nptl/descr.h

   1 /* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   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
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _DESCR_H
  21 #define _DESCR_H        1
  22
  23 #include <limits.h>
  24 #include <sched.h>
  25 #include <setjmp.h>
  26 #include <stdbool.h>
  27 #include <sys/types.h>
  28 #include <hp-timing.h>
  29 #include <list.h>
  30 #include <lowlevellock.h>
  31 #include <pthreaddef.h>
  32 #include <dl-sysdep.h>
  33 #include "../nptl_db/thread_db.h"
  34 #include <tls.h>
  35
  36
  37 #ifndef TCB_ALIGNMENT
  38 # define TCB_ALIGNMENT  sizeof (double)
  39 #endif
  40
  41
  42 /* We keep thread specific data in a special data structure, a two-level
  43    array.  The top-level array contains pointers to dynamically allocated
  44    arrays of a certain number of data pointers.  So we can implement a
  45    sparse array.  Each dynamic second-level array has
  46         PTHREAD_KEY_2NDLEVEL_SIZE
  47    entries.  This value shouldn't be too large.  */
  48 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  49
  50 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  51    keys in each subarray.  */
  52 #define PTHREAD_KEY_1STLEVEL_SIZE \
  53   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  54    / PTHREAD_KEY_2NDLEVEL_SIZE)
  55
  56
  57 /* Thread descriptor data structure.  */
  58 struct pthread
  59 {
  60   union
  61   {
  62 #if !TLS_DTV_AT_TP
  63     /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
  64     tcbhead_t header;
  65 #elif TLS_MULTIPLE_THREADS_IN_TCB
  66     struct
  67     {
  68       int multiple_threads;
  69     } header;
  70 #endif
  71
  72     /* This extra padding has no special purpose, and this structure layout
  73        is private and subject to change without affecting the official ABI.
  74        We just have it here in case it might be convenient for some
  75        implementation-specific instrumentation hack or suchlike.  */
  76     void *__padding[16];
  77   };
  78
  79   /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
  80   list_t list;
  81
  82   /* Thread ID - which is also a 'is this thread descriptor (and
  83      therefore stack) used' flag.  */
  84   pid_t tid;
  85
  86   /* List of cleanup buffers.  */
  87   struct _pthread_cleanup_buffer *cleanup;
  88
  89   /* True if events must be reported.  */
  90   bool report_events;
  91
  92   /* We allocate one block of references here.  This should be enough
  93      to avoid allocating any memory dynamically for most applications.  */
  94   struct pthread_key_data
  95   {
  96     /* Sequence number.  We use uintptr_t to not require padding on
  97        32- and 64-bit machines.  On 64-bit machines it helps to avoid
  98        wrapping, too.  */
  99     uintptr_t seq;
 100
 101     /* Data pointer.  */
 102     void *data;
 103   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 104
 105   /* Flag which is set when specific data is set.  */
 106   bool specific_used;
 107
 108   /* Two-level array for the thread-specific data.  */
 109   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 110
 111   /* True if the user provided the stack.  */
 112   bool user_stack;
 113
 114   /* Lock to synchronize access to the descriptor.  */
 115   lll_lock_t lock;
 116
 117 #if HP_TIMING_AVAIL
 118   /* Offset of the CPU clock at start thread start time.  */
 119   hp_timing_t cpuclock_offset;
 120 #endif
 121
 122   /* If the thread waits to join another one the ID of the latter is
 123      stored here.
 124
 125      In case a thread is detached this field contains a pointer of the
 126      TCB if the thread itself.  This is something which cannot happen
 127      in normal operation.  */
 128   struct pthread *joinid;
 129   /* Check whether a thread is detached.  */
 130 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 131
 132   /* Flags determining processing of cancellation.  */
 133   int cancelhandling;
 134   /* Bit set if cancellation is disabled.  */
 135 #define CANCELSTATE_BIT         0
 136 #define CANCELSTATE_BITMASK     0x01
 137   /* Bit set if asynchronous cancellation mode is selected.  */
 138 #define CANCELTYPE_BIT          1
 139 #define CANCELTYPE_BITMASK      0x02
 140   /* Bit set if canceling has been initiated.  */
 141 #define CANCELING_BIT           2
 142 #define CANCELING_BITMASK       0x04
 143   /* Bit set if canceled.  */
 144 #define CANCELED_BIT            3
 145 #define CANCELED_BITMASK        0x08
 146   /* Bit set if thread is exiting.  */
 147 #define EXITING_BIT             4
 148 #define EXITING_BITMASK         0x10
 149   /* Bit set if thread terminated and TCB is freed.  */
 150 #define TERMINATED_BIT          5
 151 #define TERMINATED_BITMASK      0x20
 152   /* Mask for the rest.  Helps the compiler to optimize.  */
 153 #define CANCEL_RESTMASK         0xffffffc0
 154
 155 #define CANCEL_ENABLED_AND_CANCELED(value) \
 156   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 157                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 158 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 159   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 160                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 161    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 162   /* Setjmp buffer to be used if try/finally is not available.  */
 163   sigjmp_buf cancelbuf;
 164 #define HAVE_CANCELBUF  1
 165
 166   /* Flags.  Including those copied from the thread attribute.  */
 167   int flags;
 168
 169   /* The result of the thread function.  */
 170   void *result;
 171
 172   /* Scheduling parameters for the new thread.  */
 173   struct sched_param schedparam;
 174   int schedpolicy;
 175
 176   /* Start position of the code to be executed and the argument passed
 177      to the function.  */
 178   void *(*start_routine) (void *);
 179   void *arg;
 180
 181   /* Debug state.  */
 182   td_eventbuf_t eventbuf;
 183   /* Next descriptor with a pending event.  */
 184   struct pthread *nextevent;
 185
 186   /* If nonzero pointer to area allocated for the stack and its
 187      size.  */
 188   void *stackblock;
 189   size_t stackblock_size;
 190   /* Size of the included guard area.  */
 191   size_t guardsize;
 192 } __attribute ((aligned (TCB_ALIGNMENT)));
 193
 194
 195 #endif  /* descr.h */