man/curs_threads.3x

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  31 .\" $Id: curs_threads.3x,v 1.46 2023/10/01 09:45:30 tom Exp $
  32 .TH curs_threads 3X 2023-10-01 "ncurses 6.4" "Library calls"
  33 .ie \n(.g .ds `` \(lq
  34 .el       .ds `` ``
  35 .ie \n(.g .ds '' \(rq
  36 .el       .ds '' ''
  37 .de bP
  38 .ie n  .IP \(bu 4
  39 .el    .IP \(bu 2
  40 ..
  41 .SH NAME
  42 \fI\%NCURSES_WINDOW_CB\fP,
  43 \fI\%NCURSES_SCREEN_CB\fP,
  44 \fB\%get_escdelay\fP,
  45 \fB\%set_escdelay\fP,
  46 \fB\%set_tabsize\fP,
  47 \fB\%use_screen\fP,
  48 \fB\%use_window\fP \-
  49 \fIcurses\fR support for multi-threaded applications
  50 .SH SYNOPSIS
  51 .nf
  52 \fB#include <curses.h>\fP
  53 .PP
  54 \fI/* data types */\fP
  55 \fBtypedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *);\fP
  56 \fBtypedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *);\fP
  57 .PP
  58 \fBint get_escdelay(void);\fP
  59 \fBint set_escdelay(int \fIms\fB);\fR
  60 \fBint set_tabsize(int \fIcols\fB);\fR
  61 .PP
  62 \fBint use_screen(SCREEN *\fIscr\fB, NCURSES_SCREEN_CB \fIfunc\fB, void *\fIdata\fB);\fR
  63 \fBint use_window(WINDOW *\fIwin\fB, NCURSES_WINDOW_CB \fIfunc\fB, void *\fIdata\fB);\fR
  64 .fi
  65 .SH DESCRIPTION
  66 The \fIncurses\fP library can be configured to support multi-threaded
  67 applications in a rudimentary way.
  68 Such configuration produces a different set of libraries,
  69 named \fIlibncursest\fP,
  70 for example,
  71 since doing so alters \fIncurses\fP's application binary interface
  72 (ABI).
  73 .PP
  74 Instead of modifying the programming interface (API) to make
  75 \fIncurses\fP functions expect an additional argument specifying a
  76 thread,
  77 the library adds a few functions,
  78 usable in any configuration,
  79 that hide the \fImutexes\fP
  80 (mutual exclusion locks)
  81 needed to prevent concurrent access to variables shared by multiple
  82 threads of execution.
  83 .PP
  84 \fIncurses\fP threading support requires the use of functions to access
  85 members of the \fI\%WINDOW\fP structure (see \fBcurs_opaque\fP(3X)).
  86 It further makes functions of the common global variables
  87 \fB\%COLORS\fP,
  88 \fB\%COLOR_PAIRS\fP,
  89 \fB\%COLS\fP,
  90 \fB\%ESCDELAY\fP,
  91 \fB\%LINES\fP,
  92 \fB\%TABSIZE\fP,
  93 \fB\%curscr\fP,
  94 \fB\%newscr\fP,
  95 and
  96 \fB\%ttytype\fP,
  97 maintaining them as as read-only values in the \fISCREEN\fP structure.
  98 .PP
  99 Even this is not enough to make an application using \fIcurses\fP
 100 thread-safe.
 101 We would expect a multi-threaded application to have threads updating
 102 separate windows (on the same device),
 103 and separate screens (on different devices).
 104 Further,
 105 applications expect a few of the global variables to be writable.
 106 The functions described here address these special situations.
 107 .PP
 108 The \fB\%ESCDELAY\fP and \fB\%TABSIZE\fP global variables are modified
 109 by some applications.
 110 To modify them in any configuration,
 111 use the \fB\%set_escdelay\fP or \fB\%set_tabsize\fP functions.
 112 Other global variables are not modifiable.
 113 \fBget_escdelay\fP retrieves \fB\%ESCDELAY\fP's value.
 114 .PP
 115 The \fBuse_window\fP and \fBuse_screen\fP functions provide
 116 coarse-grained mutexes for their respective \fI\%WINDOW\fP and
 117 \fI\%SCREEN\fP parameters;
 118 they call a user-supplied function,
 119 pass it a \fIdata\fP parameter,
 120 and return the value from the user-supplied function to the application.
 121 .\" ***************************************************************************
 122 .SS Usage
 123 All \fIncurses\fP library functions assume that the locale is not
 124 altered during operation.
 125 In addition,
 126 they use data that is maintained within a hierarchy of scopes.
 127 .bP
 128 global data used in the low-level \fIterminfo\fP or \fItermcap\fP
 129 interfaces
 130 .bP
 131 terminal data associated with a call to \fBset_curterm\fP(3X)
 132 .IP
 133 Terminal data are initialized when screens are created.
 134 .bP
 135 screen data associated with a call to \fBnewterm\fP(3X) or
 136 \fBinitscr\fP(3X)
 137 .bP
 138 window data associated with a call to \fBnewwin\fP(3X) or
 139 \fBsubwin\fP(3X)
 140 .IP
 141 Windows are associated with screens.
 142 Pads are not necessarily associated with any particular screen.
 143 .IP
 144 Most \fIcurses\fP applications operate on one or more windows within a
 145 single screen.
 146 .bP
 147 reentrant data associated with \*(``pure\*('' functions that alter no
 148 shared variables
 149 .PP
 150 The following table lists the scope of each symbol in the \fIncurses\fP
 151 library when configured to support multi-threaded applications.
 152 .PP
 153 .TS
 154 center tab(/);
 155 lb lb
 156 lb l .
 157 Symbol/Scope
 158 =
 159 BC/global
 160 COLORS/screen (read-only)
 161 COLOR_PAIR/reentrant
 162 COLOR_PAIRS/screen (read-only)
 163 COLS/screen (read-only)
 164 ESCDELAY/screen (read-only; see \fBset_escdelay\fP)
 165 LINES/screen (read-only)
 166 PAIR_NUMBER/reentrant
 167 PC/global
 168 SP/global
 169 TABSIZE/screen (read-only; see \fBset_tabsize\fP)
 170 UP/global
 171 acs_map/screen (read-only)
 172 add_wch/window (\fBstdscr\fP)
 173 add_wchnstr/window (\fBstdscr\fP)
 174 add_wchstr/window (\fBstdscr\fP)
 175 addch/window (\fBstdscr\fP)
 176 addchnstr/window (\fBstdscr\fP)
 177 addchstr/window (\fBstdscr\fP)
 178 addnstr/window (\fBstdscr\fP)
 179 addnwstr/window (\fBstdscr\fP)
 180 addstr/window (\fBstdscr\fP)
 181 addwstr/window (\fBstdscr\fP)
 182 assume_default_colors/screen
 183 attr_get/window (\fBstdscr\fP)
 184 attr_off/window (\fBstdscr\fP)
 185 attr_on/window (\fBstdscr\fP)
 186 attr_set/window (\fBstdscr\fP)
 187 attroff/window (\fBstdscr\fP)
 188 attron/window (\fBstdscr\fP)
 189 attrset/window (\fBstdscr\fP)
 190 baudrate/screen
 191 beep/screen
 192 bkgd/window (\fBstdscr\fP)
 193 bkgdset/window (\fBstdscr\fP)
 194 bkgrnd/window (\fBstdscr\fP)
 195 bkgrndset/window (\fBstdscr\fP)
 196 boolcodes/global (read-only)
 197 boolfnames/global (read-only)
 198 boolnames/global (read-only)
 199 border/window (\fBstdscr\fP)
 200 border_set/window (\fBstdscr\fP)
 201 box/window (\fBstdscr\fP)
 202 box_set/window (\fBstdscr\fP)
 203 can_change_color/terminal
 204 cbreak/screen
 205 chgat/window (\fBstdscr\fP)
 206 clear/window (\fBstdscr\fP)
 207 clearok/window
 208 clrtobot/window (\fBstdscr\fP)
 209 clrtoeol/window (\fBstdscr\fP)
 210 color_content/screen
 211 color_set/window (\fBstdscr\fP)
 212 copywin/window (locks source, target)
 213 cur_term/terminal
 214 curs_set/screen
 215 curscr/screen (read-only)
 216 curses_version/global (read-only)
 217 def_prog_mode/terminal
 218 def_shell_mode/terminal
 219 define_key/screen
 220 del_curterm/screen
 221 delay_output/screen
 222 delch/window (\fBstdscr\fP)
 223 deleteln/window (\fBstdscr\fP)
 224 delscreen/global (locks screen list, screen)
 225 delwin/global (locks window list)
 226 derwin/screen
 227 doupdate/screen
 228 dupwin/screen (locks window)
 229 echo/screen
 230 echo_wchar/window (\fBstdscr\fP)
 231 echochar/window (\fBstdscr\fP)
 232 endwin/screen
 233 erase/window (\fBstdscr\fP)
 234 erasechar/window (\fBstdscr\fP)
 235 erasewchar/window (\fBstdscr\fP)
 236 filter/global
 237 flash/terminal
 238 flushinp/screen
 239 get_wch/screen (input operation)
 240 get_wstr/screen (input operation)
 241 getattrs/window
 242 getbegx/window
 243 getbegy/window
 244 getbkgd/window
 245 getbkgrnd/window
 246 getcchar/reentrant
 247 getch/screen (input operation)
 248 getcurx/window
 249 getcury/window
 250 getmaxx/window
 251 getmaxy/window
 252 getmouse/screen (input operation)
 253 getn_wstr/screen (input operation)
 254 getnstr/screen (input operation)
 255 getparx/window
 256 getpary/window
 257 getstr/screen (input operation)
 258 getwin/screen (input operation)
 259 halfdelay/screen
 260 has_colors/terminal
 261 has_ic/terminal
 262 has_il/terminal
 263 has_key/screen
 264 hline/window (\fBstdscr\fP)
 265 hline_set/window (\fBstdscr\fP)
 266 idcok/window
 267 idlok/window
 268 immedok/window
 269 in_wch/window (\fBstdscr\fP)
 270 in_wchnstr/window (\fBstdscr\fP)
 271 in_wchstr/window (\fBstdscr\fP)
 272 inch/window (\fBstdscr\fP)
 273 inchnstr/window (\fBstdscr\fP)
 274 inchstr/window (\fBstdscr\fP)
 275 init_color/screen
 276 init_pair/screen
 277 initscr/global (locks screen list)
 278 innstr/window (\fBstdscr\fP)
 279 innwstr/window (\fBstdscr\fP)
 280 ins_nwstr/window (\fBstdscr\fP)
 281 ins_wch/window (\fBstdscr\fP)
 282 ins_wstr/window (\fBstdscr\fP)
 283 insch/window (\fBstdscr\fP)
 284 insdelln/window (\fBstdscr\fP)
 285 insertln/window (\fBstdscr\fP)
 286 insnstr/window (\fBstdscr\fP)
 287 insstr/window (\fBstdscr\fP)
 288 instr/window (\fBstdscr\fP)
 289 intrflush/terminal
 290 inwstr/window (\fBstdscr\fP)
 291 is_cleared/window
 292 is_idcok/window
 293 is_idlok/window
 294 is_immedok/window
 295 is_keypad/window
 296 is_leaveok/window
 297 is_linetouched/window
 298 is_nodelay/window
 299 is_notimeout/window
 300 is_scrollok/window
 301 is_syncok/window
 302 is_term_resized/terminal
 303 is_wintouched/window
 304 isendwin/screen
 305 key_defined/screen
 306 key_name/global (static data)
 307 keybound/screen
 308 keyname/global (static data)
 309 keyok/screen
 310 keypad/window
 311 killchar/terminal
 312 killwchar/terminal
 313 leaveok/window
 314 longname/screen
 315 mcprint/terminal
 316 meta/screen
 317 mouse_trafo/window (\fBstdscr\fP)
 318 mouseinterval/screen
 319 mousemask/screen
 320 move/window (\fBstdscr\fP)
 321 mvadd_wch/window (\fBstdscr\fP)
 322 mvadd_wchnstr/window (\fBstdscr\fP)
 323 mvadd_wchstr/window (\fBstdscr\fP)
 324 mvaddch/window (\fBstdscr\fP)
 325 mvaddchnstr/window (\fBstdscr\fP)
 326 mvaddchstr/window (\fBstdscr\fP)
 327 mvaddnstr/window (\fBstdscr\fP)
 328 mvaddnwstr/window (\fBstdscr\fP)
 329 mvaddstr/window (\fBstdscr\fP)
 330 mvaddwstr/window (\fBstdscr\fP)
 331 mvchgat/window (\fBstdscr\fP)
 332 mvcur/screen
 333 mvdelch/window (\fBstdscr\fP)
 334 mvderwin/window (\fBstdscr\fP)
 335 mvget_wch/screen (input operation)
 336 mvget_wstr/screen (input operation)
 337 mvgetch/screen (input operation)
 338 mvgetn_wstr/screen (input operation)
 339 mvgetnstr/screen (input operation)
 340 mvgetstr/screen (input operation)
 341 mvhline/window (\fBstdscr\fP)
 342 mvhline_set/window (\fBstdscr\fP)
 343 mvin_wch/window (\fBstdscr\fP)
 344 mvin_wchnstr/window (\fBstdscr\fP)
 345 mvin_wchstr/window (\fBstdscr\fP)
 346 mvinch/window (\fBstdscr\fP)
 347 mvinchnstr/window (\fBstdscr\fP)
 348 mvinchstr/window (\fBstdscr\fP)
 349 mvinnstr/window (\fBstdscr\fP)
 350 mvinnwstr/window (\fBstdscr\fP)
 351 mvins_nwstr/window (\fBstdscr\fP)
 352 mvins_wch/window (\fBstdscr\fP)
 353 mvins_wstr/window (\fBstdscr\fP)
 354 mvinsch/window (\fBstdscr\fP)
 355 mvinsnstr/window (\fBstdscr\fP)
 356 mvinsstr/window (\fBstdscr\fP)
 357 mvinstr/window (\fBstdscr\fP)
 358 mvinwstr/window (\fBstdscr\fP)
 359 mvprintw/window (\fBstdscr\fP)
 360 mvscanw/screen
 361 mvvline/window (\fBstdscr\fP)
 362 mvvline_set/window (\fBstdscr\fP)
 363 mvwadd_wch/window
 364 mvwadd_wchnstr/window
 365 mvwadd_wchstr/window
 366 mvwaddch/window
 367 mvwaddchnstr/window
 368 mvwaddchstr/window
 369 mvwaddnstr/window
 370 mvwaddnwstr/window
 371 mvwaddstr/window
 372 mvwaddwstr/window
 373 mvwchgat/window
 374 mvwdelch/window
 375 mvwget_wch/screen (input operation)
 376 mvwget_wstr/screen (input operation)
 377 mvwgetch/screen (input operation)
 378 mvwgetn_wstr/screen (input operation)
 379 mvwgetnstr/screen (input operation)
 380 mvwgetstr/screen (input operation)
 381 mvwhline/window
 382 mvwhline_set/window
 383 mvwin/window
 384 mvwin_wch/window
 385 mvwin_wchnstr/window
 386 mvwin_wchstr/window
 387 mvwinch/window
 388 mvwinchnstr/window
 389 mvwinchstr/window
 390 mvwinnstr/window
 391 mvwinnwstr/window
 392 mvwins_nwstr/window
 393 mvwins_wch/window
 394 mvwins_wstr/window
 395 mvwinsch/window
 396 mvwinsnstr/window
 397 mvwinsstr/window
 398 mvwinstr/window
 399 mvwinwstr/window
 400 mvwprintw/window
 401 mvwscanw/screen
 402 mvwvline/window
 403 mvwvline_set/window
 404 napms/reentrant
 405 newpad/global (locks window list)
 406 newscr/screen (read-only)
 407 newterm/global (locks screen list)
 408 newwin/global (locks window list)
 409 nl/screen
 410 nocbreak/screen
 411 nodelay/window
 412 noecho/screen
 413 nofilter/global
 414 nonl/screen
 415 noqiflush/terminal
 416 noraw/screen
 417 notimeout/window
 418 numcodes/global (read-only)
 419 numfnames/global (read-only)
 420 numnames/global (read-only)
 421 ospeed/global
 422 overlay/window (locks source, target)
 423 overwrite/window (locks source, target)
 424 pair_content/screen
 425 pecho_wchar/screen
 426 pechochar/screen
 427 pnoutrefresh/screen
 428 prefresh/screen
 429 printw/window
 430 putp/global
 431 putwin/window
 432 qiflush/terminal
 433 raw/screen
 434 redrawwin/window
 435 refresh/screen
 436 reset_prog_mode/screen
 437 reset_shell_mode/screen
 438 resetty/terminal
 439 resize_term/screen (locks window list)
 440 resizeterm/screen
 441 restartterm/screen
 442 ripoffline/global (static data)
 443 savetty/terminal
 444 scanw/screen
 445 scr_dump/screen
 446 scr_init/screen
 447 scr_restore/screen
 448 scr_set/screen
 449 scrl/window (\fBstdscr\fP)
 450 scroll/window
 451 scrollok/window
 452 set_curterm/screen
 453 set_escdelay/screen
 454 set_tabsize/screen
 455 set_term/global (locks screen list, screen)
 456 setcchar/reentrant
 457 setscrreg/window (\fBstdscr\fP)
 458 setupterm/global
 459 slk_attr/screen
 460 slk_attr_off/screen
 461 slk_attr_on/screen
 462 slk_attr_set/screen
 463 slk_attroff/screen
 464 slk_attron/screen
 465 slk_attrset/screen
 466 slk_clear/screen
 467 slk_color/screen
 468 slk_init/screen
 469 slk_label/screen
 470 slk_noutrefresh/screen
 471 slk_refresh/screen
 472 slk_restore/screen
 473 slk_set/screen
 474 slk_touch/screen
 475 slk_wset/screen
 476 standend/window
 477 standout/window
 478 start_color/screen
 479 \fBstdscr\fP/screen (read-only)
 480 strcodes/global (read-only)
 481 strfnames/global (read-only)
 482 strnames/global (read-only)
 483 subpad/window
 484 subwin/window
 485 syncok/window
 486 term_attrs/screen
 487 termattrs/screen
 488 termname/terminal
 489 tgetent/global
 490 tgetflag/global
 491 tgetnum/global
 492 tgetstr/global
 493 tgoto/global
 494 tigetflag/terminal
 495 tigetnum/terminal
 496 tigetstr/terminal
 497 timeout/window (\fBstdscr\fP)
 498 touchline/window
 499 touchwin/window
 500 tparm/global (static data)
 501 tputs/screen
 502 trace/global (static data)
 503 ttytype/screen (read-only)
 504 typeahead/screen
 505 unctrl/screen
 506 unget_wch/screen (input operation)
 507 ungetch/screen (input operation)
 508 ungetmouse/screen (input operation)
 509 untouchwin/window
 510 use_default_colors/screen
 511 use_env/global (static data)
 512 use_extended_names/global (static data)
 513 use_legacy_coding/screen
 514 use_screen/global (locks screen list, screen)
 515 use_window/global (locks window list, window)
 516 vid_attr/screen
 517 vid_puts/screen
 518 vidattr/screen
 519 vidputs/screen
 520 vline/window (\fBstdscr\fP)
 521 vline_set/window (\fBstdscr\fP)
 522 vw_printw/window
 523 vw_scanw/screen
 524 vwprintw/window
 525 vwscanw/screen
 526 wadd_wch/window
 527 wadd_wchnstr/window
 528 wadd_wchstr/window
 529 waddch/window
 530 waddchnstr/window
 531 waddchstr/window
 532 waddnstr/window
 533 waddnwstr/window
 534 waddstr/window
 535 waddwstr/window
 536 wattr_get/window
 537 wattr_off/window
 538 wattr_on/window
 539 wattr_set/window
 540 wattroff/window
 541 wattron/window
 542 wattrset/window
 543 wbkgd/window
 544 wbkgdset/window
 545 wbkgrnd/window
 546 wbkgrndset/window
 547 wborder/window
 548 wborder_set/window
 549 wchgat/window
 550 wclear/window
 551 wclrtobot/window
 552 wclrtoeol/window
 553 wcolor_set/window
 554 wcursyncup/screen (affects window plus parents)
 555 wdelch/window
 556 wdeleteln/window
 557 wecho_wchar/window
 558 wechochar/window
 559 wenclose/window
 560 werase/window
 561 wget_wch/screen (input operation)
 562 wget_wstr/screen (input operation)
 563 wgetbkgrnd/window
 564 wgetch/screen (input operation)
 565 wgetdelay/window
 566 wgetn_wstr/screen (input operation)
 567 wgetnstr/screen (input operation)
 568 wgetparent/window
 569 wgetscrreg/window
 570 wgetstr/screen (input operation)
 571 whline/window
 572 whline_set/window
 573 win_wch/window
 574 win_wchnstr/window
 575 win_wchstr/window
 576 winch/window
 577 winchnstr/window
 578 winchstr/window
 579 winnstr/window
 580 winnwstr/window
 581 wins_nwstr/window
 582 wins_wch/window
 583 wins_wstr/window
 584 winsch/window
 585 winsdelln/window
 586 winsertln/window
 587 winsnstr/window
 588 winsstr/window
 589 winstr/window
 590 winwstr/window
 591 wmouse_trafo/window
 592 wmove/window
 593 wnoutrefresh/screen
 594 wprintw/window
 595 wredrawln/window
 596 wrefresh/screen
 597 wresize/window (locks window list)
 598 wscanw/screen
 599 wscrl/window
 600 wsetscrreg/window
 601 wstandend/window
 602 wstandout/window
 603 wsyncdown/screen (affects window plus parents)
 604 wsyncup/screen (affects window plus parents)
 605 wtimeout/window
 606 wtouchln/window
 607 wunctrl/global (static data)
 608 wvline/window
 609 wvline_set/window
 610 .TE
 611 .\" ***************************************************************************
 612 .SH RETURN VALUE
 613 \fB\%get_escdelay\fP returns the value of \fB\%ESCDELAY\fP.
 614 \fB\%set_escdelay\fP and \fB\%set_tabsize\fP return \fBERR\fP upon
 615 failure and \fBOK\fP upon successful completion.
 616 \fB\%use_screen\fP and \fB\%use_window\fP return the \fIint\fP returned
 617 by the user-supplied function they are called with.
 618 .SH NOTES
 619 \fIncurses\fP provides both a C function and a preprocessor macro for
 620 each function documented in this page.
 621 .SH PORTABILITY
 622 These routines are specific to \fIncurses\fP.
 623 They were not supported on Version 7, BSD or System V implementations.
 624 It is recommended that any code depending on \fIncurses\fP extensions
 625 be conditioned using \fB\%NCURSES_VERSION\fP.
 626 .SH SEE ALSO
 627 \fB\%curses\fP(3X),
 628 \fB\%curs_opaque\fP(3X),
 629 \fB\%curs_variables\fP(3X)