man/curs_threads.3x

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  31 .\" $Id: curs_threads.3x,v 1.49 2023/11/25 14:09:12 tom Exp $
  32 .TH curs_threads 3X 2023-11-25 "ncurses 6.4" "Library calls"
  33 .ie \n(.g \{\
  34 .ds `` \(lq
  35 .ds '' \(rq
  36 .\}
  37 .el \{\
  38 .ie t .ds `` ``
  39 .el   .ds `` ""
  40 .ie t .ds '' ''
  41 .el   .ds '' ""
  42 .\}
  43 .
  44 .de bP
  45 .ie n  .IP \(bu 4
  46 .el    .IP \(bu 2
  47 ..
  48 .SH NAME
  49 \fI\%NCURSES_WINDOW_CB\fP,
  50 \fI\%NCURSES_SCREEN_CB\fP,
  51 \fB\%get_escdelay\fP,
  52 \fB\%set_escdelay\fP,
  53 \fB\%set_tabsize\fP,
  54 \fB\%use_screen\fP,
  55 \fB\%use_window\fP \-
  56 \fIcurses\fR support for multi-threaded applications
  57 .SH SYNOPSIS
  58 .nf
  59 \fB#include <curses.h>
  60 .PP
  61 \fI/* data types */
  62 \fBtypedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *);
  63 \fBtypedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *);
  64 .PP
  65 \fBint get_escdelay(void);
  66 \fBint set_escdelay(int \fIms\fP);
  67 \fBint set_tabsize(int \fIcols\fP);
  68 .PP
  69 \fBint use_screen(SCREEN *\fIscr\fP, NCURSES_SCREEN_CB \fIfunc\fP, void *\fIdata\fP);
  70 \fBint use_window(WINDOW *\fIwin\fP, NCURSES_WINDOW_CB \fIfunc\fP, void *\fIdata\fP);
  71 .fi
  72 .SH DESCRIPTION
  73 The \fIncurses\fP library can be configured to support multi-threaded
  74 applications in a rudimentary way.
  75 Such configuration produces a different set of libraries,
  76 named \fIlibncursest\fP,
  77 for example,
  78 since doing so alters \fIncurses\fP's application binary interface
  79 (ABI).
  80 .PP
  81 Instead of modifying the programming interface (API) to make
  82 \fIncurses\fP functions expect an additional argument specifying a
  83 thread,
  84 the library adds functions,
  85 usable in any configuration,
  86 that hide the \fImutexes\fP
  87 (mutual exclusion locks)
  88 needed to prevent concurrent access to variables shared by multiple
  89 threads of execution.
  90 .PP
  91 \fIncurses\fP threading support requires the use of functions to access
  92 members of the \fI\%WINDOW\fP structure (see \fBcurs_opaque\fP(3X)).
  93 It further makes functions of the common global variables
  94 \fB\%COLORS\fP,
  95 \fB\%COLOR_PAIRS\fP,
  96 \fB\%COLS\fP,
  97 \fB\%ESCDELAY\fP,
  98 \fB\%LINES\fP,
  99 \fB\%TABSIZE\fP,
 100 \fB\%curscr\fP,
 101 \fB\%newscr\fP,
 102 and
 103 \fB\%ttytype\fP,
 104 maintaining them as as read-only values in the \fISCREEN\fP structure.
 105 .PP
 106 Even this is not enough to make an application using \fIcurses\fP
 107 thread-safe.
 108 We would expect a multi-threaded application to have threads updating
 109 separate windows (on the same device),
 110 and separate screens (on different devices).
 111 Further,
 112 applications expect a few of the global variables to be writable.
 113 The functions described here address these special situations.
 114 .PP
 115 The \fB\%ESCDELAY\fP and \fB\%TABSIZE\fP global variables are modified
 116 by some applications.
 117 To modify them in any configuration,
 118 use the \fB\%set_escdelay\fP or \fB\%set_tabsize\fP functions.
 119 Other global variables are not modifiable.
 120 \fBget_escdelay\fP retrieves \fB\%ESCDELAY\fP's value.
 121 .PP
 122 The \fBuse_window\fP and \fBuse_screen\fP functions provide
 123 coarse-grained mutexes for their respective \fI\%WINDOW\fP and
 124 \fI\%SCREEN\fP parameters;
 125 they call a user-supplied function,
 126 pass it a \fIdata\fP parameter,
 127 and return the value from the user-supplied function to the application.
 128 .\" ***************************************************************************
 129 .SS Usage
 130 All \fIncurses\fP library functions assume that the locale is not
 131 altered during operation.
 132 In addition,
 133 they use data that is maintained within a hierarchy of scopes.
 134 .bP
 135 global data used in the low-level \fIterminfo\fP or \fItermcap\fP
 136 interfaces
 137 .bP
 138 terminal data associated with a call to \fBset_curterm\fP(3X)
 139 .IP
 140 Terminal data are initialized when screens are created.
 141 .bP
 142 screen data associated with a call to \fBnewterm\fP(3X) or
 143 \fBinitscr\fP(3X)
 144 .bP
 145 window data associated with a call to \fBnewwin\fP(3X) or
 146 \fBsubwin\fP(3X)
 147 .IP
 148 Windows are associated with screens.
 149 Pads are not necessarily associated with any particular screen.
 150 .IP
 151 Most \fIcurses\fP applications operate on one or more windows within a
 152 single screen.
 153 .bP
 154 reentrant data associated with \*(``pure\*('' functions that alter no
 155 shared variables
 156 .PP
 157 The following table lists the scope of each symbol in the \fIncurses\fP
 158 library when configured to support multi-threaded applications.
 159 .PP
 160 .TS
 161 center tab(/);
 162 lb lb
 163 lb l .
 164 Symbol/Scope
 165 =
 166 BC/global
 167 COLORS/screen (read-only)
 168 COLOR_PAIR/reentrant
 169 COLOR_PAIRS/screen (read-only)
 170 COLS/screen (read-only)
 171 ESCDELAY/screen (read-only; see \fBset_escdelay\fP)
 172 LINES/screen (read-only)
 173 PAIR_NUMBER/reentrant
 174 PC/global
 175 SP/global
 176 TABSIZE/screen (read-only; see \fBset_tabsize\fP)
 177 UP/global
 178 acs_map/screen (read-only)
 179 add_wch/window (\fBstdscr\fP)
 180 add_wchnstr/window (\fBstdscr\fP)
 181 add_wchstr/window (\fBstdscr\fP)
 182 addch/window (\fBstdscr\fP)
 183 addchnstr/window (\fBstdscr\fP)
 184 addchstr/window (\fBstdscr\fP)
 185 addnstr/window (\fBstdscr\fP)
 186 addnwstr/window (\fBstdscr\fP)
 187 addstr/window (\fBstdscr\fP)
 188 addwstr/window (\fBstdscr\fP)
 189 assume_default_colors/screen
 190 attr_get/window (\fBstdscr\fP)
 191 attr_off/window (\fBstdscr\fP)
 192 attr_on/window (\fBstdscr\fP)
 193 attr_set/window (\fBstdscr\fP)
 194 attroff/window (\fBstdscr\fP)
 195 attron/window (\fBstdscr\fP)
 196 attrset/window (\fBstdscr\fP)
 197 baudrate/screen
 198 beep/screen
 199 bkgd/window (\fBstdscr\fP)
 200 bkgdset/window (\fBstdscr\fP)
 201 bkgrnd/window (\fBstdscr\fP)
 202 bkgrndset/window (\fBstdscr\fP)
 203 boolcodes/global (read-only)
 204 boolfnames/global (read-only)
 205 boolnames/global (read-only)
 206 border/window (\fBstdscr\fP)
 207 border_set/window (\fBstdscr\fP)
 208 box/window (\fBstdscr\fP)
 209 box_set/window (\fBstdscr\fP)
 210 can_change_color/terminal
 211 cbreak/screen
 212 chgat/window (\fBstdscr\fP)
 213 clear/window (\fBstdscr\fP)
 214 clearok/window
 215 clrtobot/window (\fBstdscr\fP)
 216 clrtoeol/window (\fBstdscr\fP)
 217 color_content/screen
 218 color_set/window (\fBstdscr\fP)
 219 copywin/window (locks source, target)
 220 cur_term/terminal
 221 curs_set/screen
 222 curscr/screen (read-only)
 223 curses_version/global (read-only)
 224 def_prog_mode/terminal
 225 def_shell_mode/terminal
 226 define_key/screen
 227 del_curterm/screen
 228 delay_output/screen
 229 delch/window (\fBstdscr\fP)
 230 deleteln/window (\fBstdscr\fP)
 231 delscreen/global (locks screen list, screen)
 232 delwin/global (locks window list)
 233 derwin/screen
 234 doupdate/screen
 235 dupwin/screen (locks window)
 236 echo/screen
 237 echo_wchar/window (\fBstdscr\fP)
 238 echochar/window (\fBstdscr\fP)
 239 endwin/screen
 240 erase/window (\fBstdscr\fP)
 241 erasechar/window (\fBstdscr\fP)
 242 erasewchar/window (\fBstdscr\fP)
 243 filter/global
 244 flash/terminal
 245 flushinp/screen
 246 get_wch/screen (input operation)
 247 get_wstr/screen (input operation)
 248 getattrs/window
 249 getbegx/window
 250 getbegy/window
 251 getbkgd/window
 252 getbkgrnd/window
 253 getcchar/reentrant
 254 getch/screen (input operation)
 255 getcurx/window
 256 getcury/window
 257 getmaxx/window
 258 getmaxy/window
 259 getmouse/screen (input operation)
 260 getn_wstr/screen (input operation)
 261 getnstr/screen (input operation)
 262 getparx/window
 263 getpary/window
 264 getstr/screen (input operation)
 265 getwin/screen (input operation)
 266 halfdelay/screen
 267 has_colors/terminal
 268 has_ic/terminal
 269 has_il/terminal
 270 has_key/screen
 271 hline/window (\fBstdscr\fP)
 272 hline_set/window (\fBstdscr\fP)
 273 idcok/window
 274 idlok/window
 275 immedok/window
 276 in_wch/window (\fBstdscr\fP)
 277 in_wchnstr/window (\fBstdscr\fP)
 278 in_wchstr/window (\fBstdscr\fP)
 279 inch/window (\fBstdscr\fP)
 280 inchnstr/window (\fBstdscr\fP)
 281 inchstr/window (\fBstdscr\fP)
 282 init_color/screen
 283 init_pair/screen
 284 initscr/global (locks screen list)
 285 innstr/window (\fBstdscr\fP)
 286 innwstr/window (\fBstdscr\fP)
 287 ins_nwstr/window (\fBstdscr\fP)
 288 ins_wch/window (\fBstdscr\fP)
 289 ins_wstr/window (\fBstdscr\fP)
 290 insch/window (\fBstdscr\fP)
 291 insdelln/window (\fBstdscr\fP)
 292 insertln/window (\fBstdscr\fP)
 293 insnstr/window (\fBstdscr\fP)
 294 insstr/window (\fBstdscr\fP)
 295 instr/window (\fBstdscr\fP)
 296 intrflush/terminal
 297 inwstr/window (\fBstdscr\fP)
 298 is_cleared/window
 299 is_idcok/window
 300 is_idlok/window
 301 is_immedok/window
 302 is_keypad/window
 303 is_leaveok/window
 304 is_linetouched/window
 305 is_nodelay/window
 306 is_notimeout/window
 307 is_scrollok/window
 308 is_syncok/window
 309 is_term_resized/terminal
 310 is_wintouched/window
 311 isendwin/screen
 312 key_defined/screen
 313 key_name/global (static data)
 314 keybound/screen
 315 keyname/global (static data)
 316 keyok/screen
 317 keypad/window
 318 killchar/terminal
 319 killwchar/terminal
 320 leaveok/window
 321 longname/screen
 322 mcprint/terminal
 323 meta/screen
 324 mouse_trafo/window (\fBstdscr\fP)
 325 mouseinterval/screen
 326 mousemask/screen
 327 move/window (\fBstdscr\fP)
 328 mvadd_wch/window (\fBstdscr\fP)
 329 mvadd_wchnstr/window (\fBstdscr\fP)
 330 mvadd_wchstr/window (\fBstdscr\fP)
 331 mvaddch/window (\fBstdscr\fP)
 332 mvaddchnstr/window (\fBstdscr\fP)
 333 mvaddchstr/window (\fBstdscr\fP)
 334 mvaddnstr/window (\fBstdscr\fP)
 335 mvaddnwstr/window (\fBstdscr\fP)
 336 mvaddstr/window (\fBstdscr\fP)
 337 mvaddwstr/window (\fBstdscr\fP)
 338 mvchgat/window (\fBstdscr\fP)
 339 mvcur/screen
 340 mvdelch/window (\fBstdscr\fP)
 341 mvderwin/window (\fBstdscr\fP)
 342 mvget_wch/screen (input operation)
 343 mvget_wstr/screen (input operation)
 344 mvgetch/screen (input operation)
 345 mvgetn_wstr/screen (input operation)
 346 mvgetnstr/screen (input operation)
 347 mvgetstr/screen (input operation)
 348 mvhline/window (\fBstdscr\fP)
 349 mvhline_set/window (\fBstdscr\fP)
 350 mvin_wch/window (\fBstdscr\fP)
 351 mvin_wchnstr/window (\fBstdscr\fP)
 352 mvin_wchstr/window (\fBstdscr\fP)
 353 mvinch/window (\fBstdscr\fP)
 354 mvinchnstr/window (\fBstdscr\fP)
 355 mvinchstr/window (\fBstdscr\fP)
 356 mvinnstr/window (\fBstdscr\fP)
 357 mvinnwstr/window (\fBstdscr\fP)
 358 mvins_nwstr/window (\fBstdscr\fP)
 359 mvins_wch/window (\fBstdscr\fP)
 360 mvins_wstr/window (\fBstdscr\fP)
 361 mvinsch/window (\fBstdscr\fP)
 362 mvinsnstr/window (\fBstdscr\fP)
 363 mvinsstr/window (\fBstdscr\fP)
 364 mvinstr/window (\fBstdscr\fP)
 365 mvinwstr/window (\fBstdscr\fP)
 366 mvprintw/window (\fBstdscr\fP)
 367 mvscanw/screen
 368 mvvline/window (\fBstdscr\fP)
 369 mvvline_set/window (\fBstdscr\fP)
 370 mvwadd_wch/window
 371 mvwadd_wchnstr/window
 372 mvwadd_wchstr/window
 373 mvwaddch/window
 374 mvwaddchnstr/window
 375 mvwaddchstr/window
 376 mvwaddnstr/window
 377 mvwaddnwstr/window
 378 mvwaddstr/window
 379 mvwaddwstr/window
 380 mvwchgat/window
 381 mvwdelch/window
 382 mvwget_wch/screen (input operation)
 383 mvwget_wstr/screen (input operation)
 384 mvwgetch/screen (input operation)
 385 mvwgetn_wstr/screen (input operation)
 386 mvwgetnstr/screen (input operation)
 387 mvwgetstr/screen (input operation)
 388 mvwhline/window
 389 mvwhline_set/window
 390 mvwin/window
 391 mvwin_wch/window
 392 mvwin_wchnstr/window
 393 mvwin_wchstr/window
 394 mvwinch/window
 395 mvwinchnstr/window
 396 mvwinchstr/window
 397 mvwinnstr/window
 398 mvwinnwstr/window
 399 mvwins_nwstr/window
 400 mvwins_wch/window
 401 mvwins_wstr/window
 402 mvwinsch/window
 403 mvwinsnstr/window
 404 mvwinsstr/window
 405 mvwinstr/window
 406 mvwinwstr/window
 407 mvwprintw/window
 408 mvwscanw/screen
 409 mvwvline/window
 410 mvwvline_set/window
 411 napms/reentrant
 412 newpad/global (locks window list)
 413 newscr/screen (read-only)
 414 newterm/global (locks screen list)
 415 newwin/global (locks window list)
 416 nl/screen
 417 nocbreak/screen
 418 nodelay/window
 419 noecho/screen
 420 nofilter/global
 421 nonl/screen
 422 noqiflush/terminal
 423 noraw/screen
 424 notimeout/window
 425 numcodes/global (read-only)
 426 numfnames/global (read-only)
 427 numnames/global (read-only)
 428 ospeed/global
 429 overlay/window (locks source, target)
 430 overwrite/window (locks source, target)
 431 pair_content/screen
 432 pecho_wchar/screen
 433 pechochar/screen
 434 pnoutrefresh/screen
 435 prefresh/screen
 436 printw/window
 437 putp/global
 438 putwin/window
 439 qiflush/terminal
 440 raw/screen
 441 redrawwin/window
 442 refresh/screen
 443 reset_prog_mode/screen
 444 reset_shell_mode/screen
 445 resetty/terminal
 446 resize_term/screen (locks window list)
 447 resizeterm/screen
 448 restartterm/screen
 449 ripoffline/global (static data)
 450 savetty/terminal
 451 scanw/screen
 452 scr_dump/screen
 453 scr_init/screen
 454 scr_restore/screen
 455 scr_set/screen
 456 scrl/window (\fBstdscr\fP)
 457 scroll/window
 458 scrollok/window
 459 set_curterm/screen
 460 set_escdelay/screen
 461 set_tabsize/screen
 462 set_term/global (locks screen list, screen)
 463 setcchar/reentrant
 464 setscrreg/window (\fBstdscr\fP)
 465 setupterm/global
 466 slk_attr/screen
 467 slk_attr_off/screen
 468 slk_attr_on/screen
 469 slk_attr_set/screen
 470 slk_attroff/screen
 471 slk_attron/screen
 472 slk_attrset/screen
 473 slk_clear/screen
 474 slk_color/screen
 475 slk_init/screen
 476 slk_label/screen
 477 slk_noutrefresh/screen
 478 slk_refresh/screen
 479 slk_restore/screen
 480 slk_set/screen
 481 slk_touch/screen
 482 slk_wset/screen
 483 standend/window
 484 standout/window
 485 start_color/screen
 486 \fBstdscr\fP/screen (read-only)
 487 strcodes/global (read-only)
 488 strfnames/global (read-only)
 489 strnames/global (read-only)
 490 subpad/window
 491 subwin/window
 492 syncok/window
 493 term_attrs/screen
 494 termattrs/screen
 495 termname/terminal
 496 tgetent/global
 497 tgetflag/global
 498 tgetnum/global
 499 tgetstr/global
 500 tgoto/global
 501 tigetflag/terminal
 502 tigetnum/terminal
 503 tigetstr/terminal
 504 timeout/window (\fBstdscr\fP)
 505 touchline/window
 506 touchwin/window
 507 tparm/global (static data)
 508 tputs/screen
 509 trace/global (static data)
 510 ttytype/screen (read-only)
 511 typeahead/screen
 512 unctrl/screen
 513 unget_wch/screen (input operation)
 514 ungetch/screen (input operation)
 515 ungetmouse/screen (input operation)
 516 untouchwin/window
 517 use_default_colors/screen
 518 use_env/global (static data)
 519 use_extended_names/global (static data)
 520 use_legacy_coding/screen
 521 use_screen/global (locks screen list, screen)
 522 use_window/global (locks window list, window)
 523 vid_attr/screen
 524 vid_puts/screen
 525 vidattr/screen
 526 vidputs/screen
 527 vline/window (\fBstdscr\fP)
 528 vline_set/window (\fBstdscr\fP)
 529 vw_printw/window
 530 vw_scanw/screen
 531 vwprintw/window
 532 vwscanw/screen
 533 wadd_wch/window
 534 wadd_wchnstr/window
 535 wadd_wchstr/window
 536 waddch/window
 537 waddchnstr/window
 538 waddchstr/window
 539 waddnstr/window
 540 waddnwstr/window
 541 waddstr/window
 542 waddwstr/window
 543 wattr_get/window
 544 wattr_off/window
 545 wattr_on/window
 546 wattr_set/window
 547 wattroff/window
 548 wattron/window
 549 wattrset/window
 550 wbkgd/window
 551 wbkgdset/window
 552 wbkgrnd/window
 553 wbkgrndset/window
 554 wborder/window
 555 wborder_set/window
 556 wchgat/window
 557 wclear/window
 558 wclrtobot/window
 559 wclrtoeol/window
 560 wcolor_set/window
 561 wcursyncup/screen (affects window plus parents)
 562 wdelch/window
 563 wdeleteln/window
 564 wecho_wchar/window
 565 wechochar/window
 566 wenclose/window
 567 werase/window
 568 wget_wch/screen (input operation)
 569 wget_wstr/screen (input operation)
 570 wgetbkgrnd/window
 571 wgetch/screen (input operation)
 572 wgetdelay/window
 573 wgetn_wstr/screen (input operation)
 574 wgetnstr/screen (input operation)
 575 wgetparent/window
 576 wgetscrreg/window
 577 wgetstr/screen (input operation)
 578 whline/window
 579 whline_set/window
 580 win_wch/window
 581 win_wchnstr/window
 582 win_wchstr/window
 583 winch/window
 584 winchnstr/window
 585 winchstr/window
 586 winnstr/window
 587 winnwstr/window
 588 wins_nwstr/window
 589 wins_wch/window
 590 wins_wstr/window
 591 winsch/window
 592 winsdelln/window
 593 winsertln/window
 594 winsnstr/window
 595 winsstr/window
 596 winstr/window
 597 winwstr/window
 598 wmouse_trafo/window
 599 wmove/window
 600 wnoutrefresh/screen
 601 wprintw/window
 602 wredrawln/window
 603 wrefresh/screen
 604 wresize/window (locks window list)
 605 wscanw/screen
 606 wscrl/window
 607 wsetscrreg/window
 608 wstandend/window
 609 wstandout/window
 610 wsyncdown/screen (affects window plus parents)
 611 wsyncup/screen (affects window plus parents)
 612 wtimeout/window
 613 wtouchln/window
 614 wunctrl/global (static data)
 615 wvline/window
 616 wvline_set/window
 617 .TE
 618 .\" ***************************************************************************
 619 .SH RETURN VALUE
 620 \fB\%get_escdelay\fP returns the value of \fB\%ESCDELAY\fP.
 621 \fB\%set_escdelay\fP and \fB\%set_tabsize\fP return \fBERR\fP upon
 622 failure and \fBOK\fP upon successful completion.
 623 \fB\%use_screen\fP and \fB\%use_window\fP return the \fIint\fP returned
 624 by the user-supplied function they are called with.
 625 .SH NOTES
 626 \fIncurses\fP provides both a C function and a preprocessor macro for
 627 each function documented in this page.
 628 .SH PORTABILITY
 629 These routines are specific to \fIncurses\fP.
 630 They were not supported on Version 7, BSD or System V implementations.
 631 It is recommended that any code depending on \fIncurses\fP extensions
 632 be conditioned using \fB\%NCURSES_VERSION\fP.
 633 .SH SEE ALSO
 634 \fB\%curses\fP(3X),
 635 \fB\%curs_opaque\fP(3X),
 636 \fB\%curs_variables\fP(3X)