libpthread/linuxthreads/internals.h

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program 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        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 #ifndef _INTERNALS_H
  16 #define _INTERNALS_H   1
  17
  18 /* Internal data structures */
  19
  20 /* Includes */
  21
  22 #include <bits/libc-tsd.h> /* for _LIBC_TSD_KEY_N */
  23 #include <limits.h>
  24 #include <setjmp.h>
  25 #include <signal.h>
  26 #include <unistd.h>
  27 #include <bits/stackinfo.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include "pt-machine.h"
  31 #include "semaphore.h"
  32 #include "../linuxthreads_db/thread_dbP.h"
  33 #ifdef __UCLIBC_HAS_XLOCALE__
  34 #include <bits/uClibc_locale.h>
  35 #endif /* __UCLIBC_HAS_XLOCALE__ */
  36
  37 /* Use a funky version in a probably vein attempt at preventing gdb
  38  * from dlopen()'ing glibc's libthread_db library... */
  39 #define VERSION __stringify(__UCLIBC_MAJOR__) "." __stringify(__UCLIBC_MINOR__) "." __stringify(__UCLIBC_SUBLEVEL__)
  40
  41 #ifndef THREAD_GETMEM
  42 # define THREAD_GETMEM(descr, member) descr->member
  43 #endif
  44 #ifndef THREAD_GETMEM_NC
  45 # define THREAD_GETMEM_NC(descr, member) descr->member
  46 #endif
  47 #ifndef THREAD_SETMEM
  48 # define THREAD_SETMEM(descr, member, value) descr->member = (value)
  49 #endif
  50 #ifndef THREAD_SETMEM_NC
  51 # define THREAD_SETMEM_NC(descr, member, value) descr->member = (value)
  52 #endif
  53
  54 /* Arguments passed to thread creation routine */
  55
  56 struct pthread_start_args {
  57   void * (*start_routine)(void *); /* function to run */
  58   void * arg;                   /* its argument */
  59   sigset_t mask;                /* initial signal mask for thread */
  60   int schedpolicy;              /* initial scheduling policy (if any) */
  61   struct sched_param schedparam; /* initial scheduling parameters (if any) */
  62 };
  63
  64
  65 /* We keep thread specific data in a special data structure, a two-level
  66    array.  The top-level array contains pointers to dynamically allocated
  67    arrays of a certain number of data pointers.  So we can implement a
  68    sparse array.  Each dynamic second-level array has
  69         PTHREAD_KEY_2NDLEVEL_SIZE
  70    entries.  This value shouldn't be too large.  */
  71 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  72
  73 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  74    keys in each subarray.  */
  75 #define PTHREAD_KEY_1STLEVEL_SIZE \
  76   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  77    / PTHREAD_KEY_2NDLEVEL_SIZE)
  78
  79 typedef void (*destr_function)(void *);
  80
  81 struct pthread_key_struct {
  82   int in_use;                   /* already allocated? */
  83   destr_function destr;         /* destruction routine */
  84 };
  85
  86
  87 #define PTHREAD_START_ARGS_INITIALIZER { NULL, NULL, {{0, }}, 0, { 0 } }
  88
  89 /* The type of thread descriptors */
  90
  91 typedef struct _pthread_descr_struct * pthread_descr;
  92
  93 /* Callback interface for removing the thread from waiting on an
  94    object if it is cancelled while waiting or about to wait.
  95    This hold a pointer to the object, and a pointer to a function
  96    which ``extricates'' the thread from its enqueued state.
  97    The function takes two arguments: pointer to the wait object,
  98    and a pointer to the thread. It returns 1 if an extrication
  99    actually occured, and hence the thread must also be signalled.
 100    It returns 0 if the thread had already been extricated. */
 101
 102 typedef struct _pthread_extricate_struct {
 103     void *pu_object;
 104     int (*pu_extricate_func)(void *, pthread_descr);
 105 } pthread_extricate_if;
 106
 107 /* Atomic counter made possible by compare_and_swap */
 108
 109 struct pthread_atomic {
 110   long p_count;
 111   int p_spinlock;
 112 };
 113
 114 /* Context info for read write locks. The pthread_rwlock_info structure
 115    is information about a lock that has been read-locked by the thread
 116    in whose list this structure appears. The pthread_rwlock_context
 117    is embedded in the thread context and contains a pointer to the
 118    head of the list of lock info structures, as well as a count of
 119    read locks that are untracked, because no info structure could be
 120    allocated for them. */
 121
 122 struct _pthread_rwlock_t;
 123
 124 typedef struct _pthread_rwlock_info {
 125   struct _pthread_rwlock_info *pr_next;
 126   struct _pthread_rwlock_t *pr_lock;
 127   int pr_lock_count;
 128 } pthread_readlock_info;
 129
 130 struct _pthread_descr_struct {
 131   pthread_descr p_nextlive, p_prevlive;
 132                                 /* Double chaining of active threads */
 133   pthread_descr p_nextwaiting;  /* Next element in the queue holding the thr */
 134   pthread_descr p_nextlock;     /* can be on a queue and waiting on a lock */
 135   pthread_t p_tid;              /* Thread identifier */
 136   int p_pid;                    /* PID of Unix process */
 137   int p_priority;               /* Thread priority (== 0 if not realtime) */
 138   struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
 139   int p_signal;                 /* last signal received */
 140   sigjmp_buf * p_signal_jmp;    /* where to siglongjmp on a signal or NULL */
 141   sigjmp_buf * p_cancel_jmp;    /* where to siglongjmp on a cancel or NULL */
 142   char p_terminated;            /* true if terminated e.g. by pthread_exit */
 143   char p_detached;              /* true if detached */
 144   char p_exited;                /* true if the assoc. process terminated */
 145   void * p_retval;              /* placeholder for return value */
 146   int p_retcode;                /* placeholder for return code */
 147   pthread_descr p_joining;      /* thread joining on that thread or NULL */
 148   struct _pthread_cleanup_buffer * p_cleanup; /* cleanup functions */
 149   char p_cancelstate;           /* cancellation state */
 150   char p_canceltype;            /* cancellation type (deferred/async) */
 151   char p_canceled;              /* cancellation request pending */
 152   int * p_errnop;               /* pointer to used errno variable */
 153   int p_errno;                  /* error returned by last system call */
 154   int * p_h_errnop;             /* pointer to used h_errno variable */
 155   int p_h_errno;                /* error returned by last netdb function */
 156   char * p_in_sighandler;       /* stack address of sighandler, or NULL */
 157   char p_sigwaiting;            /* true if a sigwait() is in progress */
 158   struct pthread_start_args p_start_args; /* arguments for thread creation */
 159   void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
 160   void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
 161   int p_userstack;              /* nonzero if the user provided the stack */
 162   void *p_guardaddr;            /* address of guard area or NULL */
 163   size_t p_guardsize;           /* size of guard area */
 164   pthread_descr p_self;         /* Pointer to this structure */
 165   int p_nr;                     /* Index of descriptor in __pthread_handles */
 166   int p_report_events;         /* Nonzero if events must be reported.  */
 167   td_eventbuf_t p_eventbuf;     /* Data for event.  */
 168   struct pthread_atomic p_resume_count; /* number of times restart() was
 169                                            called on thread */
 170   char p_woken_by_cancel;       /* cancellation performed wakeup */
 171   char p_condvar_avail;         /* flag if conditional variable became avail */
 172   char p_sem_avail;             /* flag if semaphore became available */
 173   pthread_extricate_if *p_extricate; /* See above */
 174   pthread_readlock_info *p_readlock_list;  /* List of readlock info structs */
 175   pthread_readlock_info *p_readlock_free;  /* Free list of structs */
 176   int p_untracked_readlock_count;       /* Readlocks not tracked by list */
 177   /* New elements must be added at the end.  */
 178 #ifdef __UCLIBC_HAS_XLOCALE__
 179   __locale_t locale; /* thread-specific locale from uselocale() only! */
 180 #endif /* __UCLIBC_HAS_XLOCALE__ */
 181 } __attribute__ ((aligned(32))); /* We need to align the structure so that
 182                                     doubles are aligned properly.  This is 8
 183                                     bytes on MIPS and 16 bytes on MIPS64.
 184                                     32 bytes might give better cache
 185                                     utilization.  */
 186
 187 /* The type of thread handles. */
 188
 189 typedef struct pthread_handle_struct * pthread_handle;
 190
 191 struct pthread_handle_struct {
 192   struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
 193   pthread_descr h_descr;        /* Thread descriptor or NULL if invalid */
 194   char * h_bottom;              /* Lowest address in the stack thread */
 195 };
 196
 197 /* The type of messages sent to the thread manager thread */
 198
 199 struct pthread_request {
 200   pthread_descr req_thread;     /* Thread doing the request */
 201   enum {                        /* Request kind */
 202     REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
 203     REQ_POST, REQ_DEBUG, REQ_KICK
 204   } req_kind;
 205   union {                       /* Arguments for request */
 206     struct {                    /* For REQ_CREATE: */
 207       const pthread_attr_t * attr; /* thread attributes */
 208       void * (*fn)(void *);     /*   start function */
 209       void * arg;               /*   argument to start function */
 210       sigset_t mask;            /*   signal mask */
 211     } create;
 212     struct {                    /* For REQ_FREE: */
 213       pthread_t thread_id;      /*   identifier of thread to free */
 214     } free;
 215     struct {                    /* For REQ_PROCESS_EXIT: */
 216       int code;                 /*   exit status */
 217     } exit;
 218     void * post;                /* For REQ_POST: the semaphore */
 219   } req_args;
 220 };
 221
 222
 223 /* Signals used for suspend/restart and for cancellation notification.  */
 224
 225 extern int __pthread_sig_restart;
 226 extern int __pthread_sig_cancel;
 227
 228 /* Signal used for interfacing with gdb */
 229
 230 extern int __pthread_sig_debug;
 231
 232 /* Global array of thread handles, used for validating a thread id
 233    and retrieving the corresponding thread descriptor. Also used for
 234    mapping the available stack segments. */
 235
 236 extern struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX];
 237
 238 /* Descriptor of the initial thread */
 239
 240 extern struct _pthread_descr_struct __pthread_initial_thread;
 241
 242 /* Descriptor of the manager thread */
 243
 244 extern struct _pthread_descr_struct __pthread_manager_thread;
 245
 246 /* Descriptor of the main thread */
 247
 248 extern pthread_descr __pthread_main_thread;
 249
 250 /* Limit between the stack of the initial thread (above) and the
 251    stacks of other threads (below). Aligned on a STACK_SIZE boundary.
 252    Initially 0, meaning that the current thread is (by definition)
 253    the initial thread. */
 254
 255 extern char *__pthread_initial_thread_bos;
 256 #ifndef __ARCH_USE_MMU__
 257 /* For non-MMU systems, we have no idea the bounds of the initial thread
 258  * stack, so we have to track it on the fly relative to other stacks.  Do
 259  * so by scaling back our assumptions on the limits of the bos/tos relative
 260  * to the known mid point.  See also the comments in pthread_initialize(). */
 261 extern char *__pthread_initial_thread_tos, *__pthread_initial_thread_mid;
 262 #define NOMMU_INITIAL_THREAD_BOUNDS(tos,bos) \
 263         do { \
 264                 char *__tos = (tos); \
 265                 char *__bos = (bos); \
 266                 if (__tos >= __pthread_initial_thread_bos && \
 267                     __bos < __pthread_initial_thread_tos) { \
 268                         if (__bos < __pthread_initial_thread_mid) \
 269                                 __pthread_initial_thread_bos = __tos; \
 270                         else \
 271                                 __pthread_initial_thread_tos = __bos; \
 272                 } \
 273         } while (0)
 274 #else
 275 #define NOMMU_INITIAL_THREAD_BOUNDS(tos,bos) /* empty */
 276 #endif /* __ARCH_USE_MMU__ */
 277
 278
 279 /* Indicate whether at least one thread has a user-defined stack (if 1),
 280    or all threads have stacks supplied by LinuxThreads (if 0). */
 281
 282 extern int __pthread_nonstandard_stacks;
 283
 284 /* File descriptor for sending requests to the thread manager.
 285    Initially -1, meaning that __pthread_initialize_manager must be called. */
 286
 287 extern int __pthread_manager_request;
 288
 289 /* Other end of the pipe for sending requests to the thread manager. */
 290
 291 extern int __pthread_manager_reader;
 292
 293 /* Limits of the thread manager stack. */
 294
 295 extern char *__pthread_manager_thread_bos;
 296 extern char *__pthread_manager_thread_tos;
 297
 298 /* Pending request for a process-wide exit */
 299
 300 extern int __pthread_exit_requested, __pthread_exit_code;
 301
 302 /* Set to 1 by gdb if we're debugging */
 303
 304 extern volatile int __pthread_threads_debug;
 305
 306 /* Globally enabled events.  */
 307 extern volatile td_thr_events_t __pthread_threads_events;
 308
 309 /* Pointer to descriptor of thread with last event.  */
 310 extern volatile pthread_descr __pthread_last_event;
 311
 312 /* Return the handle corresponding to a thread id */
 313
 314 static __inline__ pthread_handle thread_handle(pthread_t id)
 315 {
 316   return &__pthread_handles[id % PTHREAD_THREADS_MAX];
 317 }
 318
 319 /* Validate a thread handle. Must have acquired h->h_spinlock before. */
 320
 321 static __inline__ int invalid_handle(pthread_handle h, pthread_t id)
 322 {
 323   return h->h_descr == NULL || h->h_descr->p_tid != id;
 324 }
 325
 326 /* Fill in defaults left unspecified by pt-machine.h.  */
 327
 328 /* The page size we can get from the system.  This should likely not be
 329    changed by the machine file but, you never know.  */
 330 #define __PAGE_SIZE  (sysconf (_SC_PAGESIZE))
 331
 332 /* The max size of the thread stack segments.  If the default
 333    THREAD_SELF implementation is used, this must be a power of two and
 334    a multiple of __PAGE_SIZE.  */
 335 #ifndef STACK_SIZE
 336 #ifdef __ARCH_USE_MMU__
 337 #define STACK_SIZE  (2 * 1024 * 1024)
 338 #else
 339 #define STACK_SIZE  (4 * __PAGE_SIZE)
 340 #endif
 341 #endif
 342
 343 /* The initial size of the thread stack.  Must be a multiple of __PAGE_SIZE.  */
 344 #ifndef INITIAL_STACK_SIZE
 345 #define INITIAL_STACK_SIZE  (4 * __PAGE_SIZE)
 346 #endif
 347
 348 /* Size of the thread manager stack. The "- 32" avoids wasting space
 349    with some malloc() implementations. */
 350 #ifndef THREAD_MANAGER_STACK_SIZE
 351 #define THREAD_MANAGER_STACK_SIZE  (2 * __PAGE_SIZE - 32)
 352 #endif
 353
 354 /* The base of the "array" of thread stacks.  The array will grow down from
 355    here.  Defaults to the calculated bottom of the initial application
 356    stack.  */
 357 #ifndef THREAD_STACK_START_ADDRESS
 358 #define THREAD_STACK_START_ADDRESS  __pthread_initial_thread_bos
 359 #endif
 360
 361 /* Get some notion of the current stack.  Need not be exactly the top
 362    of the stack, just something somewhere in the current frame.  */
 363 #ifndef CURRENT_STACK_FRAME
 364 #define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
 365 #endif
 366
 367 /* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the
 368    architecture doesn't need a memory barrier instruction (e.g. Intel
 369    x86).  Still we need the compiler to respect the barrier and emit
 370    all outstanding operations which modify memory.  Some architectures
 371    distinguish between full, read and write barriers.  */
 372 #ifndef MEMORY_BARRIER
 373 #define MEMORY_BARRIER() __asm__ ("" : : : "memory")
 374 #endif
 375 #ifndef READ_MEMORY_BARRIER
 376 #define READ_MEMORY_BARRIER() MEMORY_BARRIER()
 377 #endif
 378 #ifndef WRITE_MEMORY_BARRIER
 379 #define WRITE_MEMORY_BARRIER() MEMORY_BARRIER()
 380 #endif
 381
 382 /* Recover thread descriptor for the current thread */
 383
 384 extern pthread_descr __pthread_find_self (void) __attribute__ ((const)) attribute_hidden;
 385
 386 static __inline__ pthread_descr thread_self (void) __attribute__ ((const));
 387 static __inline__ pthread_descr thread_self (void)
 388 {
 389 #ifdef THREAD_SELF
 390   return THREAD_SELF;
 391 #else
 392   char *sp = CURRENT_STACK_FRAME;
 393 #ifdef __ARCH_USE_MMU__
 394   if (sp >= __pthread_initial_thread_bos)
 395     return &__pthread_initial_thread;
 396   else if (sp >= __pthread_manager_thread_bos
 397            && sp < __pthread_manager_thread_tos)
 398     return &__pthread_manager_thread;
 399   else if (__pthread_nonstandard_stacks)
 400     return __pthread_find_self();
 401   else
 402     return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
 403 #else
 404   /* For non-MMU we need to be more careful about the initial thread stack.
 405    * We refine the initial thread stack bounds dynamically as we allocate
 406    * the other stack frame such that it doesn't overlap with them. Then
 407    * we can be sure to pick the right thread according to the current SP */
 408
 409   /* Since we allow other stack frames to be above or below, we need to
 410    * treat this case special. When pthread_initialize() wasn't called yet,
 411    * only the initial thread is there. */
 412   if (__pthread_initial_thread_bos == NULL) {
 413       return &__pthread_initial_thread;
 414   }
 415   else if (sp >= __pthread_initial_thread_bos
 416            && sp < __pthread_initial_thread_tos) {
 417       return &__pthread_initial_thread;
 418   }
 419   else if (sp >= __pthread_manager_thread_bos
 420            && sp < __pthread_manager_thread_tos) {
 421       return &__pthread_manager_thread;
 422   }
 423   else {
 424       return __pthread_find_self();
 425   }
 426 #endif /* __ARCH_USE_MMU__ */
 427 #endif
 428 }
 429
 430 /* Max number of times we must spin on a spinlock calling sched_yield().
 431    After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
 432
 433 #ifndef MAX_SPIN_COUNT
 434 #define MAX_SPIN_COUNT 50
 435 #endif
 436
 437 /* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
 438    after MAX_SPIN_COUNT iterations of sched_yield().
 439    With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
 440    (Otherwise the kernel does busy-waiting for realtime threads,
 441     giving other threads no chance to run.) */
 442
 443 #ifndef SPIN_SLEEP_DURATION
 444 #define SPIN_SLEEP_DURATION 2000001
 445 #endif
 446
 447 /* Defined and used in libc.so.  */
 448 extern int __libc_multiple_threads attribute_hidden;
 449
 450 /* Internal global functions */
 451
 452 void __pthread_do_exit (void *retval, char *currentframe)
 453      __attribute__ ((__noreturn__)) attribute_hidden;
 454 void __pthread_destroy_specifics(void) attribute_hidden;
 455 void __pthread_perform_cleanup(char *currentframe) attribute_hidden;
 456 int __pthread_initialize_manager(void) attribute_hidden;
 457 void __pthread_message(char * fmt, ...)
 458      __attribute__ ((__format__ (printf, 1, 2))) attribute_hidden;
 459 int __pthread_manager(void *reqfd) attribute_hidden;
 460 int __pthread_manager_event(void *reqfd) attribute_hidden;
 461 void __pthread_manager_sighandler(int sig) attribute_hidden;
 462 void __pthread_reset_main_thread(void) attribute_hidden;
 463 void __fresetlockfiles(void) attribute_hidden;
 464 void __pthread_manager_adjust_prio(int thread_prio) attribute_hidden;
 465 void __pthread_initialize_minimal (void);
 466
 467 extern void __pthread_exit (void *retval)
 468 #if defined NOT_IN_libc && defined IS_IN_libpthread
 469         attribute_noreturn
 470 #endif
 471         ;
 472
 473 extern int __pthread_attr_setguardsize(pthread_attr_t *__attr,
 474                                        size_t __guardsize) attribute_hidden;
 475 extern int __pthread_attr_getguardsize(const pthread_attr_t *__attr,
 476                                        size_t *__guardsize) attribute_hidden;
 477 extern int __pthread_attr_setstackaddr(pthread_attr_t *__attr,
 478                                        void *__stackaddr) attribute_hidden;
 479 extern int __pthread_attr_getstackaddr(const pthread_attr_t *__attr,
 480                                        void **__stackaddr) attribute_hidden;
 481 extern int __pthread_attr_setstacksize(pthread_attr_t *__attr,
 482                                        size_t __stacksize) attribute_hidden;
 483 extern int __pthread_attr_getstacksize(const pthread_attr_t *__attr,
 484                                        size_t *__stacksize) attribute_hidden;
 485 extern int __pthread_getconcurrency(void) attribute_hidden;
 486 extern int __pthread_setconcurrency(int __level) attribute_hidden;
 487 extern void __pthread_kill_other_threads_np(void) attribute_hidden;
 488
 489 extern void __pthread_restart_old(pthread_descr th) attribute_hidden;
 490 extern void __pthread_suspend_old(pthread_descr self) attribute_hidden;
 491 extern int __pthread_timedsuspend_old(pthread_descr self, const struct timespec *abstime) attribute_hidden;
 492
 493 extern void __pthread_restart_new(pthread_descr th) attribute_hidden;
 494 extern void __pthread_suspend_new(pthread_descr self) attribute_hidden;
 495 extern int __pthread_timedsuspend_new(pthread_descr self, const struct timespec *abstime) attribute_hidden;
 496
 497 extern void __pthread_wait_for_restart_signal(pthread_descr self) attribute_hidden;
 498
 499 /* Global pointers to old or new suspend functions */
 500
 501 extern void (*__pthread_restart)(pthread_descr) attribute_hidden;
 502 extern void (*__pthread_suspend)(pthread_descr) attribute_hidden;
 503
 504 #if defined NOT_IN_libc && defined IS_IN_libpthread
 505 extern __typeof(pthread_mutex_init) __pthread_mutex_init attribute_hidden;
 506 extern __typeof(pthread_mutex_destroy) __pthread_mutex_destroy attribute_hidden;
 507 extern __typeof(pthread_mutex_lock) __pthread_mutex_lock attribute_hidden;
 508 extern __typeof(pthread_mutex_trylock) __pthread_mutex_trylock attribute_hidden;
 509 extern __typeof(pthread_mutex_unlock) __pthread_mutex_unlock attribute_hidden;
 510 #endif
 511
 512 /* Prototypes for some of the new semaphore functions.  */
 513 /*extern int __new_sem_post (sem_t * sem);*/
 514
 515 /* TSD.  */
 516 extern int __pthread_internal_tsd_set (int key, const void * pointer);
 517 extern void * __pthread_internal_tsd_get (int key);
 518 extern void ** __attribute__ ((__const__))
 519   __pthread_internal_tsd_address (int key);
 520
 521 /* The functions called the signal events.  */
 522 extern void __linuxthreads_create_event (void) attribute_hidden;
 523 extern void __linuxthreads_death_event (void) attribute_hidden;
 524 extern void __linuxthreads_reap_event (void) attribute_hidden;
 525
 526 extern int * __libc_pthread_init (void);
 527
 528 #endif /* internals.h */