lib/libc_r/uthread/uthread_create.c

   1 /*
   2  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the author nor the names of any co-contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31 #include <errno.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <fcntl.h>
  35 #include <unistd.h>
  36 #include <stddef.h>
  37 #include <sys/time.h>
  38 #include <machine/reg.h>
  39 #include "namespace.h"
  40 #include <pthread.h>
  41 #include "un-namespace.h"
  42
  43 #include "pthread_private.h"
  44 #include "libc_private.h"
  45
  46 static u_int64_t next_uniqueid = 1;
  47
  48 #define OFF(f)  offsetof(struct pthread, f)
  49 int _thread_next_offset                 = OFF(tle.tqe_next);
  50 int _thread_uniqueid_offset             = OFF(uniqueid);
  51 int _thread_state_offset                = OFF(state);
  52 int _thread_name_offset                 = OFF(name);
  53 int _thread_ctx_offset                  = OFF(ctx);
  54 #undef OFF
  55
  56 int _thread_PS_RUNNING_value            = PS_RUNNING;
  57 int _thread_PS_DEAD_value               = PS_DEAD;
  58
  59 __weak_reference(_pthread_create, pthread_create);
  60
  61 int
  62 _pthread_create(pthread_t *thread, const pthread_attr_t *attr,
  63                void *(*start_routine) (void *), void *arg)
  64 {
  65         struct pthread  *curthread = _get_curthread();
  66         struct itimerval itimer;
  67         int             f_gc = 0;
  68         int             ret = 0;
  69         pthread_t       gc_thread;
  70         pthread_t       new_thread;
  71         pthread_attr_t  pattr;
  72         void           *stack;
  73 #if !defined(__ia64__)
  74         u_long          stackp;
  75 #endif
  76
  77         if (thread == NULL)
  78                 return(EINVAL);
  79
  80         /*
  81          * Locking functions in libc are required when there are
  82          * threads other than the initial thread.
  83          */
  84         __isthreaded = 1;
  85
  86         /* Allocate memory for the thread structure: */
  87         if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
  88                 /* Insufficient memory to create a thread: */
  89                 ret = EAGAIN;
  90         } else {
  91                 /* Check if default thread attributes are required: */
  92                 if (attr == NULL || *attr == NULL) {
  93                         /* Use the default thread attributes: */
  94                         pattr = &_pthread_attr_default;
  95                 } else {
  96                         pattr = *attr;
  97                 }
  98                 /* Check if a stack was specified in the thread attributes: */
  99                 if ((stack = pattr->stackaddr_attr) != NULL) {
 100                 }
 101                 /* Allocate a stack: */
 102                 else {
 103                         stack = _thread_stack_alloc(pattr->stacksize_attr,
 104                             pattr->guardsize_attr);
 105                         if (stack == NULL) {
 106                                 ret = EAGAIN;
 107                                 free(new_thread);
 108                         }
 109                 }
 110
 111                 /* Check for errors: */
 112                 if (ret != 0) {
 113                 } else {
 114                         /* Initialise the thread structure: */
 115                         memset(new_thread, 0, sizeof(struct pthread));
 116                         new_thread->slice_usec = -1;
 117                         new_thread->stack = stack;
 118                         new_thread->start_routine = start_routine;
 119                         new_thread->arg = arg;
 120
 121                         new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
 122                             PTHREAD_CANCEL_DEFERRED;
 123
 124                         /*
 125                          * Write a magic value to the thread structure
 126                          * to help identify valid ones:
 127                          */
 128                         new_thread->magic = PTHREAD_MAGIC;
 129
 130                         /* Initialise the thread for signals: */
 131                         new_thread->sigmask = curthread->sigmask;
 132                         new_thread->sigmask_seqno = 0;
 133
 134                         /* Initialize the signal frame: */
 135                         new_thread->curframe = NULL;
 136
 137                         /* Initialise the jump buffer: */
 138                         _setjmp(new_thread->ctx.jb);
 139
 140                         /*
 141                          * Set up new stack frame so that it looks like it
 142                          * returned from a longjmp() to the beginning of
 143                          * _thread_start().
 144                          */
 145                         SET_RETURN_ADDR_JB(new_thread->ctx.jb, _thread_start);
 146
 147 #if !defined(__ia64__)
 148                         stackp = (long)new_thread->stack + pattr->stacksize_attr - sizeof(double);
 149 #if defined(__amd64__)
 150                         stackp &= ~0xFUL;
 151 #endif
 152                         /* The stack starts high and builds down: */
 153                         SET_STACK_JB(new_thread->ctx.jb, stackp);
 154 #else
 155                         SET_STACK_JB(new_thread->ctx.jb,
 156                             (long)new_thread->stack, pattr->stacksize_attr);
 157 #endif
 158
 159                         /* Copy the thread attributes: */
 160                         memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
 161
 162                         /*
 163                          * Check if this thread is to inherit the scheduling
 164                          * attributes from its parent:
 165                          */
 166                         if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
 167                                 /* Copy the scheduling attributes: */
 168                                 new_thread->base_priority =
 169                                     curthread->base_priority &
 170                                     ~PTHREAD_SIGNAL_PRIORITY;
 171                                 new_thread->attr.prio =
 172                                     curthread->base_priority &
 173                                     ~PTHREAD_SIGNAL_PRIORITY;
 174                                 new_thread->attr.sched_policy =
 175                                     curthread->attr.sched_policy;
 176                         } else {
 177                                 /*
 178                                  * Use just the thread priority, leaving the
 179                                  * other scheduling attributes as their
 180                                  * default values:
 181                                  */
 182                                 new_thread->base_priority =
 183                                     new_thread->attr.prio;
 184                         }
 185                         new_thread->active_priority = new_thread->base_priority;
 186                         new_thread->inherited_priority = 0;
 187
 188                         /* Initialize joiner to NULL (no joiner): */
 189                         new_thread->joiner = NULL;
 190
 191                         /* Initialize the mutex queue: */
 192                         TAILQ_INIT(&new_thread->mutexq);
 193
 194                         /* Initialise hooks in the thread structure: */
 195                         new_thread->specific = NULL;
 196                         new_thread->cleanup = NULL;
 197                         new_thread->flags = 0;
 198                         new_thread->poll_data.nfds = 0;
 199                         new_thread->poll_data.fds = NULL;
 200                         new_thread->continuation = NULL;
 201
 202                         /*
 203                          * Defer signals to protect the scheduling queues
 204                          * from access by the signal handler:
 205                          */
 206                         _thread_kern_sig_defer();
 207
 208                         /*
 209                          * Initialise the unique id which GDB uses to
 210                          * track threads.
 211                          */
 212                         new_thread->uniqueid = next_uniqueid++;
 213
 214                         /*
 215                          * Check if the garbage collector thread
 216                          * needs to be started.
 217                          */
 218                         f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
 219
 220                         /* Add the thread to the linked list of all threads: */
 221                         TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
 222
 223                         if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
 224                                 new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
 225                                 new_thread->state = PS_SUSPENDED;
 226                         } else {
 227                                 new_thread->state = PS_RUNNING;
 228                                 PTHREAD_PRIOQ_INSERT_TAIL(new_thread);
 229                         }
 230
 231                         /*
 232                          * Undefer and handle pending signals, yielding
 233                          * if necessary.
 234                          */
 235                         _thread_kern_sig_undefer();
 236
 237                         /* Return a pointer to the thread structure: */
 238                         (*thread) = new_thread;
 239
 240                         if (f_gc != 0) {
 241                                 /* Install the scheduling timer: */
 242                                 itimer.it_interval.tv_sec = 0;
 243                                 itimer.it_interval.tv_usec = _clock_res_usec;
 244                                 itimer.it_value = itimer.it_interval;
 245                                 if (setitimer(_ITIMER_SCHED_TIMER, &itimer,
 246                                     NULL) != 0)
 247                                         PANIC("Cannot set interval timer");
 248                         }
 249
 250                         /* Schedule the new user thread: */
 251                         _thread_kern_sched(NULL);
 252
 253                         /*
 254                          * Start a garbage collector thread
 255                          * if necessary.
 256                          */
 257                         if (f_gc && _pthread_create(&gc_thread, NULL,
 258                                     _thread_gc, NULL) != 0)
 259                                 PANIC("Can't create gc thread");
 260
 261                 }
 262         }
 263
 264         /* Return the status: */
 265         return (ret);
 266 }
 267
 268 void
 269 _thread_start(void)
 270 {
 271         struct pthread  *curthread = _get_curthread();
 272
 273         /* We just left the scheduler via longjmp: */
 274         _thread_kern_in_sched = 0;
 275
 276         /* Run the current thread's start routine with argument: */
 277         _pthread_exit(curthread->start_routine(curthread->arg));
 278
 279         /* This point should never be reached. */
 280         PANIC("Thread has resumed after exit");
 281 }