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 <limits.h>
  23 #include <unistd.h>
  24 #include <stackinfo.h>
  25
  26 #include "descr.h"
  27
  28 extern long int testandset (int *spinlock);
  29 extern int __compare_and_swap (long int *p, long int oldval, long int newval);
  30
  31 #include "semaphore.h"
  32
  33 #ifndef THREAD_GETMEM
  34 # define THREAD_GETMEM(descr, member) descr->member
  35 #endif
  36 #ifndef THREAD_GETMEM_NC
  37 # define THREAD_GETMEM_NC(descr, member) descr->member
  38 #endif
  39 #ifndef THREAD_SETMEM
  40 # define THREAD_SETMEM(descr, member, value) descr->member = (value)
  41 #endif
  42 #ifndef THREAD_SETMEM_NC
  43 # define THREAD_SETMEM_NC(descr, member, value) descr->member = (value)
  44 #endif
  45
  46 typedef void (*destr_function)(void *);
  47
  48 struct pthread_key_struct {
  49   int in_use;                   /* already allocated? */
  50   destr_function destr;         /* destruction routine */
  51 };
  52
  53
  54 #define PTHREAD_START_ARGS_INITIALIZER(fct) \
  55   { (void *(*) (void *)) fct, NULL, {{0, }}, 0, { 0 } }
  56
  57
  58 /* The type of thread handles. */
  59
  60 typedef struct pthread_handle_struct * pthread_handle;
  61
  62 struct pthread_handle_struct {
  63   struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
  64   pthread_descr h_descr;        /* Thread descriptor or NULL if invalid */
  65   char * h_bottom;              /* Lowest address in the stack thread */
  66 };
  67
  68 /* The type of messages sent to the thread manager thread */
  69
  70 struct pthread_request {
  71   pthread_descr req_thread;     /* Thread doing the request */
  72   enum {                        /* Request kind */
  73     REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
  74     REQ_POST, REQ_DEBUG, REQ_KICK, REQ_FOR_EACH_THREAD
  75   } req_kind;
  76   union {                       /* Arguments for request */
  77     struct {                    /* For REQ_CREATE: */
  78       const pthread_attr_t * attr; /* thread attributes */
  79       void * (*fn)(void *);     /*   start function */
  80       void * arg;               /*   argument to start function */
  81       sigset_t mask;            /*   signal mask */
  82     } create;
  83     struct {                    /* For REQ_FREE: */
  84       pthread_t thread_id;      /*   identifier of thread to free */
  85     } free;
  86     struct {                    /* For REQ_PROCESS_EXIT: */
  87       int code;                 /*   exit status */
  88     } exit;
  89     void * post;                /* For REQ_POST: the semaphore */
  90     struct {                    /* For REQ_FOR_EACH_THREAD: callback */
  91       void (*fn)(void *, pthread_descr);
  92       void *arg;
  93     } for_each;
  94   } req_args;
  95 };
  96
  97
  98 /* Signals used for suspend/restart and for cancellation notification.  */
  99
 100 extern int __pthread_sig_restart;
 101 extern int __pthread_sig_cancel;
 102
 103 /* Signal used for interfacing with gdb */
 104
 105 extern int __pthread_sig_debug;
 106
 107 /* Global array of thread handles, used for validating a thread id
 108    and retrieving the corresponding thread descriptor. Also used for
 109    mapping the available stack segments. */
 110
 111 extern struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX];
 112
 113 /* Descriptor of the initial thread */
 114
 115 extern struct _pthread_descr_struct __pthread_initial_thread;
 116
 117 /* Descriptor of the manager thread */
 118
 119 extern struct _pthread_descr_struct __pthread_manager_thread;
 120
 121 /* Descriptor of the main thread */
 122
 123 extern pthread_descr __pthread_main_thread;
 124
 125 /* Limit between the stack of the initial thread (above) and the
 126    stacks of other threads (below). Aligned on a STACK_SIZE boundary.
 127    Initially 0, meaning that the current thread is (by definition)
 128    the initial thread. */
 129
 130 extern char *__pthread_initial_thread_bos;
 131
 132 /* Indicate whether at least one thread has a user-defined stack (if 1),
 133    or all threads have stacks supplied by LinuxThreads (if 0). */
 134
 135 extern int __pthread_nonstandard_stacks;
 136
 137 /* File descriptor for sending requests to the thread manager.
 138    Initially -1, meaning that __pthread_initialize_manager must be called. */
 139
 140 extern int __pthread_manager_request;
 141
 142 /* Other end of the pipe for sending requests to the thread manager. */
 143
 144 extern int __pthread_manager_reader;
 145
 146 /* Limits of the thread manager stack. */
 147
 148 extern char *__pthread_manager_thread_bos;
 149 extern char *__pthread_manager_thread_tos;
 150
 151 #ifdef FLOATING_STACKS
 152 /* Maximum stack size.  */
 153 extern size_t __pthread_max_stacksize;
 154 #endif
 155
 156 /* Pending request for a process-wide exit */
 157
 158 extern int __pthread_exit_requested, __pthread_exit_code;
 159
 160 /* Set to 1 by gdb if we're debugging */
 161
 162 extern volatile int __pthread_threads_debug;
 163
 164 /* Globally enabled events.  */
 165 extern volatile td_thr_events_t __pthread_threads_events;
 166
 167 /* Pointer to descriptor of thread with last event.  */
 168 extern volatile pthread_descr __pthread_last_event;
 169
 170 /* Flag which tells whether we are executing on SMP kernel. */
 171 extern int __pthread_smp_kernel;
 172
 173 /* Return the handle corresponding to a thread id */
 174
 175 static inline pthread_handle thread_handle(pthread_t id)
 176 {
 177   return &__pthread_handles[id % PTHREAD_THREADS_MAX];
 178 }
 179
 180 /* Validate a thread handle. Must have acquired h->h_spinlock before. */
 181
 182 static inline int invalid_handle(pthread_handle h, pthread_t id)
 183 {
 184   return h->h_descr == NULL || h->h_descr->p_tid != id || h->h_descr->p_terminated;
 185 }
 186
 187 static inline int nonexisting_handle(pthread_handle h, pthread_t id)
 188 {
 189   return h->h_descr == NULL || h->h_descr->p_tid != id;
 190 }
 191
 192 /* Fill in defaults left unspecified by pt-machine.h.  */
 193
 194 /* We round up a value with page size. */
 195 #ifndef page_roundup
 196 #define page_roundup(v,p) ((((size_t) (v)) + (p) - 1) & ~((p) - 1))
 197 #endif
 198
 199 /* The page size we can get from the system.  This should likely not be
 200    changed by the machine file but, you never know.  */
 201 #ifndef PAGE_SIZE
 202 #define PAGE_SIZE  (sysconf (_SC_PAGE_SIZE))
 203 #endif
 204
 205 /* The max size of the thread stack segments.  If the default
 206    THREAD_SELF implementation is used, this must be a power of two and
 207    a multiple of PAGE_SIZE.  */
 208 #ifndef STACK_SIZE
 209 #define STACK_SIZE  (2 * 1024 * 1024)
 210 #endif
 211
 212 /* The initial size of the thread stack.  Must be a multiple of PAGE_SIZE.  */
 213 #ifndef INITIAL_STACK_SIZE
 214 #define INITIAL_STACK_SIZE  (4 * PAGE_SIZE)
 215 #endif
 216
 217 /* Size of the thread manager stack. The "- 32" avoids wasting space
 218    with some malloc() implementations. */
 219 #ifndef THREAD_MANAGER_STACK_SIZE
 220 #define THREAD_MANAGER_STACK_SIZE  (2 * PAGE_SIZE - 32)
 221 #endif
 222
 223 /* The base of the "array" of thread stacks.  The array will grow down from
 224    here.  Defaults to the calculated bottom of the initial application
 225    stack.  */
 226 #ifndef THREAD_STACK_START_ADDRESS
 227 #define THREAD_STACK_START_ADDRESS  __pthread_initial_thread_bos
 228 #endif
 229
 230 /* Get some notion of the current stack.  Need not be exactly the top
 231    of the stack, just something somewhere in the current frame.  */
 232 #ifndef CURRENT_STACK_FRAME
 233 #define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
 234 #endif
 235
 236 /* Recover thread descriptor for the current thread */
 237
 238 extern pthread_descr __pthread_find_self (void) __attribute__ ((const));
 239
 240 static inline pthread_descr thread_self (void) __attribute__ ((const));
 241 static inline pthread_descr thread_self (void)
 242 {
 243 #ifdef THREAD_SELF
 244   return THREAD_SELF;
 245 #else
 246   char *sp = CURRENT_STACK_FRAME;
 247   if (sp >= __pthread_initial_thread_bos)
 248     return &__pthread_initial_thread;
 249   else if (sp >= __pthread_manager_thread_bos
 250            && sp < __pthread_manager_thread_tos)
 251     return &__pthread_manager_thread;
 252   else if (__pthread_nonstandard_stacks)
 253     return __pthread_find_self();
 254   else
 255 #ifdef _STACK_GROWS_DOWN
 256     return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
 257 #else
 258     return (pthread_descr)((unsigned long)sp &~ (STACK_SIZE-1));
 259 #endif
 260 #endif
 261 }
 262
 263 /* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the architecture
 264    doesn't need a memory barrier instruction (e.g. Intel x86).  Some
 265    architectures distinguish between full, read and write barriers.  */
 266
 267 #ifndef MEMORY_BARRIER
 268 #define MEMORY_BARRIER()
 269 #endif
 270 #ifndef READ_MEMORY_BARRIER
 271 #define READ_MEMORY_BARRIER() MEMORY_BARRIER()
 272 #endif
 273 #ifndef WRITE_MEMORY_BARRIER
 274 #define WRITE_MEMORY_BARRIER() MEMORY_BARRIER()
 275 #endif
 276
 277 /* Max number of times we must spin on a spinlock calling sched_yield().
 278    After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
 279
 280 #ifndef MAX_SPIN_COUNT
 281 #define MAX_SPIN_COUNT 50
 282 #endif
 283
 284 /* Max number of times the spinlock in the adaptive mutex implementation
 285    spins actively on SMP systems.  */
 286
 287 #ifndef MAX_ADAPTIVE_SPIN_COUNT
 288 #define MAX_ADAPTIVE_SPIN_COUNT 100
 289 #endif
 290
 291 /* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
 292    after MAX_SPIN_COUNT iterations of sched_yield().
 293    With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
 294    (Otherwise the kernel does busy-waiting for realtime threads,
 295     giving other threads no chance to run.) */
 296
 297 #ifndef SPIN_SLEEP_DURATION
 298 #define SPIN_SLEEP_DURATION 2000001
 299 #endif
 300
 301 /* Debugging */
 302
 303 #ifdef DEBUG
 304 #include <assert.h>
 305 #define ASSERT assert
 306 #define MSG __pthread_message
 307 #else
 308 #define ASSERT(x)
 309 #define MSG(msg,arg...)
 310 #endif
 311
 312 /* Internal global functions */
 313
 314 extern void __pthread_do_exit (void *retval, char *currentframe)
 315      __attribute__ ((__noreturn__));
 316 extern void __pthread_destroy_specifics (void);
 317 extern void __pthread_perform_cleanup (char *currentframe);
 318 extern void __pthread_init_max_stacksize (void);
 319 extern int __pthread_initialize_manager (void);
 320 extern void __pthread_message (char * fmt, ...);
 321 extern int __pthread_manager (void *reqfd);
 322 extern int __pthread_manager_event (void *reqfd);
 323 extern void __pthread_manager_sighandler (int sig);
 324 extern void __pthread_reset_main_thread (void);
 325 extern void __pthread_once_fork_prepare (void);
 326 extern void __pthread_once_fork_parent (void);
 327 extern void __pthread_once_fork_child (void);
 328 extern void __flockfilelist (void);
 329 extern void __funlockfilelist (void);
 330 extern void __fresetlockfiles (void);
 331 extern void __pthread_manager_adjust_prio (int thread_prio);
 332 extern void __pthread_initialize_minimal (void);
 333
 334 extern int __pthread_attr_setguardsize (pthread_attr_t *__attr,
 335                                         size_t __guardsize);
 336 extern int __pthread_attr_getguardsize (const pthread_attr_t *__attr,
 337                                         size_t *__guardsize);
 338 extern int __pthread_attr_setstackaddr (pthread_attr_t *__attr,
 339                                         void *__stackaddr);
 340 extern int __pthread_attr_getstackaddr (const pthread_attr_t *__attr,
 341                                         void **__stackaddr);
 342 extern int __pthread_attr_setstacksize (pthread_attr_t *__attr,
 343                                         size_t __stacksize);
 344 extern int __pthread_attr_getstacksize (const pthread_attr_t *__attr,
 345                                         size_t *__stacksize);
 346 extern int __pthread_attr_setstack (pthread_attr_t *__attr, void *__stackaddr,
 347                                     size_t __stacksize);
 348 extern int __pthread_attr_getstack (const pthread_attr_t *__attr, void **__stackaddr,
 349                                     size_t *__stacksize);
 350 extern int __pthread_getconcurrency (void);
 351 extern int __pthread_setconcurrency (int __level);
 352 extern int __pthread_mutex_timedlock (pthread_mutex_t *__mutex,
 353                                       const struct timespec *__abstime);
 354 extern int __pthread_mutexattr_getpshared (const pthread_mutexattr_t *__attr,
 355                                            int *__pshared);
 356 extern int __pthread_mutexattr_setpshared (pthread_mutexattr_t *__attr,
 357                                            int __pshared);
 358 extern int __pthread_mutexattr_gettype (const pthread_mutexattr_t *__attr,
 359                                         int *__kind);
 360 extern void __pthread_kill_other_threads_np (void);
 361
 362 extern void __pthread_restart_old(pthread_descr th);
 363 extern void __pthread_suspend_old(pthread_descr self);
 364 extern int __pthread_timedsuspend_old(pthread_descr self, const struct timespec *abs);
 365
 366 extern void __pthread_restart_new(pthread_descr th);
 367 extern void __pthread_suspend_new(pthread_descr self);
 368 extern int __pthread_timedsuspend_new(pthread_descr self, const struct timespec *abs);
 369
 370 extern void __pthread_wait_for_restart_signal(pthread_descr self);
 371
 372 extern int __pthread_yield (void);
 373
 374 extern int __pthread_rwlock_timedrdlock (pthread_rwlock_t *__restrict __rwlock,
 375                                          __const struct timespec *__restrict
 376                                          __abstime);
 377 extern int __pthread_rwlock_timedwrlock (pthread_rwlock_t *__restrict __rwlock,
 378                                          __const struct timespec *__restrict
 379                                          __abstime);
 380 extern int __pthread_rwlockattr_destroy (pthread_rwlockattr_t *__attr);
 381
 382 extern int __pthread_barrierattr_getpshared (__const pthread_barrierattr_t *
 383                                              __restrict __attr,
 384                                              int *__restrict __pshared);
 385
 386 extern int __pthread_spin_lock (pthread_spinlock_t *__lock);
 387 extern int __pthread_spin_trylock (pthread_spinlock_t *__lock);
 388 extern int __pthread_spin_unlock (pthread_spinlock_t *__lock);
 389 extern int __pthread_spin_init (pthread_spinlock_t *__lock, int __pshared);
 390 extern int __pthread_spin_destroy (pthread_spinlock_t *__lock);
 391
 392 extern int __pthread_clock_gettime (hp_timing_t freq, struct timespec *tp);
 393 extern void __pthread_clock_settime (hp_timing_t offset);
 394
 395
 396 /* Global pointers to old or new suspend functions */
 397
 398 extern void (*__pthread_restart)(pthread_descr);
 399 extern void (*__pthread_suspend)(pthread_descr);
 400 extern int (*__pthread_timedsuspend)(pthread_descr, const struct timespec *);
 401
 402 /* Prototypes for the function without cancelation support when the
 403    normal version has it.  */
 404 extern int __libc_close (int fd);
 405 extern int __libc_nanosleep (const struct timespec *requested_time,
 406                              struct timespec *remaining);
 407 /* Prototypes for some of the new semaphore functions.  */
 408 extern int __new_sem_post (sem_t * sem);
 409 extern int __new_sem_init (sem_t *__sem, int __pshared, unsigned int __value);
 410 extern int __new_sem_wait (sem_t *__sem);
 411 extern int __new_sem_trywait (sem_t *__sem);
 412 extern int __new_sem_getvalue (sem_t *__restrict __sem, int *__restrict __sval);
 413 extern int __new_sem_destroy (sem_t *__sem);
 414
 415 /* Prototypes for compatibility functions.  */
 416 extern int __pthread_attr_init_2_1 (pthread_attr_t *__attr);
 417 extern int __pthread_attr_init_2_0 (pthread_attr_t *__attr);
 418 extern int __pthread_create_2_1 (pthread_t *__restrict __thread,
 419                                  const pthread_attr_t *__attr,
 420                                  void *(*__start_routine) (void *),
 421                                  void *__restrict __arg);
 422 extern int __pthread_create_2_0 (pthread_t *__restrict thread,
 423                                  const pthread_attr_t *__attr,
 424                                  void *(*__start_routine) (void *),
 425                                  void *__restrict arg);
 426
 427 /* The functions called the signal events.  */
 428 extern void __linuxthreads_create_event (void);
 429 extern void __linuxthreads_death_event (void);
 430 extern void __linuxthreads_reap_event (void);
 431
 432 /* This function is called to initialize the pthread library.  */
 433 extern void __pthread_initialize (void);
 434
 435 #endif /* internals.h */