server/thread.c

   1 /*
   2  * Server-side thread management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <signal.h>
  13 #include <stdarg.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #ifdef HAVE_SYS_MMAN_H
  18 #include <sys/mman.h>
  19 #endif
  20 #include <sys/types.h>
  21 #include <unistd.h>
  22 #include <stdarg.h>
  23
  24 #include "winbase.h"
  25
  26 #include "handle.h"
  27 #include "process.h"
  28 #include "thread.h"
  29 #include "request.h"
  30
  31
  32 /* thread queues */
  33
  34 struct thread_wait
  35 {
  36     struct thread_wait     *next;       /* next wait structure for this thread */
  37     struct thread          *thread;     /* owner thread */
  38     int                     count;      /* count of objects */
  39     int                     flags;
  40     void                   *cookie;     /* magic cookie to return to client */
  41     struct timeval          timeout;
  42     struct timeout_user    *user;
  43     struct wait_queue_entry queues[1];
  44 };
  45
  46 /* asynchronous procedure calls */
  47
  48 struct thread_apc
  49 {
  50     struct thread_apc  *next;     /* queue linked list */
  51     struct thread_apc  *prev;
  52     struct object      *owner;    /* object that queued this apc */
  53     void               *func;     /* function to call in client */
  54     enum apc_type       type;     /* type of apc function */
  55     int                 nb_args;  /* number of arguments */
  56     void               *args[1];  /* function arguments */
  57 };
  58
  59
  60 /* thread operations */
  61
  62 static void dump_thread( struct object *obj, int verbose );
  63 static int thread_signaled( struct object *obj, struct thread *thread );
  64 static void thread_poll_event( struct object *obj, int event );
  65 static void destroy_thread( struct object *obj );
  66 static struct thread_apc *thread_dequeue_apc( struct thread *thread, int system_only );
  67
  68 static const struct object_ops thread_ops =
  69 {
  70     sizeof(struct thread),      /* size */
  71     dump_thread,                /* dump */
  72     add_queue,                  /* add_queue */
  73     remove_queue,               /* remove_queue */
  74     thread_signaled,            /* signaled */
  75     no_satisfied,               /* satisfied */
  76     NULL,                       /* get_poll_events */
  77     thread_poll_event,          /* poll_event */
  78     no_get_fd,                  /* get_fd */
  79     no_flush,                   /* flush */
  80     no_get_file_info,           /* get_file_info */
  81     destroy_thread              /* destroy */
  82 };
  83
  84 static struct thread *first_thread;
  85 static struct thread *booting_thread;
  86
  87 /* initialize the structure for a newly allocated thread */
  88 inline static void init_thread_structure( struct thread *thread )
  89 {
  90     int i;
  91
  92     thread->unix_pid        = 0;  /* not known yet */
  93     thread->context         = NULL;
  94     thread->teb             = NULL;
  95     thread->mutex           = NULL;
  96     thread->debug_ctx       = NULL;
  97     thread->debug_event     = NULL;
  98     thread->queue           = NULL;
  99     thread->info            = NULL;
 100     thread->wait            = NULL;
 101     thread->system_apc.head = NULL;
 102     thread->system_apc.tail = NULL;
 103     thread->user_apc.head   = NULL;
 104     thread->user_apc.tail   = NULL;
 105     thread->error           = 0;
 106     thread->request_fd      = NULL;
 107     thread->reply_fd        = -1;
 108     thread->wait_fd         = -1;
 109     thread->state           = RUNNING;
 110     thread->attached        = 0;
 111     thread->exit_code       = 0;
 112     thread->next            = NULL;
 113     thread->prev            = NULL;
 114     thread->priority        = THREAD_PRIORITY_NORMAL;
 115     thread->affinity        = 1;
 116     thread->suspend         = 0;
 117     thread->buffer          = (void *)-1;
 118
 119     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 120         thread->inflight[i].server = thread->inflight[i].client = -1;
 121 }
 122
 123 /* create a new thread */
 124 struct thread *create_thread( int fd, struct process *process )
 125 {
 126     struct thread *thread;
 127
 128     if (!(thread = alloc_object( &thread_ops, fd ))) return NULL;
 129
 130     init_thread_structure( thread );
 131
 132     thread->process = (struct process *)grab_object( process );
 133     if (!current) current = thread;
 134
 135     if (!booting_thread)  /* first thread ever */
 136     {
 137         booting_thread = thread;
 138         lock_master_socket(1);
 139     }
 140
 141     if ((thread->next = first_thread) != NULL) thread->next->prev = thread;
 142     first_thread = thread;
 143
 144     fcntl( fd, F_SETFL, O_NONBLOCK );
 145     set_select_events( &thread->obj, POLLIN );  /* start listening to events */
 146     add_process_thread( thread->process, thread );
 147     return thread;
 148 }
 149
 150 /* handle a client event */
 151 static void thread_poll_event( struct object *obj, int event )
 152 {
 153     struct thread *thread = (struct thread *)obj;
 154     assert( obj->ops == &thread_ops );
 155
 156     if (event & (POLLERR | POLLHUP)) kill_thread( thread, 0 );
 157     else if (event & POLLIN) read_request( thread );
 158 }
 159
 160 /* cleanup everything that is no longer needed by a dead thread */
 161 /* used by destroy_thread and kill_thread */
 162 static void cleanup_thread( struct thread *thread )
 163 {
 164     int i;
 165     struct thread_apc *apc;
 166
 167     while ((apc = thread_dequeue_apc( thread, 0 ))) free( apc );
 168     if (thread->buffer != (void *)-1) munmap( thread->buffer, MAX_REQUEST_LENGTH );
 169     if (thread->reply_fd != -1) close( thread->reply_fd );
 170     if (thread->wait_fd != -1) close( thread->wait_fd );
 171     if (thread->request_fd) release_object( thread->request_fd );
 172     if (thread->queue)
 173     {
 174         if (thread->process->queue == thread->queue)
 175         {
 176             release_object( thread->process->queue );
 177             thread->process->queue = NULL;
 178         }
 179         release_object( thread->queue );
 180         thread->queue = NULL;
 181     }
 182     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 183     {
 184         if (thread->inflight[i].client != -1)
 185         {
 186             close( thread->inflight[i].server );
 187             thread->inflight[i].client = thread->inflight[i].server = -1;
 188         }
 189     }
 190     thread->buffer = (void *)-1;
 191     thread->reply_fd = -1;
 192     thread->wait_fd = -1;
 193     thread->request_fd = NULL;
 194 }
 195
 196 /* destroy a thread when its refcount is 0 */
 197 static void destroy_thread( struct object *obj )
 198 {
 199     struct thread_apc *apc;
 200     struct thread *thread = (struct thread *)obj;
 201     assert( obj->ops == &thread_ops );
 202
 203     assert( !thread->debug_ctx );  /* cannot still be debugging something */
 204     if (thread->next) thread->next->prev = thread->prev;
 205     if (thread->prev) thread->prev->next = thread->next;
 206     else first_thread = thread->next;
 207     while ((apc = thread_dequeue_apc( thread, 0 ))) free( apc );
 208     if (thread->info) release_object( thread->info );
 209     cleanup_thread( thread );
 210     release_object( thread->process );
 211 }
 212
 213 /* dump a thread on stdout for debugging purposes */
 214 static void dump_thread( struct object *obj, int verbose )
 215 {
 216     struct thread *thread = (struct thread *)obj;
 217     assert( obj->ops == &thread_ops );
 218
 219     fprintf( stderr, "Thread pid=%d teb=%p state=%d\n",
 220              thread->unix_pid, thread->teb, thread->state );
 221 }
 222
 223 static int thread_signaled( struct object *obj, struct thread *thread )
 224 {
 225     struct thread *mythread = (struct thread *)obj;
 226     return (mythread->state == TERMINATED);
 227 }
 228
 229 /* get a thread pointer from a thread id (and increment the refcount) */
 230 struct thread *get_thread_from_id( void *id )
 231 {
 232     struct thread *t = first_thread;
 233     while (t && (t != id)) t = t->next;
 234     if (t) grab_object( t );
 235     else set_error( STATUS_INVALID_PARAMETER );
 236     return t;
 237 }
 238
 239 /* get a thread from a handle (and increment the refcount) */
 240 struct thread *get_thread_from_handle( handle_t handle, unsigned int access )
 241 {
 242     return (struct thread *)get_handle_obj( current->process, handle,
 243                                             access, &thread_ops );
 244 }
 245
 246 /* find a thread from a Unix pid */
 247 struct thread *get_thread_from_pid( int pid )
 248 {
 249     struct thread *t = first_thread;
 250     while (t && (t->unix_pid != pid)) t = t->next;
 251     return t;
 252 }
 253
 254 /* set all information about a thread */
 255 static void set_thread_info( struct thread *thread,
 256                              struct set_thread_info_request *req )
 257 {
 258     if (req->mask & SET_THREAD_INFO_PRIORITY)
 259         thread->priority = req->priority;
 260     if (req->mask & SET_THREAD_INFO_AFFINITY)
 261     {
 262         if (req->affinity != 1) set_error( STATUS_INVALID_PARAMETER );
 263         else thread->affinity = req->affinity;
 264     }
 265 }
 266
 267 /* suspend a thread */
 268 int suspend_thread( struct thread *thread, int check_limit )
 269 {
 270     int old_count = thread->suspend;
 271     if (thread->suspend < MAXIMUM_SUSPEND_COUNT || !check_limit)
 272     {
 273         if (!(thread->process->suspend + thread->suspend++)) stop_thread( thread );
 274     }
 275     else set_error( STATUS_SUSPEND_COUNT_EXCEEDED );
 276     return old_count;
 277 }
 278
 279 /* resume a thread */
 280 int resume_thread( struct thread *thread )
 281 {
 282     int old_count = thread->suspend;
 283     if (thread->suspend > 0)
 284     {
 285         if (!(--thread->suspend + thread->process->suspend)) continue_thread( thread );
 286     }
 287     return old_count;
 288 }
 289
 290 /* add a thread to an object wait queue; return 1 if OK, 0 on error */
 291 int add_queue( struct object *obj, struct wait_queue_entry *entry )
 292 {
 293     grab_object( obj );
 294     entry->obj    = obj;
 295     entry->prev   = obj->tail;
 296     entry->next   = NULL;
 297     if (obj->tail) obj->tail->next = entry;
 298     else obj->head = entry;
 299     obj->tail = entry;
 300     return 1;
 301 }
 302
 303 /* remove a thread from an object wait queue */
 304 void remove_queue( struct object *obj, struct wait_queue_entry *entry )
 305 {
 306     if (entry->next) entry->next->prev = entry->prev;
 307     else obj->tail = entry->prev;
 308     if (entry->prev) entry->prev->next = entry->next;
 309     else obj->head = entry->next;
 310     release_object( obj );
 311 }
 312
 313 /* finish waiting */
 314 static void end_wait( struct thread *thread )
 315 {
 316     struct thread_wait *wait = thread->wait;
 317     struct wait_queue_entry *entry;
 318     int i;
 319
 320     assert( wait );
 321     for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 322         entry->obj->ops->remove_queue( entry->obj, entry );
 323     if (wait->user) remove_timeout_user( wait->user );
 324     thread->wait = wait->next;
 325     free( wait );
 326 }
 327
 328 /* build the thread wait structure */
 329 static int wait_on( int count, struct object *objects[], int flags, int sec, int usec )
 330 {
 331     struct thread_wait *wait;
 332     struct wait_queue_entry *entry;
 333     int i;
 334
 335     if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
 336     wait->next    = current->wait;
 337     wait->thread  = current;
 338     wait->count   = count;
 339     wait->flags   = flags;
 340     wait->user    = NULL;
 341     current->wait = wait;
 342     if (flags & SELECT_TIMEOUT)
 343     {
 344         wait->timeout.tv_sec = sec;
 345         wait->timeout.tv_usec = usec;
 346     }
 347
 348     for (i = 0, entry = wait->queues; i < count; i++, entry++)
 349     {
 350         struct object *obj = objects[i];
 351         entry->thread = current;
 352         if (!obj->ops->add_queue( obj, entry ))
 353         {
 354             wait->count = i;
 355             end_wait( current );
 356             return 0;
 357         }
 358     }
 359     return 1;
 360 }
 361
 362 /* check if the thread waiting condition is satisfied */
 363 static int check_wait( struct thread *thread )
 364 {
 365     int i, signaled;
 366     struct thread_wait *wait = thread->wait;
 367     struct wait_queue_entry *entry = wait->queues;
 368
 369     assert( wait );
 370     if (wait->flags & SELECT_ALL)
 371     {
 372         int not_ok = 0;
 373         /* Note: we must check them all anyway, as some objects may
 374          * want to do something when signaled, even if others are not */
 375         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 376             not_ok |= !entry->obj->ops->signaled( entry->obj, thread );
 377         if (not_ok) goto other_checks;
 378         /* Wait satisfied: tell it to all objects */
 379         signaled = 0;
 380         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 381             if (entry->obj->ops->satisfied( entry->obj, thread ))
 382                 signaled = STATUS_ABANDONED_WAIT_0;
 383         return signaled;
 384     }
 385     else
 386     {
 387         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 388         {
 389             if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
 390             /* Wait satisfied: tell it to the object */
 391             signaled = i;
 392             if (entry->obj->ops->satisfied( entry->obj, thread ))
 393                 signaled = i + STATUS_ABANDONED_WAIT_0;
 394             return signaled;
 395         }
 396     }
 397
 398  other_checks:
 399     if ((wait->flags & SELECT_INTERRUPTIBLE) && thread->system_apc.head) return STATUS_USER_APC;
 400     if ((wait->flags & SELECT_ALERTABLE) && thread->user_apc.head) return STATUS_USER_APC;
 401     if (wait->flags & SELECT_TIMEOUT)
 402     {
 403         struct timeval now;
 404         gettimeofday( &now, NULL );
 405         if (!time_before( &now, &wait->timeout )) return STATUS_TIMEOUT;
 406     }
 407     return -1;
 408 }
 409
 410 /* send the wakeup signal to a thread */
 411 static int send_thread_wakeup( struct thread *thread, void *cookie, int signaled )
 412 {
 413     struct wake_up_reply reply;
 414     int ret;
 415
 416     reply.cookie   = cookie;
 417     reply.signaled = signaled;
 418     if ((ret = write( thread->wait_fd, &reply, sizeof(reply) )) == sizeof(reply)) return 0;
 419     if (ret >= 0)
 420         fatal_protocol_error( thread, "partial wakeup write %d\n", ret );
 421     else if (errno == EPIPE)
 422         kill_thread( thread, 0 );  /* normal death */
 423     else
 424         fatal_protocol_perror( thread, "write" );
 425     return -1;
 426 }
 427
 428 /* attempt to wake up a thread */
 429 /* return >0 if OK, 0 if the wait condition is still not satisfied */
 430 static int wake_thread( struct thread *thread )
 431 {
 432     int signaled, count;
 433     void *cookie;
 434
 435     for (count = 0; thread->wait; count++)
 436     {
 437         if ((signaled = check_wait( thread )) == -1) break;
 438
 439         cookie = thread->wait->cookie;
 440         if (debug_level) fprintf( stderr, "%08x: *wakeup* signaled=%d cookie=%p\n",
 441                                   (unsigned int)thread, signaled, cookie );
 442         end_wait( thread );
 443         if (send_thread_wakeup( thread, cookie, signaled ) == -1) /* error */
 444             break;
 445     }
 446     return count;
 447 }
 448
 449 /* thread wait timeout */
 450 static void thread_timeout( void *ptr )
 451 {
 452     struct thread_wait *wait = ptr;
 453     struct thread *thread = wait->thread;
 454     void *cookie = wait->cookie;
 455
 456     wait->user = NULL;
 457     if (thread->wait != wait) return; /* not the top-level wait, ignore it */
 458
 459     if (debug_level) fprintf( stderr, "%08x: *wakeup* signaled=%d cookie=%p\n",
 460                               (unsigned int)thread, STATUS_TIMEOUT, cookie );
 461     end_wait( thread );
 462     send_thread_wakeup( thread, cookie, STATUS_TIMEOUT );
 463     /* check if other objects have become signaled in the meantime */
 464     wake_thread( thread );
 465 }
 466
 467 /* select on a list of handles */
 468 static void select_on( int count, void *cookie, handle_t *handles, int flags, int sec, int usec )
 469 {
 470     int ret, i;
 471     struct object *objects[MAXIMUM_WAIT_OBJECTS];
 472
 473     if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
 474     {
 475         set_error( STATUS_INVALID_PARAMETER );
 476         return;
 477     }
 478     for (i = 0; i < count; i++)
 479     {
 480         if (!(objects[i] = get_handle_obj( current->process, handles[i], SYNCHRONIZE, NULL )))
 481             break;
 482     }
 483
 484     if (i < count) goto done;
 485     if (!wait_on( count, objects, flags, sec, usec )) goto done;
 486
 487     if ((ret = check_wait( current )) != -1)
 488     {
 489         /* condition is already satisfied */
 490         end_wait( current );
 491         set_error( ret );
 492         goto done;
 493     }
 494
 495     /* now we need to wait */
 496     if (flags & SELECT_TIMEOUT)
 497     {
 498         if (!(current->wait->user = add_timeout_user( &current->wait->timeout,
 499                                                       thread_timeout, current->wait )))
 500         {
 501             end_wait( current );
 502             goto done;
 503         }
 504     }
 505     current->wait->cookie = cookie;
 506     set_error( STATUS_PENDING );
 507
 508 done:
 509     while (--i >= 0) release_object( objects[i] );
 510 }
 511
 512 /* attempt to wake threads sleeping on the object wait queue */
 513 void wake_up( struct object *obj, int max )
 514 {
 515     struct wait_queue_entry *entry = obj->head;
 516
 517     while (entry)
 518     {
 519         struct thread *thread = entry->thread;
 520         entry = entry->next;
 521         if (wake_thread( thread ))
 522         {
 523             if (max && !--max) break;
 524         }
 525     }
 526 }
 527
 528 /* queue an async procedure call */
 529 int thread_queue_apc( struct thread *thread, struct object *owner, void *func,
 530                       enum apc_type type, int system, int nb_args, ... )
 531 {
 532     struct thread_apc *apc;
 533     struct apc_queue *queue = system ? &thread->system_apc : &thread->user_apc;
 534
 535     /* cancel a possible previous APC with the same owner */
 536     if (owner) thread_cancel_apc( thread, owner, system );
 537
 538     if (!(apc = mem_alloc( sizeof(*apc) + (nb_args-1)*sizeof(apc->args[0]) ))) return 0;
 539     apc->prev    = queue->tail;
 540     apc->next    = NULL;
 541     apc->owner   = owner;
 542     apc->func    = func;
 543     apc->type    = type;
 544     apc->nb_args = nb_args;
 545     if (nb_args)
 546     {
 547         int i;
 548         va_list args;
 549         va_start( args, nb_args );
 550         for (i = 0; i < nb_args; i++) apc->args[i] = va_arg( args, void * );
 551         va_end( args );
 552     }
 553     queue->tail = apc;
 554     if (!apc->prev)  /* first one */
 555     {
 556         queue->head = apc;
 557         wake_thread( thread );
 558     }
 559     return 1;
 560 }
 561
 562 /* cancel the async procedure call owned by a specific object */
 563 void thread_cancel_apc( struct thread *thread, struct object *owner, int system )
 564 {
 565     struct thread_apc *apc;
 566     struct apc_queue *queue = system ? &thread->system_apc : &thread->user_apc;
 567     for (apc = queue->head; apc; apc = apc->next)
 568     {
 569         if (apc->owner != owner) continue;
 570         if (apc->next) apc->next->prev = apc->prev;
 571         else queue->tail = apc->prev;
 572         if (apc->prev) apc->prev->next = apc->next;
 573         else queue->head = apc->next;
 574         free( apc );
 575         return;
 576     }
 577 }
 578
 579 /* remove the head apc from the queue; the returned pointer must be freed by the caller */
 580 static struct thread_apc *thread_dequeue_apc( struct thread *thread, int system_only )
 581 {
 582     struct thread_apc *apc;
 583     struct apc_queue *queue = &thread->system_apc;
 584
 585     if (!queue->head && !system_only) queue = &thread->user_apc;
 586     if ((apc = queue->head))
 587     {
 588         if (apc->next) apc->next->prev = NULL;
 589         else queue->tail = NULL;
 590         queue->head = apc->next;
 591     }
 592     return apc;
 593 }
 594
 595 /* add an fd to the inflight list */
 596 /* return list index, or -1 on error */
 597 int thread_add_inflight_fd( struct thread *thread, int client, int server )
 598 {
 599     int i;
 600
 601     if (server == -1) return -1;
 602     if (client == -1)
 603     {
 604         close( server );
 605         return -1;
 606     }
 607
 608     /* first check if we already have an entry for this fd */
 609     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 610         if (thread->inflight[i].client == client)
 611         {
 612             close( thread->inflight[i].server );
 613             thread->inflight[i].server = server;
 614             return i;
 615         }
 616
 617     /* now find a free spot to store it */
 618     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 619         if (thread->inflight[i].client == -1)
 620         {
 621             thread->inflight[i].client = client;
 622             thread->inflight[i].server = server;
 623             return i;
 624         }
 625     return -1;
 626 }
 627
 628 /* get an inflight fd and purge it from the list */
 629 /* the fd must be closed when no longer used */
 630 int thread_get_inflight_fd( struct thread *thread, int client )
 631 {
 632     int i, ret;
 633
 634     if (client == -1) return -1;
 635
 636     do
 637     {
 638         for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 639         {
 640             if (thread->inflight[i].client == client)
 641             {
 642                 ret = thread->inflight[i].server;
 643                 thread->inflight[i].server = thread->inflight[i].client = -1;
 644                 return ret;
 645             }
 646         }
 647     } while (!receive_fd( thread->process ));  /* in case it is still in the socket buffer */
 648     return -1;
 649 }
 650
 651 /* retrieve an LDT selector entry */
 652 static void get_selector_entry( struct thread *thread, int entry,
 653                                 unsigned int *base, unsigned int *limit,
 654                                 unsigned char *flags )
 655 {
 656     if (!thread->process->ldt_copy)
 657     {
 658         set_error( STATUS_ACCESS_DENIED );
 659         return;
 660     }
 661     if (entry >= 8192)
 662     {
 663         set_error( STATUS_INVALID_PARAMETER );  /* FIXME */
 664         return;
 665     }
 666     if (suspend_for_ptrace( thread ))
 667     {
 668         unsigned char flags_buf[4];
 669         int *addr = (int *)thread->process->ldt_copy + entry;
 670         if (read_thread_int( thread, addr, base ) == -1) goto done;
 671         if (read_thread_int( thread, addr + 8192, limit ) == -1) goto done;
 672         addr = (int *)thread->process->ldt_copy + 2*8192 + (entry >> 2);
 673         if (read_thread_int( thread, addr, (int *)flags_buf ) == -1) goto done;
 674         *flags = flags_buf[entry & 3];
 675     done:
 676         resume_thread( thread );
 677     }
 678 }
 679
 680 /* kill a thread on the spot */
 681 void kill_thread( struct thread *thread, int violent_death )
 682 {
 683     if (thread->state == TERMINATED) return;  /* already killed */
 684     thread->state = TERMINATED;
 685     if (current == thread) current = NULL;
 686     if (debug_level)
 687         fprintf( stderr,"%08x: *killed* exit_code=%d\n",
 688                  (unsigned int)thread, thread->exit_code );
 689     if (thread->wait)
 690     {
 691         while (thread->wait) end_wait( thread );
 692         send_thread_wakeup( thread, NULL, STATUS_PENDING );
 693         /* if it is waiting on the socket, we don't need to send a SIGTERM */
 694         violent_death = 0;
 695     }
 696     debug_exit_thread( thread );
 697     abandon_mutexes( thread );
 698     remove_process_thread( thread->process, thread );
 699     wake_up( &thread->obj, 0 );
 700     detach_thread( thread, violent_death ? SIGTERM : 0 );
 701     remove_select_user( &thread->obj );
 702     cleanup_thread( thread );
 703     release_object( thread );
 704 }
 705
 706 /* take a snapshot of currently running threads */
 707 struct thread_snapshot *thread_snap( int *count )
 708 {
 709     struct thread_snapshot *snapshot, *ptr;
 710     struct thread *thread;
 711     int total = 0;
 712
 713     for (thread = first_thread; thread; thread = thread->next)
 714         if (thread->state != TERMINATED) total++;
 715     if (!total || !(snapshot = mem_alloc( sizeof(*snapshot) * total ))) return NULL;
 716     ptr = snapshot;
 717     for (thread = first_thread; thread; thread = thread->next)
 718     {
 719         if (thread->state == TERMINATED) continue;
 720         ptr->thread   = thread;
 721         ptr->count    = thread->obj.refcount;
 722         ptr->priority = thread->priority;
 723         grab_object( thread );
 724         ptr++;
 725     }
 726     *count = total;
 727     return snapshot;
 728 }
 729
 730 /* signal that we are finished booting on the client side */
 731 DECL_HANDLER(boot_done)
 732 {
 733     debug_level = max( debug_level, req->debug_level );
 734     if (current == booting_thread)
 735     {
 736         booting_thread = (struct thread *)~0UL;  /* make sure it doesn't match other threads */
 737         lock_master_socket(0);  /* allow other clients now */
 738     }
 739 }
 740
 741 /* create a new thread */
 742 DECL_HANDLER(new_thread)
 743 {
 744     struct thread *thread;
 745     int request_fd = thread_get_inflight_fd( current, req->request_fd );
 746
 747     if (request_fd == -1)
 748     {
 749         set_error( STATUS_INVALID_HANDLE );
 750         return;
 751     }
 752
 753     if ((thread = create_thread( request_fd, current->process )))
 754     {
 755         if (req->suspend) thread->suspend++;
 756         req->tid = thread;
 757         if ((req->handle = alloc_handle( current->process, thread,
 758                                          THREAD_ALL_ACCESS, req->inherit )))
 759         {
 760             /* thread object will be released when the thread gets killed */
 761             return;
 762         }
 763         kill_thread( thread, 1 );
 764         request_fd = -1;
 765     }
 766 }
 767
 768 /* initialize a new thread */
 769 DECL_HANDLER(init_thread)
 770 {
 771     int reply_fd = thread_get_inflight_fd( current, req->reply_fd );
 772     int wait_fd = thread_get_inflight_fd( current, req->wait_fd );
 773
 774     if (current->unix_pid)
 775     {
 776         fatal_protocol_error( current, "init_thread: already running\n" );
 777         goto error;
 778     }
 779     if (reply_fd == -1)
 780     {
 781         fatal_protocol_error( current, "bad reply fd\n" );
 782         goto error;
 783     }
 784     if (wait_fd == -1)
 785     {
 786         fatal_protocol_error( current, "bad wait fd\n" );
 787         goto error;
 788     }
 789
 790     current->unix_pid = req->unix_pid;
 791     current->teb      = req->teb;
 792     current->reply_fd = reply_fd;
 793     current->wait_fd  = wait_fd;
 794
 795     if (current->suspend + current->process->suspend > 0) stop_thread( current );
 796     if (current->process->running_threads > 1)
 797         generate_debug_event( current, CREATE_THREAD_DEBUG_EVENT, req->entry );
 798
 799     req->pid     = get_process_id( current->process );
 800     req->tid     = get_thread_id( current );
 801     req->boot    = (current == booting_thread);
 802     req->version = SERVER_PROTOCOL_VERSION;
 803     return;
 804
 805  error:
 806     if (reply_fd != -1) close( reply_fd );
 807     if (wait_fd != -1) close( wait_fd );
 808 }
 809
 810 /* set the shared buffer for a thread */
 811 DECL_HANDLER(set_thread_buffer)
 812 {
 813     unsigned int size = MAX_REQUEST_LENGTH;
 814     unsigned int offset = 0;
 815     int fd = thread_get_inflight_fd( current, req->fd );
 816
 817     req->size = size;
 818     req->offset = offset;
 819
 820     if (fd != -1)
 821     {
 822         if (ftruncate( fd, size ) == -1) file_set_error();
 823         else
 824         {
 825             void *buffer = mmap( 0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, offset );
 826             if (buffer == (void *)-1) file_set_error();
 827             else
 828             {
 829                 if (current->buffer != (void *)-1) munmap( current->buffer, size );
 830                 current->buffer = buffer;
 831             }
 832         }
 833         close( fd );
 834     }
 835     else set_error( STATUS_INVALID_HANDLE );
 836 }
 837
 838 /* terminate a thread */
 839 DECL_HANDLER(terminate_thread)
 840 {
 841     struct thread *thread;
 842
 843     req->self = 0;
 844     req->last = 0;
 845     if ((thread = get_thread_from_handle( req->handle, THREAD_TERMINATE )))
 846     {
 847         thread->exit_code = req->exit_code;
 848         if (thread != current) kill_thread( thread, 1 );
 849         else
 850         {
 851             req->self = 1;
 852             req->last = (thread->process->running_threads == 1);
 853         }
 854         release_object( thread );
 855     }
 856 }
 857
 858 /* fetch information about a thread */
 859 DECL_HANDLER(get_thread_info)
 860 {
 861     struct thread *thread;
 862     handle_t handle = req->handle;
 863
 864     if (!handle) thread = get_thread_from_id( req->tid_in );
 865     else thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION );
 866
 867     if (thread)
 868     {
 869         req->tid       = get_thread_id( thread );
 870         req->teb       = thread->teb;
 871         req->exit_code = (thread->state == TERMINATED) ? thread->exit_code : STILL_ACTIVE;
 872         req->priority  = thread->priority;
 873         release_object( thread );
 874     }
 875 }
 876
 877 /* set information about a thread */
 878 DECL_HANDLER(set_thread_info)
 879 {
 880     struct thread *thread;
 881
 882     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_INFORMATION )))
 883     {
 884         set_thread_info( thread, req );
 885         release_object( thread );
 886     }
 887 }
 888
 889 /* suspend a thread */
 890 DECL_HANDLER(suspend_thread)
 891 {
 892     struct thread *thread;
 893
 894     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 895     {
 896         req->count = suspend_thread( thread, 1 );
 897         release_object( thread );
 898     }
 899 }
 900
 901 /* resume a thread */
 902 DECL_HANDLER(resume_thread)
 903 {
 904     struct thread *thread;
 905
 906     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 907     {
 908         req->count = resume_thread( thread );
 909         release_object( thread );
 910     }
 911 }
 912
 913 /* select on a handle list */
 914 DECL_HANDLER(select)
 915 {
 916     int count = get_req_data_size(req) / sizeof(int);
 917     select_on( count, req->cookie, get_req_data(req), req->flags, req->sec, req->usec );
 918 }
 919
 920 /* queue an APC for a thread */
 921 DECL_HANDLER(queue_apc)
 922 {
 923     struct thread *thread;
 924     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 925     {
 926         thread_queue_apc( thread, NULL, req->func, APC_USER, !req->user, 1, req->param );
 927         release_object( thread );
 928     }
 929 }
 930
 931 /* get next APC to call */
 932 DECL_HANDLER(get_apc)
 933 {
 934     struct thread_apc *apc;
 935     size_t size;
 936
 937     for (;;)
 938     {
 939         if (!(apc = thread_dequeue_apc( current, !req->alertable )))
 940         {
 941             /* no more APCs */
 942             req->func    = NULL;
 943             req->type    = APC_NONE;
 944             set_req_data_size( req, 0 );
 945             return;
 946         }
 947         /* Optimization: ignore APCs that have a NULL func; they are only used
 948          * to wake up a thread, but since we got here the thread woke up already.
 949          */
 950         if (apc->func) break;
 951         free( apc );
 952     }
 953     size = apc->nb_args * sizeof(apc->args[0]);
 954     if (size > get_req_data_size(req)) size = get_req_data_size(req);
 955     req->func = apc->func;
 956     req->type = apc->type;
 957     memcpy( get_req_data(req), apc->args, size );
 958     set_req_data_size( req, size );
 959     free( apc );
 960 }
 961
 962 /* fetch a selector entry for a thread */
 963 DECL_HANDLER(get_selector_entry)
 964 {
 965     struct thread *thread;
 966     if ((thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION )))
 967     {
 968         get_selector_entry( thread, req->entry, &req->base, &req->limit, &req->flags );
 969         release_object( thread );
 970     }
 971 }