1 /* Copyright (C) 2002-2006, 2007, 2008, 2009 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/>. */
26 #include <sys/types.h>
28 #include <lowlevellock.h>
29 #include <pthreaddef.h>
30 #include "../nptl_db/thread_db.h"
32 #ifdef HAVE_FORCED_UNWIND
35 #define __need_res_state
37 #include <bits/kernel-features.h>
38 #include "uClibc-glue.h"
41 # define TCB_ALIGNMENT sizeof (double)
45 /* We keep thread specific data in a special data structure, a two-level
46 array. The top-level array contains pointers to dynamically allocated
47 arrays of a certain number of data pointers. So we can implement a
48 sparse array. Each dynamic second-level array has
49 PTHREAD_KEY_2NDLEVEL_SIZE
50 entries. This value shouldn't be too large. */
51 #define PTHREAD_KEY_2NDLEVEL_SIZE 32
53 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
54 keys in each subarray. */
55 #define PTHREAD_KEY_1STLEVEL_SIZE \
56 ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
57 / PTHREAD_KEY_2NDLEVEL_SIZE)
62 /* Internal version of the buffer to store cancellation handler
64 struct pthread_unwind_buf
74 /* This is the placeholder of the public version. */
79 /* Pointer to the previous cleanup buffer. */
80 struct pthread_unwind_buf
*prev
;
82 /* Backward compatibility: state of the old-style cleanup
83 handler at the time of the previous new-style cleanup handler
85 struct _pthread_cleanup_buffer
*cleanup
;
87 /* Cancellation type before the push call. */
94 /* Opcodes and data types for communication with the signal handler to
95 change user/group IDs. */
104 /* Data structure used by the kernel to find robust futexes. */
105 struct robust_list_head
108 long int futex_offset
;
109 void *list_op_pending
;
113 /* Data strcture used to handle thread priority protection. */
114 struct priority_protection_data
117 unsigned int priomap
[];
121 /* Thread descriptor data structure. */
126 #if !defined(TLS_DTV_AT_TP)
127 /* This overlaps the TCB as used for TLS without threads (see tls.h). */
132 int multiple_threads
;
134 # ifndef __ASSUME_PRIVATE_FUTEX
140 /* This extra padding has no special purpose, and this structure layout
141 is private and subject to change without affecting the official ABI.
142 We just have it here in case it might be convenient for some
143 implementation-specific instrumentation hack or suchlike. */
147 /* This descriptor's link on the `stack_used' or `__stack_user' list. */
150 /* Thread ID - which is also a 'is this thread descriptor (and
151 therefore stack) used' flag. */
154 /* List of robust mutexes the thread is holding. */
155 #ifdef __PTHREAD_MUTEX_HAVE_PREV
157 struct robust_list_head robust_head
;
159 /* The list above is strange. It is basically a double linked list
160 but the pointer to the next/previous element of the list points
161 in the middle of the object, the __next element. Whenever
162 casting to __pthread_list_t we need to adjust the pointer
164 # define QUEUE_PTR_ADJUST (offsetof (__pthread_list_t, __next))
166 # define ENQUEUE_MUTEX_BOTH(mutex, val) \
168 __pthread_list_t *next = (__pthread_list_t *) \
169 ((((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_head.list)) & ~1ul) \
170 - QUEUE_PTR_ADJUST); \
171 next->__prev = (void *) &mutex->__data.__list.__next; \
172 mutex->__data.__list.__next = THREAD_GETMEM (THREAD_SELF, \
174 mutex->__data.__list.__prev = (void *) &THREAD_SELF->robust_head; \
175 THREAD_SETMEM (THREAD_SELF, robust_head.list, \
176 (void *) (((uintptr_t) &mutex->__data.__list.__next) \
179 # define DEQUEUE_MUTEX(mutex) \
181 __pthread_list_t *next = (__pthread_list_t *) \
182 ((char *) (((uintptr_t) mutex->__data.__list.__next) & ~1ul) \
183 - QUEUE_PTR_ADJUST); \
184 next->__prev = mutex->__data.__list.__prev; \
185 __pthread_list_t *prev = (__pthread_list_t *) \
186 ((char *) (((uintptr_t) mutex->__data.__list.__prev) & ~1ul) \
187 - QUEUE_PTR_ADJUST); \
188 prev->__next = mutex->__data.__list.__next; \
189 mutex->__data.__list.__prev = NULL; \
190 mutex->__data.__list.__next = NULL; \
195 __pthread_slist_t robust_list
;
196 struct robust_list_head robust_head
;
199 # define ENQUEUE_MUTEX_BOTH(mutex, val) \
201 mutex->__data.__list.__next \
202 = THREAD_GETMEM (THREAD_SELF, robust_list.__next); \
203 THREAD_SETMEM (THREAD_SELF, robust_list.__next, \
204 (void *) (((uintptr_t) &mutex->__data.__list) | val)); \
206 # define DEQUEUE_MUTEX(mutex) \
208 __pthread_slist_t *runp = (__pthread_slist_t *) \
209 (((uintptr_t) THREAD_GETMEM (THREAD_SELF, robust_list.__next)) & ~1ul); \
210 if (runp == &mutex->__data.__list) \
211 THREAD_SETMEM (THREAD_SELF, robust_list.__next, runp->__next); \
214 __pthread_slist_t *next = (__pthread_slist_t *) \
215 (((uintptr_t) runp->__next) & ~1ul); \
216 while (next != &mutex->__data.__list) \
219 next = (__pthread_slist_t *) (((uintptr_t) runp->__next) & ~1ul); \
222 runp->__next = next->__next; \
223 mutex->__data.__list.__next = NULL; \
227 #define ENQUEUE_MUTEX(mutex) ENQUEUE_MUTEX_BOTH (mutex, 0)
228 #define ENQUEUE_MUTEX_PI(mutex) ENQUEUE_MUTEX_BOTH (mutex, 1)
230 /* List of cleanup buffers. */
231 struct _pthread_cleanup_buffer
*cleanup
;
233 /* Unwind information. */
234 struct pthread_unwind_buf
*cleanup_jmp_buf
;
235 #define HAVE_CLEANUP_JMP_BUF
237 /* Flags determining processing of cancellation. */
239 /* Bit set if cancellation is disabled. */
240 #define CANCELSTATE_BIT 0
241 #define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
242 /* Bit set if asynchronous cancellation mode is selected. */
243 #define CANCELTYPE_BIT 1
244 #define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
245 /* Bit set if canceling has been initiated. */
246 #define CANCELING_BIT 2
247 #define CANCELING_BITMASK (0x01 << CANCELING_BIT)
248 /* Bit set if canceled. */
249 #define CANCELED_BIT 3
250 #define CANCELED_BITMASK (0x01 << CANCELED_BIT)
251 /* Bit set if thread is exiting. */
252 #define EXITING_BIT 4
253 #define EXITING_BITMASK (0x01 << EXITING_BIT)
254 /* Bit set if thread terminated and TCB is freed. */
255 #define TERMINATED_BIT 5
256 #define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
257 /* Bit set if thread is supposed to change XID. */
259 #define SETXID_BITMASK (0x01 << SETXID_BIT)
260 /* Mask for the rest. Helps the compiler to optimize. */
261 #define CANCEL_RESTMASK 0xffffff80
263 #define CANCEL_ENABLED_AND_CANCELED(value) \
264 (((value) & (CANCELSTATE_BITMASK | CANCELED_BITMASK | EXITING_BITMASK \
265 | CANCEL_RESTMASK | TERMINATED_BITMASK)) == CANCELED_BITMASK)
266 #define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
267 (((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK \
268 | EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \
269 == (CANCELTYPE_BITMASK | CANCELED_BITMASK))
271 /* Flags. Including those copied from the thread attribute. */
274 /* We allocate one block of references here. This should be enough
275 to avoid allocating any memory dynamically for most applications. */
276 struct pthread_key_data
278 /* Sequence number. We use uintptr_t to not require padding on
279 32- and 64-bit machines. On 64-bit machines it helps to avoid
285 } specific_1stblock
[PTHREAD_KEY_2NDLEVEL_SIZE
];
287 /* Two-level array for the thread-specific data. */
288 struct pthread_key_data
*specific
[PTHREAD_KEY_1STLEVEL_SIZE
];
290 /* Flag which is set when specific data is set. */
293 /* True if events must be reported. */
296 /* True if the user provided the stack. */
299 /* True if thread must stop at startup time. */
302 /* The parent's cancel handling at the time of the pthread_create
303 call. This might be needed to undo the effects of a cancellation. */
304 int parent_cancelhandling
;
306 /* Lock to synchronize access to the descriptor. */
309 /* Lock for synchronizing setxid calls. */
312 /* If the thread waits to join another one the ID of the latter is
315 In case a thread is detached this field contains a pointer of the
316 TCB if the thread itself. This is something which cannot happen
317 in normal operation. */
318 struct pthread
*joinid
;
319 /* Check whether a thread is detached. */
320 #define IS_DETACHED(pd) ((pd)->joinid == (pd))
322 /* The result of the thread function. */
325 /* Scheduling parameters for the new thread. */
326 struct sched_param schedparam
;
329 /* Start position of the code to be executed and the argument passed
331 void *(*start_routine
) (void *);
335 td_eventbuf_t eventbuf
;
336 /* Next descriptor with a pending event. */
337 struct pthread
*nextevent
;
339 #ifdef HAVE_FORCED_UNWIND
340 /* Machine-specific unwind info. */
341 struct _Unwind_Exception exc
;
344 /* If nonzero pointer to area allocated for the stack and its
347 size_t stackblock_size
;
348 /* Size of the included guard area. */
350 /* This is what the user specified and what we will report. */
351 size_t reported_guardsize
;
353 /* Thread Priority Protection data. */
354 struct priority_protection_data
*tpp
;
356 /* Resolver state. */
357 struct __res_state res
;
359 /* This member must be last. */
362 #define PTHREAD_STRUCT_END_PADDING \
363 (sizeof (struct pthread) - offsetof (struct pthread, end_padding))
364 } __attribute ((aligned (TCB_ALIGNMENT
)));