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 <setjmp.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <sys/types.h>
  27 #include <bits/libc-tsd.h> /* for _LIBC_TSD_KEY_N */
  28
  29 #include "pt-machine.h"
  30 #include "semaphore.h"
  31 #include "../linuxthreads_db/thread_dbP.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 /* Arguments passed to thread creation routine */
  47
  48 struct pthread_start_args {
  49   void * (*start_routine)(void *); /* function to run */
  50   void * arg;                   /* its argument */
  51   sigset_t mask;                /* initial signal mask for thread */
  52   int schedpolicy;              /* initial scheduling policy (if any) */
  53   struct sched_param schedparam; /* initial scheduling parameters (if any) */
  54 };
  55
  56
  57 /* We keep thread specific data in a special data structure, a two-level
  58    array.  The top-level array contains pointers to dynamically allocated
  59    arrays of a certain number of data pointers.  So we can implement a
  60    sparse array.  Each dynamic second-level array has
  61         PTHREAD_KEY_2NDLEVEL_SIZE
  62    entries.  This value shouldn't be too large.  */
  63 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  64
  65 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  66    keys in each subarray.  */
  67 #define PTHREAD_KEY_1STLEVEL_SIZE \
  68   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  69    / PTHREAD_KEY_2NDLEVEL_SIZE)
  70
  71 typedef void (*destr_function)(void *);
  72
  73 struct pthread_key_struct {
  74   int in_use;                   /* already allocated? */
  75   destr_function destr;         /* destruction routine */
  76 };
  77
  78
  79 #define PTHREAD_START_ARGS_INITIALIZER(fct) \
  80   { (void *(*) (void *)) fct, NULL, {{0, }}, 0, { 0 } }
  81
  82 /* The type of thread descriptors */
  83
  84 typedef struct _pthread_descr_struct * pthread_descr;
  85
  86 struct _pthread_descr_struct {
  87   pthread_descr p_nextlive, p_prevlive;
  88                                 /* Double chaining of active threads */
  89   pthread_descr p_nextwaiting;  /* Next element in the queue holding the thr */
  90   pthread_descr p_nextlock;     /* can be on a queue and waiting on a lock */
  91   pthread_t p_tid;              /* Thread identifier */
  92   int p_pid;                    /* PID of Unix process */
  93   int p_priority;               /* Thread priority (== 0 if not realtime) */
  94   struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
  95   int p_signal;                 /* last signal received */
  96   sigjmp_buf * p_signal_jmp;    /* where to siglongjmp on a signal or NULL */
  97   sigjmp_buf * p_cancel_jmp;    /* where to siglongjmp on a cancel or NULL */
  98   char p_terminated;            /* true if terminated e.g. by pthread_exit */
  99   char p_detached;              /* true if detached */
 100   char p_exited;                /* true if the assoc. process terminated */
 101   void * p_retval;              /* placeholder for return value */
 102   int p_retcode;                /* placeholder for return code */
 103   pthread_descr p_joining;      /* thread joining on that thread or NULL */
 104   struct _pthread_cleanup_buffer * p_cleanup; /* cleanup functions */
 105   char p_cancelstate;           /* cancellation state */
 106   char p_canceltype;            /* cancellation type (deferred/async) */
 107   char p_canceled;              /* cancellation request pending */
 108   int * p_errnop;               /* pointer to used errno variable */
 109   int p_errno;                  /* error returned by last system call */
 110   int * p_h_errnop;             /* pointer to used h_errno variable */
 111   int p_h_errno;                /* error returned by last netdb function */
 112   char * p_in_sighandler;       /* stack address of sighandler, or NULL */
 113   char p_sigwaiting;            /* true if a sigwait() is in progress */
 114   struct pthread_start_args p_start_args; /* arguments for thread creation */
 115   void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
 116   void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
 117   int p_userstack;              /* nonzero if the user provided the stack */
 118   void *p_guardaddr;            /* address of guard area or NULL */
 119   size_t p_guardsize;           /* size of guard area */
 120   pthread_descr p_self;         /* Pointer to this structure */
 121   int p_nr;                     /* Index of descriptor in __pthread_handles */
 122   /* New elements must be added at the end.  */
 123   int p_report_events;          /* Nonzero if events must be reported.  */
 124   td_eventbuf_t p_eventbuf;     /* Data for event.  */
 125 } __attribute__ ((aligned(32))); /* We need to align the structure so that
 126                                     doubles are aligned properly.  This is 8
 127                                     bytes on MIPS and 16 bytes on MIPS64.
 128                                     32 bytes might give better cache
 129                                     utilization.  */
 130
 131
 132 /* The type of thread handles. */
 133
 134 typedef struct pthread_handle_struct * pthread_handle;
 135
 136 struct pthread_handle_struct {
 137   struct _pthread_fastlock h_lock; /* Fast lock for sychronized access */
 138   pthread_descr h_descr;        /* Thread descriptor or NULL if invalid */
 139   char * h_bottom;              /* Lowest address in the stack thread */
 140 };
 141
 142 /* The type of messages sent to the thread manager thread */
 143
 144 struct pthread_request {
 145   pthread_descr req_thread;     /* Thread doing the request */
 146   enum {                        /* Request kind */
 147     REQ_CREATE, REQ_FREE, REQ_PROCESS_EXIT, REQ_MAIN_THREAD_EXIT,
 148     REQ_POST, REQ_DEBUG
 149   } req_kind;
 150   union {                       /* Arguments for request */
 151     struct {                    /* For REQ_CREATE: */
 152       const pthread_attr_t * attr; /* thread attributes */
 153       void * (*fn)(void *);     /*   start function */
 154       void * arg;               /*   argument to start function */
 155       sigset_t mask;            /*   signal mask */
 156     } create;
 157     struct {                    /* For REQ_FREE: */
 158       pthread_t thread_id;      /*   identifier of thread to free */
 159     } free;
 160     struct {                    /* For REQ_PROCESS_EXIT: */
 161       int code;                 /*   exit status */
 162     } exit;
 163     void * post;                /* For REQ_POST: the semaphore */
 164   } req_args;
 165 };
 166
 167
 168 /* Signals used for suspend/restart and for cancellation notification.  */
 169
 170 extern int __pthread_sig_restart;
 171 extern int __pthread_sig_cancel;
 172
 173 /* Signal used for interfacing with gdb */
 174
 175 extern int __pthread_sig_debug;
 176
 177 /* Global array of thread handles, used for validating a thread id
 178    and retrieving the corresponding thread descriptor. Also used for
 179    mapping the available stack segments. */
 180
 181 extern struct pthread_handle_struct __pthread_handles[PTHREAD_THREADS_MAX];
 182
 183 /* Descriptor of the initial thread */
 184
 185 extern struct _pthread_descr_struct __pthread_initial_thread;
 186
 187 /* Descriptor of the manager thread */
 188
 189 extern struct _pthread_descr_struct __pthread_manager_thread;
 190
 191 /* Descriptor of the main thread */
 192
 193 extern pthread_descr __pthread_main_thread;
 194
 195 /* Limit between the stack of the initial thread (above) and the
 196    stacks of other threads (below). Aligned on a STACK_SIZE boundary.
 197    Initially 0, meaning that the current thread is (by definition)
 198    the initial thread. */
 199
 200 extern char *__pthread_initial_thread_bos;
 201
 202 /* Indicate whether at least one thread has a user-defined stack (if 1),
 203    or all threads have stacks supplied by LinuxThreads (if 0). */
 204
 205 extern int __pthread_nonstandard_stacks;
 206
 207 /* File descriptor for sending requests to the thread manager.
 208    Initially -1, meaning that __pthread_initialize_manager must be called. */
 209
 210 extern int __pthread_manager_request;
 211
 212 /* Other end of the pipe for sending requests to the thread manager. */
 213
 214 extern int __pthread_manager_reader;
 215
 216 /* Limits of the thread manager stack. */
 217
 218 extern char *__pthread_manager_thread_bos;
 219 extern char *__pthread_manager_thread_tos;
 220
 221 /* Pending request for a process-wide exit */
 222
 223 extern int __pthread_exit_requested, __pthread_exit_code;
 224
 225 /* Set to 1 by gdb if we're debugging */
 226
 227 extern volatile int __pthread_threads_debug;
 228
 229 /* Globally enabled events.  */
 230 extern volatile td_thr_events_t __pthread_threads_events;
 231
 232 /* Pointer to descriptor of thread with last event.  */
 233 extern volatile pthread_descr __pthread_last_event;
 234
 235 /* Return the handle corresponding to a thread id */
 236
 237 static inline pthread_handle thread_handle(pthread_t id)
 238 {
 239   return &__pthread_handles[id % PTHREAD_THREADS_MAX];
 240 }
 241
 242 /* Validate a thread handle. Must have acquired h->h_spinlock before. */
 243
 244 static inline int invalid_handle(pthread_handle h, pthread_t id)
 245 {
 246   return h->h_descr == NULL || h->h_descr->p_tid != id;
 247 }
 248
 249 /* Fill in defaults left unspecified by pt-machine.h.  */
 250
 251 /* The page size we can get from the system.  This should likely not be
 252    changed by the machine file but, you never know.  */
 253 #ifndef PAGE_SIZE
 254 #define PAGE_SIZE  (sysconf (_SC_PAGE_SIZE))
 255 #endif
 256
 257 /* The max size of the thread stack segments.  If the default
 258    THREAD_SELF implementation is used, this must be a power of two and
 259    a multiple of PAGE_SIZE.  */
 260 #ifndef STACK_SIZE
 261 #define STACK_SIZE  (2 * 1024 * 1024)
 262 #endif
 263
 264 /* The initial size of the thread stack.  Must be a multiple of PAGE_SIZE.  */
 265 #ifndef INITIAL_STACK_SIZE
 266 #define INITIAL_STACK_SIZE  (4 * PAGE_SIZE)
 267 #endif
 268
 269 /* Size of the thread manager stack. The "- 32" avoids wasting space
 270    with some malloc() implementations. */
 271 #ifndef THREAD_MANAGER_STACK_SIZE
 272 #define THREAD_MANAGER_STACK_SIZE  (2 * PAGE_SIZE - 32)
 273 #endif
 274
 275 /* The base of the "array" of thread stacks.  The array will grow down from
 276    here.  Defaults to the calculated bottom of the initial application
 277    stack.  */
 278 #ifndef THREAD_STACK_START_ADDRESS
 279 #define THREAD_STACK_START_ADDRESS  __pthread_initial_thread_bos
 280 #endif
 281
 282 /* Get some notion of the current stack.  Need not be exactly the top
 283    of the stack, just something somewhere in the current frame.  */
 284 #ifndef CURRENT_STACK_FRAME
 285 #define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
 286 #endif
 287
 288 /* Recover thread descriptor for the current thread */
 289
 290 extern pthread_descr __pthread_find_self (void) __attribute__ ((const));
 291
 292 static inline pthread_descr thread_self (void) __attribute__ ((const));
 293 static inline pthread_descr thread_self (void)
 294 {
 295 #ifdef THREAD_SELF
 296   return THREAD_SELF;
 297 #else
 298   char *sp = CURRENT_STACK_FRAME;
 299   if (sp >= __pthread_initial_thread_bos)
 300     return &__pthread_initial_thread;
 301   else if (sp >= __pthread_manager_thread_bos
 302            && sp < __pthread_manager_thread_tos)
 303     return &__pthread_manager_thread;
 304   else if (__pthread_nonstandard_stacks)
 305     return __pthread_find_self();
 306   else
 307     return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
 308 #endif
 309 }
 310
 311 /* Max number of times we must spin on a spinlock calling sched_yield().
 312    After MAX_SPIN_COUNT iterations, we put the calling thread to sleep. */
 313
 314 #ifndef MAX_SPIN_COUNT
 315 #define MAX_SPIN_COUNT 50
 316 #endif
 317
 318 /* Duration of sleep (in nanoseconds) when we can't acquire a spinlock
 319    after MAX_SPIN_COUNT iterations of sched_yield().
 320    With the 2.0 and 2.1 kernels, this MUST BE > 2ms.
 321    (Otherwise the kernel does busy-waiting for realtime threads,
 322     giving other threads no chance to run.) */
 323
 324 #ifndef SPIN_SLEEP_DURATION
 325 #define SPIN_SLEEP_DURATION 2000001
 326 #endif
 327
 328 /* Debugging */
 329
 330 #ifdef DEBUG
 331 #include <assert.h>
 332 #define ASSERT assert
 333 #define MSG __pthread_message
 334 #else
 335 #define ASSERT(x)
 336 #define MSG(msg,arg...)
 337 #endif
 338
 339 /* Internal global functions */
 340
 341 void __pthread_destroy_specifics(void);
 342 void __pthread_perform_cleanup(void);
 343 int __pthread_initialize_manager(void);
 344 void __pthread_message(char * fmt, ...);
 345 int __pthread_manager(void *reqfd);
 346 int __pthread_manager_event(void *reqfd);
 347 void __pthread_manager_sighandler(int sig);
 348 void __pthread_reset_main_thread(void);
 349 void __fresetlockfiles(void);
 350 void __pthread_manager_adjust_prio(int thread_prio);
 351
 352 extern int __pthread_attr_setguardsize (pthread_attr_t *__attr,
 353                                         size_t __guardsize) __THROW;
 354 extern int __pthread_attr_getguardsize (__const pthread_attr_t *__attr,
 355                                         size_t *__guardsize) __THROW;
 356 extern int __pthread_attr_setstackaddr (pthread_attr_t *__attr,
 357                                         void *__stackaddr) __THROW;
 358 extern int __pthread_attr_getstackaddr (__const pthread_attr_t *__attr,
 359                                         void **__stackaddr) __THROW;
 360 extern int __pthread_attr_setstacksize (pthread_attr_t *__attr,
 361                                         size_t __stacksize) __THROW;
 362 extern int __pthread_attr_getstacksize (__const pthread_attr_t *__attr,
 363                                         size_t *__stacksize) __THROW;
 364 extern int __pthread_getconcurrency (void) __THROW;
 365 extern int __pthread_setconcurrency (int __level) __THROW;
 366 extern int __pthread_mutexattr_gettype (__const pthread_mutexattr_t *__attr,
 367                                         int *__kind) __THROW;
 368 extern void __pthread_kill_other_threads_np (void) __THROW;
 369
 370 /* Prototypes for the function without cancelation support when the
 371    normal version has it.  */
 372 extern int __libc_close (int fd);
 373 extern int __libc_nanosleep (const struct timespec *requested_time,
 374                              struct timespec *remaining);
 375 extern ssize_t __libc_read (int fd, void *buf, size_t count);
 376 extern pid_t __libc_waitpid (pid_t pid, int *stat_loc, int options);
 377 extern ssize_t __libc_write (int fd, const void *buf, size_t count);
 378
 379 /* Prototypes for some of the new semaphore functions.  */
 380 extern int __new_sem_post (sem_t * sem);
 381
 382 /* The functions called the signal events.  */
 383 extern void __linuxthreads_create_event (void);
 384 extern void __linuxthreads_death_event (void);
 385 extern void __linuxthreads_reap_event (void);
 386
 387 #endif /* internals.h */