Include atomic.h in generic lowlevellock.c.
[glibc.git] / nptl / descr.h
blob58176ea2d8b6886da4c136886bd0788fa023ce50
1 /* Copyright (C) 2002-2013 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
19 #ifndef _DESCR_H
20 #define _DESCR_H 1
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>
28 #define __need_list_t
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 #include <kernel-features.h>
42 #ifndef TCB_ALIGNMENT
43 # define TCB_ALIGNMENT sizeof (double)
44 #endif
47 /* We keep thread specific data in a special data structure, a two-level
48 array. The top-level array contains pointers to dynamically allocated
49 arrays of a certain number of data pointers. So we can implement a
50 sparse array. Each dynamic second-level array has
51 PTHREAD_KEY_2NDLEVEL_SIZE
52 entries. This value shouldn't be too large. */
53 #define PTHREAD_KEY_2NDLEVEL_SIZE 32
55 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
56 keys in each subarray. */
57 #define PTHREAD_KEY_1STLEVEL_SIZE \
58 ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
59 / PTHREAD_KEY_2NDLEVEL_SIZE)
64 /* Internal version of the buffer to store cancellation handler
65 information. */
66 struct pthread_unwind_buf
68 struct
70 __jmp_buf jmp_buf;
71 int mask_was_saved;
72 } cancel_jmp_buf[1];
74 union
76 /* This is the placeholder of the public version. */
77 void *pad[4];
79 struct
81 /* Pointer to the previous cleanup buffer. */
82 struct pthread_unwind_buf *prev;
84 /* Backward compatibility: state of the old-style cleanup
85 handler at the time of the previous new-style cleanup handler
86 installment. */
87 struct _pthread_cleanup_buffer *cleanup;
89 /* Cancellation type before the push call. */
90 int canceltype;
91 } data;
92 } priv;
96 /* Opcodes and data types for communication with the signal handler to
97 change user/group IDs. */
98 struct xid_command
100 int syscall_no;
101 long int id[3];
102 volatile int cntr;
106 /* Data structure used by the kernel to find robust futexes. */
107 struct robust_list_head
109 void *list;
110 long int futex_offset;
111 void *list_op_pending;
115 /* Data strcture used to handle thread priority protection. */
116 struct priority_protection_data
118 int priomax;
119 unsigned int priomap[];
123 /* Thread descriptor data structure. */
124 struct pthread
126 union
128 #if !TLS_DTV_AT_TP
129 /* This overlaps the TCB as used for TLS without threads (see tls.h). */
130 tcbhead_t header;
131 #else
132 struct
134 /* multiple_threads is enabled either when the process has spawned at
135 least one thread or when a single-threaded process cancels itself.
136 This enables additional code to introduce locking before doing some
137 compare_and_exchange operations and also enable cancellation points.
138 The concepts of multiple threads and cancellation points ideally
139 should be separate, since it is not necessary for multiple threads to
140 have been created for cancellation points to be enabled, as is the
141 case is when single-threaded process cancels itself.
143 Since enabling multiple_threads enables additional code in
144 cancellation points and compare_and_exchange operations, there is a
145 potential for an unneeded performance hit when it is enabled in a
146 single-threaded, self-canceling process. This is OK though, since a
147 single-threaded process will enable async cancellation only when it
148 looks to cancel itself and is hence going to end anyway. */
149 int multiple_threads;
150 int gscope_flag;
151 # ifndef __ASSUME_PRIVATE_FUTEX
152 int private_futex;
153 # endif
154 } header;
155 #endif
157 /* This extra padding has no special purpose, and this structure layout
158 is private and subject to change without affecting the official ABI.
159 We just have it here in case it might be convenient for some
160 implementation-specific instrumentation hack or suchlike. */
161 void *__padding[24];
164 /* This descriptor's link on the `stack_used' or `__stack_user' list. */
165 list_t list;
167 /* Thread ID - which is also a 'is this thread descriptor (and
168 therefore stack) used' flag. */
169 pid_t tid;
171 /* Process ID - thread group ID in kernel speak. */
172 pid_t pid;
174 /* List of robust mutexes the thread is holding. */
175 #ifdef __PTHREAD_MUTEX_HAVE_PREV
176 void *robust_prev;
177 struct robust_list_head robust_head;
179 /* The list above is strange. It is basically a double linked list
180 but the pointer to the next/previous element of the list points
181 in the middle of the object, the __next element. Whenever
182 casting to __pthread_list_t we need to adjust the pointer
183 first. */
184 # define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next))
186 # define ENQUEUE_MUTEX_BOTH(mutex, val) \
187 do { \
188 __pthread_list_t *next = (__pthread_list_t *) \
189 ((((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_head.list)) & ~1ul) \
190 - QUEUE_PTR_ADJUST); \
191 next->__prev = (void *) &mutex->__data.__list.__next; \
192 mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF, \
193 robust_head.list); \
194 mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \
195 THREAD_SETMEM (THREAD_SELF, robust_head.list, \
196 (void *) (((uintptr_t) &mutex->__data.__list.__next) \
197 | val)); \
198 } while (0)
199 # define DEQUEUE_MUTEX(mutex) \
200 do { \
201 __pthread_list_t *next = (__pthread_list_t *) \
202 ((char *) (((uintptr_t) mutex->__data.__list.__next) & ~1ul) \
203 - QUEUE_PTR_ADJUST); \
204 next->__prev = mutex->__data.__list.__prev; \
205 __pthread_list_t *prev = (__pthread_list_t *) \
206 ((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul) \
207 - QUEUE_PTR_ADJUST); \
208 prev->__next = mutex->__data.__list.__next; \
209 mutex->__data.__list.__prev = NULL; \
210 mutex->__data.__list.__next = NULL; \
211 } while (0)
212 #else
213 union
215 __pthread_slist_t robust_list;
216 struct robust_list_head robust_head;
219 # define ENQUEUE_MUTEX_BOTH(mutex, val) \
220 do { \
221 mutex->__data.__list.__next \
222 = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
223 THREAD_SETMEM (THREAD_SELF, robust_list.__next, \
224 (void *) (((uintptr_t) &mutex->__data.__list) | val)); \
225 } while (0)
226 # define DEQUEUE_MUTEX(mutex) \
227 do { \
228 __pthread_slist_t *runp = (__pthread_slist_t *) \
229 (((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_list.__next)) & ~1ul); \
230 if (runp == &mutex->__data.__list) \
231 THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next); \
232 else \
234 __pthread_slist_t *next = (__pthread_slist_t *) \
235 (((uintptr_t) runp->__next) & ~1ul); \
236 while (next != &mutex->__data.__list) \
238 runp = next; \
239 next = (__pthread_slist_t *) (((uintptr_t) runp->__next) & ~1ul); \
242 runp->__next = next->__next; \
243 mutex->__data.__list.__next = NULL; \
245 } while (0)
246 #endif
247 #define ENQUEUE_MUTEX(mutex) ENQUEUE_MUTEX_BOTH (mutex, 0)
248 #define ENQUEUE_MUTEX_PI(mutex) ENQUEUE_MUTEX_BOTH (mutex, 1)
250 /* List of cleanup buffers. */
251 struct _pthread_cleanup_buffer *cleanup;
253 /* Unwind information. */
254 struct pthread_unwind_buf *cleanup_jmp_buf;
255 #define HAVE_CLEANUP_JMP_BUF
257 /* Flags determining processing of cancellation. */
258 int cancelhandling;
259 /* Bit set if cancellation is disabled. */
260 #define CANCELSTATE_BIT 0
261 #define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
262 /* Bit set if asynchronous cancellation mode is selected. */
263 #define CANCELTYPE_BIT 1
264 #define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
265 /* Bit set if canceling has been initiated. */
266 #define CANCELING_BIT 2
267 #define CANCELING_BITMASK (0x01 << CANCELING_BIT)
268 /* Bit set if canceled. */
269 #define CANCELED_BIT 3
270 #define CANCELED_BITMASK (0x01 << CANCELED_BIT)
271 /* Bit set if thread is exiting. */
272 #define EXITING_BIT 4
273 #define EXITING_BITMASK (0x01 << EXITING_BIT)
274 /* Bit set if thread terminated and TCB is freed. */
275 #define TERMINATED_BIT 5
276 #define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
277 /* Bit set if thread is supposed to change XID. */
278 #define SETXID_BIT 6
279 #define SETXID_BITMASK (0x01 << SETXID_BIT)
280 /* Mask for the rest. Helps the compiler to optimize. */
281 #define CANCEL_RESTMASK 0xffffff80
283 #define CANCEL_ENABLED_AND_CANCELED(value) \
284 (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK \
285 | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
286 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
287 (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK \
288 | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \
289 == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
291 /* Flags. Including those copied from the thread attribute. */
292 int flags;
294 /* We allocate one block of references here. This should be enough
295 to avoid allocating any memory dynamically for most applications. */
296 struct pthread_key_data
298 /* Sequence number. We use uintptr_t to not require padding on
299 32- and 64-bit machines. On 64-bit machines it helps to avoid
300 wrapping, too. */
301 uintptr_t seq;
303 /* Data pointer. */
304 void *data;
305 } specific_1stblock[PTHREAD_KEY_2NDLEVEL_SIZE];
307 /* Two-level array for the thread-specific data. */
308 struct pthread_key_data *specific[PTHREAD_KEY_1STLEVEL_SIZE];
310 /* Flag which is set when specific data is set. */
311 bool specific_used;
313 /* True if events must be reported. */
314 bool report_events;
316 /* True if the user provided the stack. */
317 bool user_stack;
319 /* True if thread must stop at startup time. */
320 bool stopped_start;
322 /* The parent's cancel handling at the time of the pthread_create
323 call. This might be needed to undo the effects of a cancellation. */
324 int parent_cancelhandling;
326 /* Lock to synchronize access to the descriptor. */
327 int lock;
329 /* Lock for synchronizing setxid calls. */
330 int setxid_futex;
332 #if HP_TIMING_AVAIL
333 /* Offset of the CPU clock at start thread start time. */
334 hp_timing_t cpuclock_offset;
335 #endif
337 /* If the thread waits to join another one the ID of the latter is
338 stored here.
340 In case a thread is detached this field contains a pointer of the
341 TCB if the thread itself. This is something which cannot happen
342 in normal operation. */
343 struct pthread *joinid;
344 /* Check whether a thread is detached. */
345 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
347 /* The result of the thread function. */
348 void *result;
350 /* Scheduling parameters for the new thread. */
351 struct sched_param schedparam;
352 int schedpolicy;
354 /* Start position of the code to be executed and the argument passed
355 to the function. */
356 void *(*start_routine) (void *);
357 void *arg;
359 /* Debug state. */
360 td_eventbuf_t eventbuf;
361 /* Next descriptor with a pending event. */
362 struct pthread *nextevent;
364 #ifdef HAVE_FORCED_UNWIND
365 /* Machine-specific unwind info. */
366 struct _Unwind_Exception exc;
367 #endif
369 /* If nonzero pointer to area allocated for the stack and its
370 size. */
371 void *stackblock;
372 size_t stackblock_size;
373 /* Size of the included guard area. */
374 size_t guardsize;
375 /* This is what the user specified and what we will report. */
376 size_t reported_guardsize;
378 /* Thread Priority Protection data. */
379 struct priority_protection_data *tpp;
381 /* Resolver state. */
382 struct __res_state res;
384 /* This member must be last. */
385 char end_padding[];
387 #define PTHREAD_STRUCT_END_PADDING \
388 (sizeof (struct pthread) - offsetof (struct pthread, end_padding))
389 } __attribute ((aligned (TCB_ALIGNMENT)));
392 #endif /* descr.h */