1 /* Basic platform-independent macro definitions for mutexes,

     2    thread-specific data and parameters for malloc.

     3    Posix threads (pthreads) version.

     4    Copyright (C) 2004 Wolfram Gloger <wg@malloc.de>.

     5 

     6 Permission to use, copy, modify, distribute, and sell this software

     7 and its documentation for any purpose is hereby granted without fee,

     8 provided that (i) the above copyright notices and this permission

     9 notice appear in all copies of the software and related documentation,

    10 and (ii) the name of Wolfram Gloger may not be used in any advertising

    11 or publicity relating to the software.

    12 

    13 THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,

    14 EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY

    15 WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

    16 

    17 IN NO EVENT SHALL WOLFRAM GLOGER BE LIABLE FOR ANY SPECIAL,

    18 INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY

    19 DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

    20 WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY

    21 OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR

    22 PERFORMANCE OF THIS SOFTWARE.

    23 */

    24 

    25 #ifndef _PTHREAD_MALLOC_MACHINE_H

    26 #define _PTHREAD_MALLOC_MACHINE_H

    27 

    28 #include <pthread.h>

    29 

    30 #undef thread_atfork_static

    31 

    32 /* Use fast inline spinlocks with gcc.  */

    33 #if (defined __i386__ || defined __x86_64__) && defined __GNUC__ && \

    34     !defined USE_NO_SPINLOCKS

    35 

    36 #include <time.h>

    37 #include <sched.h>

    38 

    39 typedef struct {

    40   volatile unsigned int lock;

    41   int pad0_;

    42 } mutex_t;

    43 

    44 #define MUTEX_INITIALIZER          { 0 }

    45 #define mutex_init(m)              ((m)->lock = 0)

    46 static inline int mutex_lock(mutex_t *m) {

    47   int cnt = 0, r;

    48   struct timespec tm;

    49 

    50   for(;;) {

    51     __asm__ __volatile__

    52       ("xchgl %0, %1"

    53        : "=r"(r), "=m"(m->lock)

    54        : "0"(1), "m"(m->lock)

    55        : "memory");

    56     if(!r)

    57       return 0;

    58     if(cnt < 50) {

    59       sched_yield();

    60       cnt++;

    61     } else {

    62       tm.tv_sec = 0;

    63       tm.tv_nsec = 2000001;

    64       nanosleep(&tm, NULL);

    65       cnt = 0;

    66     }

    67   }

    68 }

    69 static inline int mutex_trylock(mutex_t *m) {

    70   int r;

    71 

    72   __asm__ __volatile__

    73     ("xchgl %0, %1"

    74      : "=r"(r), "=m"(m->lock)

    75      : "0"(1), "m"(m->lock)

    76      : "memory");

    77   return r;

    78 }

    79 static inline int mutex_unlock(mutex_t *m) {

    80   __asm__ __volatile__ ("movl %1, %0" : "=m" (m->lock) : "g"(0) : "memory");

    81   return 0;

    82 }

    83 

    84 #else

    85 

    86 /* Normal pthread mutex.  */

    87 typedef pthread_mutex_t mutex_t;

    88 

    89 #define MUTEX_INITIALIZER          PTHREAD_MUTEX_INITIALIZER

    90 #define mutex_init(m)              pthread_mutex_init(m, NULL)

    91 #define mutex_lock(m)              pthread_mutex_lock(m)

    92 #define mutex_trylock(m)           pthread_mutex_trylock(m)

    93 #define mutex_unlock(m)            pthread_mutex_unlock(m)

    94 

    95 #endif /* (__i386__ || __x86_64__) && __GNUC__ && !USE_NO_SPINLOCKS */

    96 

    97 /* thread specific data */

    98 #if defined(__sgi) || defined(USE_TSD_DATA_HACK)

    99 

   100 /* Hack for thread-specific data, e.g. on Irix 6.x.  We can't use

   101    pthread_setspecific because that function calls malloc() itself.

   102    The hack only works when pthread_t can be converted to an integral

   103    type. */

   104 

   105 typedef void *tsd_key_t[256];

   106 #define tsd_key_create(key, destr) do { \

   107   int i; \

   108   for(i=0; i<256; i++) (*key)[i] = 0; \

   109 } while(0)

   110 #define tsd_setspecific(key, data) \

   111  (key[(unsigned)pthread_self() % 256] = (data))

   112 #define tsd_getspecific(key, vptr) \

   113  (vptr = key[(unsigned)pthread_self() % 256])

   114 

   115 #else

   116 

   117 typedef pthread_key_t tsd_key_t;

   118 

   119 #define tsd_key_create(key, destr) pthread_key_create(key, destr)

   120 #define tsd_setspecific(key, data) pthread_setspecific(key, data)

   121 #define tsd_getspecific(key, vptr) (vptr = pthread_getspecific(key))

   122 

   123 #endif

   124 

   125 /* at fork */

   126 #define thread_atfork(prepare, parent, child) \

   127                                    pthread_atfork(prepare, parent, child)

   128 

   129 #include <sysdeps/generic/malloc-machine.h>

   130 

   131 #endif /* !defined(_MALLOC_MACHINE_H) */