perlvars.h revision 1.7
1/* perlvars.h 2 * 3 * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 4 * by Larry Wall and others 5 * 6 * You may distribute under the terms of either the GNU General Public 7 * License or the Artistic License, as specified in the README file. 8 * 9 */ 10 11/* 12=head1 Global Variables 13These variables are global to an entire process. They are shared between 14all interpreters and all threads in a process. Any variables not documented 15here may be changed or removed without notice, so don't use them! 16If you feel you really do need to use an unlisted variable, first send email to 17L<perl5-porters@perl.org|mailto:perl5-porters@perl.org>. It may be that 18someone there will point out a way to accomplish what you need without using an 19internal variable. But if not, you should get a go-ahead to document and then 20use the variable. 21 22=cut 23*/ 24 25/* Don't forget to re-run regen/embed.pl to propagate changes! */ 26 27/* This file describes the "global" variables used by perl 28 * This used to be in perl.h directly but we want to abstract out into 29 * distinct files which are per-thread, per-interpreter or really global, 30 * and how they're initialized. 31 * 32 * The 'G' prefix is only needed for vars that need appropriate #defines 33 * generated in embed*.h. Such symbols are also used to generate 34 * the appropriate export list for win32. */ 35 36/* global state */ 37#if defined(USE_ITHREADS) 38PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */ 39#endif 40PERLVARI(G, curinterp, PerlInterpreter *, NULL) 41 /* currently running interpreter 42 * (initial parent interpreter under 43 * useithreads) */ 44#if defined(USE_ITHREADS) 45PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */ 46#endif 47 48/* XXX does anyone even use this? */ 49PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */ 50 51#ifndef PERL_USE_SAFE_PUTENV 52PERLVARI(G, use_safe_putenv, bool, TRUE) 53#endif 54 55#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS) 56PERLVARI(G, sig_handlers_initted, int, 0) 57#endif 58#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS 59PERLVARA(G, sig_ignoring, SIG_SIZE, int) 60 /* which signals we are ignoring */ 61#endif 62#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS 63PERLVARA(G, sig_defaulting, SIG_SIZE, int) 64#endif 65 66/* XXX signals are process-wide anyway, so we 67 * ignore the implications of this for threading */ 68#ifndef HAS_SIGACTION 69PERLVARI(G, sig_trapped, int, 0) 70#endif 71 72#ifndef PERL_MICRO 73/* If Perl has to ignore SIGPFE, this is its saved state. 74 * See perl.h macros PERL_FPU_INIT and PERL_FPU_{PRE,POST}_EXEC. */ 75PERLVAR(G, sigfpe_saved, Sighandler_t) 76PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler) 77 /* Pointer to C-level sighandler */ 78#endif 79 80/* This is constant on most architectures, a global on OS/2 */ 81#ifdef OS2 82PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */ 83#endif 84 85#ifdef USE_PERLIO 86 87# if defined(USE_ITHREADS) 88PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */ 89# endif 90 91PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */ 92PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */ 93PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */ 94#endif 95 96#ifdef HAS_MMAP 97PERLVARI(G, mmap_page_size, IV, 0) 98#endif 99 100#if defined(USE_ITHREADS) 101PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */ 102# if ! defined(USE_THREAD_SAFE_LOCALE) || defined(TS_W32_BROKEN_LOCALECONV) 103PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */ 104# endif 105# ifndef USE_THREAD_SAFE_LOCALE 106PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */ 107# endif 108#endif 109 110#ifdef USE_POSIX_2008_LOCALE 111PERLVAR(G, C_locale_obj, locale_t) 112#endif 113 114PERLVARI(G, watch_pvx, char *, NULL) 115 116/* 117=for apidoc AmU|Perl_check_t *|PL_check 118 119Array, indexed by opcode, of functions that will be called for the "check" 120phase of optree building during compilation of Perl code. For most (but 121not all) types of op, once the op has been initially built and populated 122with child ops it will be filtered through the check function referenced 123by the appropriate element of this array. The new op is passed in as the 124sole argument to the check function, and the check function returns the 125completed op. The check function may (as the name suggests) check the op 126for validity and signal errors. It may also initialise or modify parts of 127the ops, or perform more radical surgery such as adding or removing child 128ops, or even throw the op away and return a different op in its place. 129 130This array of function pointers is a convenient place to hook into the 131compilation process. An XS module can put its own custom check function 132in place of any of the standard ones, to influence the compilation of a 133particular type of op. However, a custom check function must never fully 134replace a standard check function (or even a custom check function from 135another module). A module modifying checking must instead B<wrap> the 136preexisting check function. A custom check function must be selective 137about when to apply its custom behaviour. In the usual case where 138it decides not to do anything special with an op, it must chain the 139preexisting op function. Check functions are thus linked in a chain, 140with the core's base checker at the end. 141 142For thread safety, modules should not write directly to this array. 143Instead, use the function L</wrap_op_checker>. 144 145=cut 146*/ 147 148#if defined(USE_ITHREADS) 149PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */ 150#endif 151#ifdef PERL_GLOBAL_STRUCT 152PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */ 153PERLVAR(G, check, Perl_check_t *) /* or opcode.h */ 154PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */ 155#endif 156 157#ifdef PERL_NEED_APPCTX 158PERLVAR(G, appctx, void*) /* the application context */ 159#endif 160 161#if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE) 162PERLVAR(G, timesbase, struct tms) 163#endif 164 165/* allocate a unique index to every module that calls MY_CXT_INIT */ 166 167#ifdef PERL_IMPLICIT_CONTEXT 168# ifdef USE_ITHREADS 169PERLVAR(G, my_ctx_mutex, perl_mutex) 170# endif 171PERLVARI(G, my_cxt_index, int, 0) 172#endif 173 174/* this is currently set without MUTEX protection, so keep it a type which 175 * can be set atomically (ie not a bit field) */ 176PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */ 177 178/* 179=for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin 180 181Function pointer, pointing at a function used to handle extended keywords. 182The function should be declared as 183 184 int keyword_plugin_function(pTHX_ 185 char *keyword_ptr, STRLEN keyword_len, 186 OP **op_ptr) 187 188The function is called from the tokeniser, whenever a possible keyword 189is seen. C<keyword_ptr> points at the word in the parser's input 190buffer, and C<keyword_len> gives its length; it is not null-terminated. 191The function is expected to examine the word, and possibly other state 192such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it 193as an extended keyword. If it does not, the function should return 194C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue. 195 196If the function wants to handle the keyword, it first must 197parse anything following the keyword that is part of the syntax 198introduced by the keyword. See L</Lexer interface> for details. 199 200When a keyword is being handled, the plugin function must build 201a tree of C<OP> structures, representing the code that was parsed. 202The root of the tree must be stored in C<*op_ptr>. The function then 203returns a constant indicating the syntactic role of the construct that 204it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or 205C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement 206construct cannot be used inside an expression (except via C<do BLOCK> 207and similar), and an expression is not a complete statement (it requires 208at least a terminating semicolon). 209 210When a keyword is handled, the plugin function may also have 211(compile-time) side effects. It may modify C<%^H>, define functions, and 212so on. Typically, if side effects are the main purpose of a handler, 213it does not wish to generate any ops to be included in the normal 214compilation. In this case it is still required to supply an op tree, 215but it suffices to generate a single null op. 216 217That's how the C<*PL_keyword_plugin> function needs to behave overall. 218Conventionally, however, one does not completely replace the existing 219handler function. Instead, take a copy of C<PL_keyword_plugin> before 220assigning your own function pointer to it. Your handler function should 221look for keywords that it is interested in and handle those. Where it 222is not interested, it should call the saved plugin function, passing on 223the arguments it received. Thus C<PL_keyword_plugin> actually points 224at a chain of handler functions, all of which have an opportunity to 225handle keywords, and only the last function in the chain (built into 226the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>. 227 228For thread safety, modules should not set this variable directly. 229Instead, use the function L</wrap_keyword_plugin>. 230 231=cut 232*/ 233 234#if defined(USE_ITHREADS) 235PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */ 236#endif 237PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard) 238 239PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */ 240PERLVARI(G, op_seq, UV, 0) /* dump.c */ 241 242#ifdef USE_ITHREADS 243PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */ 244#endif 245 246/* Restricted hashes placeholder value. 247 In theory, the contents are never used, only the address. 248 In practice, &PL_sv_placeholder is returned by some APIs, and the calling 249 code is checking SvOK(). */ 250 251PERLVAR(G, sv_placeholder, SV) 252 253#if defined(MYMALLOC) && defined(USE_ITHREADS) 254PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */ 255#endif 256 257PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */ 258PERLVARA(G, hash_seed_w, PERL_HASH_SEED_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 259#if defined(PERL_HASH_STATE_BYTES) 260PERLVARA(G, hash_state_w, PERL_HASH_STATE_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 261#endif 262#if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE) 263PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */ 264#endif 265 266/* The path separator can vary depending on whether we're running under DCL or 267 * a Unix shell. 268 */ 269#ifdef __VMS 270PERLVAR(G, perllib_sep, char) 271#endif 272 273PERLVAR(G, AboveLatin1, SV *) 274PERLVAR(G, Assigned_invlist, SV *) 275PERLVAR(G, GCB_invlist, SV *) 276PERLVAR(G, HasMultiCharFold, SV *) 277PERLVAR(G, InMultiCharFold, SV *) 278PERLVAR(G, Latin1, SV *) 279PERLVAR(G, LB_invlist, SV *) 280PERLVAR(G, NonFinalFold, SV *) 281PERLVAR(G, SB_invlist, SV *) 282PERLVAR(G, SCX_invlist, SV *) 283PERLVAR(G, UpperLatin1, SV *) /* Code points 128 - 255 */ 284 285/* List of characters that participate in any fold defined by Unicode */ 286PERLVAR(G, in_some_fold, SV *) 287 288PERLVAR(G, utf8_idcont, SV *) 289PERLVAR(G, utf8_idstart, SV *) 290PERLVAR(G, utf8_perl_idcont, SV *) 291PERLVAR(G, utf8_perl_idstart, SV *) 292PERLVAR(G, utf8_xidcont, SV *) 293PERLVAR(G, utf8_xidstart, SV *) 294PERLVAR(G, WB_invlist, SV *) 295PERLVARA(G, XPosix_ptrs, POSIX_CC_COUNT, SV *) 296PERLVARA(G, Posix_ptrs, POSIX_CC_COUNT, SV *) 297PERLVAR(G, utf8_toupper, SV *) 298PERLVAR(G, utf8_totitle, SV *) 299PERLVAR(G, utf8_tolower, SV *) 300PERLVAR(G, utf8_tofold, SV *) 301PERLVAR(G, utf8_tosimplefold, SV *) 302PERLVAR(G, utf8_charname_begin, SV *) 303PERLVAR(G, utf8_charname_continue, SV *) 304PERLVAR(G, utf8_mark, SV *) 305PERLVARI(G, InBitmap, SV *, NULL) 306PERLVAR(G, CCC_non0_non230, SV *) 307PERLVAR(G, Private_Use, SV *) 308 309/* Definitions of user-defined \p{} properties, as the subs that define them 310 * are only called once */ 311PERLVARI(G, user_def_props, HV *, NULL) 312 313#if defined(USE_ITHREADS) 314PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props 315 was defined in */ 316PERLVAR(G, user_prop_mutex, perl_mutex) /* Mutex for manipulating 317 PL_user_defined_properties */ 318#endif 319 320/* Everything that folds to a given character, for case insensitivity regex 321 * matching */ 322PERLVAR(G, utf8_foldclosures, SV *) 323 324/* these record the best way to to perform certain IO operations while 325 * atomically setting FD_CLOEXEC. On the first call, a probe is done 326 * and the result recorded for use by subsequent calls. 327 * In theory these variables aren't thread-safe, but the worst that can 328 * happen is that two treads will both do an initial probe 329 */ 330PERLVARI(G, strategy_dup, int, 0) /* doio.c */ 331PERLVARI(G, strategy_dup2, int, 0) /* doio.c */ 332PERLVARI(G, strategy_open, int, 0) /* doio.c */ 333PERLVARI(G, strategy_open3, int, 0) /* doio.c */ 334PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */ 335PERLVARI(G, strategy_socket, int, 0) /* doio.c */ 336PERLVARI(G, strategy_accept, int, 0) /* doio.c */ 337PERLVARI(G, strategy_pipe, int, 0) /* doio.c */ 338PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */ 339 340#ifdef PERL_IMPLICIT_CONTEXT 341# ifdef PERL_GLOBAL_STRUCT_PRIVATE 342/* per-module array of pointers to MY_CXT_KEY constants. 343 * It simulates each module having a static my_cxt_index var on builds 344 * which don't allow static vars */ 345PERLVARI(G, my_cxt_keys, const char **, NULL) 346PERLVARI(G, my_cxt_keys_size, int, 0) /* size of PL_my_cxt_keys */ 347# endif 348#endif 349