, just take it
			set_owner( this, thrd );

			LIB_DEBUG_PRINT_SAFE("Kernel :  mon is free \n");
		}
		else if( this->owner == thrd) {
			// We already have the monitor, just note how many times we took it
			this->recursion += 1;

			LIB_DEBUG_PRINT_SAFE("Kernel :  mon already owned \n");
		}
		else if( is_accepted( this, group) ) {
			// Some one was waiting for us, enter
			set_owner( this, thrd );

			// Reset mask
			reset_mask( this );

			LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts \n");
		}
		else {
			LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");

			// Some one else has the monitor, wait in line for it
			append( this->entry_queue, thrd );
			BlockInternal( &this->lock );

			LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);

			// BlockInternal will unlock spinlock, no need to unlock ourselves
			return;
		}

		LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);

		// Release the lock and leave
		unlock( this->lock );
		return;
	}

	static void __enter_monitor_dtor( monitor_desc * this, fptr_t func ) {
		// Lock the monitor spinlock
		DO_LOCK( this->lock DEBUG_CTX2 );
		thread_desc * thrd = this_thread;

		LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);


		if( !this->owner ) {
			LIB_DEBUG_PRINT_SAFE("Kernel : Destroying free mon %p\n", this);

			// No one has the monitor, just take it
			set_owner( this, thrd );

			unlock( this->lock );
			return;
		}
		else if( this->owner == thrd) {
			// We already have the monitor... but where about to destroy it so the nesting will fail
			// Abort!
			abortf("Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.");
		}

		__lock_size_t count = 1;
		monitor_desc ** monitors = &this;
		__monitor_group_t group = { &this, 1, func };
		if( is_accepted( this, group) ) {
			LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts dtor, block and signal it \n");

			// Wake the thread that is waiting for this
			__condition_criterion_t * urgent = pop( this->signal_stack );
			verify( urgent );

			// Reset mask
			reset_mask( this );

			// Create the node specific to this wait operation
			wait_ctx_primed( this_thread, 0 )

			// Some one else has the monitor, wait for him to finish and then run
			BlockInternal( &this->lock, urgent->owner->waiting_thread );

			// Some one was waiting for us, enter
			set_owner( this, thrd );
		}
		else {
			LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");

			wait_ctx( this_thread, 0 )
			this->dtor_node = &waiter;

			// Some one else has the monitor, wait in line for it
			append( this->entry_queue, thrd );
			BlockInternal( &this->lock );

			// BlockInternal will unlock spinlock, no need to unlock ourselves
			return;
		}

		LIB_DEBUG_PRINT_SAFE("Kernel : Destroying %p\n", this);

	}

	// Leave single monitor
	void __leave_monitor_desc( monitor_desc * this ) {
		// Lock the monitor spinlock, DO_LOCK to reduce contention
		DO_LOCK( this->lock DEBUG_CTX2 );

		LIB_DEBUG_PRINT_SAFE("Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner);

		verifyf( this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", this_thread, this->owner, this->recursion, this );

		// Leaving a recursion level, decrement the counter
		this->recursion -= 1;

		// If we haven't left the last level of recursion
		// it means we don't need to do anything
		if( this->recursion != 0) {
			LIB_DEBUG_PRINT_SAFE("Kernel :  recursion still %d\n", this->recursion);
			unlock( this->lock );
			return;
		}

		// Get the next thread, will be null on low contention monitor
		thread_desc * new_owner = next_thread( this );

		// We can now let other threads in safely
		unlock( this->lock );

		//We need to wake-up the thread
		WakeThread( new_owner );
	}

	// Leave single monitor for the last time
	void __leave_dtor_monitor_desc( monitor_desc * this ) {
		LIB_DEBUG_DO(
			if( this_thread != this->owner ) {
				abortf("Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner);
			}
			if( this->recursion != 1 ) {
				abortf("Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
			}
		)
	}

	// Leave the thread monitor
	// last routine called by a thread.
	// Should never return
	void __leave_thread_monitor( thread_desc * thrd ) {
		monitor_desc * this = &thrd->self_mon;

		// Lock the monitor now
		DO_LOCK( this->lock DEBUG_CTX2 );

		disable_interrupts();

		thrd->self_cor.state = Halted;

		verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );

		// Leaving a recursion level, decrement the counter
		this->recursion -= 1;

		// If we haven't left the last level of recursion
		// it must mean there is an error
		if( this->recursion != 0) { abortf("Thread internal monitor has unbalanced recursion"); }

		// Fetch the next thread, can be null
		thread_desc * new_owner = next_thread( this );

		// Leave the thread, this will unlock the spinlock
		// Use leave thread instead of BlockInternal which is
		// specialized for this case and supports null new_owner
		LeaveThread( &this->lock, new_owner );

		// Control flow should never reach here!
	}
}

// Enter multiple monitor
// relies on the monitor array being sorted
static inline void enter( __monitor_group_t monitors ) {
	for( __lock_size_t i = 0; i < monitors.size; i++) {
		__enter_monitor_desc( monitors.list[i], monitors );
	}
}

// Leave multiple monitor
// relies on the monitor array being sorted
static inline void leave(monitor_desc * monitors [], __lock_size_t count) {
	for( __lock_size_t i = count - 1; i >= 0; i--) {
		__leave_monitor_desc( monitors[i] );
	}
}

// Ctor for monitor guard
// Sorts monitors before entering
void ?{}( monitor_guard_t & this, monitor_desc * m [], __lock_size_t count, fptr_t func ) {
	// Store current array
	this.m = m;
	this.count = count;

	// Sort monitors based on address -> TODO use a sort specialized for small numbers
	__libcfa_small_sort(this.m, count);

	// Save previous thread context
	this.[prev_mntrs, prev_count, prev_func] = this_thread->monitors.[list, size, func];

	// Update thread context (needed for conditions)
	this_thread->monitors.[list, size, func] = [m, count, func];

	// LIB_DEBUG_PRINT_SAFE("MGUARD : enter %d\n", count);

	// Enter the monitors in order
	__monitor_group_t group = {this.m, this.count, func};
	enter( group );

	// LIB_DEBUG_PRINT_SAFE("MGUARD : entered\n");
}


// Dtor for monitor guard
void ^?{}( monitor_guard_t & this ) {
	// LIB_DEBUG_PRINT_SAFE("MGUARD : leaving %d\n", this.count);

	// Leave the monitors in order
	leave( this.m, this.count );

	// LIB_DEBUG_PRINT_SAFE("MGUARD : left\n");

	// Restore thread context
	this_thread->monitors.[list, size, func] = this.[prev_mntrs, prev_count, prev_func];
}

// Ctor for monitor guard
// Sorts monitors before entering
void ?{}( monitor_dtor_guard_t & this, monitor_desc * m [], fptr_t func ) {
	// Store current array
	this.m = *m;

	// Save previous thread context
	this.[prev_mntrs, prev_count, prev_func] = this_thread->monitors.[list, size, func];

	// Update thread context (needed for conditions)
	this_thread->monitors.[list, size, func] = [m, 1, func];

	__enter_monitor_dtor( this.m, func );
}

// Dtor for monitor guard
void ^?{}( monitor_dtor_guard_t & this ) {
	// Leave the monitors in order
	__leave_dtor_monitor_desc( this.m );

	// Restore thread context
	this_thread->monitors.[list, size, func] = this.[prev_mntrs, prev_count, prev_func];
}

//-----------------------------------------------------------------------------
// Internal scheduling types
void ?{}(__condition_node_t & this, thread_desc * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
	this.waiting_thread = waiting_thread;
	this.count = count;
	this.next = NULL;
	this.user_info = user_info;
}

void ?{}(__condition_criterion_t & this ) {
	this.ready  = false;
	this.target = NULL;
	this.owner  = NULL;
	this.next   = NULL;
}

void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t & owner ) {
	this.ready  = false;
	this.target = target;
	this.owner  = &owner;
	this.next   = NULL;
}

//-----------------------------------------------------------------------------
// Internal scheduling
void wait( condition & this, uintptr_t user_info = 0 ) {
	brand_condition( this );

	// Check that everything is as expected
	assertf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
	verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );

	// Create storage for monitor context
	monitor_ctx( this.monitors, this.monitor_count );

	// Create the node specific to this wait operation
	wait_ctx( this_thread, user_info );

	// Append the current wait operation to the ones already queued on the condition
	// We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
	append( this.blocked, &waiter );

	// Lock all monitors (aggregates the locks as well)
	lock_all( monitors, locks, count );

	// Find the next thread(s) to run
	__lock_size_t thread_count = 0;
	thread_desc * threads[ count ];
	__builtin_memset( threads, 0, sizeof( threads ) );

	// Save monitor states
	monitor_save;

	// Remove any duplicate threads
	for( __lock_size_t i = 0; i < count; i++) {
		thread_desc * new_owner = next_thread( monitors[i] );
		insert_unique( threads, thread_count, new_owner );
	}

	// Everything is ready to go to sleep
	BlockInternal( locks, count, threads, thread_count );

	// We are back, restore the owners and recursions
	monitor_restore;
}

bool signal( condition & this ) {
	if( is_empty( this ) ) { return false; }

	//Check that everything is as expected
	verify( this.monitors );
	verify( this.monitor_count != 0 );

	//Some more checking in debug
	LIB_DEBUG_DO(
		thread_desc * this_thrd = this_thread;
		if ( this.monitor_count != this_thrd->monitors.size ) {
			abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", &this, this.monitor_count, this_thrd->monitors.size );
		}

		for(int i = 0; i < this.monitor_count; i++) {
			if ( this.monitors[i] != this_thrd->monitors.list[i] ) {
				abortf( "Signal on condition %p made with different monitor, expected %p got %i", &this, this.monitors[i], this_thrd->monitors.list[i] );
			}
		}
	);

	__lock_size_t count = this.monitor_count;

	// Lock all monitors
	lock_all( this.monitors, NULL, count );

	//Pop the head of the waiting queue
	__condition_node_t * node = pop_head( this.blocked );

	//Add the thread to the proper AS stack
	for(int i = 0; i < count; i++) {
		__condition_criterion_t * crit = &node->criteria[i];
		assert( !crit->ready );
		push( crit->target->signal_stack, crit );
	}

	//Release
	unlock_all( this.monitors, count );

	return true;
}

bool signal_block( condition & this ) {
	if( !this.blocked.head ) { return false; }

	//Check that everything is as expected
	verifyf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
	verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );

	// Create storage for monitor context
	monitor_ctx( this.monitors, this.monitor_count );

	// Lock all monitors (aggregates the locks them as well)
	lock_all( monitors, locks, count );

	// Create the node specific to this wait operation
	wait_ctx_primed( this_thread, 0 )

	//save contexts
	monitor_save;

	//Find the thread to run
	thread_desc * signallee = pop_head( this.blocked )->waiting_thread;
	set_owner( monitors, count, signallee );

	LIB_DEBUG_PRINT_BUFFER_DECL( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );

	//Everything is ready to go to sleep
	BlockInternal( locks, count, &signallee, 1 );


	// WE WOKE UP


	LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel :   signal_block returned\n" );

	//We are back, restore the masks and recursions
	monitor_restore;

	return true;
}

// Access the user_info of the thread waiting at the front of the queue
uintptr_t front( condition & this ) {
	verifyf( !is_empty(this),
		"Attempt to access user data on an empty condition.\n"
		"Possible cause is not checking if the condition is empty before reading stored data."
	);
	return this.blocked.head->user_info;
}

//-----------------------------------------------------------------------------
// External scheduling
// cases to handle :
// 	- target already there :
// 		block and wake
// 	- dtor already there
// 		put thread on signaller stack
// 	- non-blocking
// 		return else
// 	- timeout
// 		return timeout
// 	- block
// 		setup mask
// 		block
void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
	// This statment doesn't have a contiguous list of monitors...
	// Create one!
	__lock_size_t max = count_max( mask );
	monitor_desc * mon_storage[max];
	__builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
	__lock_size_t actual_count = aggregate( mon_storage, mask );

	LIB_DEBUG_PRINT_BUFFER_DECL( "Kernel : waitfor %d (s: %d, m: %d)\n", actual_count, mask.size, (__lock_size_t)max);

	if(actual_count == 0) return;

	LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : waitfor internal proceeding\n");

	// Create storage for monitor context
	monitor_ctx( mon_storage, actual_count );

	// Lock all monitors (aggregates the locks as well)
	lock_all( monitors, locks, count );

	{
		// Check if the entry queue
		thread_desc * next; int index;
		[next, index] = search_entry_queue( mask, monitors, count );

		if( next ) {
			*mask.accepted = index;
			if( mask.clauses[index].is_dtor ) {
				LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : dtor already there\n");
				verifyf( mask.clauses[index].size == 1        , "ERROR: Accepted dtor has more than 1 mutex parameter." );

				monitor_desc * mon2dtor = mask.clauses[index].list[0];
				verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );

				__condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
				push( mon2dtor->signal_stack, dtor_crit );

				unlock_all( locks, count );
			}
			else {
				LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : thread present, baton-passing\n");

				// Create the node specific to this wait operation
				wait_ctx_primed( this_thread, 0 );

				// Save monitor states
				monitor_save;

				LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel :  baton of %d monitors : ", count );
				#ifdef __CFA_DEBUG_PRINT__
					for( int i = 0; i < count; i++) {
						LIB_DEBUG_PRINT_BUFFER_LOCAL( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
					}
				#endif
				LIB_DEBUG_PRINT_BUFFER_LOCAL( "\n");

				// Set the owners to be the next thread
				set_owner( monitors, count, next );

				// Everything is ready to go to sleep
				BlockInternal( locks, count, &next, 1 );

				// We are back, restore the owners and recursions
				monitor_restore;

				LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : thread present, returned\n");
			}

			LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);

			return;
		}
	}


	if( duration == 0 ) {
		LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : non-blocking, exiting\n");

		unlock_all( locks, count );

		LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);
		return;
	}


	verifyf( duration < 0, "Timeout on waitfor statments not supported yet.");

	LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : blocking waitfor\n");

	// Create the node specific to this wait operation
	wait_ctx_primed( this_thread, 0 );

	monitor_save;
	set_mask( monitors, count, mask );

	for( __lock_size_t i = 0; i < count; i++) {
		verify( monitors[i]->owner == this_thread );
	}

	//Everything is ready to go to sleep
	BlockInternal( locks, count );


	// WE WOKE UP


	//We are back, restore the masks and recursions
	monitor_restore;

	LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : exiting\n");

	LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);
}

//-----------------------------------------------------------------------------
// Utilities

static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
	// LIB_DEBUG_PRINT_SAFE("Kernal :   Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );

	//Pass the monitor appropriately
	this->owner = owner;

	//We are passing the monitor to someone else, which means recursion level is not 0
	this->recursion = owner ? 1 : 0;
}

static inline void set_owner( monitor_desc * monitors [], __lock_size_t count, thread_desc * owner ) {
	monitors[0]->owner     = owner;
	monitors[0]->recursion = 1;
	for( __lock_size_t i = 1; i < count; i++ ) {
		monitors[i]->owner     = owner;
		monitors[i]->recursion = 0;
	}
}

static inline void set_mask( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
	for( __lock_size_t i = 0; i < count; i++) {
		storage[i]->mask = mask;
	}
}

static inline void reset_mask( monitor_desc * this ) {
	this->mask.accepted = NULL;
	this->mask.clauses = NULL;
	this->mask.size = 0;
}

static inline thread_desc * next_thread( monitor_desc * this ) {
	//Check the signaller stack
	LIB_DEBUG_PRINT_SAFE("Kernel :  mon %p AS-stack top %p\n", this, this->signal_stack.top);
	__condition_criterion_t * urgent = pop( this->signal_stack );
	if( urgent ) {
		//The signaller stack is not empty,
		//regardless of if we are ready to baton pass,
		//we need to set the monitor as in use
		set_owner( this,  urgent->owner->waiting_thread );

		return check_condition( urgent );
	}

	// No signaller thread
	// Get the next thread in the entry_queue
	thread_desc * new_owner = pop_head( this->entry_queue );
	set_owner( this, new_owner );

	return new_owner;
}

static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & group ) {
	__acceptable_t * it = this->mask.clauses; // Optim
	__lock_size_t count = this->mask.size;

	// Check if there are any acceptable functions
	if( !it ) return false;

	// If this isn't the first monitor to test this, there is no reason to repeat the test.
	if( this != group[0] ) return group[0]->mask.accepted >= 0;

	// For all acceptable functions check if this is the current function.
	for( __lock_size_t i = 0; i < count; i++, it++ ) {
		if( *it == group ) {
			*this->mask.accepted = i;
			return true;
		}
	}

	// No function matched
	return false;
}

static inline void init( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
	for( __lock_size_t i = 0; i < count; i++) {
		(criteria[i]){ monitors[i], waiter };
	}

	waiter.criteria = criteria;
}

static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
	for( __lock_size_t i = 0; i < count; i++) {
		(criteria[i]){ monitors[i], waiter };
		LIB_DEBUG_PRINT_SAFE( "Kernel :  target %p = %p\n", criteria[i].target, &criteria[i] );
		push( criteria[i].target->signal_stack, &criteria[i] );
	}

	waiter.criteria = criteria;
}

static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
	for( __lock_size_t i = 0; i < count; i++ ) {
		DO_LOCK( *locks[i] DEBUG_CTX2 );
	}
}

static inline void lock_all( monitor_desc * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
	for( __lock_size_t i = 0; i < count; i++ ) {
		__spinlock_t * l = &source[i]->lock;
		DO_LOCK( *l DEBUG_CTX2 );
		if(locks) locks[i] = l;
	}
}

static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
	for( __lock_size_t i = 0; i < count; i++ ) {
		unlock( *locks[i] );
	}
}

static inline void unlock_all( monitor_desc * locks [], __lock_size_t count ) {
	for( __lock_size_t i = 0; i < count; i++ ) {
		unlock( locks[i]->lock );
	}
}

static inline void save(
	monitor_desc * ctx [],
	__lock_size_t count,
	__attribute((unused)) __spinlock_t * locks [],
	unsigned int /*out*/ recursions [],
	__waitfor_mask_t /*out*/ masks []
) {
	for( __lock_size_t i = 0; i < count; i++ ) {
		recursions[i] = ctx[i]->recursion;
		masks[i]      = ctx[i]->mask;
	}
}

static inline void restore(
	monitor_desc * ctx [],
	__lock_size_t count,
	__spinlock_t * locks [],
	unsigned int /*out*/ recursions [],
	__waitfor_mask_t /*out*/ masks []
) {
	lock_all( locks, count );
	for( __lock_size_t i = 0; i < count; i++ ) {
		ctx[i]->recursion = recursions[i];
		ctx[i]->mask      = masks[i];
	}
	unlock_all( locks, count );
}

// Function has 2 different behavior
// 1 - Marks a monitors as being ready to run
// 2 - Checks if all the monitors are ready to run
//     if so return the thread to run
static inline thread_desc * check_condition( __condition_criterion_t * target ) {
	__condition_node_t * node = target->owner;
	unsigned short count = node->count;
	__condition_criterion_t * criteria = node->criteria;

	bool ready2run = true;

	for(	int i = 0; i < count; i++ ) {

		// LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target );
		if( &criteria[i] == target ) {
			criteria[i].ready = true;
			// LIB_DEBUG_PRINT_SAFE( "True\n" );
		}

		ready2run = criteria[i].ready && ready2run;
	}

	LIB_DEBUG_PRINT_SAFE( "Kernel :  Runing %i (%p)\n", ready2run, ready2run ? node->waiting_thread : NULL );
	return ready2run ? node->waiting_thread : NULL;
}

static inline void brand_condition( condition & this ) {
	thread_desc * thrd = this_thread;
	if( !this.monitors ) {
		// LIB_DEBUG_PRINT_SAFE("Branding\n");
		assertf( thrd->monitors.list != NULL, "No current monitor to brand condition %p", thrd->monitors.list );
		this.monitor_count = thrd->monitors.size;

		this.monitors = (monitor_desc **)malloc( this.monitor_count * sizeof( *this.monitors ) );
		for( int i = 0; i < this.monitor_count; i++ ) {
			this.monitors[i] = thrd->monitors.list[i];
		}
	}
}

static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor_desc * monitors [], __lock_size_t count ) {

	__thread_queue_t & entry_queue = monitors[0]->entry_queue;

	// For each thread in the entry-queue
	for(	thread_desc ** thrd_it = &entry_queue.head;
		*thrd_it;
		thrd_it = &(*thrd_it)->next
	) {
		// For each acceptable check if it matches
		int i = 0;
		__acceptable_t * end = mask.clauses + mask.size;
		for( __acceptable_t * it = mask.clauses; it != end; it++, i++ ) {
			// Check if we have a match
			if( *it == (*thrd_it)->monitors ) {

				// If we have a match return it
				// after removeing it from the entry queue
				return [remove( entry_queue, thrd_it ), i];
			}
		}
	}

	return [0, -1];
}

forall(dtype T | sized( T ))
static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
	if( !val ) return size;

	for( __lock_size_t i = 0; i <= size; i++) {
		if( array[i] == val ) return size;
	}

	array[size] = val;
	size = size + 1;
	return size;
}

static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
	__lock_size_t max = 0;
	for( __lock_size_t i = 0; i < mask.size; i++ ) {
		max += mask.clauses[i].size;
	}
	return max;
}

static inline __lock_size_t aggregate( monitor_desc * storage [], const __waitfor_mask_t & mask ) {
	__lock_size_t size = 0;
	for( __lock_size_t i = 0; i < mask.size; i++ ) {
		__libcfa_small_sort( mask.clauses[i].list, mask.clauses[i].size );
		for( __lock_size_t j = 0; j < mask.clauses[i].size; j++) {
			insert_unique( storage, size, mask.clauses[i].list[j] );
		}
	}
	// TODO insertion sort instead of this
	__libcfa_small_sort( storage, size );
	return size;
}

void ?{}( __condition_blocked_queue_t & this ) {
	this.head = NULL;
	this.tail = &this.head;
}

void append( __condition_blocked_queue_t & this, __condition_node_t * c ) {
	verify(this.tail != NULL);
	*this.tail = c;
	this.tail = &c->next;
}

__condition_node_t * pop_head( __condition_blocked_queue_t & this ) {
	__condition_node_t * head = this.head;
	if( head ) {
		this.head = head->next;
		if( !head->next ) {
			this.tail = &this.head;
		}
		head->next = NULL;
	}
	return head;
}

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