sysdeps/nptl/internaltypes.h

   1 /* Copyright (C) 2002-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _INTERNALTYPES_H
  19 #define _INTERNALTYPES_H        1
  20
  21 #include <stdint.h>
  22 #include <atomic.h>
  23 #include <endian.h>
  24
  25
  26 struct pthread_attr
  27 {
  28   /* Scheduler parameters and priority.  */
  29   struct sched_param schedparam;
  30   int schedpolicy;
  31   /* Various flags like detachstate, scope, etc.  */
  32   int flags;
  33   /* Size of guard area.  */
  34   size_t guardsize;
  35   /* Stack handling.  */
  36   void *stackaddr;
  37   size_t stacksize;
  38
  39   /* Allocated via a call to __pthread_attr_extension once needed.  */
  40   struct pthread_attr_extension *extension;
  41   void *unused;
  42 };
  43
  44 #define ATTR_FLAG_DETACHSTATE           0x0001
  45 #define ATTR_FLAG_NOTINHERITSCHED       0x0002
  46 #define ATTR_FLAG_SCOPEPROCESS          0x0004
  47 #define ATTR_FLAG_STACKADDR             0x0008
  48 #define ATTR_FLAG_OLDATTR               0x0010
  49 #define ATTR_FLAG_SCHED_SET             0x0020
  50 #define ATTR_FLAG_POLICY_SET            0x0040
  51 #define ATTR_FLAG_DO_RSEQ               0x0080
  52
  53 /* Used to allocate a pthread_attr_t object which is also accessed
  54    internally.  */
  55 union pthread_attr_transparent
  56 {
  57   pthread_attr_t external;
  58   struct pthread_attr internal;
  59 };
  60
  61 /* Extension space for pthread attributes.  Referenced by the
  62    extension member of struct pthread_attr.  */
  63 struct pthread_attr_extension
  64 {
  65   /* Affinity map.  */
  66   cpu_set_t *cpuset;
  67   size_t cpusetsize;
  68
  69   sigset_t sigmask;
  70   bool sigmask_set;
  71 };
  72
  73 /* Mutex attribute data structure.  */
  74 struct pthread_mutexattr
  75 {
  76   /* Identifier for the kind of mutex.
  77
  78      Bit 31 is set if the mutex is to be shared between processes.
  79
  80      Bit 0 to 30 contain one of the PTHREAD_MUTEX_ values to identify
  81      the type of the mutex.  */
  82   int mutexkind;
  83 };
  84
  85
  86 /* Conditional variable attribute data structure.  */
  87 struct pthread_condattr
  88 {
  89   /* Combination of values:
  90
  91      Bit 0                : flag whether conditional variable will be
  92                             sharable between processes.
  93      Bit 1-COND_CLOCK_BITS: Clock ID.  COND_CLOCK_BITS is the number of bits
  94                             needed to represent the ID of the clock.  */
  95   int value;
  96 };
  97 #define COND_CLOCK_BITS 1
  98
  99
 100 /* Read-write lock variable attribute data structure.  */
 101 struct pthread_rwlockattr
 102 {
 103   int lockkind;
 104   int pshared;
 105 };
 106
 107
 108 /* Barrier data structure.  See pthread_barrier_wait for a description
 109    of how these fields are used.  */
 110 struct pthread_barrier
 111 {
 112   unsigned int in;
 113   unsigned int current_round;
 114   unsigned int count;
 115   int shared;
 116   unsigned int out;
 117 };
 118 /* See pthread_barrier_wait for a description.  */
 119 #define BARRIER_IN_THRESHOLD (UINT_MAX/2)
 120
 121
 122 /* Barrier variable attribute data structure.  */
 123 struct pthread_barrierattr
 124 {
 125   int pshared;
 126 };
 127
 128
 129 /* Thread-local data handling.  */
 130 struct pthread_key_struct
 131 {
 132   /* Sequence numbers.  Even numbers indicated vacant entries.  Note
 133      that zero is even.  We use uintptr_t to not require padding on
 134      32- and 64-bit machines.  On 64-bit machines it helps to avoid
 135      wrapping, too.  */
 136   uintptr_t seq;
 137
 138   /* Destructor for the data.  */
 139   void (*destr) (void *);
 140 };
 141
 142 /* Check whether an entry is unused.  */
 143 #define KEY_UNUSED(p) (((p) & 1) == 0)
 144 /* Check whether a key is usable.  We cannot reuse an allocated key if
 145    the sequence counter would overflow after the next destroy call.
 146    This would mean that we potentially free memory for a key with the
 147    same sequence.  This is *very* unlikely to happen, A program would
 148    have to create and destroy a key 2^31 times (on 32-bit platforms,
 149    on 64-bit platforms that would be 2^63).  If it should happen we
 150    simply don't use this specific key anymore.  */
 151 #define KEY_USABLE(p) (((uintptr_t) (p)) < ((uintptr_t) ((p) + 2)))
 152
 153
 154 /* Handling of read-write lock data.  */
 155 // XXX For now there is only one flag.  Maybe more in future.
 156 #define RWLOCK_RECURSIVE(rwlock) ((rwlock)->__data.__flags != 0)
 157
 158
 159 /* Semaphore variable structure.  */
 160 struct new_sem
 161 {
 162 #if __HAVE_64B_ATOMICS
 163   /* The data field holds both value (in the least-significant 32 bits) and
 164      nwaiters.  */
 165 # if __BYTE_ORDER == __LITTLE_ENDIAN
 166 #  define SEM_VALUE_OFFSET 0
 167 # elif __BYTE_ORDER == __BIG_ENDIAN
 168 #  define SEM_VALUE_OFFSET 1
 169 # else
 170 # error Unsupported byte order.
 171 # endif
 172 # define SEM_NWAITERS_SHIFT 32
 173 # define SEM_VALUE_MASK (~(unsigned int)0)
 174   uint64_t data;
 175   int private;
 176   int pad;
 177 #else
 178 # define SEM_VALUE_SHIFT 1
 179 # define SEM_NWAITERS_MASK ((unsigned int)1)
 180   unsigned int value;
 181   int private;
 182   int pad;
 183   unsigned int nwaiters;
 184 #endif
 185 };
 186
 187 struct old_sem
 188 {
 189   unsigned int value;
 190 };
 191
 192
 193 /* Compatibility type for old conditional variable interfaces.  */
 194 typedef struct
 195 {
 196   pthread_cond_t *cond;
 197 } pthread_cond_2_0_t;
 198
 199 #endif  /* internaltypes.h */