1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11 
  12 /*
  13  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  14  * Copyright 2017 RackTop Systems.
  15  */
  16 
  17 /*
  18  * mutex(9f)
  19  */
  20 
  21 /* This is the API we're emulating */
  22 #include <sys/mutex.h>
  23 
  24 #include <sys/errno.h>
  25 #include <sys/debug.h>
  26 #include <sys/thread.h>
  27 
  28 int     _lwp_mutex_lock(lwp_mutex_t *);
  29 int     _lwp_mutex_unlock(lwp_mutex_t *);
  30 int     _lwp_mutex_trylock(lwp_mutex_t *);
  31 
  32 extern clock_t ddi_get_lbolt(void);
  33 extern void clock2ts(clock_t, timespec_t *);
  34 
  35 static const lwp_mutex_t default_mutex =
  36         {{0, 0, 0, {USYNC_THREAD}, _MUTEX_MAGIC},
  37         {{{0, 0, 0, 0, 0, 0, 0, 0}}}, 0};
  38 
  39 /* ARGSUSED */
  40 void
  41 kmutex_init(kmutex_t *mp, char *name, kmutex_type_t typ, void *arg)
  42 {
  43         mp->m_lock = default_mutex;
  44         mp->m_owner = _KTHREAD_INVALID;
  45 }
  46 
  47 /* ARGSUSED */
  48 void
  49 kmutex_destroy(kmutex_t *mp)
  50 {
  51         mp->m_owner = _KTHREAD_INVALID;
  52 }
  53 
  54 void
  55 kmutex_enter(kmutex_t *mp)
  56 {
  57         VERIFY(0 == _lwp_mutex_lock(&mp->m_lock));
  58         mp->m_owner = _curthread();
  59 }
  60 
  61 int
  62 mutex_tryenter(kmutex_t *mp)
  63 {
  64         int rc;
  65 
  66         rc = _lwp_mutex_trylock(&mp->m_lock);
  67         if (rc == 0) {
  68                 mp->m_owner = _curthread();
  69                 return (1);
  70         }
  71         return (0);
  72 }
  73 
  74 void
  75 kmutex_exit(kmutex_t *mp)
  76 {
  77         ASSERT(mp->m_owner == _curthread());
  78         mp->m_owner = _KTHREAD_INVALID;
  79         (void) _lwp_mutex_unlock(&mp->m_lock);
  80 }
  81 
  82 /*
  83  * Returns the kthread_t * of the owner.
  84  */
  85 void *
  86 mutex_owner(const kmutex_t *mp)
  87 {
  88         return (mp->m_owner);
  89 }
  90 
  91 int
  92 mutex_owned(const kmutex_t *mp)
  93 {
  94         void *t = _curthread();
  95         return (t == mp->m_owner);
  96 }