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 #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 cleanup buffers.  */
 138   struct _pthread_cleanup_buffer *cleanup;
 139
 140   /* Unwind information.  */
 141   struct pthread_unwind_buf *cleanup_jmp_buf;
 142 #define HAVE_CLEANUP_JMP_BUF
 143
 144   /* Flags determining processing of cancellation.  */
 145   int cancelhandling;
 146   /* Bit set if cancellation is disabled.  */
 147 #define CANCELSTATE_BIT         0
 148 #define CANCELSTATE_BITMASK     0x01
 149   /* Bit set if asynchronous cancellation mode is selected.  */
 150 #define CANCELTYPE_BIT          1
 151 #define CANCELTYPE_BITMASK      0x02
 152   /* Bit set if canceling has been initiated.  */
 153 #define CANCELING_BIT           2
 154 #define CANCELING_BITMASK       0x04
 155   /* Bit set if canceled.  */
 156 #define CANCELED_BIT            3
 157 #define CANCELED_BITMASK        0x08
 158   /* Bit set if thread is exiting.  */
 159 #define EXITING_BIT             4
 160 #define EXITING_BITMASK         0x10
 161   /* Bit set if thread terminated and TCB is freed.  */
 162 #define TERMINATED_BIT          5
 163 #define TERMINATED_BITMASK      0x20
 164   /* Mask for the rest.  Helps the compiler to optimize.  */
 165 #define CANCEL_RESTMASK         0xffffffc0
 166
 167 #define CANCEL_ENABLED_AND_CANCELED(value) \
 168   (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK       \
 169                | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
 170 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
 171   (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
 172                | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
 173    == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
 174
 175   /* We allocate one block of references here.  This should be enough
 176      to avoid allocating any memory dynamically for most applications.  */
 177   struct pthread_key_data
 178   {
 179     /* Sequence number.  We use uintptr_t to not require padding on
 180        32- and 64-bit machines.  On 64-bit machines it helps to avoid
 181        wrapping, too.  */
 182     uintptr_t seq;
 183
 184     /* Data pointer.  */
 185     void *data;
 186   } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
 187
 188   /* Flag which is set when specific data is set.  */
 189   bool specific_used;
 190
 191   /* Two-level array for the thread-specific data.  */
 192   struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
 193
 194   /* True if events must be reported.  */
 195   bool report_events;
 196
 197   /* True if the user provided the stack.  */
 198   bool user_stack;
 199
 200   /* True if thread must stop at startup time.  */
 201   bool stopped_start;
 202
 203   /* Lock to synchronize access to the descriptor.  */
 204   lll_lock_t lock;
 205
 206 #if HP_TIMING_AVAIL
 207   /* Offset of the CPU clock at start thread start time.  */
 208   hp_timing_t cpuclock_offset;
 209 #endif
 210
 211   /* If the thread waits to join another one the ID of the latter is
 212      stored here.
 213
 214      In case a thread is detached this field contains a pointer of the
 215      TCB if the thread itself.  This is something which cannot happen
 216      in normal operation.  */
 217   struct pthread *joinid;
 218   /* Check whether a thread is detached.  */
 219 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
 220
 221   /* Flags.  Including those copied from the thread attribute.  */
 222   int flags;
 223
 224   /* The result of the thread function.  */
 225   void *result;
 226
 227   /* Scheduling parameters for the new thread.  */
 228   struct sched_param schedparam;
 229   int schedpolicy;
 230
 231   /* Start position of the code to be executed and the argument passed
 232      to the function.  */
 233   void *(*start_routine) (void *);
 234   void *arg;
 235
 236   /* Debug state.  */
 237   td_eventbuf_t eventbuf;
 238   /* Next descriptor with a pending event.  */
 239   struct pthread *nextevent;
 240
 241 #ifdef HAVE_FORCED_UNWIND
 242   /* Machine-specific unwind info.  */
 243   struct _Unwind_Exception exc;
 244 #endif
 245
 246   /* If nonzero pointer to area allocated for the stack and its
 247      size.  */
 248   void *stackblock;
 249   size_t stackblock_size;
 250   /* Size of the included guard area.  */
 251   size_t guardsize;
 252   /* This is what the user specified and what we will report.  */
 253   size_t reported_guardsize;
 254
 255   /* Resolver state.  */
 256   struct __res_state res;
 257 } __attribute ((aligned (TCB_ALIGNMENT)));
 258
 259
 260 #endif  /* descr.h */