Subversion Repositories HelenOS

Rev

Rev 2131 | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  1. /*
  2.  * Copyright (c) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup sync
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #ifndef KERN_SPINLOCK_H_
  36. #define KERN_SPINLOCK_H_
  37.  
  38. #include <arch/types.h>
  39. #include <preemption.h>
  40. #include <atomic.h>
  41. #include <debug.h>
  42.  
  43. #ifdef CONFIG_SMP
  44. typedef struct {
  45. #ifdef CONFIG_DEBUG_SPINLOCK
  46.     char *name;
  47. #endif
  48.     atomic_t val;
  49. } spinlock_t;
  50.  
  51. /*
  52.  * SPINLOCK_DECLARE is to be used for dynamically allocated spinlocks,
  53.  * where the lock gets initialized in run time.
  54.  */
  55. #define SPINLOCK_DECLARE(slname)    spinlock_t slname
  56. #define SPINLOCK_EXTERN(slname)     extern spinlock_t slname
  57.  
  58. /*
  59.  * SPINLOCK_INITIALIZE is to be used for statically allocated spinlocks.
  60.  * It declares and initializes the lock.
  61.  */
  62. #ifdef CONFIG_DEBUG_SPINLOCK
  63. #define SPINLOCK_INITIALIZE(slname)     \
  64.     spinlock_t slname = {       \
  65.         .name = #slname,    \
  66.         .val = { 0 }        \
  67.     }
  68. #else
  69. #define SPINLOCK_INITIALIZE(slname)     \
  70.     spinlock_t slname = {       \
  71.         .val = { 0 }        \
  72.     }
  73. #endif
  74.  
  75. extern void spinlock_initialize(spinlock_t *sl, char *name);
  76. extern int spinlock_trylock(spinlock_t *sl);
  77. extern void spinlock_lock_debug(spinlock_t *sl);
  78.  
  79. #ifdef CONFIG_DEBUG_SPINLOCK
  80. #  define spinlock_lock(x) spinlock_lock_debug(x)
  81. #else
  82. #  define spinlock_lock(x) atomic_lock_arch(&(x)->val)
  83. #endif
  84.  
  85. /** Unlock spinlock
  86.  *
  87.  * Unlock spinlock.
  88.  *
  89.  * @param sl Pointer to spinlock_t structure.
  90.  */
  91. static inline void spinlock_unlock(spinlock_t *sl)
  92. {
  93.     ASSERT(atomic_get(&sl->val) != 0);
  94.  
  95.     /*
  96.      * Prevent critical section code from bleeding out this way down.
  97.      */
  98.     CS_LEAVE_BARRIER();
  99.    
  100.     atomic_set(&sl->val, 0);
  101.     preemption_enable();
  102. }
  103.  
  104. #ifdef CONFIG_DEBUG_SPINLOCK
  105.  
  106. extern int printf(const char *, ...);
  107.  
  108. #define DEADLOCK_THRESHOLD      100000000
  109. #define DEADLOCK_PROBE_INIT(pname)  count_t pname = 0
  110. #define DEADLOCK_PROBE(pname, value)                    \
  111.     if ((pname)++ > (value)) {                  \
  112.         (pname) = 0;                        \
  113.         printf("Deadlock probe %s: exceeded threshold %d\n",    \
  114.             "cpu%d: function=%s, line=%d\n",            \
  115.             #pname, (value), CPU->id, __FUNCTION__, __LINE__);  \
  116.     }
  117. #else
  118. #define DEADLOCK_PROBE_INIT(pname)
  119. #define DEADLOCK_PROBE(pname, value)
  120. #endif
  121.  
  122. #else
  123.  
  124. /* On UP systems, spinlocks are effectively left out. */
  125. #define SPINLOCK_DECLARE(name)
  126. #define SPINLOCK_EXTERN(name)
  127. #define SPINLOCK_INITIALIZE(name)
  128.  
  129. #define spinlock_initialize(x, name)
  130. #define spinlock_lock(x)        preemption_disable()
  131. #define spinlock_trylock(x)         (preemption_disable(), 1)
  132. #define spinlock_unlock(x)      preemption_enable()
  133.  
  134. #define DEADLOCK_PROBE_INIT(pname)
  135. #define DEADLOCK_PROBE(pname, value)
  136.  
  137. #endif
  138.  
  139. #endif
  140.  
  141. /** @}
  142.  */
  143.