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 <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #ifdef HAVE_SYS_MMAN_H
  16 #include <sys/mman.h>
  17 #endif
  18 #include <sys/types.h>
  19 #include <sys/uio.h>
  20 #include <unistd.h>
  21 #include <stdarg.h>
  22
  23
  24 #include "winbase.h"
  25 #include "winerror.h"
  26
  27 #include "handle.h"
  28 #include "process.h"
  29 #include "thread.h"
  30 #include "request.h"
  31
  32
  33 /* thread queues */
  34
  35 struct wait_queue_entry
  36 {
  37     struct wait_queue_entry *next;
  38     struct wait_queue_entry *prev;
  39     struct object           *obj;
  40     struct thread           *thread;
  41 };
  42
  43 struct thread_wait
  44 {
  45     int                     count;      /* count of objects */
  46     int                     flags;
  47     struct timeval          timeout;
  48     struct timeout_user    *user;
  49     sleep_reply             reply;      /* function to build the reply */
  50     struct wait_queue_entry queues[1];
  51 };
  52
  53 /* asynchronous procedure calls */
  54
  55 struct thread_apc
  56 {
  57     void                   *func;    /* function to call in client */
  58     void                   *param;   /* function param */
  59 };
  60 #define MAX_THREAD_APC  16  /* Max outstanding APCs for a thread */
  61
  62
  63 /* thread operations */
  64
  65 static void dump_thread( struct object *obj, int verbose );
  66 static int thread_signaled( struct object *obj, struct thread *thread );
  67 extern void thread_poll_event( struct object *obj, int event );
  68 static void destroy_thread( struct object *obj );
  69
  70 static const struct object_ops thread_ops =
  71 {
  72     sizeof(struct thread),      /* size */
  73     dump_thread,                /* dump */
  74     add_queue,                  /* add_queue */
  75     remove_queue,               /* remove_queue */
  76     thread_signaled,            /* signaled */
  77     no_satisfied,               /* satisfied */
  78     NULL,                       /* get_poll_events */
  79     thread_poll_event,          /* poll_event */
  80     no_read_fd,                 /* get_read_fd */
  81     no_write_fd,                /* get_write_fd */
  82     no_flush,                   /* flush */
  83     no_get_file_info,           /* get_file_info */
  84     destroy_thread              /* destroy */
  85 };
  86
  87 static struct thread *first_thread;
  88
  89 /* allocate the buffer for the communication with the client */
  90 static int alloc_client_buffer( struct thread *thread )
  91 {
  92     int fd;
  93
  94     if ((fd = create_anonymous_file()) == -1) return -1;
  95     if (ftruncate( fd, MAX_REQUEST_LENGTH ) == -1) goto error;
  96     if ((thread->buffer = mmap( 0, MAX_REQUEST_LENGTH, PROT_READ | PROT_WRITE,
  97                                 MAP_SHARED, fd, 0 )) == (void*)-1) goto error;
  98     return fd;
  99
 100  error:
 101     file_set_error();
 102     if (fd != -1) close( fd );
 103     return -1;
 104 }
 105
 106 /* create a new thread */
 107 static struct thread *create_thread( int fd, struct process *process, int suspend )
 108 {
 109     struct thread *thread;
 110     int buf_fd;
 111
 112     int flags = fcntl( fd, F_GETFL, 0 );
 113     fcntl( fd, F_SETFL, flags | O_NONBLOCK );
 114
 115     if (!(thread = alloc_object( &thread_ops, fd ))) return NULL;
 116
 117     thread->unix_pid    = 0;  /* not known yet */
 118     thread->teb         = NULL;
 119     thread->mutex       = NULL;
 120     thread->debug_ctx   = NULL;
 121     thread->wait        = NULL;
 122     thread->apc         = NULL;
 123     thread->apc_count   = 0;
 124     thread->error       = 0;
 125     thread->pass_fd     = -1;
 126     thread->state       = RUNNING;
 127     thread->attached    = 0;
 128     thread->exit_code   = 0x103;  /* STILL_ACTIVE */
 129     thread->next        = NULL;
 130     thread->prev        = NULL;
 131     thread->priority    = THREAD_PRIORITY_NORMAL;
 132     thread->affinity    = 1;
 133     thread->suspend     = (suspend != 0);
 134     thread->buffer      = (void *)-1;
 135     thread->last_req    = REQ_GET_THREAD_BUFFER;
 136
 137     if (!first_thread)  /* creating the first thread */
 138     {
 139         current = thread;
 140         thread->process = process = create_initial_process();
 141         assert( process );
 142     }
 143     else thread->process = (struct process *)grab_object( process );
 144
 145     if ((thread->next = first_thread) != NULL) thread->next->prev = thread;
 146     first_thread = thread;
 147     add_process_thread( process, thread );
 148
 149     if ((buf_fd = alloc_client_buffer( thread )) == -1) goto error;
 150
 151     set_select_events( &thread->obj, POLLIN );  /* start listening to events */
 152     set_reply_fd( thread, buf_fd );  /* send the fd to the client */
 153     send_reply( thread );
 154     return thread;
 155
 156  error:
 157     remove_process_thread( process, thread );
 158     release_object( thread );
 159     return NULL;
 160 }
 161
 162 /* create the initial thread and start the main server loop */
 163 void create_initial_thread( int fd )
 164 {
 165     create_thread( fd, NULL, 0 );
 166     select_loop();
 167 }
 168
 169 /* handle a client event */
 170 void thread_poll_event( struct object *obj, int event )
 171 {
 172     struct thread *thread = (struct thread *)obj;
 173     assert( obj->ops == &thread_ops );
 174
 175     if (event & (POLLERR | POLLHUP)) kill_thread( thread, BROKEN_PIPE );
 176     else
 177     {
 178         if (event & POLLOUT) write_request( thread );
 179         if (event & POLLIN) read_request( thread );
 180     }
 181 }
 182
 183 /* destroy a thread when its refcount is 0 */
 184 static void destroy_thread( struct object *obj )
 185 {
 186     struct thread *thread = (struct thread *)obj;
 187     assert( obj->ops == &thread_ops );
 188
 189     assert( !thread->debug_ctx );  /* cannot still be debugging something */
 190     release_object( thread->process );
 191     if (thread->next) thread->next->prev = thread->prev;
 192     if (thread->prev) thread->prev->next = thread->next;
 193     else first_thread = thread->next;
 194     if (thread->apc) free( thread->apc );
 195     if (thread->buffer != (void *)-1) munmap( thread->buffer, MAX_REQUEST_LENGTH );
 196     if (thread->pass_fd != -1) close( thread->pass_fd );
 197 }
 198
 199 /* dump a thread on stdout for debugging purposes */
 200 static void dump_thread( struct object *obj, int verbose )
 201 {
 202     struct thread *thread = (struct thread *)obj;
 203     assert( obj->ops == &thread_ops );
 204
 205     fprintf( stderr, "Thread pid=%d teb=%p state=%d\n",
 206              thread->unix_pid, thread->teb, thread->state );
 207 }
 208
 209 static int thread_signaled( struct object *obj, struct thread *thread )
 210 {
 211     struct thread *mythread = (struct thread *)obj;
 212     return (mythread->state == TERMINATED);
 213 }
 214
 215 /* get a thread pointer from a thread id (and increment the refcount) */
 216 struct thread *get_thread_from_id( void *id )
 217 {
 218     struct thread *t = first_thread;
 219     while (t && (t != id)) t = t->next;
 220     if (t) grab_object( t );
 221     return t;
 222 }
 223
 224 /* get a thread from a handle (and increment the refcount) */
 225 struct thread *get_thread_from_handle( int handle, unsigned int access )
 226 {
 227     return (struct thread *)get_handle_obj( current->process, handle,
 228                                             access, &thread_ops );
 229 }
 230
 231 /* find a thread from a Unix pid */
 232 struct thread *get_thread_from_pid( int pid )
 233 {
 234     struct thread *t = first_thread;
 235     while (t && (t->unix_pid != pid)) t = t->next;
 236     return t;
 237 }
 238
 239 /* set all information about a thread */
 240 static void set_thread_info( struct thread *thread,
 241                              struct set_thread_info_request *req )
 242 {
 243     if (req->mask & SET_THREAD_INFO_PRIORITY)
 244         thread->priority = req->priority;
 245     if (req->mask & SET_THREAD_INFO_AFFINITY)
 246     {
 247         if (req->affinity != 1) set_error( ERROR_INVALID_PARAMETER );
 248         else thread->affinity = req->affinity;
 249     }
 250 }
 251
 252 /* suspend a thread */
 253 int suspend_thread( struct thread *thread, int check_limit )
 254 {
 255     int old_count = thread->suspend;
 256     if (thread->suspend < MAXIMUM_SUSPEND_COUNT || !check_limit)
 257     {
 258         if (!(thread->process->suspend + thread->suspend++)) stop_thread( thread );
 259     }
 260     else set_error( ERROR_SIGNAL_REFUSED );
 261     return old_count;
 262 }
 263
 264 /* resume a thread */
 265 int resume_thread( struct thread *thread )
 266 {
 267     int old_count = thread->suspend;
 268     if (thread->suspend > 0)
 269     {
 270         if (!(--thread->suspend + thread->process->suspend)) continue_thread( thread );
 271     }
 272     return old_count;
 273 }
 274
 275 /* suspend all threads but the current */
 276 void suspend_all_threads( void )
 277 {
 278     struct thread *thread;
 279     for ( thread = first_thread; thread; thread = thread->next )
 280         if ( thread != current )
 281             suspend_thread( thread, 0 );
 282 }
 283
 284 /* resume all threads but the current */
 285 void resume_all_threads( void )
 286 {
 287     struct thread *thread;
 288     for ( thread = first_thread; thread; thread = thread->next )
 289         if ( thread != current )
 290             resume_thread( thread );
 291 }
 292
 293 /* add a thread to an object wait queue; return 1 if OK, 0 on error */
 294 int add_queue( struct object *obj, struct wait_queue_entry *entry )
 295 {
 296     grab_object( obj );
 297     entry->obj    = obj;
 298     entry->prev   = obj->tail;
 299     entry->next   = NULL;
 300     if (obj->tail) obj->tail->next = entry;
 301     else obj->head = entry;
 302     obj->tail = entry;
 303     return 1;
 304 }
 305
 306 /* remove a thread from an object wait queue */
 307 void remove_queue( struct object *obj, struct wait_queue_entry *entry )
 308 {
 309     if (entry->next) entry->next->prev = entry->prev;
 310     else obj->tail = entry->prev;
 311     if (entry->prev) entry->prev->next = entry->next;
 312     else obj->head = entry->next;
 313     release_object( obj );
 314 }
 315
 316 /* finish waiting */
 317 static void end_wait( struct thread *thread )
 318 {
 319     struct thread_wait *wait = thread->wait;
 320     struct wait_queue_entry *entry;
 321     int i;
 322
 323     assert( wait );
 324     for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 325         entry->obj->ops->remove_queue( entry->obj, entry );
 326     if (wait->user) remove_timeout_user( wait->user );
 327     free( wait );
 328     thread->wait = NULL;
 329 }
 330
 331 /* build the thread wait structure */
 332 static int wait_on( int count, struct object *objects[], int flags,
 333                     int timeout, sleep_reply func )
 334 {
 335     struct thread_wait *wait;
 336     struct wait_queue_entry *entry;
 337     int i;
 338
 339     if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
 340     current->wait = wait;
 341     wait->count   = count;
 342     wait->flags   = flags;
 343     wait->user    = NULL;
 344     wait->reply   = func;
 345     if (flags & SELECT_TIMEOUT)
 346     {
 347         gettimeofday( &wait->timeout, 0 );
 348         add_timeout( &wait->timeout, timeout );
 349     }
 350
 351     for (i = 0, entry = wait->queues; i < count; i++, entry++)
 352     {
 353         struct object *obj = objects[i];
 354         entry->thread = current;
 355         if (!obj->ops->add_queue( obj, entry ))
 356         {
 357             wait->count = i;
 358             end_wait( current );
 359             return 0;
 360         }
 361     }
 362     return 1;
 363 }
 364
 365 /* check if the thread waiting condition is satisfied */
 366 static int check_wait( struct thread *thread, struct object **object )
 367 {
 368     int i, signaled;
 369     struct thread_wait *wait = thread->wait;
 370     struct wait_queue_entry *entry = wait->queues;
 371
 372     assert( wait );
 373     *object = NULL;
 374     if (wait->flags & SELECT_ALL)
 375     {
 376         int not_ok = 0;
 377         /* Note: we must check them all anyway, as some objects may
 378          * want to do something when signaled, even if others are not */
 379         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 380             not_ok |= !entry->obj->ops->signaled( entry->obj, thread );
 381         if (not_ok) goto other_checks;
 382         /* Wait satisfied: tell it to all objects */
 383         signaled = 0;
 384         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 385             if (entry->obj->ops->satisfied( entry->obj, thread ))
 386                 signaled = STATUS_ABANDONED_WAIT_0;
 387         return signaled;
 388     }
 389     else
 390     {
 391         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 392         {
 393             if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
 394             /* Wait satisfied: tell it to the object */
 395             signaled = i;
 396             *object = entry->obj;
 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_ALERTABLE) && thread->apc) return STATUS_USER_APC;
 405     if (wait->flags & SELECT_TIMEOUT)
 406     {
 407         struct timeval now;
 408         gettimeofday( &now, NULL );
 409         if (!time_before( &now, &wait->timeout )) return STATUS_TIMEOUT;
 410     }
 411     return -1;
 412 }
 413
 414 /* build a reply to the select request */
 415 static void build_select_reply( struct thread *thread, struct object *obj, int signaled )
 416 {
 417     struct select_request *req = get_req_ptr( thread );
 418     req->signaled = signaled;
 419 }
 420
 421 /* attempt to wake up a thread */
 422 /* return 1 if OK, 0 if the wait condition is still not satisfied */
 423 static int wake_thread( struct thread *thread )
 424 {
 425     int signaled;
 426     struct object *object;
 427     if ((signaled = check_wait( thread, &object )) == -1) return 0;
 428     thread->error = 0;
 429     thread->wait->reply( thread, object, signaled );
 430     end_wait( thread );
 431     return 1;
 432 }
 433
 434 /* thread wait timeout */
 435 static void thread_timeout( void *ptr )
 436 {
 437     struct thread *thread = ptr;
 438     if (debug_level) fprintf( stderr, "%08x: *timeout*\n", (unsigned int)thread );
 439     assert( thread->wait );
 440     thread->error = 0;
 441     thread->wait->user = NULL;
 442     thread->wait->reply( thread, NULL, STATUS_TIMEOUT );
 443     end_wait( thread );
 444     send_reply( thread );
 445 }
 446
 447 /* sleep on a list of objects */
 448 int sleep_on( int count, struct object *objects[], int flags, int timeout, sleep_reply func )
 449 {
 450     assert( !current->wait );
 451     if (!wait_on( count, objects, flags, timeout, func )) return 0;
 452     if (wake_thread( current )) return 1;
 453     /* now we need to wait */
 454     if (flags & SELECT_TIMEOUT)
 455     {
 456         if (!(current->wait->user = add_timeout_user( &current->wait->timeout,
 457                                                       thread_timeout, current )))
 458         {
 459             end_wait( current );
 460             return 0;
 461         }
 462     }
 463     return 1;
 464 }
 465
 466 /* select on a list of handles */
 467 static int select_on( int count, int *handles, int flags, int timeout )
 468 {
 469     int ret = 0;
 470     int i;
 471     struct object *objects[MAXIMUM_WAIT_OBJECTS];
 472
 473     if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
 474     {
 475         set_error( ERROR_INVALID_PARAMETER );
 476         return 0;
 477     }
 478     for (i = 0; i < count; i++)
 479     {
 480         if (!(objects[i] = get_handle_obj( current->process, handles[i], SYNCHRONIZE, NULL )))
 481             break;
 482     }
 483     if (i == count) ret = sleep_on( count, objects, flags, timeout, build_select_reply );
 484     while (--i >= 0) release_object( objects[i] );
 485     return ret;
 486 }
 487
 488 /* attempt to wake threads sleeping on the object wait queue */
 489 void wake_up( struct object *obj, int max )
 490 {
 491     struct wait_queue_entry *entry = obj->head;
 492
 493     while (entry)
 494     {
 495         struct thread *thread = entry->thread;
 496         entry = entry->next;
 497         if (wake_thread( thread ))
 498         {
 499             send_reply( thread );
 500             if (max && !--max) break;
 501         }
 502     }
 503 }
 504
 505 /* queue an async procedure call */
 506 static int thread_queue_apc( struct thread *thread, void *func, void *param )
 507 {
 508     struct thread_apc *apc;
 509     if (!thread->apc)
 510     {
 511         if (!(thread->apc = mem_alloc( MAX_THREAD_APC * sizeof(*apc) )))
 512             return 0;
 513         thread->apc_count = 0;
 514     }
 515     else if (thread->apc_count >= MAX_THREAD_APC) return 0;
 516     thread->apc[thread->apc_count].func  = func;
 517     thread->apc[thread->apc_count].param = param;
 518     thread->apc_count++;
 519     if (thread->wait)
 520     {
 521         if (wake_thread( thread )) send_reply( thread );
 522     }
 523     return 1;
 524 }
 525
 526 /* kill a thread on the spot */
 527 void kill_thread( struct thread *thread, int exit_code )
 528 {
 529     if (thread->state == TERMINATED) return;  /* already killed */
 530     thread->state = TERMINATED;
 531     thread->exit_code = exit_code;
 532     if (current == thread) current = NULL;
 533     if (debug_level) trace_kill( thread );
 534     if (thread->wait) end_wait( thread );
 535     debug_exit_thread( thread, exit_code );
 536     abandon_mutexes( thread );
 537     remove_process_thread( thread->process, thread );
 538     wake_up( &thread->obj, 0 );
 539     detach_thread( thread );
 540     remove_select_user( &thread->obj );
 541     release_object( thread );
 542 }
 543
 544 /* create a new thread */
 545 DECL_HANDLER(new_thread)
 546 {
 547     struct thread *thread;
 548     struct process *process;
 549
 550     if ((process = get_process_from_id( req->pid )))
 551     {
 552         if ((fd = dup(fd)) != -1)
 553         {
 554             if ((thread = create_thread( fd, process, req->suspend )))
 555             {
 556                 req->tid = thread;
 557                 if ((req->handle = alloc_handle( current->process, thread,
 558                                                  THREAD_ALL_ACCESS, req->inherit )) == -1)
 559                     release_object( thread );
 560                 /* else will be released when the thread gets killed */
 561             }
 562             else close( fd );
 563         }
 564         else file_set_error();
 565         release_object( process );
 566     }
 567 }
 568
 569 /* retrieve the thread buffer file descriptor */
 570 DECL_HANDLER(get_thread_buffer)
 571 {
 572     fatal_protocol_error( current, "get_thread_buffer: should never get called directly\n" );
 573 }
 574
 575 /* initialize a new thread */
 576 DECL_HANDLER(init_thread)
 577 {
 578     if (current->unix_pid)
 579     {
 580         fatal_protocol_error( current, "init_thread: already running\n" );
 581         return;
 582     }
 583     current->unix_pid = req->unix_pid;
 584     current->teb      = req->teb;
 585     if (current->suspend + current->process->suspend > 0) stop_thread( current );
 586     req->pid = current->process;
 587     req->tid = current;
 588 }
 589
 590 /* terminate a thread */
 591 DECL_HANDLER(terminate_thread)
 592 {
 593     struct thread *thread;
 594
 595     if ((thread = get_thread_from_handle( req->handle, THREAD_TERMINATE )))
 596     {
 597         kill_thread( thread, req->exit_code );
 598         release_object( thread );
 599     }
 600 }
 601
 602 /* fetch information about a thread */
 603 DECL_HANDLER(get_thread_info)
 604 {
 605     struct thread *thread;
 606
 607     if ((thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION )))
 608     {
 609         req->tid       = thread;
 610         req->exit_code = thread->exit_code;
 611         req->priority  = thread->priority;
 612         release_object( thread );
 613     }
 614 }
 615
 616 /* set information about a thread */
 617 DECL_HANDLER(set_thread_info)
 618 {
 619     struct thread *thread;
 620
 621     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_INFORMATION )))
 622     {
 623         set_thread_info( thread, req );
 624         release_object( thread );
 625     }
 626 }
 627
 628 /* suspend a thread */
 629 DECL_HANDLER(suspend_thread)
 630 {
 631     struct thread *thread;
 632
 633     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 634     {
 635         req->count = suspend_thread( thread, 1 );
 636         release_object( thread );
 637     }
 638 }
 639
 640 /* resume a thread */
 641 DECL_HANDLER(resume_thread)
 642 {
 643     struct thread *thread;
 644
 645     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 646     {
 647         req->count = resume_thread( thread );
 648         release_object( thread );
 649     }
 650 }
 651
 652 /* select on a handle list */
 653 DECL_HANDLER(select)
 654 {
 655     if (!select_on( req->count, req->handles, req->flags, req->timeout ))
 656         req->signaled = -1;
 657 }
 658
 659 /* queue an APC for a thread */
 660 DECL_HANDLER(queue_apc)
 661 {
 662     struct thread *thread;
 663     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 664     {
 665         thread_queue_apc( thread, req->func, req->param );
 666         release_object( thread );
 667     }
 668 }
 669
 670 /* get list of APC to call */
 671 DECL_HANDLER(get_apcs)
 672 {
 673     if ((req->count = current->apc_count))
 674     {
 675         memcpy( req->apcs, current->apc, current->apc_count * sizeof(*current->apc) );
 676         free( current->apc );
 677         current->apc = NULL;
 678         current->apc_count = 0;
 679     }
 680 }