nptl/descr.h

   1 /* Copyright (C) 2002, 2003, 2004, 2005, 2006 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 #define __need_res_state
  39 #include <resolv.h>
  40
  41 #ifndef TCB_ALIGNMENT
  42 # define TCB_ALIGNMENT  sizeof (double)
  43 #endif
  44
  45
  46 /* We keep thread specific data in a special data structure, a two-level
  47    array.  The top-level array contains pointers to dynamically allocated
  48    arrays of a certain number of data pointers.  So we can implement a
  49    sparse array.  Each dynamic second-level array has
  50         PTHREAD_KEY_2NDLEVEL_SIZE
  51    entries.  This value shouldn't be too large.  */
  52 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  53
  54 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  55    keys in each subarray.  */
  56 #define PTHREAD_KEY_1STLEVEL_SIZE \
  57   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  58    / PTHREAD_KEY_2NDLEVEL_SIZE)
  59
  60
  61
  62
  63 /* Internal version of the buffer to store cancellation handler
  64    information.  */
  65 struct pthread_unwind_buf
  66 {
  67   struct
  68   {
  69     __jmp_buf jmp_buf;
  70     int mask_was_saved;
  71   } cancel_jmp_buf[1];
  72
  73   union
  74   {
  75     /* This is the placeholder of the public version.  */
  76     void *pad[4];
  77
  78     struct
  79     {
  80       /* Pointer to the previous cleanup buffer.  */
  81       struct pthread_unwind_buf *prev;
  82
  83       /* Backward compatibility: state of the old-style cleanup
  84          handler at the time of the previous new-style cleanup handler
  85          installment.  */
  86       struct _pthread_cleanup_buffer *cleanup;
  87
  88       /* Cancellation type before the push call.  */
  89       int canceltype;
  90     } data;
  91   } priv;
  92 };
  93
  94
  95 /* Opcodes and data types for communication with the signal handler to
  96    change user/group IDs.  */
  97 struct xid_command
  98 {
  99   int syscall_no;
 100   long int id[3];
 101   volatile int cntr;
 102 };
 103
 104
 105 /* Thread descriptor data structure.  */
 106 struct pthread
 107 {
 108   union
 109   {
 110 #if !TLS_DTV_AT_TP
 111     /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
 112     tcbhead_t header;
 113 #else
 114     struct
 115     {
 116       int multiple_threads;
 117     } header;
 118 #endif
 119
 120     /* This extra padding has no special purpose, and this structure layout
 121        is private and subject to change without affecting the official ABI.
 122        We just have it here in case it might be convenient for some
 123        implementation-specific instrumentation hack or suchlike.  */
 124     void *__padding[16];
 125   };
 126
 127   /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
 128   list_t list;
 129
 130   /* Thread ID - which is also a 'is this thread descriptor (and
 131      therefore stack) used' flag.  */
 132   pid_t tid;
 133
 134   /* Process ID - thread group ID in kernel speak.  */
 135   pid_t pid;
 136
 137   /* List of robust mutexes the thread is holding.  */
 138 #ifdef __PTHREAD_MUTEX_HAVE_PREV
 139   __pthread_list_t robust_list;
 140
 141 # define ENQUEUE_MUTEX(mutex) \
 142   do {                                                                        \
 143     __pthread_list_t *next = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
 144     next->__prev = &mutex->__data.__list;                                     \
 145     mutex->__data.__list.__next = next;                                       \
 146     mutex->__data.__list.__prev = &THREAD_SELF->robust_list;                  \
 147     THREAD_SETMEM (THREAD_SELF, robust_list.__next, &mutex->__data.__list);   \
 148   } while (0)
 149 # define DEQUEUE_MUTEX(mutex) \
 150   do {                                                                        \
 151     mutex->__data.__list.__next->__prev = mutex->__data.__list.__prev;        \
 152     mutex->__data.__list.__prev->__next = mutex->__data.__list.__next;        \
 153     mutex->__data.__list.__prev = NULL;                                       \
 154     mutex->__data.__list.__next = NULL;                                       \
 155   } while (0)
 156 #else
 157   __pthread_slist_t robust_list;
 158
 159 # define ENQUEUE_MUTEX(mutex) \
 160   do {                                                                        \
 161     mutex->__data.__list.__next                                               \
 162       = THREAD_GETMEM (THREAD_SELF, robust_list.__next);                      \
 163     THREAD_SETMEM (THREAD_SELF, robust_list.__next, &mutex->__data.__list);   \
 164   } while (0)
 165 # define DEQUEUE_MUTEX(mutex) \
 166   do {                                                                        \
 167     __pthread_slist_t *runp = THREAD_GETMEM (THREAD_SELF, robust_list.__next);\
 168     if (runp == &mutex->__data.__list)                                        \
 169       THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next);          \
 170     else                                                                      \
 171       {                                                                       \
 172         while (runp->__next != &mutex->__data.__list)                         \
 173           runp = runp->__next;                                                \
 174                                                                               \
 175         runp->__next = runp->__next->__next;                                  \
 176         mutex->__data.__list.__next = NULL;                                   \
 177       }                                                                       \
 178   } while (0)
 179 #endif
 180
 181   /* List of cleanup buffers.  */
 182   struct _pthread_cleanup_buffer *cleanup;
 183
 184   /* Unwind information.  */
 185   struct pthread_unwind_buf *cleanup_jmp_buf;
 186 #define HAVE_CLEANUP_JMP_BUF
 187
 188   /* Flags determining processing of cancellation.  */
 189   int cancelhandling;
 190   /* Bit set if cancellation is disabled.  */
 191 #define CANCELSTATE_BIT         0
 192 #define CANCELSTATE_BITMASK     0x01
 193   /* Bit set if asynchronous cancellation mode is selected.  */
 194 #define CANCELTYPE_BIT          1
 195 #define CANCELTYPE_BITMASK      0x02
 196   /* Bit set if canceling has been initiated.  */
 197 #define CANCELING_BIT           2
 198 #define CANCELING_BITMASK       0x04
 199   /* Bit set if canceled.  */
 200 #define CANCELED_BIT            3
 201 #define CANCELED_BITMASK        0x08
 202   /* Bit set if thread is exiting.  */
 203 #define EXITING_BIT             4
 204 #define EXITING_BITMASK         0x10
 205   /* Bit set if thread terminated and TCB is freed.  */
 206 #define TERMINATED_BIT          5
 207 #define TERMINATED_BITMASK      0x20
 208   /* Bit set if thread is supposed to change XID.  */
 209 #define SETXID_BIT              6
 210 #define SETXID_BITMASK          0x40
 211   /* Mask for the rest.  Helps the compiler to optimize.  */
 212 #define CANCEL_RESTMASK         0xffffff80
 213
 214 #define CANCEL_ENABLED_AND_CANCELED(value) \
 215   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 216                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 217 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 218   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 219                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 220    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 221
 222   /* We allocate one block of references here.  This should be enough
 223      to avoid allocating any memory dynamically for most applications.  */
 224   struct pthread_key_data
 225   {
 226     /* Sequence number.  We use uintptr_t to not require padding on
 227        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 228        wrapping, too.  */
 229     uintptr_t seq;
 230
 231     /* Data pointer.  */
 232     void *data;
 233   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 234
 235   /* Two-level array for the thread-specific data.  */
 236   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 237
 238   /* Flag which is set when specific data is set.  */
 239   bool specific_used;
 240
 241   /* True if events must be reported.  */
 242   bool report_events;
 243
 244   /* True if the user provided the stack.  */
 245   bool user_stack;
 246
 247   /* True if thread must stop at startup time.  */
 248   bool stopped_start;
 249
 250   /* Lock to synchronize access to the descriptor.  */
 251   lll_lock_t lock;
 252
 253   /* Lock for synchronizing setxid calls.  */
 254   lll_lock_t setxid_futex;
 255
 256 #if HP_TIMING_AVAIL
 257   /* Offset of the CPU clock at start thread start time.  */
 258   hp_timing_t cpuclock_offset;
 259 #endif
 260
 261   /* If the thread waits to join another one the ID of the latter is
 262      stored here.
 263
 264      In case a thread is detached this field contains a pointer of the
 265      TCB if the thread itself.  This is something which cannot happen
 266      in normal operation.  */
 267   struct pthread *joinid;
 268   /* Check whether a thread is detached.  */
 269 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 270
 271   /* Flags.  Including those copied from the thread attribute.  */
 272   int flags;
 273
 274   /* The result of the thread function.  */
 275   void *result;
 276
 277   /* Scheduling parameters for the new thread.  */
 278   struct sched_param schedparam;
 279   int schedpolicy;
 280
 281   /* Start position of the code to be executed and the argument passed
 282      to the function.  */
 283   void *(*start_routine) (void *);
 284   void *arg;
 285
 286   /* Debug state.  */
 287   td_eventbuf_t eventbuf;
 288   /* Next descriptor with a pending event.  */
 289   struct pthread *nextevent;
 290
 291 #ifdef HAVE_FORCED_UNWIND
 292   /* Machine-specific unwind info.  */
 293   struct _Unwind_Exception exc;
 294 #endif
 295
 296   /* If nonzero pointer to area allocated for the stack and its
 297      size.  */
 298   void *stackblock;
 299   size_t stackblock_size;
 300   /* Size of the included guard area.  */
 301   size_t guardsize;
 302   /* This is what the user specified and what we will report.  */
 303   size_t reported_guardsize;
 304
 305   /* Resolver state.  */
 306   struct __res_state res;
 307
 308   /* If you add fields after the res field above, please adjust
 309      the following macro.  */
 310 #define PTHREAD_STRUCT_END_PADDING \
 311   (sizeof (struct pthread) - offsetof (struct pthread, res) \
 312    - sizeof (((struct pthread *) 0)->res))
 313
 314 } __attribute ((aligned (TCB_ALIGNMENT)));
 315
 316
 317 #endif  /* descr.h */