nptl/descr.h

   1 /* Copyright (C) 2002, 2003, 2004 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 #ifdef __need_struct_pthread_size
  31 #define lll_lock_t int
  32 #else
  33 #include <lowlevellock.h>
  34 #include <pthreaddef.h>
  35 #include <dl-sysdep.h>
  36 #endif
  37 #include "../nptl_db/thread_db.h"
  38 #include <tls.h>
  39 #ifdef HAVE_FORCED_UNWIND
  40 # include <unwind.h>
  41 #endif
  42 #define __need_res_state
  43 #include <resolv.h>
  44
  45 #ifndef TCB_ALIGNMENT
  46 # define TCB_ALIGNMENT  sizeof (double)
  47 #endif
  48
  49
  50 /* We keep thread specific data in a special data structure, a two-level
  51    array.  The top-level array contains pointers to dynamically allocated
  52    arrays of a certain number of data pointers.  So we can implement a
  53    sparse array.  Each dynamic second-level array has
  54         PTHREAD_KEY_2NDLEVEL_SIZE
  55    entries.  This value shouldn't be too large.  */
  56 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  57
  58 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  59    keys in each subarray.  */
  60 #define PTHREAD_KEY_1STLEVEL_SIZE \
  61   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  62    / PTHREAD_KEY_2NDLEVEL_SIZE)
  63
  64
  65
  66
  67 /* Internal version of the buffer to store cancellation handler
  68    information.  */
  69 struct pthread_unwind_buf
  70 {
  71   struct
  72   {
  73     __jmp_buf jmp_buf;
  74     int mask_was_saved;
  75   } cancel_jmp_buf[1];
  76
  77   union
  78   {
  79     /* This is the placeholder of the public version.  */
  80     void *pad[4];
  81
  82     struct
  83     {
  84       /* Pointer to the previous cleanup buffer.  */
  85       struct pthread_unwind_buf *prev;
  86
  87       /* Backward compatibility: state of the old-style cleanup
  88          handler at the time of the previous new-style cleanup handler
  89          installment.  */
  90       struct _pthread_cleanup_buffer *cleanup;
  91
  92       /* Cancellation type before the push call.  */
  93       int canceltype;
  94     } data;
  95   } priv;
  96 };
  97
  98
  99 /* Opcodes and data types for communication with the signal handler to
 100    change user/group IDs.  */
 101 struct xid_command
 102 {
 103   int syscall_no;
 104   long id[3];
 105   volatile int cntr;
 106 };
 107
 108
 109 /* Thread descriptor data structure.  */
 110 struct pthread
 111 {
 112   union
 113   {
 114 #if !TLS_DTV_AT_TP
 115     /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
 116     tcbhead_t header;
 117 #else
 118     struct
 119     {
 120       int multiple_threads;
 121     } header;
 122 #endif
 123
 124     /* This extra padding has no special purpose, and this structure layout
 125        is private and subject to change without affecting the official ABI.
 126        We just have it here in case it might be convenient for some
 127        implementation-specific instrumentation hack or suchlike.  */
 128     void *__padding[16];
 129   };
 130
 131   /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
 132   list_t list;
 133
 134   /* Thread ID - which is also a 'is this thread descriptor (and
 135      therefore stack) used' flag.  */
 136   pid_t tid;
 137
 138   /* Process ID - thread group ID in kernel speak.  */
 139   pid_t pid;
 140
 141   /* List of cleanup buffers.  */
 142   struct _pthread_cleanup_buffer *cleanup;
 143
 144   /* Unwind information.  */
 145   struct pthread_unwind_buf *cleanup_jmp_buf;
 146 #define HAVE_CLEANUP_JMP_BUF
 147
 148   /* Flags determining processing of cancellation.  */
 149   int cancelhandling;
 150   /* Bit set if cancellation is disabled.  */
 151 #define CANCELSTATE_BIT         0
 152 #define CANCELSTATE_BITMASK     0x01
 153   /* Bit set if asynchronous cancellation mode is selected.  */
 154 #define CANCELTYPE_BIT          1
 155 #define CANCELTYPE_BITMASK      0x02
 156   /* Bit set if canceling has been initiated.  */
 157 #define CANCELING_BIT           2
 158 #define CANCELING_BITMASK       0x04
 159   /* Bit set if canceled.  */
 160 #define CANCELED_BIT            3
 161 #define CANCELED_BITMASK        0x08
 162   /* Bit set if thread is exiting.  */
 163 #define EXITING_BIT             4
 164 #define EXITING_BITMASK         0x10
 165   /* Bit set if thread terminated and TCB is freed.  */
 166 #define TERMINATED_BIT          5
 167 #define TERMINATED_BITMASK      0x20
 168   /* Mask for the rest.  Helps the compiler to optimize.  */
 169 #define CANCEL_RESTMASK         0xffffffc0
 170
 171 #define CANCEL_ENABLED_AND_CANCELED(value) \
 172   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 173                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 174 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 175   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 176                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 177    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 178
 179   /* We allocate one block of references here.  This should be enough
 180      to avoid allocating any memory dynamically for most applications.  */
 181   struct pthread_key_data
 182   {
 183     /* Sequence number.  We use uintptr_t to not require padding on
 184        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 185        wrapping, too.  */
 186     uintptr_t seq;
 187
 188     /* Data pointer.  */
 189     void *data;
 190   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 191
 192   /* Flag which is set when specific data is set.  */
 193   bool specific_used;
 194
 195   /* Two-level array for the thread-specific data.  */
 196   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 197
 198   /* True if events must be reported.  */
 199   bool report_events;
 200
 201   /* True if the user provided the stack.  */
 202   bool user_stack;
 203
 204   /* True if thread must stop at startup time.  */
 205   bool stopped_start;
 206
 207   /* Lock to synchronize access to the descriptor.  */
 208   lll_lock_t lock;
 209
 210 #if HP_TIMING_AVAIL
 211   /* Offset of the CPU clock at start thread start time.  */
 212   hp_timing_t cpuclock_offset;
 213 #endif
 214
 215   /* If the thread waits to join another one the ID of the latter is
 216      stored here.
 217
 218      In case a thread is detached this field contains a pointer of the
 219      TCB if the thread itself.  This is something which cannot happen
 220      in normal operation.  */
 221   struct pthread *joinid;
 222   /* Check whether a thread is detached.  */
 223 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 224
 225   /* Flags.  Including those copied from the thread attribute.  */
 226   int flags;
 227
 228   /* The result of the thread function.  */
 229   void *result;
 230
 231   /* Scheduling parameters for the new thread.  */
 232   struct sched_param schedparam;
 233   int schedpolicy;
 234
 235   /* Start position of the code to be executed and the argument passed
 236      to the function.  */
 237   void *(*start_routine) (void *);
 238   void *arg;
 239
 240   /* Debug state.  */
 241   td_eventbuf_t eventbuf;
 242   /* Next descriptor with a pending event.  */
 243   struct pthread *nextevent;
 244
 245 #ifdef HAVE_FORCED_UNWIND
 246   /* Machine-specific unwind info.  */
 247   struct _Unwind_Exception exc;
 248 #endif
 249
 250   /* If nonzero pointer to area allocated for the stack and its
 251      size.  */
 252   void *stackblock;
 253   size_t stackblock_size;
 254   /* Size of the included guard area.  */
 255   size_t guardsize;
 256   /* This is what the user specified and what we will report.  */
 257   size_t reported_guardsize;
 258
 259   /* Resolver state.  */
 260   struct __res_state res;
 261 } __attribute ((aligned (TCB_ALIGNMENT)));
 262
 263
 264 #endif  /* descr.h */