[thirdparty/glibc.git] / nptl / pthread_mutex_lock.c

/* Copyright (C) 2002-2013 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <not-cancel.h>
#include "pthreadP.h"
#include <lowlevellock.h>
#include <stap-probe.h>

#ifndef lll_lock_elision
#define lll_lock_elision(lock, try_lock, private)	({ \
      lll_lock (lock, private); 0; })
#endif

#ifndef lll_trylock_elision
#define lll_trylock_elision(a,t) lll_trylock(a)
#endif

#ifndef LLL_MUTEX_LOCK
# define LLL_MUTEX_LOCK(mutex) \
  lll_lock ((mutex)->__data.__lock, PTHREAD_MUTEX_PSHARED (mutex))
# define LLL_MUTEX_TRYLOCK(mutex) \
  lll_trylock ((mutex)->__data.__lock)
# define LLL_ROBUST_MUTEX_LOCK(mutex, id) \
  lll_robust_lock ((mutex)->__data.__lock, id, \
		   PTHREAD_ROBUST_MUTEX_PSHARED (mutex))
# define LLL_MUTEX_LOCK_ELISION(mutex) \
  lll_lock_elision ((mutex)->__data.__lock, (mutex)->__data.__elision, \
		   PTHREAD_MUTEX_PSHARED (mutex))
# define LLL_MUTEX_TRYLOCK_ELISION(mutex) \
  lll_trylock_elision((mutex)->__data.__lock, (mutex)->__data.__elision, \
		   PTHREAD_MUTEX_PSHARED (mutex))
#endif

#ifndef FORCE_ELISION
#define FORCE_ELISION(m, s)
#endif

static int __pthread_mutex_lock_full (pthread_mutex_t *mutex)
     __attribute_noinline__;

int
__pthread_mutex_lock (mutex)
     pthread_mutex_t *mutex;
{
  assert (sizeof (mutex->__size) >= sizeof (mutex->__data));

  unsigned int type = PTHREAD_MUTEX_TYPE_ELISION (mutex);

  LIBC_PROBE (mutex_entry, 1, mutex);

  if (__builtin_expect (type & ~(PTHREAD_MUTEX_KIND_MASK_NP
				 | PTHREAD_MUTEX_ELISION_FLAGS_NP), 0))
    return __pthread_mutex_lock_full (mutex);

  if (__builtin_expect (type == PTHREAD_MUTEX_TIMED_NP, 1))
    {
      FORCE_ELISION (mutex, goto elision);
    simple:
      /* Normal mutex.  */
      LLL_MUTEX_LOCK (mutex);
      assert (mutex->__data.__owner == 0);
    }
#ifdef HAVE_ELISION
  else if (__builtin_expect (type == PTHREAD_MUTEX_TIMED_ELISION_NP, 1))
    {
  elision: __attribute__((unused))
      /* This case can never happen on a system without elision,
         as the mutex type initialization functions will not
	 allow to set the elision flags.  */
      /* Don't record owner or users for elision case. This is a
         tail call.  */
      return LLL_MUTEX_LOCK_ELISION (mutex);
    }
#endif
  else if (__builtin_expect (PTHREAD_MUTEX_TYPE (mutex)
			     == PTHREAD_MUTEX_RECURSIVE_NP, 1))
    {
      /* Recursive mutex.  */
      pid_t id = THREAD_GETMEM (THREAD_SELF, tid);

      /* Check whether we already hold the mutex.  */
      if (mutex->__data.__owner == id)
	{
	  /* Just bump the counter.  */
	  if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
	    /* Overflow of the counter.  */
	    return EAGAIN;

	  ++mutex->__data.__count;

	  return 0;
	}

      /* We have to get the mutex.  */
      LLL_MUTEX_LOCK (mutex);

      assert (mutex->__data.__owner == 0);
      mutex->__data.__count = 1;
    }
  else if (__builtin_expect (PTHREAD_MUTEX_TYPE (mutex)
			  == PTHREAD_MUTEX_ADAPTIVE_NP, 1))
    {
      if (! __is_smp)
	goto simple;

      if (LLL_MUTEX_TRYLOCK (mutex) != 0)
	{
	  int cnt = 0;
	  int max_cnt = MIN (MAX_ADAPTIVE_COUNT,
			     mutex->__data.__spins * 2 + 10);
	  do
	    {
	      if (cnt++ >= max_cnt)
		{
		  LLL_MUTEX_LOCK (mutex);
		  break;
		}

#ifdef BUSY_WAIT_NOP
	      BUSY_WAIT_NOP;
#endif
	    }
	  while (LLL_MUTEX_TRYLOCK (mutex) != 0);

	  mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
	}
      assert (mutex->__data.__owner == 0);
    }
  else
    {
      pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
      assert (PTHREAD_MUTEX_TYPE (mutex) == PTHREAD_MUTEX_ERRORCHECK_NP);
      /* Check whether we already hold the mutex.  */
      if (__builtin_expect (mutex->__data.__owner == id, 0))
	return EDEADLK;
      goto simple;
    }

  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);

  /* Record the ownership.  */
  mutex->__data.__owner = id;
#ifndef NO_INCR
  ++mutex->__data.__nusers;
#endif

  LIBC_PROBE (mutex_acquired, 1, mutex);

  return 0;
}

static int
__pthread_mutex_lock_full (pthread_mutex_t *mutex)
{
  int oldval;
  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);

  switch (PTHREAD_MUTEX_TYPE (mutex))
    {
    case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP:
    case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
    case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
    case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
		     &mutex->__data.__list.__next);

      oldval = mutex->__data.__lock;
      do
	{
	again:
	  if ((oldval & FUTEX_OWNER_DIED) != 0)
	    {
	      /* The previous owner died.  Try locking the mutex.  */
	      int newval = id;
#ifdef NO_INCR
	      newval |= FUTEX_WAITERS;
#else
	      newval |= (oldval & FUTEX_WAITERS);
#endif

	      newval
		= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
						       newval, oldval);

	      if (newval != oldval)
		{
		  oldval = newval;
		  goto again;
		}

	      /* We got the mutex.  */
	      mutex->__data.__count = 1;
	      /* But it is inconsistent unless marked otherwise.  */
	      mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;

	      ENQUEUE_MUTEX (mutex);
	      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);

	      /* Note that we deliberately exit here.  If we fall
		 through to the end of the function __nusers would be
		 incremented which is not correct because the old
		 owner has to be discounted.  If we are not supposed
		 to increment __nusers we actually have to decrement
		 it here.  */
#ifdef NO_INCR
	      --mutex->__data.__nusers;
#endif

	      return EOWNERDEAD;
	    }

	  /* Check whether we already hold the mutex.  */
	  if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
	    {
	      int kind = PTHREAD_MUTEX_TYPE (mutex);
	      if (kind == PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP)
		{
		  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
				 NULL);
		  return EDEADLK;
		}

	      if (kind == PTHREAD_MUTEX_ROBUST_RECURSIVE_NP)
		{
		  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
				 NULL);

		  /* Just bump the counter.  */
		  if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
		    /* Overflow of the counter.  */
		    return EAGAIN;

		  ++mutex->__data.__count;

		  return 0;
		}
	    }

	  oldval = LLL_ROBUST_MUTEX_LOCK (mutex, id);

	  if (__builtin_expect (mutex->__data.__owner
				== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
	    {
	      /* This mutex is now not recoverable.  */
	      mutex->__data.__count = 0;
	      lll_unlock (mutex->__data.__lock,
			  PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
	      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	      return ENOTRECOVERABLE;
	    }
	}
      while ((oldval & FUTEX_OWNER_DIED) != 0);

      mutex->__data.__count = 1;
      ENQUEUE_MUTEX (mutex);
      THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
      break;

    case PTHREAD_MUTEX_PI_RECURSIVE_NP:
    case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
    case PTHREAD_MUTEX_PI_NORMAL_NP:
    case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
    case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
    case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
    case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
    case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
      {
	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
	int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP;

	if (robust)
	  /* Note: robust PI futexes are signaled by setting bit 0.  */
	  THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
			 (void *) (((uintptr_t) &mutex->__data.__list.__next)
				   | 1));

	oldval = mutex->__data.__lock;

	/* Check whether we already hold the mutex.  */
	if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
	  {
	    if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
	      {
		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
		return EDEADLK;
	      }

	    if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
	      {
		THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);

		/* Just bump the counter.  */
		if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
		  /* Overflow of the counter.  */
		  return EAGAIN;

		++mutex->__data.__count;

		return 0;
	      }
	  }

	int newval = id;
#ifdef NO_INCR
	newval |= FUTEX_WAITERS;
#endif
	oldval = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
						      newval, 0);

	if (oldval != 0)
	  {
	    /* The mutex is locked.  The kernel will now take care of
	       everything.  */
	    int private = (robust
			   ? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
			   : PTHREAD_MUTEX_PSHARED (mutex));
	    INTERNAL_SYSCALL_DECL (__err);
	    int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
				      __lll_private_flag (FUTEX_LOCK_PI,
							  private), 1, 0);

	    if (INTERNAL_SYSCALL_ERROR_P (e, __err)
		&& (INTERNAL_SYSCALL_ERRNO (e, __err) == ESRCH
		    || INTERNAL_SYSCALL_ERRNO (e, __err) == EDEADLK))
	      {
		assert (INTERNAL_SYSCALL_ERRNO (e, __err) != EDEADLK
			|| (kind != PTHREAD_MUTEX_ERRORCHECK_NP
			    && kind != PTHREAD_MUTEX_RECURSIVE_NP));
		/* ESRCH can happen only for non-robust PI mutexes where
		   the owner of the lock died.  */
		assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust);

		/* Delay the thread indefinitely.  */
		while (1)
		  pause_not_cancel ();
	      }

	    oldval = mutex->__data.__lock;

	    assert (robust || (oldval & FUTEX_OWNER_DIED) == 0);
	  }

	if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
	  {
	    atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);

	    /* We got the mutex.  */
	    mutex->__data.__count = 1;
	    /* But it is inconsistent unless marked otherwise.  */
	    mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;

	    ENQUEUE_MUTEX_PI (mutex);
	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);

	    /* Note that we deliberately exit here.  If we fall
	       through to the end of the function __nusers would be
	       incremented which is not correct because the old owner
	       has to be discounted.  If we are not supposed to
	       increment __nusers we actually have to decrement it here.  */
#ifdef NO_INCR
	    --mutex->__data.__nusers;
#endif

	    return EOWNERDEAD;
	  }

	if (robust
	    && __builtin_expect (mutex->__data.__owner
				 == PTHREAD_MUTEX_NOTRECOVERABLE, 0))
	  {
	    /* This mutex is now not recoverable.  */
	    mutex->__data.__count = 0;

	    INTERNAL_SYSCALL_DECL (__err);
	    INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
			      __lll_private_flag (FUTEX_UNLOCK_PI,
						  PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
			      0, 0);

	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	    return ENOTRECOVERABLE;
	  }

	mutex->__data.__count = 1;
	if (robust)
	  {
	    ENQUEUE_MUTEX_PI (mutex);
	    THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	  }
      }
      break;

    case PTHREAD_MUTEX_PP_RECURSIVE_NP:
    case PTHREAD_MUTEX_PP_ERRORCHECK_NP:
    case PTHREAD_MUTEX_PP_NORMAL_NP:
    case PTHREAD_MUTEX_PP_ADAPTIVE_NP:
      {
	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;

	oldval = mutex->__data.__lock;

	/* Check whether we already hold the mutex.  */
	if (mutex->__data.__owner == id)
	  {
	    if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
	      return EDEADLK;

	    if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
	      {
		/* Just bump the counter.  */
		if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
		  /* Overflow of the counter.  */
		  return EAGAIN;

		++mutex->__data.__count;

		return 0;
	      }
	  }

	int oldprio = -1, ceilval;
	do
	  {
	    int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK)
			  >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;

	    if (__pthread_current_priority () > ceiling)
	      {
		if (oldprio != -1)
		  __pthread_tpp_change_priority (oldprio, -1);
		return EINVAL;
	      }

	    int retval = __pthread_tpp_change_priority (oldprio, ceiling);
	    if (retval)
	      return retval;

	    ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
	    oldprio = ceiling;

	    oldval
	      = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
#ifdef NO_INCR
						     ceilval | 2,
#else
						     ceilval | 1,
#endif
						     ceilval);

	    if (oldval == ceilval)
	      break;

	    do
	      {
		oldval
		  = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
							 ceilval | 2,
							 ceilval | 1);

		if ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval)
		  break;

		if (oldval != ceilval)
		  lll_futex_wait (&mutex->__data.__lock, ceilval | 2,
				  PTHREAD_MUTEX_PSHARED (mutex));
	      }
	    while (atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
							ceilval | 2, ceilval)
		   != ceilval);
	  }
	while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval);

	assert (mutex->__data.__owner == 0);
	mutex->__data.__count = 1;
      }
      break;

    default:
      /* Correct code cannot set any other type.  */
      return EINVAL;
    }

  /* Record the ownership.  */
  mutex->__data.__owner = id;
#ifndef NO_INCR
  ++mutex->__data.__nusers;
#endif

  LIBC_PROBE (mutex_acquired, 1, mutex);

  return 0;
}
#ifndef __pthread_mutex_lock
strong_alias (__pthread_mutex_lock, pthread_mutex_lock)
hidden_def (__pthread_mutex_lock)
#endif


#ifdef NO_INCR
void
__pthread_mutex_cond_lock_adjust (mutex)
     pthread_mutex_t *mutex;
{
  assert ((mutex->__data.__kind & PTHREAD_MUTEX_PRIO_INHERIT_NP) != 0);
  assert ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) == 0);
  assert ((mutex->__data.__kind & PTHREAD_MUTEX_PSHARED_BIT) == 0);

  /* Record the ownership.  */
  pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
  mutex->__data.__owner = id;

  if (mutex->__data.__kind == PTHREAD_MUTEX_PI_RECURSIVE_NP)
    ++mutex->__data.__count;
}
#endif
Commit	Line	Data
568035b7	1	/* Copyright (C) 2002-2013 Free Software Foundation, Inc.
76a50749 UD	2	This file is part of the GNU C Library.
	3	Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
76a50749	18
3892d906	19	#include <assert.h>
76a50749	20	#include <errno.h>
1bcfb5a5	21	#include <stdlib.h>
df47504c	22	#include <unistd.h>
b894c2ea	23	#include <not-cancel.h>
76a50749 UD	24	#include "pthreadP.h"
76a50749 UD	25	#include <lowlevellock.h>
5acf7263	26	#include <stap-probe.h>
76a50749	27
e8c659d7 AK	28	#ifndef lll_lock_elision
	29	#define lll_lock_elision(lock, try_lock, private) ({ \
	30	lll_lock (lock, private); 0; })
	31	#endif
	32
	33	#ifndef lll_trylock_elision
	34	#define lll_trylock_elision(a,t) lll_trylock(a)
	35	#endif
76a50749	36
69431c9a	37	#ifndef LLL_MUTEX_LOCK
5bd8a249 UD	38	# define LLL_MUTEX_LOCK(mutex) \
	39	lll_lock ((mutex)->__data.__lock, PTHREAD_MUTEX_PSHARED (mutex))
	40	# define LLL_MUTEX_TRYLOCK(mutex) \
	41	lll_trylock ((mutex)->__data.__lock)
	42	# define LLL_ROBUST_MUTEX_LOCK(mutex, id) \
	43	lll_robust_lock ((mutex)->__data.__lock, id, \
	44	PTHREAD_ROBUST_MUTEX_PSHARED (mutex))
e8c659d7 AK	45	# define LLL_MUTEX_LOCK_ELISION(mutex) \
	46	lll_lock_elision ((mutex)->__data.__lock, (mutex)->__data.__elision, \
	47	PTHREAD_MUTEX_PSHARED (mutex))
	48	# define LLL_MUTEX_TRYLOCK_ELISION(mutex) \
	49	lll_trylock_elision((mutex)->__data.__lock, (mutex)->__data.__elision, \
	50	PTHREAD_MUTEX_PSHARED (mutex))
69431c9a UD	51	#endif
69431c9a UD	52
e8c659d7 AK	53	#ifndef FORCE_ELISION
	54	#define FORCE_ELISION(m, s)
	55	#endif
69431c9a	56
6de79a49 UD	57	static int __pthread_mutex_lock_full (pthread_mutex_t *mutex)
	58	__attribute_noinline__;
	59
76a50749 UD	60	int
	61	__pthread_mutex_lock (mutex)
	62	pthread_mutex_t *mutex;
	63	{
2c0b891a UD	64	assert (sizeof (mutex->__size) >= sizeof (mutex->__data));
2c0b891a UD	65
e8c659d7	66	unsigned int type = PTHREAD_MUTEX_TYPE_ELISION (mutex);
5acf7263 RM	67
	68	LIBC_PROBE (mutex_entry, 1, mutex);
	69
e8c659d7 AK	70	if (__builtin_expect (type & ~(PTHREAD_MUTEX_KIND_MASK_NP
e8c659d7 AK	71	\| PTHREAD_MUTEX_ELISION_FLAGS_NP), 0))
6de79a49 UD	72	return __pthread_mutex_lock_full (mutex);
6de79a49 UD	73
e8c659d7	74	if (__builtin_expect (type == PTHREAD_MUTEX_TIMED_NP, 1))
6de79a49	75	{
e8c659d7	76	FORCE_ELISION (mutex, goto elision);
6de79a49 UD	77	simple:
	78	/* Normal mutex. */
	79	LLL_MUTEX_LOCK (mutex);
	80	assert (mutex->__data.__owner == 0);
	81	}
e8c659d7 AK	82	#ifdef HAVE_ELISION
	83	else if (__builtin_expect (type == PTHREAD_MUTEX_TIMED_ELISION_NP, 1))
	84	{
	85	elision: __attribute__((unused))
	86	/* This case can never happen on a system without elision,
	87	as the mutex type initialization functions will not
	88	allow to set the elision flags. */
	89	/* Don't record owner or users for elision case. This is a
	90	tail call. */
	91	return LLL_MUTEX_LOCK_ELISION (mutex);
	92	}
	93	#endif
	94	else if (__builtin_expect (PTHREAD_MUTEX_TYPE (mutex)
	95	== PTHREAD_MUTEX_RECURSIVE_NP, 1))
76a50749 UD	96	{
76a50749 UD	97	/* Recursive mutex. */
e8c659d7	98	pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
6de79a49	99
76a50749	100	/* Check whether we already hold the mutex. */
9a7178d6	101	if (mutex->__data.__owner == id)
76a50749 UD	102	{
	103	/* Just bump the counter. */
	104	if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
	105	/* Overflow of the counter. */
	106	return EAGAIN;
	107
	108	++mutex->__data.__count;
76a50749	109
3892d906	110	return 0;
76a50749	111	}
3892d906 UD	112
3892d906 UD	113	/* We have to get the mutex. */
5bd8a249	114	LLL_MUTEX_LOCK (mutex);
3892d906	115
1bcfb5a5	116	assert (mutex->__data.__owner == 0);
3892d906	117	mutex->__data.__count = 1;
6de79a49	118	}
e8c659d7 AK	119	else if (__builtin_expect (PTHREAD_MUTEX_TYPE (mutex)
e8c659d7 AK	120	== PTHREAD_MUTEX_ADAPTIVE_NP, 1))
6de79a49	121	{
2c0b891a UD	122	if (! __is_smp)
	123	goto simple;
	124
5bd8a249	125	if (LLL_MUTEX_TRYLOCK (mutex) != 0)
2c0b891a UD	126	{
	127	int cnt = 0;
	128	int max_cnt = MIN (MAX_ADAPTIVE_COUNT,
	129	mutex->__data.__spins * 2 + 10);
	130	do
	131	{
	132	if (cnt++ >= max_cnt)
	133	{
5bd8a249	134	LLL_MUTEX_LOCK (mutex);
2c0b891a UD	135	break;
	136	}
	137
	138	#ifdef BUSY_WAIT_NOP
	139	BUSY_WAIT_NOP;
	140	#endif
	141	}
5bd8a249	142	while (LLL_MUTEX_TRYLOCK (mutex) != 0);
2c0b891a UD	143
	144	mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
	145	}
1bcfb5a5	146	assert (mutex->__data.__owner == 0);
6de79a49 UD	147	}
	148	else
	149	{
e8c659d7 AK	150	pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
e8c659d7 AK	151	assert (PTHREAD_MUTEX_TYPE (mutex) == PTHREAD_MUTEX_ERRORCHECK_NP);
6de79a49 UD	152	/* Check whether we already hold the mutex. */
	153	if (__builtin_expect (mutex->__data.__owner == id, 0))
	154	return EDEADLK;
	155	goto simple;
	156	}
1bcfb5a5	157
e8c659d7 AK	158	pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
e8c659d7 AK	159
6de79a49 UD	160	/* Record the ownership. */
	161	mutex->__data.__owner = id;
	162	#ifndef NO_INCR
	163	++mutex->__data.__nusers;
	164	#endif
	165
5acf7263 RM	166	LIBC_PROBE (mutex_acquired, 1, mutex);
5acf7263 RM	167
6de79a49 UD	168	return 0;
	169	}
	170
	171	static int
	172	__pthread_mutex_lock_full (pthread_mutex_t *mutex)
	173	{
	174	int oldval;
	175	pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
	176
	177	switch (PTHREAD_MUTEX_TYPE (mutex))
	178	{
0f6699ea UD	179	case PTHREAD_MUTEX_ROBUST_RECURSIVE_NP:
	180	case PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP:
	181	case PTHREAD_MUTEX_ROBUST_NORMAL_NP:
	182	case PTHREAD_MUTEX_ROBUST_ADAPTIVE_NP:
	183	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
	184	&mutex->__data.__list.__next);
	185
683040c3 UD	186	oldval = mutex->__data.__lock;
683040c3 UD	187	do
1bcfb5a5	188	{
0f6699ea	189	again:
683040c3 UD	190	if ((oldval & FUTEX_OWNER_DIED) != 0)
	191	{
	192	/* The previous owner died. Try locking the mutex. */
0f6699ea UD	193	int newval = id;
	194	#ifdef NO_INCR
	195	newval \|= FUTEX_WAITERS;
113ad5fc UD	196	#else
113ad5fc UD	197	newval \|= (oldval & FUTEX_WAITERS);
0f6699ea UD	198	#endif
	199
	200	newval
052757bf	201	= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
0f6699ea UD	202	newval, oldval);
	203
	204	if (newval != oldval)
683040c3	205	{
683040c3	206	oldval = newval;
0f6699ea	207	goto again;
683040c3	208	}
1bcfb5a5	209
683040c3 UD	210	/* We got the mutex. */
	211	mutex->__data.__count = 1;
	212	/* But it is inconsistent unless marked otherwise. */
	213	mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
	214
	215	ENQUEUE_MUTEX (mutex);
0f6699ea	216	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
683040c3 UD	217
	218	/* Note that we deliberately exit here. If we fall
	219	through to the end of the function __nusers would be
	220	incremented which is not correct because the old
	221	owner has to be discounted. If we are not supposed
	222	to increment __nusers we actually have to decrement
	223	it here. */
	224	#ifdef NO_INCR
	225	--mutex->__data.__nusers;
	226	#endif
1bcfb5a5	227
683040c3 UD	228	return EOWNERDEAD;
683040c3 UD	229	}
1bcfb5a5	230
683040c3	231	/* Check whether we already hold the mutex. */
0f6699ea	232	if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
683040c3	233	{
5bd8a249 UD	234	int kind = PTHREAD_MUTEX_TYPE (mutex);
5bd8a249 UD	235	if (kind == PTHREAD_MUTEX_ROBUST_ERRORCHECK_NP)
0f6699ea UD	236	{
	237	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
	238	NULL);
	239	return EDEADLK;
	240	}
1bcfb5a5	241
5bd8a249	242	if (kind == PTHREAD_MUTEX_ROBUST_RECURSIVE_NP)
683040c3	243	{
0f6699ea UD	244	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
	245	NULL);
	246
683040c3 UD	247	/* Just bump the counter. */
	248	if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
	249	/* Overflow of the counter. */
	250	return EAGAIN;
1bcfb5a5	251
683040c3	252	++mutex->__data.__count;
1bcfb5a5	253
683040c3 UD	254	return 0;
	255	}
	256	}
1bcfb5a5	257
5bd8a249	258	oldval = LLL_ROBUST_MUTEX_LOCK (mutex, id);
1bcfb5a5	259
683040c3 UD	260	if (__builtin_expect (mutex->__data.__owner
	261	== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
	262	{
	263	/* This mutex is now not recoverable. */
	264	mutex->__data.__count = 0;
5bd8a249 UD	265	lll_unlock (mutex->__data.__lock,
5bd8a249 UD	266	PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
0f6699ea	267	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
683040c3 UD	268	return ENOTRECOVERABLE;
683040c3 UD	269	}
1bcfb5a5	270	}
683040c3	271	while ((oldval & FUTEX_OWNER_DIED) != 0);
1bcfb5a5	272
683040c3	273	mutex->__data.__count = 1;
1bcfb5a5	274	ENQUEUE_MUTEX (mutex);
0f6699ea	275	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
2c0b891a	276	break;
dcc73a8d	277
df47504c UD	278	case PTHREAD_MUTEX_PI_RECURSIVE_NP:
	279	case PTHREAD_MUTEX_PI_ERRORCHECK_NP:
	280	case PTHREAD_MUTEX_PI_NORMAL_NP:
	281	case PTHREAD_MUTEX_PI_ADAPTIVE_NP:
	282	case PTHREAD_MUTEX_PI_ROBUST_RECURSIVE_NP:
	283	case PTHREAD_MUTEX_PI_ROBUST_ERRORCHECK_NP:
	284	case PTHREAD_MUTEX_PI_ROBUST_NORMAL_NP:
	285	case PTHREAD_MUTEX_PI_ROBUST_ADAPTIVE_NP:
	286	{
	287	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
	288	int robust = mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP;
	289
	290	if (robust)
	291	/* Note: robust PI futexes are signaled by setting bit 0. */
	292	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending,
	293	(void *) (((uintptr_t) &mutex->__data.__list.__next)
	294	\| 1));
	295
	296	oldval = mutex->__data.__lock;
	297
	298	/* Check whether we already hold the mutex. */
	299	if (__builtin_expect ((oldval & FUTEX_TID_MASK) == id, 0))
	300	{
	301	if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
	302	{
	303	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	304	return EDEADLK;
	305	}
	306
	307	if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
	308	{
	309	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	310
	311	/* Just bump the counter. */
	312	if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
	313	/* Overflow of the counter. */
	314	return EAGAIN;
	315
	316	++mutex->__data.__count;
	317
	318	return 0;
	319	}
	320	}
	321
	322	int newval = id;
	323	#ifdef NO_INCR
	324	newval \|= FUTEX_WAITERS;
	325	#endif
052757bf	326	oldval = atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
df47504c UD	327	newval, 0);
	328
	329	if (oldval != 0)
	330	{
	331	/* The mutex is locked. The kernel will now take care of
	332	everything. */
efac1fce UD	333	int private = (robust
	334	? PTHREAD_ROBUST_MUTEX_PSHARED (mutex)
	335	: PTHREAD_MUTEX_PSHARED (mutex));
df47504c UD	336	INTERNAL_SYSCALL_DECL (__err);
df47504c UD	337	int e = INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
efac1fce UD	338	__lll_private_flag (FUTEX_LOCK_PI,
efac1fce UD	339	private), 1, 0);
df47504c UD	340
	341	if (INTERNAL_SYSCALL_ERROR_P (e, __err)
	342	&& (INTERNAL_SYSCALL_ERRNO (e, __err) == ESRCH
	343	\|\| INTERNAL_SYSCALL_ERRNO (e, __err) == EDEADLK))
	344	{
	345	assert (INTERNAL_SYSCALL_ERRNO (e, __err) != EDEADLK
	346	\|\| (kind != PTHREAD_MUTEX_ERRORCHECK_NP
	347	&& kind != PTHREAD_MUTEX_RECURSIVE_NP));
	348	/* ESRCH can happen only for non-robust PI mutexes where
	349	the owner of the lock died. */
	350	assert (INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH \|\| !robust);
	351
	352	/* Delay the thread indefinitely. */
	353	while (1)
b894c2ea	354	pause_not_cancel ();
df47504c UD	355	}
	356
	357	oldval = mutex->__data.__lock;
	358
	359	assert (robust \|\| (oldval & FUTEX_OWNER_DIED) == 0);
	360	}
	361
	362	if (__builtin_expect (oldval & FUTEX_OWNER_DIED, 0))
	363	{
	364	atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
	365
	366	/* We got the mutex. */
	367	mutex->__data.__count = 1;
	368	/* But it is inconsistent unless marked otherwise. */
	369	mutex->__data.__owner = PTHREAD_MUTEX_INCONSISTENT;
	370
	371	ENQUEUE_MUTEX_PI (mutex);
	372	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	373
	374	/* Note that we deliberately exit here. If we fall
	375	through to the end of the function __nusers would be
	376	incremented which is not correct because the old owner
	377	has to be discounted. If we are not supposed to
	378	increment __nusers we actually have to decrement it here. */
	379	#ifdef NO_INCR
	380	--mutex->__data.__nusers;
	381	#endif
	382
	383	return EOWNERDEAD;
	384	}
	385
	386	if (robust
	387	&& __builtin_expect (mutex->__data.__owner
	388	== PTHREAD_MUTEX_NOTRECOVERABLE, 0))
	389	{
	390	/* This mutex is now not recoverable. */
	391	mutex->__data.__count = 0;
	392
	393	INTERNAL_SYSCALL_DECL (__err);
	394	INTERNAL_SYSCALL (futex, __err, 4, &mutex->__data.__lock,
efac1fce	395	__lll_private_flag (FUTEX_UNLOCK_PI,
6de79a49	396	PTHREAD_ROBUST_MUTEX_PSHARED (mutex)),
efac1fce	397	0, 0);
df47504c UD	398
	399	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	400	return ENOTRECOVERABLE;
	401	}
	402
	403	mutex->__data.__count = 1;
	404	if (robust)
	405	{
	406	ENQUEUE_MUTEX_PI (mutex);
	407	THREAD_SETMEM (THREAD_SELF, robust_head.list_op_pending, NULL);
	408	}
	409	}
	410	break;
	411
f17efcb4 UD	412	case PTHREAD_MUTEX_PP_RECURSIVE_NP:
	413	case PTHREAD_MUTEX_PP_ERRORCHECK_NP:
	414	case PTHREAD_MUTEX_PP_NORMAL_NP:
	415	case PTHREAD_MUTEX_PP_ADAPTIVE_NP:
	416	{
	417	int kind = mutex->__data.__kind & PTHREAD_MUTEX_KIND_MASK_NP;
	418
	419	oldval = mutex->__data.__lock;
	420
	421	/* Check whether we already hold the mutex. */
	422	if (mutex->__data.__owner == id)
	423	{
	424	if (kind == PTHREAD_MUTEX_ERRORCHECK_NP)
	425	return EDEADLK;
	426
	427	if (kind == PTHREAD_MUTEX_RECURSIVE_NP)
	428	{
	429	/* Just bump the counter. */
	430	if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
	431	/* Overflow of the counter. */
	432	return EAGAIN;
	433
	434	++mutex->__data.__count;
	435
	436	return 0;
	437	}
	438	}
	439
	440	int oldprio = -1, ceilval;
	441	do
	442	{
	443	int ceiling = (oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK)
	444	>> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
	445
	446	if (__pthread_current_priority () > ceiling)
	447	{
	448	if (oldprio != -1)
	449	__pthread_tpp_change_priority (oldprio, -1);
	450	return EINVAL;
	451	}
	452
6de79a49	453	int retval = __pthread_tpp_change_priority (oldprio, ceiling);
f17efcb4 UD	454	if (retval)
	455	return retval;
	456
	457	ceilval = ceiling << PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
	458	oldprio = ceiling;
	459
	460	oldval
052757bf	461	= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
f17efcb4 UD	462	#ifdef NO_INCR
	463	ceilval \| 2,
	464	#else
	465	ceilval \| 1,
	466	#endif
	467	ceilval);
	468
	469	if (oldval == ceilval)
	470	break;
	471
	472	do
	473	{
	474	oldval
052757bf	475	= atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
f17efcb4 UD	476	ceilval \| 2,
	477	ceilval \| 1);
	478
	479	if ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval)
	480	break;
	481
	482	if (oldval != ceilval)
835abc5c	483	lll_futex_wait (&mutex->__data.__lock, ceilval \| 2,
5bd8a249	484	PTHREAD_MUTEX_PSHARED (mutex));
f17efcb4	485	}
052757bf	486	while (atomic_compare_and_exchange_val_acq (&mutex->__data.__lock,
f17efcb4 UD	487	ceilval \| 2, ceilval)
	488	!= ceilval);
	489	}
	490	while ((oldval & PTHREAD_MUTEX_PRIO_CEILING_MASK) != ceilval);
	491
	492	assert (mutex->__data.__owner == 0);
	493	mutex->__data.__count = 1;
	494	}
	495	break;
	496
dcc73a8d UD	497	default:
	498	/* Correct code cannot set any other type. */
	499	return EINVAL;
76a50749 UD	500	}
76a50749 UD	501
3892d906	502	/* Record the ownership. */
3892d906 UD	503	mutex->__data.__owner = id;
	504	#ifndef NO_INCR
	505	++mutex->__data.__nusers;
	506	#endif
	507
5acf7263 RM	508	LIBC_PROBE (mutex_acquired, 1, mutex);
5acf7263 RM	509
6de79a49	510	return 0;
76a50749	511	}
69431c9a	512	#ifndef __pthread_mutex_lock
76a50749	513	strong_alias (__pthread_mutex_lock, pthread_mutex_lock)
4d17e683	514	hidden_def (__pthread_mutex_lock)
69431c9a	515	#endif
b0948ffd UD	516
	517
	518	#ifdef NO_INCR
	519	void
	520	__pthread_mutex_cond_lock_adjust (mutex)
	521	pthread_mutex_t *mutex;
	522	{
	523	assert ((mutex->__data.__kind & PTHREAD_MUTEX_PRIO_INHERIT_NP) != 0);
	524	assert ((mutex->__data.__kind & PTHREAD_MUTEX_ROBUST_NORMAL_NP) == 0);
	525	assert ((mutex->__data.__kind & PTHREAD_MUTEX_PSHARED_BIT) == 0);
	526
	527	/* Record the ownership. */
	528	pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
	529	mutex->__data.__owner = id;
	530
	531	if (mutex->__data.__kind == PTHREAD_MUTEX_PI_RECURSIVE_NP)
	532	++mutex->__data.__count;
	533	}
	534	#endif