]> git.ipfire.org Git - thirdparty/glibc.git/blame - nptl/descr.h
Consolidate non cancellable nanosleep call
[thirdparty/glibc.git] / nptl / descr.h
CommitLineData
bfff8b1b 1/* Copyright (C) 2002-2017 Free Software Foundation, Inc.
76a50749
UD
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
59ba27a6
PE
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
76a50749
UD
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>
500b3a49 28#include <list_t.h>
76a50749
UD
29#include <lowlevellock.h>
30#include <pthreaddef.h>
afb2e954 31#include <dl-sysdep.h>
76a50749 32#include "../nptl_db/thread_db.h"
d4f64e1a 33#include <tls.h>
3e2ee6f0 34#include <unwind.h>
500b3a49 35#include <bits/types/res_state.h>
6df7ffad 36#include <kernel-features.h>
76a50749
UD
37
38#ifndef TCB_ALIGNMENT
39# define TCB_ALIGNMENT sizeof (double)
40#endif
41
42
43/* We keep thread specific data in a special data structure, a two-level
44 array. The top-level array contains pointers to dynamically allocated
45 arrays of a certain number of data pointers. So we can implement a
46 sparse array. Each dynamic second-level array has
47 PTHREAD_KEY_2NDLEVEL_SIZE
48 entries. This value shouldn't be too large. */
49#define PTHREAD_KEY_2NDLEVEL_SIZE 32
50
51/* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
52 keys in each subarray. */
53#define PTHREAD_KEY_1STLEVEL_SIZE \
54 ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
55 / PTHREAD_KEY_2NDLEVEL_SIZE)
56
57
6efd4814
UD
58
59
60/* Internal version of the buffer to store cancellation handler
61 information. */
62struct pthread_unwind_buf
63{
68107ec0
UD
64 struct
65 {
66 __jmp_buf jmp_buf;
67 int mask_was_saved;
68 } cancel_jmp_buf[1];
69
6efd4814
UD
70 union
71 {
72 /* This is the placeholder of the public version. */
68107ec0 73 void *pad[4];
6efd4814
UD
74
75 struct
76 {
6efd4814 77 /* Pointer to the previous cleanup buffer. */
49b65043 78 struct pthread_unwind_buf *prev;
6efd4814
UD
79
80 /* Backward compatibility: state of the old-style cleanup
81 handler at the time of the previous new-style cleanup handler
82 installment. */
83 struct _pthread_cleanup_buffer *cleanup;
84
85 /* Cancellation type before the push call. */
86 int canceltype;
87 } data;
88 } priv;
6efd4814
UD
89};
90
91
2edb61e3
UD
92/* Opcodes and data types for communication with the signal handler to
93 change user/group IDs. */
94struct xid_command
95{
96 int syscall_no;
b007ce7c 97 long int id[3];
2edb61e3 98 volatile int cntr;
771eb141 99 volatile int error; /* -1: no call yet, 0: success seen, >0: error seen. */
2edb61e3
UD
100};
101
102
0f6699ea
UD
103/* Data structure used by the kernel to find robust futexes. */
104struct robust_list_head
105{
106 void *list;
107 long int futex_offset;
108 void *list_op_pending;
109};
110
111
f17efcb4
UD
112/* Data strcture used to handle thread priority protection. */
113struct priority_protection_data
114{
115 int priomax;
116 unsigned int priomap[];
117};
118
119
76a50749
UD
120/* Thread descriptor data structure. */
121struct pthread
122{
76a50749
UD
123 union
124 {
55c11fbd
RM
125#if !TLS_DTV_AT_TP
126 /* This overlaps the TCB as used for TLS without threads (see tls.h). */
127 tcbhead_t header;
bbde8527 128#else
468777e1
UD
129 struct
130 {
439bf404
SP
131 /* multiple_threads is enabled either when the process has spawned at
132 least one thread or when a single-threaded process cancels itself.
133 This enables additional code to introduce locking before doing some
134 compare_and_exchange operations and also enable cancellation points.
135 The concepts of multiple threads and cancellation points ideally
136 should be separate, since it is not necessary for multiple threads to
137 have been created for cancellation points to be enabled, as is the
138 case is when single-threaded process cancels itself.
139
140 Since enabling multiple_threads enables additional code in
141 cancellation points and compare_and_exchange operations, there is a
142 potential for an unneeded performance hit when it is enabled in a
143 single-threaded, self-canceling process. This is OK though, since a
144 single-threaded process will enable async cancellation only when it
145 looks to cancel itself and is hence going to end anyway. */
468777e1 146 int multiple_threads;
991fa82b 147 int gscope_flag;
6df7ffad
UD
148# ifndef __ASSUME_PRIVATE_FUTEX
149 int private_futex;
150# endif
468777e1 151 } header;
d4f64e1a
RM
152#endif
153
55c11fbd
RM
154 /* This extra padding has no special purpose, and this structure layout
155 is private and subject to change without affecting the official ABI.
156 We just have it here in case it might be convenient for some
157 implementation-specific instrumentation hack or suchlike. */
9e9b8cb8 158 void *__padding[24];
55c11fbd
RM
159 };
160
d4f64e1a
RM
161 /* This descriptor's link on the `stack_used' or `__stack_user' list. */
162 list_t list;
76a50749 163
bd8bb78b
UD
164 /* Thread ID - which is also a 'is this thread descriptor (and
165 therefore stack) used' flag. */
166 pid_t tid;
167
c579f48e
AZ
168 /* Ununsed. */
169 pid_t pid_ununsed;
cb5b9388 170
1bcfb5a5 171 /* List of robust mutexes the thread is holding. */
1bcfb5a5 172#ifdef __PTHREAD_MUTEX_HAVE_PREV
0f6699ea
UD
173 void *robust_prev;
174 struct robust_list_head robust_head;
175
176 /* The list above is strange. It is basically a double linked list
177 but the pointer to the next/previous element of the list points
178 in the middle of the object, the __next element. Whenever
179 casting to __pthread_list_t we need to adjust the pointer
8f9450a0
TR
180 first.
181 These operations are effectively concurrent code in that the thread
182 can get killed at any point in time and the kernel takes over. Thus,
183 the __next elements are a kind of concurrent list and we need to
184 enforce using compiler barriers that the individual operations happen
185 in such a way that the kernel always sees a consistent list. The
186 backward links (ie, the __prev elements) are not used by the kernel.
187 FIXME We should use relaxed MO atomic operations here and signal fences
188 because this kind of concurrency is similar to synchronizing with a
189 signal handler. */
0f6699ea 190# define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next))
b007ce7c 191
df47504c 192# define ENQUEUE_MUTEX_BOTH(mutex, val) \
1bcfb5a5 193 do { \
df47504c
UD
194 __pthread_list_t *next = (__pthread_list_t *) \
195 ((((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_head.list)) & ~1ul) \
196 - QUEUE_PTR_ADJUST); \
0f6699ea 197 next->__prev = (void *) &mutex->__data.__list.__next; \
df47504c
UD
198 mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF, \
199 robust_head.list); \
0f6699ea 200 mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \
8f9450a0
TR
201 /* Ensure that the new list entry is ready before we insert it. */ \
202 __asm ("" ::: "memory"); \
0f6699ea 203 THREAD_SETMEM (THREAD_SELF, robust_head.list, \
df47504c
UD
204 (void *) (((uintptr_t) &mutex->__data.__list.__next) \
205 | val)); \
1bcfb5a5
UD
206 } while (0)
207# define DEQUEUE_MUTEX(mutex) \
208 do { \
0f6699ea 209 __pthread_list_t *next = (__pthread_list_t *) \
df47504c
UD
210 ((char *) (((uintptr_t) mutex->__data.__list.__next) & ~1ul) \
211 - QUEUE_PTR_ADJUST); \
0f6699ea
UD
212 next->__prev = mutex->__data.__list.__prev; \
213 __pthread_list_t *prev = (__pthread_list_t *) \
df47504c
UD
214 ((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul) \
215 - QUEUE_PTR_ADJUST); \
0f6699ea 216 prev->__next = mutex->__data.__list.__next; \
8f9450a0
TR
217 /* Ensure that we remove the entry from the list before we change the \
218 __next pointer of the entry, which is read by the kernel. */ \
219 __asm ("" ::: "memory"); \
b007ce7c
UD
220 mutex->__data.__list.__prev = NULL; \
221 mutex->__data.__list.__next = NULL; \
1bcfb5a5
UD
222 } while (0)
223#else
0f6699ea
UD
224 union
225 {
226 __pthread_slist_t robust_list;
227 struct robust_list_head robust_head;
228 };
b007ce7c 229
df47504c 230# define ENQUEUE_MUTEX_BOTH(mutex, val) \
1bcfb5a5 231 do { \
b007ce7c
UD
232 mutex->__data.__list.__next \
233 = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
8f9450a0
TR
234 /* Ensure that the new list entry is ready before we insert it. */ \
235 __asm ("" ::: "memory"); \
df47504c 236 THREAD_SETMEM (THREAD_SELF, robust_list.__next, \
457b559e 237 (void *) (((uintptr_t) &mutex->__data.__list) | val)); \
1bcfb5a5
UD
238 } while (0)
239# define DEQUEUE_MUTEX(mutex) \
240 do { \
df47504c
UD
241 __pthread_slist_t *runp = (__pthread_slist_t *) \
242 (((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_list.__next)) & ~1ul); \
b007ce7c 243 if (runp == &mutex->__data.__list) \
683040c3 244 THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next); \
1bcfb5a5
UD
245 else \
246 { \
df47504c
UD
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 } \
1bcfb5a5 254 \
df47504c 255 runp->__next = next->__next; \
8f9450a0
TR
256 /* Ensure that we remove the entry from the list before we change the \
257 __next pointer of the entry, which is read by the kernel. */ \
258 __asm ("" ::: "memory"); \
b007ce7c 259 mutex->__data.__list.__next = NULL; \
1bcfb5a5
UD
260 } \
261 } while (0)
262#endif
df47504c
UD
263#define ENQUEUE_MUTEX(mutex) ENQUEUE_MUTEX_BOTH (mutex, 0)
264#define ENQUEUE_MUTEX_PI(mutex) ENQUEUE_MUTEX_BOTH (mutex, 1)
1bcfb5a5 265
86bfff4d
UD
266 /* List of cleanup buffers. */
267 struct _pthread_cleanup_buffer *cleanup;
268
6efd4814 269 /* Unwind information. */
49b65043 270 struct pthread_unwind_buf *cleanup_jmp_buf;
6efd4814
UD
271#define HAVE_CLEANUP_JMP_BUF
272
c70ad7d7
UD
273 /* Flags determining processing of cancellation. */
274 int cancelhandling;
275 /* Bit set if cancellation is disabled. */
276#define CANCELSTATE_BIT 0
bd03a1af 277#define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
c70ad7d7
UD
278 /* Bit set if asynchronous cancellation mode is selected. */
279#define CANCELTYPE_BIT 1
bd03a1af 280#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
c70ad7d7
UD
281 /* Bit set if canceling has been initiated. */
282#define CANCELING_BIT 2
bd03a1af 283#define CANCELING_BITMASK (0x01 << CANCELING_BIT)
c70ad7d7
UD
284 /* Bit set if canceled. */
285#define CANCELED_BIT 3
bd03a1af 286#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
c70ad7d7
UD
287 /* Bit set if thread is exiting. */
288#define EXITING_BIT 4
bd03a1af 289#define EXITING_BITMASK (0x01 << EXITING_BIT)
c70ad7d7
UD
290 /* Bit set if thread terminated and TCB is freed. */
291#define TERMINATED_BIT 5
bd03a1af 292#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
dff9a7a1
UD
293 /* Bit set if thread is supposed to change XID. */
294#define SETXID_BIT 6
bd03a1af 295#define SETXID_BITMASK (0x01 << SETXID_BIT)
c70ad7d7 296 /* Mask for the rest. Helps the compiler to optimize. */
dff9a7a1 297#define CANCEL_RESTMASK 0xffffff80
c70ad7d7
UD
298
299#define CANCEL_ENABLED_AND_CANCELED(value) \
300 (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK \
301 | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
302#define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
303 (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK \
304 | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \
305 == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
5869d4ec 306
341c566f
UD
307 /* Flags. Including those copied from the thread attribute. */
308 int flags;
309
5869d4ec
UD
310 /* We allocate one block of references here. This should be enough
311 to avoid allocating any memory dynamically for most applications. */
76a50749
UD
312 struct pthread_key_data
313 {
314 /* Sequence number. We use uintptr_t to not require padding on
315 32- and 64-bit machines. On 64-bit machines it helps to avoid
316 wrapping, too. */
317 uintptr_t seq;
318
319 /* Data pointer. */
320 void *data;
5869d4ec
UD
321 } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
322
a334319f
UD
323 /* Two-level array for the thread-specific data. */
324 struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
325
dff9a7a1
UD
326 /* Flag which is set when specific data is set. */
327 bool specific_used;
328
c70ad7d7
UD
329 /* True if events must be reported. */
330 bool report_events;
331
76a50749
UD
332 /* True if the user provided the stack. */
333 bool user_stack;
334
5f66b766
UD
335 /* True if thread must stop at startup time. */
336 bool stopped_start;
337
b051fc44
UD
338 /* The parent's cancel handling at the time of the pthread_create
339 call. This might be needed to undo the effects of a cancellation. */
340 int parent_cancelhandling;
341
5869d4ec 342 /* Lock to synchronize access to the descriptor. */
e51deae7 343 int lock;
76a50749 344
dff9a7a1 345 /* Lock for synchronizing setxid calls. */
45a8f0e6 346 unsigned int setxid_futex;
dff9a7a1 347
76a50749
UD
348#if HP_TIMING_AVAIL
349 /* Offset of the CPU clock at start thread start time. */
350 hp_timing_t cpuclock_offset;
351#endif
352
353 /* If the thread waits to join another one the ID of the latter is
354 stored here.
355
356 In case a thread is detached this field contains a pointer of the
357 TCB if the thread itself. This is something which cannot happen
358 in normal operation. */
359 struct pthread *joinid;
360 /* Check whether a thread is detached. */
361#define IS_DETACHED(pd) ((pd)->joinid == (pd))
362
76a50749
UD
363 /* The result of the thread function. */
364 void *result;
365
366 /* Scheduling parameters for the new thread. */
367 struct sched_param schedparam;
368 int schedpolicy;
369
370 /* Start position of the code to be executed and the argument passed
371 to the function. */
372 void *(*start_routine) (void *);
373 void *arg;
374
375 /* Debug state. */
376 td_eventbuf_t eventbuf;
377 /* Next descriptor with a pending event. */
378 struct pthread *nextevent;
379
68107ec0
UD
380 /* Machine-specific unwind info. */
381 struct _Unwind_Exception exc;
68107ec0 382
76a50749
UD
383 /* If nonzero pointer to area allocated for the stack and its
384 size. */
385 void *stackblock;
386 size_t stackblock_size;
387 /* Size of the included guard area. */
388 size_t guardsize;
5adac0e4
UD
389 /* This is what the user specified and what we will report. */
390 size_t reported_guardsize;
0e9d6240 391
f17efcb4
UD
392 /* Thread Priority Protection data. */
393 struct priority_protection_data *tpp;
394
0e9d6240
UD
395 /* Resolver state. */
396 struct __res_state res;
253eb3a0 397
c5132ca1
RM
398 /* This member must be last. */
399 char end_padding[];
253eb3a0 400
c5132ca1
RM
401#define PTHREAD_STRUCT_END_PADDING \
402 (sizeof (struct pthread) - offsetof (struct pthread, end_padding))
76a50749
UD
403} __attribute ((aligned (TCB_ALIGNMENT)));
404
405
406#endif /* descr.h */