[apple/libpthread.git] / kern / synch_internal.h

/*
 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */

#ifndef __SYNCH_INTERNAL_H__
#define __SYNCH_INTERNAL_H__

// kwe_state
enum {
	KWE_THREAD_INWAIT = 1,
	KWE_THREAD_PREPOST,
	KWE_THREAD_BROADCAST,
};

#define _PTHREAD_MTX_OPT_PSHARED 0x010
#define _PTHREAD_MTX_OPT_NOTIFY 0x1000	/* notify to drop mutex handling in cvwait */
#define _PTHREAD_MTX_OPT_MUTEX	0x2000 /* this is a mutex type  */


#define PTHRW_COUNT_SHIFT	8
#define PTHRW_INC		(1 << PTHRW_COUNT_SHIFT)
#define PTHRW_BIT_MASK		((1 << PTHRW_COUNT_SHIFT) - 1)
#define PTHRW_COUNT_MASK 	((uint32_t)~PTHRW_BIT_MASK)
#define PTHRW_MAX_READERS 	PTHRW_COUNT_MASK

// L word
#define PTH_RWL_KBIT		0x01 	// cannot acquire in user mode
#define PTH_RWL_EBIT		0x02	// exclusive lock in progress
#define PTH_RWL_WBIT		0x04	// write waiters pending in kernel
#define PTH_RWL_PBIT		0x04	// prepost (cv) pending in kernel

#define PTH_RWL_MTX_WAIT	0x20 	// in cvar in mutex wait
#define PTH_RWL_UBIT		0x40	// lock is unlocked (no readers or writers)
#define PTH_RWL_MBIT		0x40	// overlapping grants from kernel (only in updateval)
#define PTH_RWL_IBIT		0x80	// lock reset, held until first successful unlock

#define PTHRW_RWL_INIT		PTH_RWL_IBIT	// reset on the lock bits (U)
#define PTHRW_RWLOCK_INIT	(PTH_RWL_IBIT | PTH_RWL_UBIT)   // reset on the lock bits (U)

// S word
#define PTH_RWS_SBIT		0x01	// kernel transition seq not set yet
#define PTH_RWS_IBIT		0x02	// Sequence is not set on return from kernel

#define PTH_RWS_CV_CBIT		PTH_RWS_SBIT	// kernel has cleared all info w.r.s.t CV
#define PTH_RWS_CV_PBIT		PTH_RWS_IBIT	// kernel has prepost/fake structs only,no waiters
#define PTH_RWS_CV_BITSALL	(PTH_RWS_CV_CBIT | PTH_RWS_CV_PBIT)
#define PTH_RWS_CV_MBIT		PTH_RWL_MBIT    // to indicate prepost return from kernel
#define PTH_RWS_CV_RESET_PBIT	((uint32_t)~PTH_RWS_CV_PBIT)

#define PTH_RWS_WSVBIT		0x04	// save W bit

#define PTHRW_RWS_SAVEMASK	(PTH_RWS_WSVBIT)	// save bits mask

#define PTHRW_RWS_INIT		PTH_RWS_SBIT	// reset on the lock bits (U)

// rw_flags
#define PTHRW_KERN_PROCESS_SHARED	0x10
#define PTHRW_KERN_PROCESS_PRIVATE	0x20

#define PTHREAD_MTX_TID_SWITCHING (uint64_t)-1

// L word tests
#define is_rwl_ebit_set(x) (((x) & PTH_RWL_EBIT) != 0)
#define is_rwl_wbit_set(x) (((x) & PTH_RWL_WBIT) != 0)
#define is_rwl_ebit_clear(x) (((x) & PTH_RWL_EBIT) == 0)
#define is_rwl_readoverlap(x) (((x) & PTH_RWL_MBIT) != 0)

// S word tests
#define is_rws_sbit_set(x) (((x) & PTH_RWS_SBIT) != 0)
#define is_rws_unlockinit_set(x) (((x) & PTH_RWS_IBIT) != 0)
#define is_rws_savemask_set(x) (((x) & PTHRW_RWS_SAVEMASK) != 0)
#define is_rws_pbit_set(x) (((x) & PTH_RWS_CV_PBIT) != 0)

// kwe_flags
#define KWE_FLAG_LOCKPREPOST	0x1 // cvwait caused a lock prepost

static inline int
is_seqlower(uint32_t x, uint32_t y)
{
	x &= PTHRW_COUNT_MASK;
	y &= PTHRW_COUNT_MASK;
	if (x < y) {
		return ((y - x) < (PTHRW_MAX_READERS / 2));
	} else {
		return ((x - y) > (PTHRW_MAX_READERS / 2));
	}
}

static inline int
is_seqlower_eq(uint32_t x, uint32_t y)
{
	if ((x & PTHRW_COUNT_MASK) == (y & PTHRW_COUNT_MASK)) {
		return 1;
	} else {
		return is_seqlower(x, y);
	}
}

static inline int
is_seqhigher(uint32_t x, uint32_t y)
{
	x &= PTHRW_COUNT_MASK;
	y &= PTHRW_COUNT_MASK;
	if (x > y) {
		return ((x - y) < (PTHRW_MAX_READERS / 2));
	} else {
		return ((y - x) > (PTHRW_MAX_READERS / 2));
	}
}

static inline int
is_seqhigher_eq(uint32_t x, uint32_t y)
{
	if ((x & PTHRW_COUNT_MASK) == (y & PTHRW_COUNT_MASK)) {
		return 1;
	} else {
		return is_seqhigher(x,y);
	}
}

static inline int
diff_genseq(uint32_t x, uint32_t y)
{
	x &= PTHRW_COUNT_MASK;
	y &= PTHRW_COUNT_MASK;
	if (x == y) {
		return 0;
	} else if (x > y)  {
		return x - y;
	} else {
		return ((PTHRW_MAX_READERS - y) + x + PTHRW_INC);
	}
}

static inline int
find_diff(uint32_t upto, uint32_t lowest)
{
	uint32_t diff;
	
	if (upto == lowest)
		return(0);
#if 0
	diff = diff_genseq(upto, lowest);
#else
        if (is_seqlower(upto, lowest) != 0)
                diff = diff_genseq(lowest, upto);
        else
                diff = diff_genseq(upto, lowest);
#endif
	diff = (diff >> PTHRW_COUNT_SHIFT);
	return(diff);
}

#endif /* __SYNCH_INTERNAL_H__ */
Commit	Line	Data
f1a1da6c A	1	/*
	2	* Copyright (c) 2000-2013 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23
	24	#ifndef __SYNCH_INTERNAL_H__
	25	#define __SYNCH_INTERNAL_H__
	26
214d78a2 A	27	// kwe_state
	28	enum {
	29	KWE_THREAD_INWAIT = 1,
	30	KWE_THREAD_PREPOST,
	31	KWE_THREAD_BROADCAST,
	32	};
f1a1da6c A	33
	34	#define _PTHREAD_MTX_OPT_PSHARED 0x010
	35	#define _PTHREAD_MTX_OPT_NOTIFY 0x1000 /* notify to drop mutex handling in cvwait */
	36	#define _PTHREAD_MTX_OPT_MUTEX 0x2000 /* this is a mutex type */
	37
	38
	39	#define PTHRW_COUNT_SHIFT 8
	40	#define PTHRW_INC (1 << PTHRW_COUNT_SHIFT)
	41	#define PTHRW_BIT_MASK ((1 << PTHRW_COUNT_SHIFT) - 1)
	42	#define PTHRW_COUNT_MASK ((uint32_t)~PTHRW_BIT_MASK)
	43	#define PTHRW_MAX_READERS PTHRW_COUNT_MASK
	44
	45	// L word
	46	#define PTH_RWL_KBIT 0x01 // cannot acquire in user mode
	47	#define PTH_RWL_EBIT 0x02 // exclusive lock in progress
	48	#define PTH_RWL_WBIT 0x04 // write waiters pending in kernel
	49	#define PTH_RWL_PBIT 0x04 // prepost (cv) pending in kernel
	50
	51	#define PTH_RWL_MTX_WAIT 0x20 // in cvar in mutex wait
a0619f9c A	52	#define PTH_RWL_UBIT 0x40 // lock is unlocked (no readers or writers)
a0619f9c A	53	#define PTH_RWL_MBIT 0x40 // overlapping grants from kernel (only in updateval)
f1a1da6c A	54	#define PTH_RWL_IBIT 0x80 // lock reset, held until first successful unlock
	55
	56	#define PTHRW_RWL_INIT PTH_RWL_IBIT // reset on the lock bits (U)
a0619f9c	57	#define PTHRW_RWLOCK_INIT (PTH_RWL_IBIT \| PTH_RWL_UBIT) // reset on the lock bits (U)
f1a1da6c A	58
	59	// S word
	60	#define PTH_RWS_SBIT 0x01 // kernel transition seq not set yet
	61	#define PTH_RWS_IBIT 0x02 // Sequence is not set on return from kernel
	62
	63	#define PTH_RWS_CV_CBIT PTH_RWS_SBIT // kernel has cleared all info w.r.s.t CV
	64	#define PTH_RWS_CV_PBIT PTH_RWS_IBIT // kernel has prepost/fake structs only,no waiters
	65	#define PTH_RWS_CV_BITSALL (PTH_RWS_CV_CBIT \| PTH_RWS_CV_PBIT)
	66	#define PTH_RWS_CV_MBIT PTH_RWL_MBIT // to indicate prepost return from kernel
	67	#define PTH_RWS_CV_RESET_PBIT ((uint32_t)~PTH_RWS_CV_PBIT)
	68
	69	#define PTH_RWS_WSVBIT 0x04 // save W bit
	70
	71	#define PTHRW_RWS_SAVEMASK (PTH_RWS_WSVBIT) // save bits mask
	72
	73	#define PTHRW_RWS_INIT PTH_RWS_SBIT // reset on the lock bits (U)
f1a1da6c A	74
	75	// rw_flags
	76	#define PTHRW_KERN_PROCESS_SHARED 0x10
	77	#define PTHRW_KERN_PROCESS_PRIVATE 0x20
	78
	79	#define PTHREAD_MTX_TID_SWITCHING (uint64_t)-1
	80
	81	// L word tests
f1a1da6c A	82	#define is_rwl_ebit_set(x) (((x) & PTH_RWL_EBIT) != 0)
	83	#define is_rwl_wbit_set(x) (((x) & PTH_RWL_WBIT) != 0)
	84	#define is_rwl_ebit_clear(x) (((x) & PTH_RWL_EBIT) == 0)
	85	#define is_rwl_readoverlap(x) (((x) & PTH_RWL_MBIT) != 0)
	86
	87	// S word tests
214d78a2 A	88	#define is_rws_sbit_set(x) (((x) & PTH_RWS_SBIT) != 0)
	89	#define is_rws_unlockinit_set(x) (((x) & PTH_RWS_IBIT) != 0)
	90	#define is_rws_savemask_set(x) (((x) & PTHRW_RWS_SAVEMASK) != 0)
	91	#define is_rws_pbit_set(x) (((x) & PTH_RWS_CV_PBIT) != 0)
	92
	93	// kwe_flags
	94	#define KWE_FLAG_LOCKPREPOST 0x1 // cvwait caused a lock prepost
f1a1da6c A	95
	96	static inline int
	97	is_seqlower(uint32_t x, uint32_t y)
	98	{
	99	x &= PTHRW_COUNT_MASK;
	100	y &= PTHRW_COUNT_MASK;
	101	if (x < y) {
	102	return ((y - x) < (PTHRW_MAX_READERS / 2));
	103	} else {
	104	return ((x - y) > (PTHRW_MAX_READERS / 2));
	105	}
	106	}
	107
	108	static inline int
	109	is_seqlower_eq(uint32_t x, uint32_t y)
	110	{
	111	if ((x & PTHRW_COUNT_MASK) == (y & PTHRW_COUNT_MASK)) {
	112	return 1;
	113	} else {
	114	return is_seqlower(x, y);
	115	}
	116	}
	117
	118	static inline int
	119	is_seqhigher(uint32_t x, uint32_t y)
	120	{
	121	x &= PTHRW_COUNT_MASK;
	122	y &= PTHRW_COUNT_MASK;
	123	if (x > y) {
	124	return ((x - y) < (PTHRW_MAX_READERS / 2));
	125	} else {
	126	return ((y - x) > (PTHRW_MAX_READERS / 2));
	127	}
	128	}
	129
	130	static inline int
	131	is_seqhigher_eq(uint32_t x, uint32_t y)
	132	{
	133	if ((x & PTHRW_COUNT_MASK) == (y & PTHRW_COUNT_MASK)) {
	134	return 1;
	135	} else {
	136	return is_seqhigher(x,y);
	137	}
	138	}
	139
	140	static inline int
	141	diff_genseq(uint32_t x, uint32_t y)
	142	{
	143	x &= PTHRW_COUNT_MASK;
	144	y &= PTHRW_COUNT_MASK;
	145	if (x == y) {
	146	return 0;
	147	} else if (x > y) {
	148	return x - y;
	149	} else {
	150	return ((PTHRW_MAX_READERS - y) + x + PTHRW_INC);
	151	}
	152	}
	153
	154	static inline int
	155	find_diff(uint32_t upto, uint32_t lowest)
	156	{
	157	uint32_t diff;
	158
159	if (upto == lowest)
160	return(0);
161	#if 0
162	diff = diff_genseq(upto, lowest);
163	#else
164	if (is_seqlower(upto, lowest) != 0)
165	diff = diff_genseq(lowest, upto);
166	else
167	diff = diff_genseq(upto, lowest);
168	#endif
169	diff = (diff >> PTHRW_COUNT_SHIFT);
170	return(diff);
171	}
172
173	#endif /* __SYNCH_INTERNAL_H__ */