fbtl/descr.h

   1 /* Copyright (C) 2002-2013 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _DESCR_H
  20 #define _DESCR_H        1
  21
  22 #include <limits.h>
  23 #include <sched.h>
  24 #include <setjmp.h>
  25 #include <stdbool.h>
  26 #include <sys/types.h>
  27 #include <hp-timing.h>
  28 #define __need_list_t
  29 #include <list.h>
  30 #include <lowlevellock.h>
  31 #include <pthreaddef.h>
  32 #include <dl-sysdep.h>
  33 #include "../fbtl_db/thread_db.h"
  34 #include <tls.h>
  35 #include <unwind.h>
  36 #define __need_res_state
  37 #include <resolv.h>
  38 #include <kernel-features.h>
  39 #include <fpu_control.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 /* Data structure used by the kernel to find robust futexes.  */
 106 struct robust_list_head
 107 {
 108   void *list;
 109   long int futex_offset;
 110   void *list_op_pending;
 111 };
 112
 113
 114 /* Data strcture used to handle thread priority protection.  */
 115 struct priority_protection_data
 116 {
 117   int priomax;
 118   unsigned int priomap[];
 119 };
 120
 121
 122 /* Thread descriptor data structure.  */
 123 struct pthread
 124 {
 125   union
 126   {
 127 #if !TLS_DTV_AT_TP
 128     /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
 129     tcbhead_t header;
 130 #else
 131     struct
 132     {
 133       /* multiple_threads is enabled either when the process has spawned at
 134          least one thread or when a single-threaded process cancels itself.
 135          This enables additional code to introduce locking before doing some
 136          compare_and_exchange operations and also enable cancellation points.
 137          The concepts of multiple threads and cancellation points ideally
 138          should be separate, since it is not necessary for multiple threads to
 139          have been created for cancellation points to be enabled, as is the
 140          case is when single-threaded process cancels itself.
 141
 142          Since enabling multiple_threads enables additional code in
 143          cancellation points and compare_and_exchange operations, there is a
 144          potential for an unneeded performance hit when it is enabled in a
 145          single-threaded, self-canceling process.  This is OK though, since a
 146          single-threaded process will enable async cancellation only when it
 147          looks to cancel itself and is hence going to end anyway.  */
 148       int multiple_threads;
 149       int gscope_flag;
 150 # ifndef __ASSUME_PRIVATE_FUTEX
 151       int private_futex;
 152 # endif
 153     } header;
 154 #endif
 155
 156     /* This extra padding has no special purpose, and this structure layout
 157        is private and subject to change without affecting the official ABI.
 158        We just have it here in case it might be convenient for some
 159        implementation-specific instrumentation hack or suchlike.  */
 160     void *__padding[24];
 161   };
 162
 163   /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
 164   list_t list;
 165
 166   /* Thread ID - which is also a 'is this thread descriptor (and
 167      therefore stack) used' flag.  */
 168 #if (__BYTE_ORDER == __LITTLE_ENDIAN) || (__WORDSIZE == 32)
 169   union {
 170   pid_t tid;
 171   long ktid;
 172   };
 173 #else
 174 #error untested padding layout:
 175   union {
 176     struct {
 177       int   __pad_tid;
 178       pid_t tid;
 179     };
 180     long ktid;
 181   };
 182 #endif
 183
 184   /* Process ID - thread group ID in kernel speak.  */
 185   pid_t pid_unused;
 186
 187   /* List of robust mutexes the thread is holding.  */
 188 #ifdef __PTHREAD_MUTEX_HAVE_PREV
 189   void *robust_prev;
 190   struct robust_list_head robust_head;
 191
 192   /* The list above is strange.  It is basically a double linked list
 193      but the pointer to the next/previous element of the list points
 194      in the middle of the object, the __next element.  Whenever
 195      casting to __pthread_list_t we need to adjust the pointer
 196      first.  */
 197 # define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next))
 198
 199 # define ENQUEUE_MUTEX_BOTH(mutex, val)                                       \
 200   do {                                                                        \
 201     __pthread_list_t *next = (__pthread_list_t *)                             \
 202       ((((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_head.list)) & ~1ul)   \
 203        - QUEUE_PTR_ADJUST);                                                   \
 204     next->__prev = (void *) &mutex->__data.__list.__next;                     \
 205     mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF,                 \
 206                                                  robust_head.list);           \
 207     mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head;         \
 208     THREAD_SETMEM (THREAD_SELF, robust_head.list,                             \
 209                    (void *) (((uintptr_t) &mutex->__data.__list.__next)       \
 210                              | val));                                         \
 211   } while (0)
 212 # define DEQUEUE_MUTEX(mutex) \
 213   do {                                                                        \
 214     __pthread_list_t *next = (__pthread_list_t *)                             \
 215       ((char *) (((uintptr_t) mutex->__data.__list.__next) & ~1ul)            \
 216        - QUEUE_PTR_ADJUST);                                                   \
 217     next->__prev = mutex->__data.__list.__prev;                               \
 218     __pthread_list_t *prev = (__pthread_list_t *)                             \
 219       ((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul)            \
 220        - QUEUE_PTR_ADJUST);                                                   \
 221     prev->__next = mutex->__data.__list.__next;                               \
 222     mutex->__data.__list.__prev = NULL;                                       \
 223     mutex->__data.__list.__next = NULL;                                       \
 224   } while (0)
 225 #else
 226   union
 227   {
 228     __pthread_slist_t robust_list;
 229     struct robust_list_head robust_head;
 230   };
 231
 232 # define ENQUEUE_MUTEX_BOTH(mutex, val)                                       \
 233   do {                                                                        \
 234     mutex->__data.__list.__next                                               \
 235       = THREAD_GETMEM (THREAD_SELF, robust_list.__next);                      \
 236     THREAD_SETMEM (THREAD_SELF, robust_list.__next,                           \
 237                    (void *) (((uintptr_t) &mutex->__data.__list) | val));     \
 238   } while (0)
 239 # define DEQUEUE_MUTEX(mutex) \
 240   do {                                                                        \
 241     __pthread_slist_t *runp = (__pthread_slist_t *)                           \
 242       (((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_list.__next)) & ~1ul); \
 243     if (runp == &mutex->__data.__list)                                        \
 244       THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next);          \
 245     else                                                                      \
 246       {                                                                       \
 247         __pthread_slist_t *next = (__pthread_slist_t *)               \
 248           (((uintptr_t) runp->__next) & ~1ul);                                \
 249         while (next != &mutex->__data.__list)                                 \
 250           {                                                                   \
 251             runp = next;                                                      \
 252             next = (__pthread_slist_t *) (((uintptr_t) runp->__next) & ~1ul); \
 253           }                                                                   \
 254                                                                               \
 255         runp->__next = next->__next;                                          \
 256         mutex->__data.__list.__next = NULL;                                   \
 257       }                                                                       \
 258   } while (0)
 259 #endif
 260 #define ENQUEUE_MUTEX(mutex) ENQUEUE_MUTEX_BOTH (mutex, 0)
 261 #define ENQUEUE_MUTEX_PI(mutex) ENQUEUE_MUTEX_BOTH (mutex, 1)
 262
 263   /* List of cleanup buffers.  */
 264   struct _pthread_cleanup_buffer *cleanup;
 265
 266   /* Unwind information.  */
 267   struct pthread_unwind_buf *cleanup_jmp_buf;
 268 #define HAVE_CLEANUP_JMP_BUF
 269
 270   /* Flags determining processing of cancellation.  */
 271   int cancelhandling;
 272   /* Bit set if cancellation is disabled.  */
 273 #define CANCELSTATE_BIT         0
 274 #define CANCELSTATE_BITMASK     (0x01 << CANCELSTATE_BIT)
 275   /* Bit set if asynchronous cancellation mode is selected.  */
 276 #define CANCELTYPE_BIT          1
 277 #define CANCELTYPE_BITMASK      (0x01 << CANCELTYPE_BIT)
 278   /* Bit set if canceling has been initiated.  */
 279 #define CANCELING_BIT           2
 280 #define CANCELING_BITMASK       (0x01 << CANCELING_BIT)
 281   /* Bit set if canceled.  */
 282 #define CANCELED_BIT            3
 283 #define CANCELED_BITMASK        (0x01 << CANCELED_BIT)
 284   /* Bit set if thread is exiting.  */
 285 #define EXITING_BIT             4
 286 #define EXITING_BITMASK         (0x01 << EXITING_BIT)
 287   /* Bit set if thread terminated and TCB is freed.  */
 288 #define TERMINATED_BIT          5
 289 #define TERMINATED_BITMASK      (0x01 << TERMINATED_BIT)
 290   /* Bit set if thread is supposed to change XID.  */
 291 #define SETXID_BIT              6
 292 #define SETXID_BITMASK          (0x01 << SETXID_BIT)
 293   /* Mask for the rest.  Helps the compiler to optimize.  */
 294 #define CANCEL_RESTMASK         0xffffff80
 295
 296 #define CANCEL_ENABLED_AND_CANCELED(value) \
 297   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 298                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 299 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 300   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 301                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 302    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 303
 304   /* Flags.  Including those copied from the thread attribute.  */
 305   int flags;
 306
 307   /* We allocate one block of references here.  This should be enough
 308      to avoid allocating any memory dynamically for most applications.  */
 309   struct pthread_key_data
 310   {
 311     /* Sequence number.  We use uintptr_t to not require padding on
 312        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 313        wrapping, too.  */
 314     uintptr_t seq;
 315
 316     /* Data pointer.  */
 317     void *data;
 318   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 319
 320   /* Two-level array for the thread-specific data.  */
 321   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 322
 323   /* Flag which is set when specific data is set.  */
 324   bool specific_used;
 325
 326   /* True if events must be reported.  */
 327   bool report_events;
 328
 329   /* True if the user provided the stack.  */
 330   bool user_stack;
 331
 332   /* True if thread must stop at startup time.  */
 333   bool stopped_start;
 334
 335   /* The parent's cancel handling at the time of the pthread_create
 336      call.  This might be needed to undo the effects of a cancellation.  */
 337   int parent_cancelhandling;
 338
 339   /* Lock to synchronize access to the descriptor.  */
 340   int lock;
 341
 342   /* Lock for synchronizing setxid calls.  */
 343   int setxid_futex;
 344
 345 #if HP_TIMING_AVAIL
 346   /* Offset of the CPU clock at start thread start time.  */
 347   hp_timing_t cpuclock_offset;
 348 #endif
 349
 350   /* If the thread waits to join another one the ID of the latter is
 351      stored here.
 352
 353      In case a thread is detached this field contains a pointer of the
 354      TCB if the thread itself.  This is something which cannot happen
 355      in normal operation.  */
 356   struct pthread *joinid;
 357   /* Check whether a thread is detached.  */
 358 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 359
 360   /* The result of the thread function.  */
 361   void *result;
 362
 363   /* Scheduling parameters for the new thread.  */
 364   struct sched_param schedparam;
 365   int schedpolicy;
 366
 367   /* Start position of the code to be executed and the argument passed
 368      to the function.  */
 369   void *(*start_routine) (void *);
 370   void *arg;
 371
 372   /* Debug state.  */
 373   td_eventbuf_t eventbuf;
 374   /* Next descriptor with a pending event.  */
 375   struct pthread *nextevent;
 376
 377   /* Machine-specific unwind info.  */
 378   struct _Unwind_Exception exc;
 379
 380   /* If nonzero pointer to area allocated for the stack and its
 381      size.  */
 382   void *stackblock;
 383   size_t stackblock_size;
 384   /* Size of the included guard area.  */
 385   size_t guardsize;
 386   /* This is what the user specified and what we will report.  */
 387   size_t reported_guardsize;
 388
 389   /* Thread Priority Protection data.  */
 390   struct priority_protection_data *tpp;
 391
 392   /* Resolver state.  */
 393   struct __res_state res;
 394
 395   /* FPU initial control word */
 396   fpu_control_t fpu_control_init;
 397
 398   /* This member must be last.  */
 399   char end_padding[];
 400
 401 #define PTHREAD_STRUCT_END_PADDING \
 402   (sizeof (struct pthread) - offsetof (struct pthread, end_padding))
 403 } __attribute ((aligned (TCB_ALIGNMENT)));
 404
 405
 406 #endif  /* descr.h */