about summary refs log tree commit diff
path: root/nptl/descr.h
blob: d5491c13558f86b696b6cd1bee8b23e11a4e97d3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
/* Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _DESCR_H
#define _DESCR_H	1

#include <limits.h>
#include <sched.h>
#include <setjmp.h>
#include <stdbool.h>
#include <sys/types.h>
#include <hp-timing.h>
#include <list.h>
#include <lowlevellock.h>
#include <pthreaddef.h>
#include <dl-sysdep.h>
#include "../nptl_db/thread_db.h"
#include <tls.h>
#ifdef HAVE_FORCED_UNWIND
# include <unwind.h>
#endif
#define __need_res_state
#include <resolv.h>

#ifndef TCB_ALIGNMENT
# define TCB_ALIGNMENT	sizeof (double)
#endif


/* We keep thread specific data in a special data structure, a two-level
   array.  The top-level array contains pointers to dynamically allocated
   arrays of a certain number of data pointers.  So we can implement a
   sparse array.  Each dynamic second-level array has
        PTHREAD_KEY_2NDLEVEL_SIZE
   entries.  This value shouldn't be too large.  */
#define PTHREAD_KEY_2NDLEVEL_SIZE       32

/* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
   keys in each subarray.  */
#define PTHREAD_KEY_1STLEVEL_SIZE \
  ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
   / PTHREAD_KEY_2NDLEVEL_SIZE)




/* Internal version of the buffer to store cancellation handler
   information.  */
struct pthread_unwind_buf
{
  struct
  {
    __jmp_buf jmp_buf;
    int mask_was_saved;
  } cancel_jmp_buf[1];

  union
  {
    /* This is the placeholder of the public version.  */
    void *pad[4];

    struct
    {
      /* Pointer to the previous cleanup buffer.  */
      struct pthread_unwind_buf *prev;

      /* Backward compatibility: state of the old-style cleanup
	 handler at the time of the previous new-style cleanup handler
	 installment.  */
      struct _pthread_cleanup_buffer *cleanup;

      /* Cancellation type before the push call.  */
      int canceltype;
    } data;
  } priv;
};


/* Opcodes and data types for communication with the signal handler to
   change user/group IDs.  */
struct xid_command
{
  int syscall_no;
  long int id[3];
  volatile int cntr;
};


/* Thread descriptor data structure.  */
struct pthread
{
  union
  {
#if !TLS_DTV_AT_TP
    /* This overlaps the TCB as used for TLS without threads (see tls.h).  */
    tcbhead_t header;
#else
    struct
    {
      int multiple_threads;
    } header;
#endif

    /* This extra padding has no special purpose, and this structure layout
       is private and subject to change without affecting the official ABI.
       We just have it here in case it might be convenient for some
       implementation-specific instrumentation hack or suchlike.  */
    void *__padding[16];
  };

  /* This descriptor's link on the `stack_used' or `__stack_user' list.  */
  list_t list;

  /* Thread ID - which is also a 'is this thread descriptor (and
     therefore stack) used' flag.  */
  pid_t tid;

  /* Process ID - thread group ID in kernel speak.  */
  pid_t pid;

  /* List of robust mutexes the thread is holding.  */
#ifdef __PTHREAD_MUTEX_HAVE_PREV
  __pthread_list_t robust_list;

# define ENQUEUE_MUTEX(mutex) \
  do {									      \
    __pthread_list_t *next = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
    next->__prev = &mutex->__data.__list;				      \
    mutex->__data.__list.__next = next;					      \
    mutex->__data.__list.__prev = &THREAD_SELF->robust_list;		      \
    THREAD_SETMEM (THREAD_SELF, robust_list.__next, &mutex->__data.__list);   \
  } while (0)
# define DEQUEUE_MUTEX(mutex) \
  do {									      \
    mutex->__data.__list.__next->__prev = mutex->__data.__list.__prev;	      \
    mutex->__data.__list.__prev->__next = mutex->__data.__list.__next;	      \
    mutex->__data.__list.__prev = NULL;					      \
    mutex->__data.__list.__next = NULL;					      \
  } while (0)
#else
  __pthread_slist_t robust_list;

# define ENQUEUE_MUTEX(mutex) \
  do {									      \
    mutex->__data.__list.__next						      \
      = THREAD_GETMEM (THREAD_SELF, robust_list.__next);		      \
    THREAD_SETMEM (THREAD_SELF, robust_list.__next, &mutex->__data.__list);   \
  } while (0)
# define DEQUEUE_MUTEX(mutex) \
  do {									      \
    __pthread_slist_t *runp = THREAD_GETMEM (THREAD_SELF, robust_list.__next);\
    if (runp == &mutex->__data.__list)					      \
      THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next);	      \
    else								      \
      {									      \
	while (runp->__next != &mutex->__data.__list)			      \
	  runp = runp->__next;						      \
									      \
	runp->__next = runp->__next->__next;				      \
	mutex->__data.__list.__next = NULL;				      \
      }									      \
  } while (0)
#endif

  /* List of cleanup buffers.  */
  struct _pthread_cleanup_buffer *cleanup;

  /* Unwind information.  */
  struct pthread_unwind_buf *cleanup_jmp_buf;
#define HAVE_CLEANUP_JMP_BUF

  /* Flags determining processing of cancellation.  */
  int cancelhandling;
  /* Bit set if cancellation is disabled.  */
#define CANCELSTATE_BIT		0
#define CANCELSTATE_BITMASK	0x01
  /* Bit set if asynchronous cancellation mode is selected.  */
#define CANCELTYPE_BIT		1
#define CANCELTYPE_BITMASK	0x02
  /* Bit set if canceling has been initiated.  */
#define CANCELING_BIT		2
#define CANCELING_BITMASK	0x04
  /* Bit set if canceled.  */
#define CANCELED_BIT		3
#define CANCELED_BITMASK	0x08
  /* Bit set if thread is exiting.  */
#define EXITING_BIT		4
#define EXITING_BITMASK		0x10
  /* Bit set if thread terminated and TCB is freed.  */
#define TERMINATED_BIT		5
#define TERMINATED_BITMASK	0x20
  /* Bit set if thread is supposed to change XID.  */
#define SETXID_BIT		6
#define SETXID_BITMASK		0x40
  /* Mask for the rest.  Helps the compiler to optimize.  */
#define CANCEL_RESTMASK		0xffffff80

#define CANCEL_ENABLED_AND_CANCELED(value) \
  (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK	      \
	       | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
#define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
  (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK    \
	       | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK))     \
   == (CANCELTYPE_BITMASK | CANCELED_BITMASK))

  /* We allocate one block of references here.  This should be enough
     to avoid allocating any memory dynamically for most applications.  */
  struct pthread_key_data
  {
    /* Sequence number.  We use uintptr_t to not require padding on
       32- and 64-bit machines.  On 64-bit machines it helps to avoid
       wrapping, too.  */
    uintptr_t seq;

    /* Data pointer.  */
    void *data;
  } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];

  /* Two-level array for the thread-specific data.  */
  struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];

  /* Flag which is set when specific data is set.  */
  bool specific_used;

  /* True if events must be reported.  */
  bool report_events;

  /* True if the user provided the stack.  */
  bool user_stack;

  /* True if thread must stop at startup time.  */
  bool stopped_start;

  /* Lock to synchronize access to the descriptor.  */
  lll_lock_t lock;

  /* Lock for synchronizing setxid calls.  */
  lll_lock_t setxid_futex;

#if HP_TIMING_AVAIL
  /* Offset of the CPU clock at start thread start time.  */
  hp_timing_t cpuclock_offset;
#endif

  /* If the thread waits to join another one the ID of the latter is
     stored here.

     In case a thread is detached this field contains a pointer of the
     TCB if the thread itself.  This is something which cannot happen
     in normal operation.  */
  struct pthread *joinid;
  /* Check whether a thread is detached.  */
#define IS_DETACHED(pd) ((pd)->joinid == (pd))

  /* Flags.  Including those copied from the thread attribute.  */
  int flags;

  /* The result of the thread function.  */
  void *result;

  /* Scheduling parameters for the new thread.  */
  struct sched_param schedparam;
  int schedpolicy;

  /* Start position of the code to be executed and the argument passed
     to the function.  */
  void *(*start_routine) (void *);
  void *arg;

  /* Debug state.  */
  td_eventbuf_t eventbuf;
  /* Next descriptor with a pending event.  */
  struct pthread *nextevent;

#ifdef HAVE_FORCED_UNWIND
  /* Machine-specific unwind info.  */
  struct _Unwind_Exception exc;
#endif

  /* If nonzero pointer to area allocated for the stack and its
     size.  */
  void *stackblock;
  size_t stackblock_size;
  /* Size of the included guard area.  */
  size_t guardsize;
  /* This is what the user specified and what we will report.  */
  size_t reported_guardsize;

  /* Resolver state.  */
  struct __res_state res;

  /* If you add fields after the res field above, please adjust
     the following macro.  */
#define PTHREAD_STRUCT_END_PADDING \
  (sizeof (struct pthread) - offsetof (struct pthread, res) \
   - sizeof (((struct pthread *) 0)->res))

} __attribute ((aligned (TCB_ALIGNMENT)));


#endif	/* descr.h */