server/thread.c

   1 /*
   2  * Server-side thread management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <signal.h>
  28 #include <stdarg.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <sys/types.h>
  33 #include <unistd.h>
  34 #include <time.h>
  35
  36 #include "windef.h"
  37 #include "winbase.h"
  38
  39 #include "file.h"
  40 #include "handle.h"
  41 #include "process.h"
  42 #include "thread.h"
  43 #include "request.h"
  44 #include "user.h"
  45
  46
  47 /* thread queues */
  48
  49 struct thread_wait
  50 {
  51     struct thread_wait     *next;       /* next wait structure for this thread */
  52     struct thread          *thread;     /* owner thread */
  53     int                     count;      /* count of objects */
  54     int                     flags;
  55     void                   *cookie;     /* magic cookie to return to client */
  56     struct timeval          timeout;
  57     struct timeout_user    *user;
  58     struct wait_queue_entry queues[1];
  59 };
  60
  61 /* asynchronous procedure calls */
  62
  63 struct thread_apc
  64 {
  65     struct thread_apc  *next;     /* queue linked list */
  66     struct thread_apc  *prev;
  67     struct object      *owner;    /* object that queued this apc */
  68     void               *func;     /* function to call in client */
  69     enum apc_type       type;     /* type of apc function */
  70     int                 nb_args;  /* number of arguments */
  71     void               *arg1;     /* function arguments */
  72     void               *arg2;
  73     void               *arg3;
  74 };
  75
  76
  77 /* thread operations */
  78
  79 static void dump_thread( struct object *obj, int verbose );
  80 static int thread_signaled( struct object *obj, struct thread *thread );
  81 static void thread_poll_event( struct fd *fd, int event );
  82 static void destroy_thread( struct object *obj );
  83 static struct thread_apc *thread_dequeue_apc( struct thread *thread, int system_only );
  84
  85 static const struct object_ops thread_ops =
  86 {
  87     sizeof(struct thread),      /* size */
  88     dump_thread,                /* dump */
  89     add_queue,                  /* add_queue */
  90     remove_queue,               /* remove_queue */
  91     thread_signaled,            /* signaled */
  92     no_satisfied,               /* satisfied */
  93     no_get_fd,                  /* get_fd */
  94     destroy_thread              /* destroy */
  95 };
  96
  97 static const struct fd_ops thread_fd_ops =
  98 {
  99     NULL,                       /* get_poll_events */
 100     thread_poll_event,          /* poll_event */
 101     no_flush,                   /* flush */
 102     no_get_file_info,           /* get_file_info */
 103     no_queue_async,             /* queue_async */
 104     no_cancel_async             /* cancel_async */
 105 };
 106
 107 static struct thread *first_thread;
 108 static struct thread *booting_thread;
 109
 110 /* initialize the structure for a newly allocated thread */
 111 inline static void init_thread_structure( struct thread *thread )
 112 {
 113     int i;
 114
 115     thread->unix_pid        = -1;  /* not known yet */
 116     thread->unix_tid        = -1;  /* not known yet */
 117     thread->context         = NULL;
 118     thread->teb             = NULL;
 119     thread->mutex           = NULL;
 120     thread->debug_ctx       = NULL;
 121     thread->debug_event     = NULL;
 122     thread->queue           = NULL;
 123     thread->wait            = NULL;
 124     thread->system_apc.head = NULL;
 125     thread->system_apc.tail = NULL;
 126     thread->user_apc.head   = NULL;
 127     thread->user_apc.tail   = NULL;
 128     thread->error           = 0;
 129     thread->req_data        = NULL;
 130     thread->req_toread      = 0;
 131     thread->reply_data      = NULL;
 132     thread->reply_towrite   = 0;
 133     thread->request_fd      = NULL;
 134     thread->reply_fd        = NULL;
 135     thread->wait_fd         = NULL;
 136     thread->state           = RUNNING;
 137     thread->attached        = 0;
 138     thread->exit_code       = 0;
 139     thread->next            = NULL;
 140     thread->prev            = NULL;
 141     thread->priority        = THREAD_PRIORITY_NORMAL;
 142     thread->affinity        = 1;
 143     thread->suspend         = 0;
 144     thread->creation_time   = time(NULL);
 145     thread->exit_time       = 0;
 146
 147     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 148         thread->inflight[i].server = thread->inflight[i].client = -1;
 149 }
 150
 151 /* create a new thread */
 152 struct thread *create_thread( int fd, struct process *process )
 153 {
 154     struct thread *thread;
 155
 156     if (!(thread = alloc_object( &thread_ops ))) return NULL;
 157
 158     init_thread_structure( thread );
 159
 160     thread->process = (struct process *)grab_object( process );
 161     if (!current) current = thread;
 162
 163     if (!booting_thread)  /* first thread ever */
 164     {
 165         booting_thread = thread;
 166         lock_master_socket(1);
 167     }
 168
 169     if ((thread->next = first_thread) != NULL) thread->next->prev = thread;
 170     first_thread = thread;
 171
 172     if (!(thread->id = alloc_ptid( thread )))
 173     {
 174         release_object( thread );
 175         return NULL;
 176     }
 177     if (!(thread->request_fd = create_anonymous_fd( &thread_fd_ops, fd, &thread->obj )))
 178     {
 179         release_object( thread );
 180         return NULL;
 181     }
 182
 183     thread->token = (struct token *) grab_object( process->token );
 184
 185     set_fd_events( thread->request_fd, POLLIN );  /* start listening to events */
 186     add_process_thread( thread->process, thread );
 187     return thread;
 188 }
 189
 190 /* handle a client event */
 191 static void thread_poll_event( struct fd *fd, int event )
 192 {
 193     struct thread *thread = get_fd_user( fd );
 194     assert( thread->obj.ops == &thread_ops );
 195
 196     if (event & (POLLERR | POLLHUP)) kill_thread( thread, 0 );
 197     else if (event & POLLIN) read_request( thread );
 198     else if (event & POLLOUT) write_reply( thread );
 199 }
 200
 201 /* cleanup everything that is no longer needed by a dead thread */
 202 /* used by destroy_thread and kill_thread */
 203 static void cleanup_thread( struct thread *thread )
 204 {
 205     int i;
 206     struct thread_apc *apc;
 207
 208     while ((apc = thread_dequeue_apc( thread, 0 ))) free( apc );
 209     if (thread->req_data) free( thread->req_data );
 210     if (thread->reply_data) free( thread->reply_data );
 211     if (thread->request_fd) release_object( thread->request_fd );
 212     if (thread->reply_fd) release_object( thread->reply_fd );
 213     if (thread->wait_fd) release_object( thread->wait_fd );
 214     free_msg_queue( thread );
 215     cleanup_clipboard_thread(thread);
 216     destroy_thread_windows( thread );
 217     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 218     {
 219         if (thread->inflight[i].client != -1)
 220         {
 221             close( thread->inflight[i].server );
 222             thread->inflight[i].client = thread->inflight[i].server = -1;
 223         }
 224     }
 225     thread->req_data = NULL;
 226     thread->reply_data = NULL;
 227     thread->request_fd = NULL;
 228     thread->reply_fd = NULL;
 229     thread->wait_fd = NULL;
 230
 231     if (thread == booting_thread)  /* killing booting thread */
 232     {
 233         booting_thread = NULL;
 234         lock_master_socket(0);
 235     }
 236 }
 237
 238 /* destroy a thread when its refcount is 0 */
 239 static void destroy_thread( struct object *obj )
 240 {
 241     struct thread_apc *apc;
 242     struct thread *thread = (struct thread *)obj;
 243     assert( obj->ops == &thread_ops );
 244
 245     assert( !thread->debug_ctx );  /* cannot still be debugging something */
 246     if (thread->next) thread->next->prev = thread->prev;
 247     if (thread->prev) thread->prev->next = thread->next;
 248     else first_thread = thread->next;
 249     while ((apc = thread_dequeue_apc( thread, 0 ))) free( apc );
 250     cleanup_thread( thread );
 251     release_object( thread->process );
 252     if (thread->id) free_ptid( thread->id );
 253     if (thread->token) release_object( thread->token );
 254 }
 255
 256 /* dump a thread on stdout for debugging purposes */
 257 static void dump_thread( struct object *obj, int verbose )
 258 {
 259     struct thread *thread = (struct thread *)obj;
 260     assert( obj->ops == &thread_ops );
 261
 262     fprintf( stderr, "Thread id=%04x unix pid=%d unix tid=%d teb=%p state=%d\n",
 263              thread->id, thread->unix_pid, thread->unix_tid, thread->teb, thread->state );
 264 }
 265
 266 static int thread_signaled( struct object *obj, struct thread *thread )
 267 {
 268     struct thread *mythread = (struct thread *)obj;
 269     return (mythread->state == TERMINATED);
 270 }
 271
 272 /* get a thread pointer from a thread id (and increment the refcount) */
 273 struct thread *get_thread_from_id( thread_id_t id )
 274 {
 275     struct object *obj = get_ptid_entry( id );
 276
 277     if (obj && obj->ops == &thread_ops) return (struct thread *)grab_object( obj );
 278     set_win32_error( ERROR_INVALID_THREAD_ID );
 279     return NULL;
 280 }
 281
 282 /* get a thread from a handle (and increment the refcount) */
 283 struct thread *get_thread_from_handle( obj_handle_t handle, unsigned int access )
 284 {
 285     return (struct thread *)get_handle_obj( current->process, handle,
 286                                             access, &thread_ops );
 287 }
 288
 289 /* find a thread from a Unix pid */
 290 struct thread *get_thread_from_pid( int pid )
 291 {
 292     struct thread *t;
 293
 294     for (t = first_thread; t; t = t->next) if (t->unix_tid == pid) return t;
 295     for (t = first_thread; t; t = t->next) if (t->unix_pid == pid) return t;
 296     return NULL;
 297 }
 298
 299 /* set all information about a thread */
 300 static void set_thread_info( struct thread *thread,
 301                              const struct set_thread_info_request *req )
 302 {
 303     if (req->mask & SET_THREAD_INFO_PRIORITY)
 304         thread->priority = req->priority;
 305     if (req->mask & SET_THREAD_INFO_AFFINITY)
 306     {
 307         if (req->affinity != 1) set_error( STATUS_INVALID_PARAMETER );
 308         else thread->affinity = req->affinity;
 309     }
 310 }
 311
 312 /* stop a thread (at the Unix level) */
 313 void stop_thread( struct thread *thread )
 314 {
 315     /* can't stop a thread while initialisation is in progress */
 316     if (is_process_init_done(thread->process)) send_thread_signal( thread, SIGUSR1 );
 317 }
 318
 319 /* suspend a thread */
 320 static int suspend_thread( struct thread *thread )
 321 {
 322     int old_count = thread->suspend;
 323     if (thread->suspend < MAXIMUM_SUSPEND_COUNT)
 324     {
 325         if (!(thread->process->suspend + thread->suspend++)) stop_thread( thread );
 326     }
 327     else set_error( STATUS_SUSPEND_COUNT_EXCEEDED );
 328     return old_count;
 329 }
 330
 331 /* resume a thread */
 332 static int resume_thread( struct thread *thread )
 333 {
 334     int old_count = thread->suspend;
 335     if (thread->suspend > 0)
 336     {
 337         if (!(--thread->suspend + thread->process->suspend)) wake_thread( thread );
 338     }
 339     return old_count;
 340 }
 341
 342 /* add a thread to an object wait queue; return 1 if OK, 0 on error */
 343 int add_queue( struct object *obj, struct wait_queue_entry *entry )
 344 {
 345     grab_object( obj );
 346     entry->obj    = obj;
 347     entry->prev   = obj->tail;
 348     entry->next   = NULL;
 349     if (obj->tail) obj->tail->next = entry;
 350     else obj->head = entry;
 351     obj->tail = entry;
 352     return 1;
 353 }
 354
 355 /* remove a thread from an object wait queue */
 356 void remove_queue( struct object *obj, struct wait_queue_entry *entry )
 357 {
 358     if (entry->next) entry->next->prev = entry->prev;
 359     else obj->tail = entry->prev;
 360     if (entry->prev) entry->prev->next = entry->next;
 361     else obj->head = entry->next;
 362     release_object( obj );
 363 }
 364
 365 /* finish waiting */
 366 static void end_wait( struct thread *thread )
 367 {
 368     struct thread_wait *wait = thread->wait;
 369     struct wait_queue_entry *entry;
 370     int i;
 371
 372     assert( wait );
 373     for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 374         entry->obj->ops->remove_queue( entry->obj, entry );
 375     if (wait->user) remove_timeout_user( wait->user );
 376     thread->wait = wait->next;
 377     free( wait );
 378 }
 379
 380 /* build the thread wait structure */
 381 static int wait_on( int count, struct object *objects[], int flags, const abs_time_t *timeout )
 382 {
 383     struct thread_wait *wait;
 384     struct wait_queue_entry *entry;
 385     int i;
 386
 387     if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
 388     wait->next    = current->wait;
 389     wait->thread  = current;
 390     wait->count   = count;
 391     wait->flags   = flags;
 392     wait->user    = NULL;
 393     current->wait = wait;
 394     if (flags & SELECT_TIMEOUT)
 395     {
 396         wait->timeout.tv_sec  = timeout->sec;
 397         wait->timeout.tv_usec = timeout->usec;
 398     }
 399
 400     for (i = 0, entry = wait->queues; i < count; i++, entry++)
 401     {
 402         struct object *obj = objects[i];
 403         entry->thread = current;
 404         if (!obj->ops->add_queue( obj, entry ))
 405         {
 406             wait->count = i;
 407             end_wait( current );
 408             return 0;
 409         }
 410     }
 411     return 1;
 412 }
 413
 414 /* check if the thread waiting condition is satisfied */
 415 static int check_wait( struct thread *thread )
 416 {
 417     int i, signaled;
 418     struct thread_wait *wait = thread->wait;
 419     struct wait_queue_entry *entry = wait->queues;
 420
 421     /* Suspended threads may not acquire locks */
 422     if( thread->process->suspend + thread->suspend > 0 ) return -1;
 423
 424     assert( wait );
 425     if (wait->flags & SELECT_ALL)
 426     {
 427         int not_ok = 0;
 428         /* Note: we must check them all anyway, as some objects may
 429          * want to do something when signaled, even if others are not */
 430         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 431             not_ok |= !entry->obj->ops->signaled( entry->obj, thread );
 432         if (not_ok) goto other_checks;
 433         /* Wait satisfied: tell it to all objects */
 434         signaled = 0;
 435         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 436             if (entry->obj->ops->satisfied( entry->obj, thread ))
 437                 signaled = STATUS_ABANDONED_WAIT_0;
 438         return signaled;
 439     }
 440     else
 441     {
 442         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 443         {
 444             if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
 445             /* Wait satisfied: tell it to the object */
 446             signaled = i;
 447             if (entry->obj->ops->satisfied( entry->obj, thread ))
 448                 signaled = i + STATUS_ABANDONED_WAIT_0;
 449             return signaled;
 450         }
 451     }
 452
 453  other_checks:
 454     if ((wait->flags & SELECT_INTERRUPTIBLE) && thread->system_apc.head) return STATUS_USER_APC;
 455     if ((wait->flags & SELECT_ALERTABLE) && thread->user_apc.head) return STATUS_USER_APC;
 456     if (wait->flags & SELECT_TIMEOUT)
 457     {
 458         struct timeval now;
 459         gettimeofday( &now, NULL );
 460         if (!time_before( &now, &wait->timeout )) return STATUS_TIMEOUT;
 461     }
 462     return -1;
 463 }
 464
 465 /* send the wakeup signal to a thread */
 466 static int send_thread_wakeup( struct thread *thread, void *cookie, int signaled )
 467 {
 468     struct wake_up_reply reply;
 469     int ret;
 470
 471     reply.cookie   = cookie;
 472     reply.signaled = signaled;
 473     if ((ret = write( get_unix_fd( thread->wait_fd ), &reply, sizeof(reply) )) == sizeof(reply))
 474         return 0;
 475     if (ret >= 0)
 476         fatal_protocol_error( thread, "partial wakeup write %d\n", ret );
 477     else if (errno == EPIPE)
 478         kill_thread( thread, 0 );  /* normal death */
 479     else
 480         fatal_protocol_perror( thread, "write" );
 481     return -1;
 482 }
 483
 484 /* attempt to wake up a thread */
 485 /* return >0 if OK, 0 if the wait condition is still not satisfied */
 486 int wake_thread( struct thread *thread )
 487 {
 488     int signaled, count;
 489     void *cookie;
 490
 491     for (count = 0; thread->wait; count++)
 492     {
 493         if ((signaled = check_wait( thread )) == -1) break;
 494
 495         cookie = thread->wait->cookie;
 496         if (debug_level) fprintf( stderr, "%04x: *wakeup* signaled=%d cookie=%p\n",
 497                                   thread->id, signaled, cookie );
 498         end_wait( thread );
 499         if (send_thread_wakeup( thread, cookie, signaled ) == -1) /* error */
 500             break;
 501     }
 502     return count;
 503 }
 504
 505 /* thread wait timeout */
 506 static void thread_timeout( void *ptr )
 507 {
 508     struct thread_wait *wait = ptr;
 509     struct thread *thread = wait->thread;
 510     void *cookie = wait->cookie;
 511
 512     wait->user = NULL;
 513     if (thread->wait != wait) return; /* not the top-level wait, ignore it */
 514     if (thread->suspend + thread->process->suspend > 0) return;  /* suspended, ignore it */
 515
 516     if (debug_level) fprintf( stderr, "%04x: *wakeup* signaled=%d cookie=%p\n",
 517                               thread->id, STATUS_TIMEOUT, cookie );
 518     end_wait( thread );
 519     if (send_thread_wakeup( thread, cookie, STATUS_TIMEOUT ) == -1) return;
 520     /* check if other objects have become signaled in the meantime */
 521     wake_thread( thread );
 522 }
 523
 524 /* select on a list of handles */
 525 static void select_on( int count, void *cookie, const obj_handle_t *handles,
 526                        int flags, const abs_time_t *timeout )
 527 {
 528     int ret, i;
 529     struct object *objects[MAXIMUM_WAIT_OBJECTS];
 530
 531     if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
 532     {
 533         set_error( STATUS_INVALID_PARAMETER );
 534         return;
 535     }
 536     for (i = 0; i < count; i++)
 537     {
 538         if (!(objects[i] = get_handle_obj( current->process, handles[i], SYNCHRONIZE, NULL )))
 539             break;
 540     }
 541
 542     if (i < count) goto done;
 543     if (!wait_on( count, objects, flags, timeout )) goto done;
 544
 545     if ((ret = check_wait( current )) != -1)
 546     {
 547         /* condition is already satisfied */
 548         end_wait( current );
 549         set_error( ret );
 550         goto done;
 551     }
 552
 553     /* now we need to wait */
 554     if (flags & SELECT_TIMEOUT)
 555     {
 556         if (!(current->wait->user = add_timeout_user( &current->wait->timeout,
 557                                                       thread_timeout, current->wait )))
 558         {
 559             end_wait( current );
 560             goto done;
 561         }
 562     }
 563     current->wait->cookie = cookie;
 564     set_error( STATUS_PENDING );
 565
 566 done:
 567     while (--i >= 0) release_object( objects[i] );
 568 }
 569
 570 /* attempt to wake threads sleeping on the object wait queue */
 571 void wake_up( struct object *obj, int max )
 572 {
 573     struct wait_queue_entry *entry = obj->head;
 574
 575     while (entry)
 576     {
 577         struct thread *thread = entry->thread;
 578         entry = entry->next;
 579         if (wake_thread( thread ))
 580         {
 581             if (max && !--max) break;
 582         }
 583     }
 584 }
 585
 586 /* queue an async procedure call */
 587 int thread_queue_apc( struct thread *thread, struct object *owner, void *func,
 588                       enum apc_type type, int system, void *arg1, void *arg2, void *arg3 )
 589 {
 590     struct thread_apc *apc;
 591     struct apc_queue *queue = system ? &thread->system_apc : &thread->user_apc;
 592
 593     /* cancel a possible previous APC with the same owner */
 594     if (owner) thread_cancel_apc( thread, owner, system );
 595     if (thread->state == TERMINATED) return 0;
 596
 597     if (!(apc = mem_alloc( sizeof(*apc) ))) return 0;
 598     apc->prev   = queue->tail;
 599     apc->next   = NULL;
 600     apc->owner  = owner;
 601     apc->func   = func;
 602     apc->type   = type;
 603     apc->arg1   = arg1;
 604     apc->arg2   = arg2;
 605     apc->arg3   = arg3;
 606     queue->tail = apc;
 607     if (!apc->prev)  /* first one */
 608     {
 609         queue->head = apc;
 610         wake_thread( thread );
 611     }
 612     else apc->prev->next = apc;
 613
 614     return 1;
 615 }
 616
 617 /* cancel the async procedure call owned by a specific object */
 618 void thread_cancel_apc( struct thread *thread, struct object *owner, int system )
 619 {
 620     struct thread_apc *apc;
 621     struct apc_queue *queue = system ? &thread->system_apc : &thread->user_apc;
 622     for (apc = queue->head; apc; apc = apc->next)
 623     {
 624         if (apc->owner != owner) continue;
 625         if (apc->next) apc->next->prev = apc->prev;
 626         else queue->tail = apc->prev;
 627         if (apc->prev) apc->prev->next = apc->next;
 628         else queue->head = apc->next;
 629         free( apc );
 630         return;
 631     }
 632 }
 633
 634 /* remove the head apc from the queue; the returned pointer must be freed by the caller */
 635 static struct thread_apc *thread_dequeue_apc( struct thread *thread, int system_only )
 636 {
 637     struct thread_apc *apc;
 638     struct apc_queue *queue = &thread->system_apc;
 639
 640     if (!queue->head && !system_only) queue = &thread->user_apc;
 641     if ((apc = queue->head))
 642     {
 643         if (apc->next) apc->next->prev = NULL;
 644         else queue->tail = NULL;
 645         queue->head = apc->next;
 646     }
 647     return apc;
 648 }
 649
 650 /* add an fd to the inflight list */
 651 /* return list index, or -1 on error */
 652 int thread_add_inflight_fd( struct thread *thread, int client, int server )
 653 {
 654     int i;
 655
 656     if (server == -1) return -1;
 657     if (client == -1)
 658     {
 659         close( server );
 660         return -1;
 661     }
 662
 663     /* first check if we already have an entry for this fd */
 664     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 665         if (thread->inflight[i].client == client)
 666         {
 667             close( thread->inflight[i].server );
 668             thread->inflight[i].server = server;
 669             return i;
 670         }
 671
 672     /* now find a free spot to store it */
 673     for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 674         if (thread->inflight[i].client == -1)
 675         {
 676             thread->inflight[i].client = client;
 677             thread->inflight[i].server = server;
 678             return i;
 679         }
 680     return -1;
 681 }
 682
 683 /* get an inflight fd and purge it from the list */
 684 /* the fd must be closed when no longer used */
 685 int thread_get_inflight_fd( struct thread *thread, int client )
 686 {
 687     int i, ret;
 688
 689     if (client == -1) return -1;
 690
 691     do
 692     {
 693         for (i = 0; i < MAX_INFLIGHT_FDS; i++)
 694         {
 695             if (thread->inflight[i].client == client)
 696             {
 697                 ret = thread->inflight[i].server;
 698                 thread->inflight[i].server = thread->inflight[i].client = -1;
 699                 return ret;
 700             }
 701         }
 702     } while (!receive_fd( thread->process ));  /* in case it is still in the socket buffer */
 703     return -1;
 704 }
 705
 706 /* retrieve an LDT selector entry */
 707 static void get_selector_entry( struct thread *thread, int entry,
 708                                 unsigned int *base, unsigned int *limit,
 709                                 unsigned char *flags )
 710 {
 711     if (!thread->process->ldt_copy)
 712     {
 713         set_error( STATUS_ACCESS_DENIED );
 714         return;
 715     }
 716     if (entry >= 8192)
 717     {
 718         set_error( STATUS_INVALID_PARAMETER );  /* FIXME */
 719         return;
 720     }
 721     if (suspend_for_ptrace( thread ))
 722     {
 723         unsigned char flags_buf[4];
 724         int *addr = (int *)thread->process->ldt_copy + entry;
 725         if (read_thread_int( thread, addr, base ) == -1) goto done;
 726         if (read_thread_int( thread, addr + 8192, limit ) == -1) goto done;
 727         addr = (int *)thread->process->ldt_copy + 2*8192 + (entry >> 2);
 728         if (read_thread_int( thread, addr, (int *)flags_buf ) == -1) goto done;
 729         *flags = flags_buf[entry & 3];
 730     done:
 731         resume_after_ptrace( thread );
 732     }
 733 }
 734
 735 /* kill a thread on the spot */
 736 void kill_thread( struct thread *thread, int violent_death )
 737 {
 738     if (thread->state == TERMINATED) return;  /* already killed */
 739     thread->state = TERMINATED;
 740     thread->exit_time = time(NULL);
 741     if (current == thread) current = NULL;
 742     if (debug_level)
 743         fprintf( stderr,"%04x: *killed* exit_code=%d\n",
 744                  thread->id, thread->exit_code );
 745     if (thread->wait)
 746     {
 747         while (thread->wait) end_wait( thread );
 748         send_thread_wakeup( thread, NULL, STATUS_PENDING );
 749         /* if it is waiting on the socket, we don't need to send a SIGTERM */
 750         violent_death = 0;
 751     }
 752     kill_console_processes( thread, 0 );
 753     debug_exit_thread( thread );
 754     abandon_mutexes( thread );
 755     remove_process_thread( thread->process, thread );
 756     wake_up( &thread->obj, 0 );
 757     detach_thread( thread, violent_death ? SIGTERM : 0 );
 758     cleanup_thread( thread );
 759     release_object( thread );
 760 }
 761
 762 /* take a snapshot of currently running threads */
 763 struct thread_snapshot *thread_snap( int *count )
 764 {
 765     struct thread_snapshot *snapshot, *ptr;
 766     struct thread *thread;
 767     int total = 0;
 768
 769     for (thread = first_thread; thread; thread = thread->next)
 770         if (thread->state != TERMINATED) total++;
 771     if (!total || !(snapshot = mem_alloc( sizeof(*snapshot) * total ))) return NULL;
 772     ptr = snapshot;
 773     for (thread = first_thread; thread; thread = thread->next)
 774     {
 775         if (thread->state == TERMINATED) continue;
 776         ptr->thread   = thread;
 777         ptr->count    = thread->obj.refcount;
 778         ptr->priority = thread->priority;
 779         grab_object( thread );
 780         ptr++;
 781     }
 782     *count = total;
 783     return snapshot;
 784 }
 785
 786 /* signal that we are finished booting on the client side */
 787 DECL_HANDLER(boot_done)
 788 {
 789     debug_level = max( debug_level, req->debug_level );
 790     if (current == booting_thread)
 791     {
 792         booting_thread = (struct thread *)~0UL;  /* make sure it doesn't match other threads */
 793         lock_master_socket(0);  /* allow other clients now */
 794     }
 795 }
 796
 797 /* create a new thread */
 798 DECL_HANDLER(new_thread)
 799 {
 800     struct thread *thread;
 801     int request_fd = thread_get_inflight_fd( current, req->request_fd );
 802
 803     if (request_fd == -1 || fcntl( request_fd, F_SETFL, O_NONBLOCK ) == -1)
 804     {
 805         if (request_fd != -1) close( request_fd );
 806         set_error( STATUS_INVALID_HANDLE );
 807         return;
 808     }
 809
 810     if ((thread = create_thread( request_fd, current->process )))
 811     {
 812         if (req->suspend) thread->suspend++;
 813         reply->tid = get_thread_id( thread );
 814         if ((reply->handle = alloc_handle( current->process, thread,
 815                                            THREAD_ALL_ACCESS, req->inherit )))
 816         {
 817             /* thread object will be released when the thread gets killed */
 818             return;
 819         }
 820         kill_thread( thread, 1 );
 821     }
 822 }
 823
 824 /* initialize a new thread */
 825 DECL_HANDLER(init_thread)
 826 {
 827     int reply_fd = thread_get_inflight_fd( current, req->reply_fd );
 828     int wait_fd = thread_get_inflight_fd( current, req->wait_fd );
 829
 830     if (current->unix_pid != -1)
 831     {
 832         fatal_protocol_error( current, "init_thread: already running\n" );
 833         goto error;
 834     }
 835     if (reply_fd == -1 || fcntl( reply_fd, F_SETFL, O_NONBLOCK ) == -1)
 836     {
 837         fatal_protocol_error( current, "bad reply fd\n" );
 838         goto error;
 839     }
 840     if (wait_fd == -1)
 841     {
 842         fatal_protocol_error( current, "bad wait fd\n" );
 843         goto error;
 844     }
 845     if (!(current->reply_fd = create_anonymous_fd( &thread_fd_ops, reply_fd, &current->obj )))
 846     {
 847         reply_fd = -1;
 848         fatal_protocol_error( current, "could not allocate reply fd\n" );
 849         goto error;
 850     }
 851     if (!(current->wait_fd  = create_anonymous_fd( &thread_fd_ops, wait_fd, &current->obj )))
 852         return;
 853
 854     current->unix_pid = req->unix_pid;
 855     current->unix_tid = req->unix_tid;
 856     current->teb      = req->teb;
 857
 858     if (current->suspend + current->process->suspend > 0) stop_thread( current );
 859     if (current->process->running_threads > 1)
 860         generate_debug_event( current, CREATE_THREAD_DEBUG_EVENT, req->entry );
 861
 862     reply->pid     = get_process_id( current->process );
 863     reply->tid     = get_thread_id( current );
 864     reply->boot    = (current == booting_thread);
 865     reply->version = SERVER_PROTOCOL_VERSION;
 866     return;
 867
 868  error:
 869     if (reply_fd != -1) close( reply_fd );
 870     if (wait_fd != -1) close( wait_fd );
 871 }
 872
 873 /* terminate a thread */
 874 DECL_HANDLER(terminate_thread)
 875 {
 876     struct thread *thread;
 877
 878     reply->self = 0;
 879     reply->last = 0;
 880     if ((thread = get_thread_from_handle( req->handle, THREAD_TERMINATE )))
 881     {
 882         thread->exit_code = req->exit_code;
 883         if (thread != current) kill_thread( thread, 1 );
 884         else
 885         {
 886             reply->self = 1;
 887             reply->last = (thread->process->running_threads == 1);
 888         }
 889         release_object( thread );
 890     }
 891 }
 892
 893 /* open a handle to a thread */
 894 DECL_HANDLER(open_thread)
 895 {
 896     struct thread *thread = get_thread_from_id( req->tid );
 897
 898     reply->handle = 0;
 899     if (thread)
 900     {
 901         reply->handle = alloc_handle( current->process, thread, req->access, req->inherit );
 902         release_object( thread );
 903     }
 904 }
 905
 906 /* fetch information about a thread */
 907 DECL_HANDLER(get_thread_info)
 908 {
 909     struct thread *thread;
 910     obj_handle_t handle = req->handle;
 911
 912     if (!handle) thread = get_thread_from_id( req->tid_in );
 913     else thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION );
 914
 915     if (thread)
 916     {
 917         reply->pid            = get_process_id( thread->process );
 918         reply->tid            = get_thread_id( thread );
 919         reply->teb            = thread->teb;
 920         reply->exit_code      = (thread->state == TERMINATED) ? thread->exit_code : STILL_ACTIVE;
 921         reply->priority       = thread->priority;
 922         reply->affinity       = thread->affinity;
 923         reply->creation_time  = thread->creation_time;
 924         reply->exit_time      = thread->exit_time;
 925
 926         release_object( thread );
 927     }
 928 }
 929
 930 /* set information about a thread */
 931 DECL_HANDLER(set_thread_info)
 932 {
 933     struct thread *thread;
 934
 935     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_INFORMATION )))
 936     {
 937         set_thread_info( thread, req );
 938         release_object( thread );
 939     }
 940 }
 941
 942 /* suspend a thread */
 943 DECL_HANDLER(suspend_thread)
 944 {
 945     struct thread *thread;
 946
 947     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 948     {
 949         if (thread->state == TERMINATED) set_error( STATUS_ACCESS_DENIED );
 950         else reply->count = suspend_thread( thread );
 951         release_object( thread );
 952     }
 953 }
 954
 955 /* resume a thread */
 956 DECL_HANDLER(resume_thread)
 957 {
 958     struct thread *thread;
 959
 960     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 961     {
 962         if (thread->state == TERMINATED) set_error( STATUS_ACCESS_DENIED );
 963         else reply->count = resume_thread( thread );
 964         release_object( thread );
 965     }
 966 }
 967
 968 /* select on a handle list */
 969 DECL_HANDLER(select)
 970 {
 971     int count = get_req_data_size() / sizeof(int);
 972     select_on( count, req->cookie, get_req_data(), req->flags, &req->timeout );
 973 }
 974
 975 /* queue an APC for a thread */
 976 DECL_HANDLER(queue_apc)
 977 {
 978     struct thread *thread;
 979     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 980     {
 981         thread_queue_apc( thread, NULL, req->func, APC_USER, !req->user,
 982                           req->arg1, req->arg2, req->arg3 );
 983         release_object( thread );
 984     }
 985 }
 986
 987 /* get next APC to call */
 988 DECL_HANDLER(get_apc)
 989 {
 990     struct thread_apc *apc;
 991
 992     for (;;)
 993     {
 994         if (!(apc = thread_dequeue_apc( current, !req->alertable )))
 995         {
 996             /* no more APCs */
 997             reply->func = NULL;
 998             reply->type = APC_NONE;
 999             return;
1000         }
1001         /* Optimization: ignore APCs that have a NULL func; they are only used
1002          * to wake up a thread, but since we got here the thread woke up already.
1003          * Exception: for APC_ASYNC_IO, func == NULL is legal.
1004          */
1005         if (apc->func || apc->type == APC_ASYNC_IO) break;
1006         free( apc );
1007     }
1008     reply->func = apc->func;
1009     reply->type = apc->type;
1010     reply->arg1 = apc->arg1;
1011     reply->arg2 = apc->arg2;
1012     reply->arg3 = apc->arg3;
1013     free( apc );
1014 }
1015
1016 /* fetch a selector entry for a thread */
1017 DECL_HANDLER(get_selector_entry)
1018 {
1019     struct thread *thread;
1020     if ((thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION )))
1021     {
1022         get_selector_entry( thread, req->entry, &reply->base, &reply->limit, &reply->flags );
1023         release_object( thread );
1024     }
1025 }