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