nptl/descr.h

   1 /* Copyright (C) 2002, 2003, 2004, 2005 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 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   pthread_mutex_t *robust_list;
 139
 140 #ifdef __PTHREAD_MUTEX_HAVE_PREV
 141 # define ENQUEUE_MUTEX(mutex) \
 142   do {                                                                        \
 143     mutex->__data.__next = THREAD_GETMEM (THREAD_SELF, robust_list);          \
 144     THREAD_SETMEM (THREAD_SELF, robust_list, mutex);                          \
 145     if (mutex->__data.__next != NULL)                                         \
 146       mutex->__data.__next->__data.__prev = mutex;                            \
 147     mutex->__data.__prev = NULL;                                              \
 148   } while (0)
 149 # define DEQUEUE_MUTEX(mutex) \
 150   do {                                                                        \
 151     if (mutex->__data.__prev == NULL)                                         \
 152       THREAD_SETMEM (THREAD_SELF, robust_list, mutex->__data.__next);         \
 153     else                                                                      \
 154       mutex->__data.__prev->__data.__next = mutex->__data.__next;             \
 155     if (mutex->__data.__next != NULL)                                         \
 156       mutex->__data.__next->__data.__prev = mutex->__data.__prev;             \
 157     mutex->__data.__prev = NULL;                                              \
 158     mutex->__data.__next = NULL;                                              \
 159   } while (0)
 160 #else
 161 # define ENQUEUE_MUTEX(mutex) \
 162   do {                                                                        \
 163     mutex->__data.__next = THREAD_GETMEM (THREAD_SELF, robust_list);          \
 164     THREAD_SETMEM (THREAD_SELF, robust_list, mutex);                          \
 165   } while (0)
 166 # define DEQUEUE_MUTEX(mutex) \
 167   do {                                                                        \
 168     pthread_mutex_t *runp = THREAD_GETMEM (THREAD_SELF, robust_list);         \
 169     if (runp == mutex)                                                        \
 170       THREAD_SETMEM (THREAD_SELF, robust_list, runp->__data.__next);          \
 171     else                                                                      \
 172       {                                                                       \
 173         while (runp->__data.__next != mutex)                                  \
 174           runp = runp->__data.__next;                                         \
 175                                                                               \
 176         runp->__data.__next = runp->__data.__next->__data.__next;             \
 177         mutex->__data.__next = NULL;                                          \
 178       }                                                                       \
 179   } while (0)
 180 #endif
 181
 182   /* List of cleanup buffers.  */
 183   struct _pthread_cleanup_buffer *cleanup;
 184
 185   /* Unwind information.  */
 186   struct pthread_unwind_buf *cleanup_jmp_buf;
 187 #define HAVE_CLEANUP_JMP_BUF
 188
 189   /* Flags determining processing of cancellation.  */
 190   int cancelhandling;
 191   /* Bit set if cancellation is disabled.  */
 192 #define CANCELSTATE_BIT         0
 193 #define CANCELSTATE_BITMASK     0x01
 194   /* Bit set if asynchronous cancellation mode is selected.  */
 195 #define CANCELTYPE_BIT          1
 196 #define CANCELTYPE_BITMASK      0x02
 197   /* Bit set if canceling has been initiated.  */
 198 #define CANCELING_BIT           2
 199 #define CANCELING_BITMASK       0x04
 200   /* Bit set if canceled.  */
 201 #define CANCELED_BIT            3
 202 #define CANCELED_BITMASK        0x08
 203   /* Bit set if thread is exiting.  */
 204 #define EXITING_BIT             4
 205 #define EXITING_BITMASK         0x10
 206   /* Bit set if thread terminated and TCB is freed.  */
 207 #define TERMINATED_BIT          5
 208 #define TERMINATED_BITMASK      0x20
 209   /* Bit set if thread is supposed to change XID.  */
 210 #define SETXID_BIT              6
 211 #define SETXID_BITMASK          0x40
 212   /* Mask for the rest.  Helps the compiler to optimize.  */
 213 #define CANCEL_RESTMASK         0xffffff80
 214
 215 #define CANCEL_ENABLED_AND_CANCELED(value) \
 216   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 217                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 218 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 219   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 220                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 221    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 222
 223   /* We allocate one block of references here.  This should be enough
 224      to avoid allocating any memory dynamically for most applications.  */
 225   struct pthread_key_data
 226   {
 227     /* Sequence number.  We use uintptr_t to not require padding on
 228        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 229        wrapping, too.  */
 230     uintptr_t seq;
 231
 232     /* Data pointer.  */
 233     void *data;
 234   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 235
 236   /* Two-level array for the thread-specific data.  */
 237   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 238
 239   /* Flag which is set when specific data is set.  */
 240   bool specific_used;
 241
 242   /* True if events must be reported.  */
 243   bool report_events;
 244
 245   /* True if the user provided the stack.  */
 246   bool user_stack;
 247
 248   /* True if thread must stop at startup time.  */
 249   bool stopped_start;
 250
 251   /* Lock to synchronize access to the descriptor.  */
 252   lll_lock_t lock;
 253
 254   /* Lock for synchronizing setxid calls.  */
 255   lll_lock_t setxid_futex;
 256
 257 #if HP_TIMING_AVAIL
 258   /* Offset of the CPU clock at start thread start time.  */
 259   hp_timing_t cpuclock_offset;
 260 #endif
 261
 262   /* If the thread waits to join another one the ID of the latter is
 263      stored here.
 264
 265      In case a thread is detached this field contains a pointer of the
 266      TCB if the thread itself.  This is something which cannot happen
 267      in normal operation.  */
 268   struct pthread *joinid;
 269   /* Check whether a thread is detached.  */
 270 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 271
 272   /* Flags.  Including those copied from the thread attribute.  */
 273   int flags;
 274
 275   /* The result of the thread function.  */
 276   void *result;
 277
 278   /* Scheduling parameters for the new thread.  */
 279   struct sched_param schedparam;
 280   int schedpolicy;
 281
 282   /* Start position of the code to be executed and the argument passed
 283      to the function.  */
 284   void *(*start_routine) (void *);
 285   void *arg;
 286
 287   /* Debug state.  */
 288   td_eventbuf_t eventbuf;
 289   /* Next descriptor with a pending event.  */
 290   struct pthread *nextevent;
 291
 292 #ifdef HAVE_FORCED_UNWIND
 293   /* Machine-specific unwind info.  */
 294   struct _Unwind_Exception exc;
 295 #endif
 296
 297   /* If nonzero pointer to area allocated for the stack and its
 298      size.  */
 299   void *stackblock;
 300   size_t stackblock_size;
 301   /* Size of the included guard area.  */
 302   size_t guardsize;
 303   /* This is what the user specified and what we will report.  */
 304   size_t reported_guardsize;
 305
 306   /* Resolver state.  */
 307   struct __res_state res;
 308
 309   /* If you add fields after the res field above, please adjust
 310      the following macro.  */
 311 #define PTHREAD_STRUCT_END_PADDING \
 312   (sizeof (struct pthread) - offsetof (struct pthread, res) \
 313    - sizeof (((struct pthread *) 0)->res))
 314
 315 } __attribute ((aligned (TCB_ALIGNMENT)));
 316
 317
 318 #endif  /* descr.h */