server/thread.c

   1 /*
   2  * Server-side thread management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <fcntl.h>
   9 #include <signal.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/mman.h>
  14 #include <sys/types.h>
  15 #include <sys/uio.h>
  16 #include <unistd.h>
  17 #include <stdarg.h>
  18
  19
  20 #include "winbase.h"
  21 #include "winerror.h"
  22
  23 #include "handle.h"
  24 #include "process.h"
  25 #include "thread.h"
  26 #include "request.h"
  27
  28
  29 /* thread queues */
  30
  31 struct wait_queue_entry
  32 {
  33     struct wait_queue_entry *next;
  34     struct wait_queue_entry *prev;
  35     struct object           *obj;
  36     struct thread           *thread;
  37 };
  38
  39 struct thread_wait
  40 {
  41     int                     count;      /* count of objects */
  42     int                     flags;
  43     struct timeval          timeout;
  44     struct timeout_user    *user;
  45     struct wait_queue_entry queues[1];
  46 };
  47
  48 /* asynchronous procedure calls */
  49
  50 struct thread_apc
  51 {
  52     void                   *func;    /* function to call in client */
  53     void                   *param;   /* function param */
  54 };
  55 #define MAX_THREAD_APC  16  /* Max outstanding APCs for a thread */
  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 destroy_thread( struct object *obj );
  63
  64 static const struct object_ops thread_ops =
  65 {
  66     sizeof(struct thread),
  67     dump_thread,
  68     add_queue,
  69     remove_queue,
  70     thread_signaled,
  71     no_satisfied,
  72     no_read_fd,
  73     no_write_fd,
  74     no_flush,
  75     no_get_file_info,
  76     destroy_thread
  77 };
  78
  79 static struct thread *first_thread;
  80
  81 /* allocate the buffer for the communication with the client */
  82 static int alloc_client_buffer( struct thread *thread )
  83 {
  84     int fd;
  85
  86     if ((fd = create_anonymous_file()) == -1) return -1;
  87     if (ftruncate( fd, MAX_REQUEST_LENGTH ) == -1) goto error;
  88     if ((thread->buffer = mmap( 0, MAX_REQUEST_LENGTH, PROT_READ | PROT_WRITE,
  89                                 MAP_SHARED, fd, 0 )) == (void*)-1) goto error;
  90     return fd;
  91
  92  error:
  93     file_set_error();
  94     if (fd != -1) close( fd );
  95     return -1;
  96 }
  97
  98 /* create a new thread */
  99 static struct thread *create_thread( int fd, struct process *process, int suspend )
 100 {
 101     struct thread *thread;
 102     int buf_fd;
 103
 104     if (!(thread = alloc_object( &thread_ops ))) return NULL;
 105
 106     thread->client      = NULL;
 107     thread->unix_pid    = 0;  /* not known yet */
 108     thread->teb         = NULL;
 109     thread->mutex       = NULL;
 110     thread->debug_ctx   = NULL;
 111     thread->debug_first = NULL;
 112     thread->debug_event = NULL;
 113     thread->wait        = NULL;
 114     thread->apc         = NULL;
 115     thread->apc_count   = 0;
 116     thread->error       = 0;
 117     thread->state       = STARTING;
 118     thread->exit_code   = 0x103;  /* STILL_ACTIVE */
 119     thread->next        = NULL;
 120     thread->prev        = NULL;
 121     thread->priority    = THREAD_PRIORITY_NORMAL;
 122     thread->affinity    = 1;
 123     thread->suspend     = (suspend != 0);
 124     thread->buffer      = (void *)-1;
 125     thread->last_req    = REQ_GET_THREAD_BUFFER;
 126
 127     if (!first_thread)  /* creating the first thread */
 128     {
 129         current = thread;
 130         thread->process = process = create_initial_process();
 131         assert( process );
 132     }
 133     else thread->process = (struct process *)grab_object( process );
 134
 135     if ((thread->next = first_thread) != NULL) thread->next->prev = thread;
 136     first_thread = thread;
 137     add_process_thread( process, thread );
 138
 139     if ((buf_fd = alloc_client_buffer( thread )) == -1) goto error;
 140     if (!(thread->client = add_client( fd, thread )))
 141     {
 142         close( buf_fd );
 143         goto error;
 144     }
 145     set_reply_fd( thread, buf_fd );  /* send the fd to the client */
 146     send_reply( thread );
 147     return thread;
 148
 149  error:
 150     remove_process_thread( process, thread );
 151     release_object( thread );
 152     return NULL;
 153 }
 154
 155 /* create the initial thread and start the main server loop */
 156 void create_initial_thread( int fd )
 157 {
 158     create_thread( fd, NULL, 0 );
 159     select_loop();
 160 }
 161
 162 /* destroy a thread when its refcount is 0 */
 163 static void destroy_thread( struct object *obj )
 164 {
 165     struct thread *thread = (struct thread *)obj;
 166     assert( obj->ops == &thread_ops );
 167
 168     assert( !thread->debug_ctx );  /* cannot still be debugging something */
 169     release_object( thread->process );
 170     if (thread->next) thread->next->prev = thread->prev;
 171     if (thread->prev) thread->prev->next = thread->next;
 172     else first_thread = thread->next;
 173     if (thread->apc) free( thread->apc );
 174     if (thread->buffer != (void *)-1) munmap( thread->buffer, MAX_REQUEST_LENGTH );
 175 }
 176
 177 /* dump a thread on stdout for debugging purposes */
 178 static void dump_thread( struct object *obj, int verbose )
 179 {
 180     struct thread *thread = (struct thread *)obj;
 181     assert( obj->ops == &thread_ops );
 182
 183     fprintf( stderr, "Thread pid=%d teb=%p state=%d\n",
 184              thread->unix_pid, thread->teb, thread->state );
 185 }
 186
 187 static int thread_signaled( struct object *obj, struct thread *thread )
 188 {
 189     struct thread *mythread = (struct thread *)obj;
 190     return (mythread->state == TERMINATED);
 191 }
 192
 193 /* get a thread pointer from a thread id (and increment the refcount) */
 194 struct thread *get_thread_from_id( void *id )
 195 {
 196     struct thread *t = first_thread;
 197     while (t && (t != id)) t = t->next;
 198     if (t) grab_object( t );
 199     return t;
 200 }
 201
 202 /* get a thread from a handle (and increment the refcount) */
 203 struct thread *get_thread_from_handle( int handle, unsigned int access )
 204 {
 205     return (struct thread *)get_handle_obj( current->process, handle,
 206                                             access, &thread_ops );
 207 }
 208
 209 /* set all information about a thread */
 210 static void set_thread_info( struct thread *thread,
 211                              struct set_thread_info_request *req )
 212 {
 213     if (req->mask & SET_THREAD_INFO_PRIORITY)
 214         thread->priority = req->priority;
 215     if (req->mask & SET_THREAD_INFO_AFFINITY)
 216     {
 217         if (req->affinity != 1) set_error( ERROR_INVALID_PARAMETER );
 218         else thread->affinity = req->affinity;
 219     }
 220 }
 221
 222 /* suspend a thread */
 223 static int suspend_thread( struct thread *thread )
 224 {
 225     int old_count = thread->suspend;
 226     if (thread->suspend < MAXIMUM_SUSPEND_COUNT)
 227     {
 228         if (!(thread->process->suspend + thread->suspend++))
 229         {
 230             if (thread->unix_pid) kill( thread->unix_pid, SIGSTOP );
 231         }
 232     }
 233     return old_count;
 234 }
 235
 236 /* resume a thread */
 237 static int resume_thread( struct thread *thread )
 238 {
 239     int old_count = thread->suspend;
 240     if (thread->suspend > 0)
 241     {
 242         if (!(--thread->suspend + thread->process->suspend))
 243         {
 244             if (thread->unix_pid) kill( thread->unix_pid, SIGCONT );
 245         }
 246     }
 247     return old_count;
 248 }
 249
 250 /* suspend all threads but the current */
 251 void suspend_all_threads( void )
 252 {
 253     struct thread *thread;
 254     for ( thread = first_thread; thread; thread = thread->next )
 255         if ( thread != current )
 256             suspend_thread( thread );
 257 }
 258
 259 /* resume all threads but the current */
 260 void resume_all_threads( void )
 261 {
 262     struct thread *thread;
 263     for ( thread = first_thread; thread; thread = thread->next )
 264         if ( thread != current )
 265             resume_thread( thread );
 266 }
 267
 268 /* add a thread to an object wait queue; return 1 if OK, 0 on error */
 269 int add_queue( struct object *obj, struct wait_queue_entry *entry )
 270 {
 271     grab_object( obj );
 272     entry->obj    = obj;
 273     entry->prev   = obj->tail;
 274     entry->next   = NULL;
 275     if (obj->tail) obj->tail->next = entry;
 276     else obj->head = entry;
 277     obj->tail = entry;
 278     return 1;
 279 }
 280
 281 /* remove a thread from an object wait queue */
 282 void remove_queue( struct object *obj, struct wait_queue_entry *entry )
 283 {
 284     if (entry->next) entry->next->prev = entry->prev;
 285     else obj->tail = entry->prev;
 286     if (entry->prev) entry->prev->next = entry->next;
 287     else obj->head = entry->next;
 288     release_object( obj );
 289 }
 290
 291 /* finish waiting */
 292 static void end_wait( struct thread *thread )
 293 {
 294     struct thread_wait *wait = thread->wait;
 295     struct wait_queue_entry *entry;
 296     int i;
 297
 298     assert( wait );
 299     for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 300         entry->obj->ops->remove_queue( entry->obj, entry );
 301     if (wait->user) remove_timeout_user( wait->user );
 302     free( wait );
 303     thread->wait = NULL;
 304 }
 305
 306 /* build the thread wait structure */
 307 static int wait_on( struct thread *thread, int count,
 308                     int *handles, int flags, int timeout )
 309 {
 310     struct thread_wait *wait;
 311     struct wait_queue_entry *entry;
 312     struct object *obj;
 313     int i;
 314
 315     if ((count < 0) || (count > MAXIMUM_WAIT_OBJECTS))
 316     {
 317         set_error( ERROR_INVALID_PARAMETER );
 318         return 0;
 319     }
 320     if (!(wait = mem_alloc( sizeof(*wait) + (count-1) * sizeof(*entry) ))) return 0;
 321     thread->wait  = wait;
 322     wait->count   = count;
 323     wait->flags   = flags;
 324     wait->user    = NULL;
 325     if (flags & SELECT_TIMEOUT) make_timeout( &wait->timeout, timeout );
 326
 327     for (i = 0, entry = wait->queues; i < count; i++, entry++)
 328     {
 329         if (!(obj = get_handle_obj( thread->process, handles[i],
 330                                     SYNCHRONIZE, NULL )))
 331         {
 332             wait->count = i - 1;
 333             end_wait( thread );
 334             return 0;
 335         }
 336         entry->thread = thread;
 337         if (!obj->ops->add_queue( obj, entry ))
 338         {
 339             wait->count = i - 1;
 340             end_wait( thread );
 341             return 0;
 342         }
 343         release_object( obj );
 344     }
 345     return 1;
 346 }
 347
 348 /* check if the thread waiting condition is satisfied */
 349 static int check_wait( struct thread *thread, int *signaled )
 350 {
 351     int i;
 352     struct thread_wait *wait = thread->wait;
 353     struct wait_queue_entry *entry = wait->queues;
 354
 355     assert( wait );
 356     if (wait->flags & SELECT_ALL)
 357     {
 358         int not_ok = 0;
 359         /* Note: we must check them all anyway, as some objects may
 360          * want to do something when signaled, even if others are not */
 361         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 362             not_ok |= !entry->obj->ops->signaled( entry->obj, thread );
 363         if (not_ok) goto other_checks;
 364         /* Wait satisfied: tell it to all objects */
 365         *signaled = 0;
 366         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 367             if (entry->obj->ops->satisfied( entry->obj, thread ))
 368                 *signaled = STATUS_ABANDONED_WAIT_0;
 369         return 1;
 370     }
 371     else
 372     {
 373         for (i = 0, entry = wait->queues; i < wait->count; i++, entry++)
 374         {
 375             if (!entry->obj->ops->signaled( entry->obj, thread )) continue;
 376             /* Wait satisfied: tell it to the object */
 377             *signaled = i;
 378             if (entry->obj->ops->satisfied( entry->obj, thread ))
 379                 *signaled = i + STATUS_ABANDONED_WAIT_0;
 380             return 1;
 381         }
 382     }
 383
 384  other_checks:
 385     if ((wait->flags & SELECT_ALERTABLE) && thread->apc)
 386     {
 387         *signaled = STATUS_USER_APC;
 388         return 1;
 389     }
 390     if (wait->flags & SELECT_TIMEOUT)
 391     {
 392         struct timeval now;
 393         gettimeofday( &now, NULL );
 394         if ((now.tv_sec > wait->timeout.tv_sec) ||
 395             ((now.tv_sec == wait->timeout.tv_sec) &&
 396              (now.tv_usec >= wait->timeout.tv_usec)))
 397         {
 398             *signaled = STATUS_TIMEOUT;
 399             return 1;
 400         }
 401     }
 402     return 0;
 403 }
 404
 405 /* attempt to wake up a thread */
 406 /* return 1 if OK, 0 if the wait condition is still not satisfied */
 407 static int wake_thread( struct thread *thread )
 408 {
 409     struct select_request *req = get_req_ptr( thread );
 410
 411     if (!check_wait( thread, &req->signaled )) return 0;
 412     end_wait( thread );
 413     return 1;
 414 }
 415
 416 /* sleep on a list of objects */
 417 static void sleep_on( struct thread *thread, int count, int *handles, int flags, int timeout )
 418 {
 419     struct select_request *req;
 420     assert( !thread->wait );
 421     if (!wait_on( thread, count, handles, flags, timeout )) goto error;
 422     if (wake_thread( thread )) return;
 423     /* now we need to wait */
 424     if (flags & SELECT_TIMEOUT)
 425     {
 426         if (!(thread->wait->user = add_timeout_user( &thread->wait->timeout,
 427                                                      call_timeout_handler, thread )))
 428             goto error;
 429     }
 430     thread->state = SLEEPING;
 431     return;
 432
 433  error:
 434     req = get_req_ptr( thread );
 435     req->signaled = -1;
 436 }
 437
 438 /* timeout for the current thread */
 439 void thread_timeout(void)
 440 {
 441     struct select_request *req = get_req_ptr( current );
 442
 443     assert( current->wait );
 444     current->wait->user = NULL;
 445     end_wait( current );
 446     req->signaled = STATUS_TIMEOUT;
 447     send_reply( current );
 448 }
 449
 450 /* attempt to wake threads sleeping on the object wait queue */
 451 void wake_up( struct object *obj, int max )
 452 {
 453     struct wait_queue_entry *entry = obj->head;
 454
 455     while (entry)
 456     {
 457         struct thread *thread = entry->thread;
 458         entry = entry->next;
 459         if (wake_thread( thread ))
 460         {
 461             send_reply( thread );
 462             if (max && !--max) break;
 463         }
 464     }
 465 }
 466
 467 /* queue an async procedure call */
 468 static int thread_queue_apc( struct thread *thread, void *func, void *param )
 469 {
 470     struct thread_apc *apc;
 471     if (!thread->apc)
 472     {
 473         if (!(thread->apc = mem_alloc( MAX_THREAD_APC * sizeof(*apc) )))
 474             return 0;
 475         thread->apc_count = 0;
 476     }
 477     else if (thread->apc_count >= MAX_THREAD_APC) return 0;
 478     thread->apc[thread->apc_count].func  = func;
 479     thread->apc[thread->apc_count].param = param;
 480     thread->apc_count++;
 481     if (thread->wait)
 482     {
 483         if (wake_thread( thread )) send_reply( thread );
 484     }
 485     return 1;
 486 }
 487
 488 /* kill a thread on the spot */
 489 void kill_thread( struct thread *thread, int exit_code )
 490 {
 491     if (thread->state == TERMINATED) return;  /* already killed */
 492     if (thread->unix_pid) kill( thread->unix_pid, SIGTERM );
 493     remove_client( thread->client, exit_code ); /* this will call thread_killed */
 494 }
 495
 496 /* a thread has been killed */
 497 void thread_killed( struct thread *thread, int exit_code )
 498 {
 499     thread->state = TERMINATED;
 500     thread->exit_code = exit_code;
 501     if (thread->wait) end_wait( thread );
 502     debug_exit_thread( thread, exit_code );
 503     abandon_mutexes( thread );
 504     remove_process_thread( thread->process, thread );
 505     wake_up( &thread->obj, 0 );
 506     release_object( thread );
 507 }
 508
 509 /* create a new thread */
 510 DECL_HANDLER(new_thread)
 511 {
 512     struct thread *thread;
 513     struct process *process;
 514
 515     if ((process = get_process_from_id( req->pid )))
 516     {
 517         if ((fd = dup(fd)) != -1)
 518         {
 519             if ((thread = create_thread( fd, process, req->suspend )))
 520             {
 521                 req->tid = thread;
 522                 if ((req->handle = alloc_handle( current->process, thread,
 523                                                  THREAD_ALL_ACCESS, req->inherit )) == -1)
 524                     release_object( thread );
 525                 /* else will be released when the thread gets killed */
 526             }
 527             else close( fd );
 528         }
 529         else file_set_error();
 530         release_object( process );
 531     }
 532 }
 533
 534 /* retrieve the thread buffer file descriptor */
 535 DECL_HANDLER(get_thread_buffer)
 536 {
 537     fatal_protocol_error( current, "get_thread_buffer: should never get called directly\n" );
 538 }
 539
 540 /* initialize a new thread */
 541 DECL_HANDLER(init_thread)
 542 {
 543     if (current->state != STARTING)
 544     {
 545         fatal_protocol_error( current, "init_thread: already running\n" );
 546         return;
 547     }
 548     current->state    = RUNNING;
 549     current->unix_pid = req->unix_pid;
 550     current->teb      = req->teb;
 551     if (current->suspend + current->process->suspend > 0)
 552         kill( current->unix_pid, SIGSTOP );
 553     req->pid = current->process;
 554     req->tid = current;
 555 }
 556
 557 /* terminate a thread */
 558 DECL_HANDLER(terminate_thread)
 559 {
 560     struct thread *thread;
 561
 562     if ((thread = get_thread_from_handle( req->handle, THREAD_TERMINATE )))
 563     {
 564         kill_thread( thread, req->exit_code );
 565         release_object( thread );
 566     }
 567 }
 568
 569 /* fetch information about a thread */
 570 DECL_HANDLER(get_thread_info)
 571 {
 572     struct thread *thread;
 573
 574     if ((thread = get_thread_from_handle( req->handle, THREAD_QUERY_INFORMATION )))
 575     {
 576         req->tid       = thread;
 577         req->exit_code = thread->exit_code;
 578         req->priority  = thread->priority;
 579         release_object( thread );
 580     }
 581 }
 582
 583 /* set information about a thread */
 584 DECL_HANDLER(set_thread_info)
 585 {
 586     struct thread *thread;
 587
 588     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_INFORMATION )))
 589     {
 590         set_thread_info( thread, req );
 591         release_object( thread );
 592     }
 593 }
 594
 595 /* suspend a thread */
 596 DECL_HANDLER(suspend_thread)
 597 {
 598     struct thread *thread;
 599
 600     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 601     {
 602         req->count = suspend_thread( thread );
 603         release_object( thread );
 604     }
 605 }
 606
 607 /* resume a thread */
 608 DECL_HANDLER(resume_thread)
 609 {
 610     struct thread *thread;
 611
 612     if ((thread = get_thread_from_handle( req->handle, THREAD_SUSPEND_RESUME )))
 613     {
 614         req->count = resume_thread( thread );
 615         release_object( thread );
 616     }
 617 }
 618
 619 /* select on a handle list */
 620 DECL_HANDLER(select)
 621 {
 622     sleep_on( current, req->count, req->handles, req->flags, req->timeout );
 623 }
 624
 625 /* queue an APC for a thread */
 626 DECL_HANDLER(queue_apc)
 627 {
 628     struct thread *thread;
 629     if ((thread = get_thread_from_handle( req->handle, THREAD_SET_CONTEXT )))
 630     {
 631         thread_queue_apc( thread, req->func, req->param );
 632         release_object( thread );
 633     }
 634 }
 635
 636 /* get list of APC to call */
 637 DECL_HANDLER(get_apcs)
 638 {
 639     if ((req->count = current->apc_count))
 640     {
 641         memcpy( req->apcs, current->apc, current->apc_count * sizeof(*current->apc) );
 642         free( current->apc );
 643         current->apc = NULL;
 644         current->apc_count = 0;
 645     }
 646 }