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