[urcu.git] / ticketlock-testwait / mem-progress.spin

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (c) 2009 Mathieu Desnoyers
 */

/* 16 CPUs max (byte has 8 bits, divided in two) */

#ifndef CONFIG_BITS_PER_BYTE
#define BITS_PER_BYTE		8
#else
// test progress failure with shorter byte size. Will fail with 5 proc.
#define BITS_PER_BYTE		CONFIG_BITS_PER_BYTE
#endif

#define HBPB			(BITS_PER_BYTE / 2)	/* 4 */
#define HMASK			((1 << HBPB) - 1)	/* 0x0F */

/* for byte type */
#define LOW_HALF(val)		((val) & HMASK)
#define LOW_HALF_INC		1

#define HIGH_HALF(val)		((val) & (HMASK << HBPB))
#define HIGH_HALF_INC		(1 << HBPB)

byte lock = 0;
byte refcount = 0;

#define need_pause()	(_pid == 2)

/*
 * do_pause() disabled:
 * get similar effect by disabling weak fairness.
 */
/*
 * Test weak fairness by either not pausing or cycling for any number of
 * steps, or forever.
 * Models a slow thread. Should be added between each atomic steps.
 * To test for wait-freedom (no starvation of a specific thread), add do_pause
 * in threads other than the one we are checking for progress (and which
 * contains the progress label).
 * To test for lock-freedom (system-wide progress), add to all threads except
 * one. All threads contain progress labels.
 */
inline do_pause()
{
	if
	:: need_pause() ->
		do
		:: 1 ->
			skip;
		od;
	:: 1 ->
		skip;
	fi;
}

inline spin_lock(lock, ticket)
{
	atomic {
		ticket = HIGH_HALF(lock) >> HBPB;
		lock = lock + HIGH_HALF_INC;	/* overflow expected */
	}

	do
	:: 1 ->
		if
		:: (LOW_HALF(lock) == ticket) ->
			break;
		:: else ->
			skip;
		fi;
	od;
}

inline spin_unlock(lock)
{
	lock = HIGH_HALF(lock) | LOW_HALF(lock + LOW_HALF_INC);
}

proctype proc_A()
{
	byte ticket;

	do
	:: 1 ->
progress_A:
		spin_lock(lock, ticket);
		refcount = refcount + 1;
		refcount = refcount - 1;
		spin_unlock(lock);
	od;
}

proctype proc_B()
{
	byte ticket;

	do
	:: 1 ->
progress_B:
		//do_pause();
		spin_lock(lock, ticket);
		refcount = refcount + 1;
		//do_pause();
		refcount = refcount - 1;
		spin_unlock(lock);
	od;
}

init
{
	run proc_A();
	run proc_B();
	run proc_B();
	run proc_B();
	run proc_B();
}
Commit	Line	Data
5c020b8d MD	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* This program is distributed in the hope that it will be useful,
	8	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	9	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	10	* GNU General Public License for more details.
	11	*
	12	* You should have received a copy of the GNU General Public License
	13	* along with this program; if not, write to the Free Software
	14	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	15	*
	16	* Copyright (c) 2009 Mathieu Desnoyers
	17	*/
	18
	19	/* 16 CPUs max (byte has 8 bits, divided in two) */
	20
	21	#ifndef CONFIG_BITS_PER_BYTE
	22	#define BITS_PER_BYTE 8
	23	#else
	24	// test progress failure with shorter byte size. Will fail with 5 proc.
	25	#define BITS_PER_BYTE CONFIG_BITS_PER_BYTE
	26	#endif
	27
	28	#define HBPB (BITS_PER_BYTE / 2) /* 4 */
	29	#define HMASK ((1 << HBPB) - 1) /* 0x0F */
	30
	31	/* for byte type */
	32	#define LOW_HALF(val) ((val) & HMASK)
	33	#define LOW_HALF_INC 1
	34
	35	#define HIGH_HALF(val) ((val) & (HMASK << HBPB))
	36	#define HIGH_HALF_INC (1 << HBPB)
	37
	38	byte lock = 0;
	39	byte refcount = 0;
	40
	41	#define need_pause() (_pid == 2)
	42
f96ba336 MD	43	/*
	44	* do_pause() disabled:
	45	* get similar effect by disabling weak fairness.
	46	*/
5c020b8d MD	47	/*
	48	* Test weak fairness by either not pausing or cycling for any number of
	49	* steps, or forever.
	50	* Models a slow thread. Should be added between each atomic steps.
	51	* To test for wait-freedom (no starvation of a specific thread), add do_pause
	52	* in threads other than the one we are checking for progress (and which
	53	* contains the progress label).
	54	* To test for lock-freedom (system-wide progress), add to all threads except
	55	* one. All threads contain progress labels.
	56	*/
	57	inline do_pause()
	58	{
	59	if
	60	:: need_pause() ->
6e634233	61	do
5c020b8d	62	:: 1 ->
6e634233 MD	63	skip;
	64	od;
	65	:: 1 ->
5c020b8d MD	66	skip;
	67	fi;
	68	}
	69
	70	inline spin_lock(lock, ticket)
	71	{
	72	atomic {
	73	ticket = HIGH_HALF(lock) >> HBPB;
	74	lock = lock + HIGH_HALF_INC; /* overflow expected */
	75	}
	76
	77	do
	78	:: 1 ->
	79	if
	80	:: (LOW_HALF(lock) == ticket) ->
	81	break;
	82	:: else ->
	83	skip;
	84	fi;
	85	od;
	86	}
	87
	88	inline spin_unlock(lock)
	89	{
	90	lock = HIGH_HALF(lock) \| LOW_HALF(lock + LOW_HALF_INC);
	91	}
	92
	93	proctype proc_A()
	94	{
	95	byte ticket;
	96
	97	do
	98	:: 1 ->
	99	progress_A:
	100	spin_lock(lock, ticket);
	101	refcount = refcount + 1;
	102	refcount = refcount - 1;
	103	spin_unlock(lock);
	104	od;
	105	}
	106
	107	proctype proc_B()
	108	{
	109	byte ticket;
	110
	111	do
	112	:: 1 ->
f96ba336 MD	113	progress_B:
f96ba336 MD	114	//do_pause();
5c020b8d MD	115	spin_lock(lock, ticket);
5c020b8d MD	116	refcount = refcount + 1;
f96ba336	117	//do_pause();
5c020b8d MD	118	refcount = refcount - 1;
	119	spin_unlock(lock);
	120	od;
	121	}
	122
	123	init
	124	{
	125	run proc_A();
	126	run proc_B();
	127	run proc_B();
	128	run proc_B();
	129	run proc_B();
	130	}