1 /* Internal defenitions for pthreads library.
2 Copyright (C) 2000-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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 <https://www.gnu.org/licenses/>. */
19 #ifndef _PT_INTERNAL_H
20 #define _PT_INTERNAL_H 1
27 #include <bits/types/res_state.h>
33 #include <pt-sysdep.h>
34 #include <pt-machdep.h>
36 #if IS_IN (libpthread)
37 # include <ldsodefs.h>
45 /* The thread is running and joinable. */
47 /* The thread is running and detached. */
49 /* A joinable thread exited and its return code is available. */
51 /* The thread structure is unallocated and available for reuse. */
55 #ifndef PTHREAD_KEY_MEMBERS
56 # define PTHREAD_KEY_MEMBERS
59 #ifndef PTHREAD_SYSDEP_MEMBERS
60 # define PTHREAD_SYSDEP_MEMBERS
63 /* This structure describes a POSIX thread. */
69 unsigned int nr_refs
; /* Detached threads have a self reference only,
70 while joinable threads have two references.
71 These are used to keep the structure valid at
72 thread destruction. Detaching/joining a thread
76 pthread_mutex_t cancel_lock
; /* Protect cancel_xxx members. */
77 void (*cancel_hook
) (void *); /* Called to unblock a thread blocking
78 in a cancellation point (namely,
79 __pthread_cond_timedwait_internal). */
80 void *cancel_hook_arg
;
89 int stack
; /* Nonzero if the stack was allocated. */
95 enum pthread_state state
;
96 pthread_mutex_t state_lock
; /* Locks the state. */
97 pthread_cond_t state_cond
; /* Signalled when the state changes. */
100 struct __res_state res_state
;
102 /* Indicates whether is a C11 thread created by thrd_creat. */
105 /* Initial sigset for the thread. */
106 sigset_t init_sigset
;
108 /* Thread context. */
109 struct pthread_mcontext mcontext
;
113 PTHREAD_SYSDEP_MEMBERS
117 /* Queue links. Since PREVP is used to determine if a thread has been
118 awaken, it must be protected by the queue lock. */
119 struct __pthread
*next
, **prevp
;
122 /* Enqueue an element THREAD on the queue *HEAD. */
124 __pthread_enqueue (struct __pthread
**head
, struct __pthread
*thread
)
126 assert (thread
->prevp
== 0);
128 thread
->next
= *head
;
129 thread
->prevp
= head
;
131 (*head
)->prevp
= &thread
->next
;
135 /* Dequeue the element THREAD from the queue it is connected to. */
137 __pthread_dequeue (struct __pthread
*thread
)
140 assert (thread
->prevp
);
143 thread
->next
->prevp
= thread
->prevp
;
144 *thread
->prevp
= thread
->next
;
148 /* Iterate over QUEUE storing each element in ELEMENT. */
149 #define __pthread_queue_iterate(queue, element) \
150 for (struct __pthread *__pdi_next = (queue); \
151 ((element) = __pdi_next) \
152 && ((__pdi_next = __pdi_next->next), \
156 /* Iterate over QUEUE dequeuing each element, storing it in
158 #define __pthread_dequeuing_iterate(queue, element) \
159 for (struct __pthread *__pdi_next = (queue); \
160 ((element) = __pdi_next) \
161 && ((__pdi_next = __pdi_next->next), \
162 ((element)->prevp = 0), \
166 /* The total number of threads currently active. */
167 extern unsigned int __pthread_total
;
169 /* Concurrency hint. */
170 extern int __pthread_concurrency
;
172 /* The size of the thread ID lookup table. */
173 extern int __pthread_max_threads
;
175 #define __pthread_getid(thread) \
176 ({ struct __pthread *__t = NULL; \
177 __libc_rwlock_rdlock (GL (dl_pthread_threads_lock)); \
178 if (thread <= __pthread_max_threads) \
179 __t = GL (dl_pthread_threads)[thread - 1]; \
180 __libc_rwlock_unlock (GL (dl_pthread_threads_lock)); \
183 #define __pthread_setid(thread, pthread) \
184 __libc_rwlock_wrlock (GL (dl_pthread_threads_lock)); \
185 GL (dl_pthread_threads)[thread - 1] = pthread; \
186 __libc_rwlock_unlock (GL (dl_pthread_threads_lock));
188 /* Similar to pthread_self, but returns the thread descriptor instead
190 #ifndef _pthread_self
191 extern struct __pthread
*_pthread_self (void);
194 /* Stores the stack of cleanup handlers for the thread. */
195 extern __thread
struct __pthread_cancelation_handler
*__pthread_cleanup_stack
;
198 /* Initialize the pthreads library. */
199 extern void ___pthread_init (void);
201 /* Internal version of pthread_create. Rather than return the new
202 tid, we return the whole __pthread structure in *PTHREAD. */
203 extern int __pthread_create_internal (struct __pthread
**__restrict pthread
,
204 const pthread_attr_t
*__restrict attr
,
205 void *(*start_routine
) (void *),
206 void *__restrict arg
);
208 /* Allocate a new thread structure and a pthread thread ID (but not a
209 kernel thread or a stack). THREAD has one reference. */
210 extern int __pthread_alloc (struct __pthread
**thread
);
212 /* Deallocate the thread structure. This is the dual of
213 __pthread_alloc (N.B. it does not call __pthread_stack_dealloc nor
214 __pthread_thread_terminate). THREAD loses one reference and is
215 released if the reference counter drops to 0. */
216 extern void __pthread_dealloc (struct __pthread
*thread
);
219 /* Allocate a stack of size STACKSIZE. The stack base shall be
220 returned in *STACKADDR. */
221 extern int __pthread_stack_alloc (void **stackaddr
, size_t stacksize
);
223 /* Deallocate the stack STACKADDR of size STACKSIZE. */
224 extern void __pthread_stack_dealloc (void *stackaddr
, size_t stacksize
);
227 /* Setup thread THREAD's context. */
228 extern int __pthread_setup (struct __pthread
*__restrict thread
,
229 void (*entry_point
) (struct __pthread
*,
232 void *(*start_routine
) (void *),
233 void *__restrict arg
);
236 /* Allocate a kernel thread (and any miscellaneous system dependent
237 resources) for THREAD; it must not be placed on the run queue. */
238 extern int __pthread_thread_alloc (struct __pthread
*thread
);
240 /* Start THREAD making it eligible to run. */
241 extern int __pthread_thread_start (struct __pthread
*thread
);
243 /* Terminate the kernel thread associated with THREAD, and deallocate its
244 stack as well as any other kernel resource associated with it.
245 In addition, THREAD looses one reference.
247 This function can be called by any thread, including the target thread.
248 Since some resources that are destroyed along the kernel thread are
249 stored in thread-local variables, the conditions required for this
250 function to behave correctly are a bit unusual : as long as the target
251 thread hasn't been started, any thread can terminate it, but once it
252 has started, no other thread can terminate it, so that thread-local
253 variables created by that thread are correctly released. */
254 extern void __pthread_thread_terminate (struct __pthread
*thread
);
257 /* Called by a thread just before it calls the provided start
259 extern void __pthread_startup (void);
262 extern void __pthread_block (struct __pthread
*thread
);
264 /* Block THREAD until *ABSTIME is reached. */
265 extern error_t
__pthread_timedblock (struct __pthread
*__restrict thread
,
266 const struct timespec
*__restrict abstime
,
269 /* Block THREAD with interrupts. */
270 extern error_t
__pthread_block_intr (struct __pthread
*thread
);
272 /* Block THREAD until *ABSTIME is reached, with interrupts. */
273 extern error_t
__pthread_timedblock_intr (struct __pthread
*__restrict thread
,
274 const struct timespec
*__restrict abstime
,
278 extern void __pthread_wakeup (struct __pthread
*thread
);
281 /* Perform a cancelation. The CANCEL_LOCK member of the given thread must
282 be locked before calling this function, which must unlock it. */
283 extern int __pthread_do_cancel (struct __pthread
*thread
);
286 /* Initialize the thread specific data structures. THREAD must be the
288 extern error_t
__pthread_init_specific (struct __pthread
*thread
);
290 /* Call the destructors on all of the thread specific data in THREAD.
291 THREAD must be the calling thread. */
292 extern void __pthread_destroy_specific (struct __pthread
*thread
);
295 /* Initialize newly create thread *THREAD's signal state data
297 extern error_t
__pthread_sigstate_init (struct __pthread
*thread
);
299 /* Destroy the signal state data structures associcated with thread
301 extern void __pthread_sigstate_destroy (struct __pthread
*thread
);
303 /* Modify thread *THREAD's signal state. */
304 extern error_t
__pthread_sigstate (struct __pthread
*__restrict thread
, int how
,
305 const sigset_t
*__restrict set
,
306 sigset_t
*__restrict oset
,
309 /* If supported, check that MUTEX is locked by the caller. */
310 extern int __pthread_mutex_checklocked (pthread_mutex_t
*mtx
);
313 /* Default thread attributes. */
314 extern struct __pthread_attr __pthread_default_attr
;
316 /* Default barrier attributes. */
317 extern const struct __pthread_barrierattr __pthread_default_barrierattr
;
319 /* Default rdlock attributes. */
320 extern const struct __pthread_rwlockattr __pthread_default_rwlockattr
;
322 /* Default condition attributes. */
323 extern const struct __pthread_condattr __pthread_default_condattr
;
325 /* Semaphore encoding.
326 See nptl implementation for the details. */
329 #if __HAVE_64B_ATOMICS
330 /* The data field holds both value (in the least-significant 32 bits) and
332 # if __BYTE_ORDER == __LITTLE_ENDIAN
333 # define SEM_VALUE_OFFSET 0
334 # elif __BYTE_ORDER == __BIG_ENDIAN
335 # define SEM_VALUE_OFFSET 1
337 # error Unsupported byte order.
339 # define SEM_NWAITERS_SHIFT 32
340 # define SEM_VALUE_MASK (~(unsigned int)0)
343 #define __SEMAPHORE_INITIALIZER(value, pshared) \
344 { (value), (pshared) }
346 # define SEM_VALUE_SHIFT 1
347 # define SEM_NWAITERS_MASK ((unsigned int)1)
349 unsigned int nwaiters
;
351 #define __SEMAPHORE_INITIALIZER(value, pshared) \
352 { (value) << SEM_VALUE_SHIFT, 0, (pshared) }
356 extern int __sem_waitfast (struct new_sem
*isem
, int definitive_result
);
358 #endif /* pt-internal.h */