nptl/descr.h

   1 /* Copyright (C) 2002 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 "../nptl_db/thread_db.h"
  33
  34
  35 #ifndef TCB_ALIGNMENT
  36 # define TCB_ALIGNMENT  sizeof (double)
  37 #endif
  38
  39
  40 /* We keep thread specific data in a special data structure, a two-level
  41    array.  The top-level array contains pointers to dynamically allocated
  42    arrays of a certain number of data pointers.  So we can implement a
  43    sparse array.  Each dynamic second-level array has
  44         PTHREAD_KEY_2NDLEVEL_SIZE
  45    entries.  This value shouldn't be too large.  */
  46 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  47
  48 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  49    keys in each subarray.  */
  50 #define PTHREAD_KEY_1STLEVEL_SIZE \
  51   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  52    / PTHREAD_KEY_2NDLEVEL_SIZE)
  53
  54
  55 /* Thread descriptor data structure.  */
  56 struct pthread
  57 {
  58   /* XXX Remove this union for IA-64 style TLS module */
  59   union
  60   {
  61     /* It is very important to always append new elements.  The offsets
  62        of some of the elements of the struct are used in assembler code.  */
  63     struct
  64     {
  65       void *tcb;                /* Pointer to the TCB.  This is not always
  66                                    the address of this thread descriptor.  */
  67       union dtv *dtvp;
  68       struct pthread *self;       /* Pointer to this structure */
  69       list_t list;
  70       int multiple_threads;
  71     } data;
  72     void *__padding[16];
  73   } header;
  74
  75   /* Two-level array for the thread-specific data.  */
  76   struct pthread_key_data
  77   {
  78     /* Sequence number.  We use uintptr_t to not require padding on
  79        32- and 64-bit machines.  On 64-bit machines it helps to avoid
  80        wrapping, too.  */
  81     uintptr_t seq;
  82
  83     /* Data pointer.  */
  84     void *data;
  85   } *specific[PTHREAD_KEY_1STLEVEL_SIZE];
  86   /* We allocate one block of references here.  This should be enough
  87      to avoid allocating any memory dynamically for most applications.  */
  88   struct pthread_key_data specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
  89   /* Flag which is set when specific data is set.  */
  90   bool specific_used;
  91
  92   /* True if the user provided the stack.  */
  93   bool user_stack;
  94
  95   /* True if events must be reported.  */
  96   bool report_events;
  97
  98   /* Lock to syncronize access to the descriptor.  */
  99   lll_lock_t lock;
 100
 101 #if HP_TIMING_AVAIL
 102   /* Offset of the CPU clock at start thread start time.  */
 103   hp_timing_t cpuclock_offset;
 104 #endif
 105
 106   /* If the thread waits to join another one the ID of the latter is
 107      stored here.
 108
 109      In case a thread is detached this field contains a pointer of the
 110      TCB if the thread itself.  This is something which cannot happen
 111      in normal operation.  */
 112   struct pthread *joinid;
 113   /* Check whether a thread is detached.  */
 114 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 115
 116   /* List of cleanup buffers.  */
 117   struct _pthread_cleanup_buffer *cleanup;
 118   /* Flags determining processing of cancellation.  */
 119   int cancelhandling;
 120   /* Bit set if cancellation is disabled.  */
 121 #define CANCELSTATE_BIT         0
 122 #define CANCELSTATE_BITMASK     0x01
 123   /* Bit set if asynchronous cancellation mode is selected.  */
 124 #define CANCELTYPE_BIT          1
 125 #define CANCELTYPE_BITMASK      0x02
 126   /* Bit set if canceled.  */
 127 #define CANCELED_BIT            2
 128 #define CANCELED_BITMASK        0x04
 129   /* Bit set if thread is exiting.  */
 130 #define EXITING_BIT             3
 131 #define EXITING_BITMASK         0x08
 132   /* Bit set if thread terminated and TCB is freed.  */
 133 #define TERMINATED_BIT          4
 134 #define TERMINATED_BITMASK      0x10
 135   /* Mask for the rest.  Helps the compiler to optimize.  */
 136 #define CANCEL_RESTMASK         0xffffffe0
 137
 138 #define CANCEL_ENABLED_AND_CANCELED(value) \
 139   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 140                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 141 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 142   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 143                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 144    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 145   /* Setjmp buffer to be used if try/finally is not available.  */
 146   sigjmp_buf cancelbuf;
 147 #define HAVE_CANCELBUF  1
 148
 149   /* Thread ID - which is also a 'is this thread descriptor (and
 150      therefore stack) used' flag.  */
 151   pid_t tid;
 152
 153   /* Flags.  Including those copied from the thread attribute.  */
 154   int flags;
 155
 156   /* The result of the thread function.  */
 157   void *result;
 158
 159   /* Scheduling parameters for the new thread.  */
 160   struct sched_param schedparam;
 161   int schedpolicy;
 162
 163   /* Start position of the code to be executed and the argument passed
 164      to the function.  */
 165   void *(*start_routine) (void *);
 166   void *arg;
 167
 168   /* Debug state.  */
 169   td_eventbuf_t eventbuf;
 170   /* Next descriptor with a pending event.  */
 171   struct pthread *nextevent;
 172
 173   /* If nonzero pointer to area allocated for the stack and its
 174      size.  */
 175   void *stackblock;
 176   size_t stackblock_size;
 177   /* Size of the included guard area.  */
 178   size_t guardsize;
 179 } __attribute ((aligned (TCB_ALIGNMENT)));
 180
 181
 182 #endif  /* descr.h */