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 #ifdef HAVE_FORCED_UNWIND
  36 # include <unwind.h>
  37 #endif
  38
  39
  40 #ifndef TCB_ALIGNMENT
  41 # define TCB_ALIGNMENT  sizeof (double)
  42 #endif
  43
  44
  45 /* We keep thread specific data in a special data structure, a two-level
  46    array.  The top-level array contains pointers to dynamically allocated
  47    arrays of a certain number of data pointers.  So we can implement a
  48    sparse array.  Each dynamic second-level array has
  49         PTHREAD_KEY_2NDLEVEL_SIZE
  50    entries.  This value shouldn't be too large.  */
  51 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  52
  53 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  54    keys in each subarray.  */
  55 #define PTHREAD_KEY_1STLEVEL_SIZE \
  56   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  57    / PTHREAD_KEY_2NDLEVEL_SIZE)
  58
  59
  60
  61
  62 /* Internal version of the buffer to store cancellation handler
  63    information.  */
  64 struct pthread_unwind_buf
  65 {
  66   struct
  67   {
  68     __jmp_buf jmp_buf;
  69     int mask_was_saved;
  70   } cancel_jmp_buf[1];
  71
  72   union
  73   {
  74     /* This is the placeholder of the public version.  */
  75     void *pad[4];
  76
  77     struct
  78     {
  79       /* Pointer to the previous cleanup buffer.  */
  80       __pthread_unwind_buf_t *prev;
  81
  82       /* Backward compatibility: state of the old-style cleanup
  83          handler at the time of the previous new-style cleanup handler
  84          installment.  */
  85       struct _pthread_cleanup_buffer *cleanup;
  86
  87       /* Cancellation type before the push call.  */
  88       int canceltype;
  89     } data;
  90   } priv;
  91 };
  92
  93
  94 /* Thread descriptor data structure.  */
  95 struct pthread
  96 {
  97   union
  98   {
  99 #if !TLS_DTV_AT_TP
 100     /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
 101     tcbhead_t header;
 102 #elif TLS_MULTIPLE_THREADS_IN_TCB
 103     struct
 104     {
 105       int multiple_threads;
 106     } header;
 107 #endif
 108
 109     /* This extra padding has no special purpose, and this structure layout
 110        is private and subject to change without affecting the official ABI.
 111        We just have it here in case it might be convenient for some
 112        implementation-specific instrumentation hack or suchlike.  */
 113     void *__padding[16];
 114   };
 115
 116   /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
 117   list_t list;
 118
 119   /* Thread ID - which is also a 'is this thread descriptor (and
 120      therefore stack) used' flag.  */
 121   pid_t tid;
 122
 123   /* List of cleanup buffers.  */
 124   struct _pthread_cleanup_buffer *cleanup;
 125
 126   /* Unwind information.  */
 127   __pthread_unwind_buf_t *cleanup_jmp_buf;
 128 #define HAVE_CLEANUP_JMP_BUF
 129
 130   /* Flags determining processing of cancellation.  */
 131   int cancelhandling;
 132   /* Bit set if cancellation is disabled.  */
 133 #define CANCELSTATE_BIT         0
 134 #define CANCELSTATE_BITMASK     0x01
 135   /* Bit set if asynchronous cancellation mode is selected.  */
 136 #define CANCELTYPE_BIT          1
 137 #define CANCELTYPE_BITMASK      0x02
 138   /* Bit set if canceling has been initiated.  */
 139 #define CANCELING_BIT           2
 140 #define CANCELING_BITMASK       0x04
 141   /* Bit set if canceled.  */
 142 #define CANCELED_BIT            3
 143 #define CANCELED_BITMASK        0x08
 144   /* Bit set if thread is exiting.  */
 145 #define EXITING_BIT             4
 146 #define EXITING_BITMASK         0x10
 147   /* Bit set if thread terminated and TCB is freed.  */
 148 #define TERMINATED_BIT          5
 149 #define TERMINATED_BITMASK      0x20
 150   /* Mask for the rest.  Helps the compiler to optimize.  */
 151 #define CANCEL_RESTMASK         0xffffffc0
 152
 153 #define CANCEL_ENABLED_AND_CANCELED(value) \
 154   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 155                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 156 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 157   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 158                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 159    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 160
 161   /* We allocate one block of references here.  This should be enough
 162      to avoid allocating any memory dynamically for most applications.  */
 163   struct pthread_key_data
 164   {
 165     /* Sequence number.  We use uintptr_t to not require padding on
 166        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 167        wrapping, too.  */
 168     uintptr_t seq;
 169
 170     /* Data pointer.  */
 171     void *data;
 172   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 173
 174   /* Flag which is set when specific data is set.  */
 175   bool specific_used;
 176
 177   /* Two-level array for the thread-specific data.  */
 178   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 179
 180   /* True if events must be reported.  */
 181   bool report_events;
 182
 183   /* True if the user provided the stack.  */
 184   bool user_stack;
 185
 186   /* Lock to synchronize access to the descriptor.  */
 187   lll_lock_t lock;
 188
 189 #if HP_TIMING_AVAIL
 190   /* Offset of the CPU clock at start thread start time.  */
 191   hp_timing_t cpuclock_offset;
 192 #endif
 193
 194   /* If the thread waits to join another one the ID of the latter is
 195      stored here.
 196
 197      In case a thread is detached this field contains a pointer of the
 198      TCB if the thread itself.  This is something which cannot happen
 199      in normal operation.  */
 200   struct pthread *joinid;
 201   /* Check whether a thread is detached.  */
 202 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 203
 204   /* Flags.  Including those copied from the thread attribute.  */
 205   int flags;
 206
 207   /* The result of the thread function.  */
 208   void *result;
 209
 210   /* Scheduling parameters for the new thread.  */
 211   struct sched_param schedparam;
 212   int schedpolicy;
 213
 214   /* Start position of the code to be executed and the argument passed
 215      to the function.  */
 216   void *(*start_routine) (void *);
 217   void *arg;
 218
 219   /* Debug state.  */
 220   td_eventbuf_t eventbuf;
 221   /* Next descriptor with a pending event.  */
 222   struct pthread *nextevent;
 223
 224 #ifdef HAVE_FORCED_UNWIND
 225   /* Machine-specific unwind info.  */
 226   struct _Unwind_Exception exc;
 227 #endif
 228
 229   /* If nonzero pointer to area allocated for the stack and its
 230      size.  */
 231   void *stackblock;
 232   size_t stackblock_size;
 233   /* Size of the included guard area.  */
 234   size_t guardsize;
 235 } __attribute ((aligned (TCB_ALIGNMENT)));
 236
 237
 238 #endif  /* descr.h */