linuxthreads/descr.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 _DESCR_H
  16 #define _DESCR_H        1
  17
  18 #define __need_res_state
  19 #include <resolv.h>
  20 #include <sched.h>
  21 #include <setjmp.h>
  22 #include <signal.h>
  23 #include <sys/types.h>
  24 #include <hp-timing.h>
  25 #include <bits/libc-tsd.h> /* for _LIBC_TSD_KEY_N */
  26
  27
  28 /* The type of thread descriptors */
  29 typedef struct _pthread_descr_struct *pthread_descr;
  30
  31
  32 /* Some more includes.  */
  33 #include <pt-machine.h>
  34 #include <linuxthreads_db/thread_dbP.h>
  35
  36
  37 /* Arguments passed to thread creation routine */
  38 struct pthread_start_args {
  39   void *(*start_routine)(void *); /* function to run */
  40   void *arg;                      /* its argument */
  41   sigset_t mask;                  /* initial signal mask for thread */
  42   int schedpolicy;                /* initial scheduling policy (if any) */
  43   struct sched_param schedparam;  /* initial scheduling parameters (if any) */
  44 };
  45
  46
  47 /* Callback interface for removing the thread from waiting on an
  48    object if it is cancelled while waiting or about to wait.
  49    This hold a pointer to the object, and a pointer to a function
  50    which ``extricates'' the thread from its enqueued state.
  51    The function takes two arguments: pointer to the wait object,
  52    and a pointer to the thread. It returns 1 if an extrication
  53    actually occured, and hence the thread must also be signalled.
  54    It returns 0 if the thread had already been extricated. */
  55 typedef struct _pthread_extricate_struct {
  56     void *pu_object;
  57     int (*pu_extricate_func)(void *, pthread_descr);
  58 } pthread_extricate_if;
  59
  60
  61 /* Atomic counter made possible by compare_and_swap */
  62 struct pthread_atomic {
  63   long p_count;
  64   int p_spinlock;
  65 };
  66
  67
  68 /* Context info for read write locks. The pthread_rwlock_info structure
  69    is information about a lock that has been read-locked by the thread
  70    in whose list this structure appears. The pthread_rwlock_context
  71    is embedded in the thread context and contains a pointer to the
  72    head of the list of lock info structures, as well as a count of
  73    read locks that are untracked, because no info structure could be
  74    allocated for them. */
  75 struct _pthread_rwlock_t;
  76 typedef struct _pthread_rwlock_info {
  77   struct _pthread_rwlock_info *pr_next;
  78   struct _pthread_rwlock_t *pr_lock;
  79   int pr_lock_count;
  80 } pthread_readlock_info;
  81
  82
  83 /* We keep thread specific data in a special data structure, a two-level
  84    array.  The top-level array contains pointers to dynamically allocated
  85    arrays of a certain number of data pointers.  So we can implement a
  86    sparse array.  Each dynamic second-level array has
  87         PTHREAD_KEY_2NDLEVEL_SIZE
  88    entries.  This value shouldn't be too large.  */
  89 #define PTHREAD_KEY_2NDLEVEL_SIZE       32
  90
  91 /* We need to address PTHREAD_KEYS_MAX key with PTHREAD_KEY_2NDLEVEL_SIZE
  92    keys in each subarray.  */
  93 #define PTHREAD_KEY_1STLEVEL_SIZE \
  94   ((PTHREAD_KEYS_MAX + PTHREAD_KEY_2NDLEVEL_SIZE - 1) \
  95    / PTHREAD_KEY_2NDLEVEL_SIZE)
  96
  97
  98 union dtv;
  99
 100
 101 struct _pthread_descr_struct {
 102   /* XXX Remove this union for IA-64 style TLS module */
 103   union {
 104     struct {
 105       void *tcb;                /* Pointer to the TCB.  This is not always
 106                                    the address of this thread descriptor.  */
 107       union dtv *dtvp;
 108       pthread_descr self;       /* Pointer to this structure */
 109     } data;
 110     void *__padding[16];
 111   } p_header;
 112   pthread_descr p_nextlive, p_prevlive;
 113                                 /* Double chaining of active threads */
 114   pthread_descr p_nextwaiting;  /* Next element in the queue holding the thr */
 115   pthread_descr p_nextlock;     /* can be on a queue and waiting on a lock */
 116   pthread_t p_tid;              /* Thread identifier */
 117   int p_pid;                    /* PID of Unix process */
 118   int p_priority;               /* Thread priority (== 0 if not realtime) */
 119   struct _pthread_fastlock * p_lock; /* Spinlock for synchronized accesses */
 120   int p_signal;                 /* last signal received */
 121   sigjmp_buf * p_signal_jmp;    /* where to siglongjmp on a signal or NULL */
 122   sigjmp_buf * p_cancel_jmp;    /* where to siglongjmp on a cancel or NULL */
 123   char p_terminated;            /* true if terminated e.g. by pthread_exit */
 124   char p_detached;              /* true if detached */
 125   char p_exited;                /* true if the assoc. process terminated */
 126   void * p_retval;              /* placeholder for return value */
 127   int p_retcode;                /* placeholder for return code */
 128   pthread_descr p_joining;      /* thread joining on that thread or NULL */
 129   struct _pthread_cleanup_buffer * p_cleanup; /* cleanup functions */
 130   char p_cancelstate;           /* cancellation state */
 131   char p_canceltype;            /* cancellation type (deferred/async) */
 132   char p_canceled;              /* cancellation request pending */
 133   char * p_in_sighandler;       /* stack address of sighandler, or NULL */
 134   char p_sigwaiting;            /* true if a sigwait() is in progress */
 135   struct pthread_start_args p_start_args; /* arguments for thread creation */
 136   void ** p_specific[PTHREAD_KEY_1STLEVEL_SIZE]; /* thread-specific data */
 137 #if !(USE_TLS && HAVE___THREAD)
 138   void * p_libc_specific[_LIBC_TSD_KEY_N]; /* thread-specific data for libc */
 139   int * p_errnop;               /* pointer to used errno variable */
 140   int p_errno;                  /* error returned by last system call */
 141   int * p_h_errnop;             /* pointer to used h_errno variable */
 142   int p_h_errno;                /* error returned by last netdb function */
 143   struct __res_state *p_resp;   /* Pointer to resolver state */
 144   struct __res_state p_res;     /* per-thread resolver state */
 145 #endif
 146   int p_userstack;              /* nonzero if the user provided the stack */
 147   void *p_guardaddr;            /* address of guard area or NULL */
 148   size_t p_guardsize;           /* size of guard area */
 149   int p_nr;                     /* Index of descriptor in __pthread_handles */
 150   int p_report_events;          /* Nonzero if events must be reported.  */
 151   td_eventbuf_t p_eventbuf;     /* Data for event.  */
 152   struct pthread_atomic p_resume_count; /* number of times restart() was
 153                                            called on thread */
 154   char p_woken_by_cancel;       /* cancellation performed wakeup */
 155   char p_condvar_avail;         /* flag if conditional variable became avail */
 156   char p_sem_avail;             /* flag if semaphore became available */
 157   pthread_extricate_if *p_extricate; /* See above */
 158   pthread_readlock_info *p_readlock_list;  /* List of readlock info structs */
 159   pthread_readlock_info *p_readlock_free;  /* Free list of structs */
 160   int p_untracked_readlock_count;       /* Readlocks not tracked by list */
 161   int p_inheritsched;           /* copied from the thread attribute */
 162 #if HP_TIMING_AVAIL
 163   hp_timing_t p_cpuclock_offset; /* Initial CPU clock for thread.  */
 164 #endif
 165 #ifdef USE_TLS
 166   char *p_stackaddr;            /* Stack address.  */
 167 #endif
 168   /* New elements must be added at the end.  */
 169 } __attribute__ ((aligned(32))); /* We need to align the structure so that
 170                                     doubles are aligned properly.  This is 8
 171                                     bytes on MIPS and 16 bytes on MIPS64.
 172                                     32 bytes might give better cache
 173                                     utilization.  */
 174
 175
 176
 177 /* Limit between the stack of the initial thread (above) and the
 178    stacks of other threads (below). Aligned on a STACK_SIZE boundary.
 179    Initially 0, meaning that the current thread is (by definition)
 180    the initial thread. */
 181
 182 extern char *__pthread_initial_thread_bos;
 183
 184 /* Descriptor of the initial thread */
 185
 186 extern struct _pthread_descr_struct __pthread_initial_thread;
 187
 188 /* Limits of the thread manager stack. */
 189
 190 extern char *__pthread_manager_thread_bos;
 191 extern char *__pthread_manager_thread_tos;
 192
 193 /* Descriptor of the manager thread */
 194
 195 extern struct _pthread_descr_struct __pthread_manager_thread;
 196
 197 /* Indicate whether at least one thread has a user-defined stack (if 1),
 198    or all threads have stacks supplied by LinuxThreads (if 0). */
 199
 200 extern int __pthread_nonstandard_stacks;
 201
 202 /* The max size of the thread stack segments.  If the default
 203    THREAD_SELF implementation is used, this must be a power of two and
 204    a multiple of PAGE_SIZE.  */
 205 #ifndef STACK_SIZE
 206 #define STACK_SIZE  (2 * 1024 * 1024)
 207 #endif
 208
 209 /* Get some notion of the current stack.  Need not be exactly the top
 210    of the stack, just something somewhere in the current frame.  */
 211 #ifndef CURRENT_STACK_FRAME
 212 #define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
 213 #endif
 214
 215 /* Recover thread descriptor for the current thread */
 216
 217 extern pthread_descr __pthread_find_self (void) __attribute__ ((const));
 218
 219 static inline pthread_descr thread_self (void) __attribute__ ((const));
 220 static inline pthread_descr thread_self (void)
 221 {
 222 #ifdef THREAD_SELF
 223   return THREAD_SELF;
 224 #else
 225   char *sp = CURRENT_STACK_FRAME;
 226   if (sp >= __pthread_initial_thread_bos)
 227     return &__pthread_initial_thread;
 228   else if (sp >= __pthread_manager_thread_bos
 229            && sp < __pthread_manager_thread_tos)
 230     return &__pthread_manager_thread;
 231   else if (__pthread_nonstandard_stacks)
 232     return __pthread_find_self();
 233   else
 234 #ifdef _STACK_GROWS_DOWN
 235     return (pthread_descr)(((unsigned long)sp | (STACK_SIZE-1))+1) - 1;
 236 #else
 237     return (pthread_descr)((unsigned long)sp &~ (STACK_SIZE-1));
 238 #endif
 239 #endif
 240 }
 241
 242 #endif  /* descr.h */