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 13 These variables are global to an entire process. They are shared between 14 all interpreters and all threads in a process. Any variables not documented 15 here may be changed or removed without notice, so don't use them! 16 If you feel you really do need to use an unlisted variable, first send email to 17 L<perl5-porters@perl.org|mailto:perl5-porters@perl.org>. It may be that 18 someone there will point out a way to accomplish what you need without using an 19 internal variable. But if not, you should get a go-ahead to document and then 20 use 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) 38 PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */ 39 #endif 40 PERLVARI(G, curinterp, PerlInterpreter *, NULL) 41 /* currently running interpreter 42 * (initial parent interpreter under 43 * useithreads) */ 44 #if defined(USE_ITHREADS) 45 PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */ 46 #endif 47 48 /* XXX does anyone even use this? */ 49 PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */ 50 51 #ifndef PERL_USE_SAFE_PUTENV 52 PERLVARI(G, use_safe_putenv, bool, TRUE) 53 #endif 54 55 #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS) 56 PERLVARI(G, sig_handlers_initted, int, 0) 57 #endif 58 #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS 59 PERLVARA(G, sig_ignoring, SIG_SIZE, int) 60 /* which signals we are ignoring */ 61 #endif 62 #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS 63 PERLVARA(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 69 PERLVARI(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. */ 75 PERLVAR(G, sigfpe_saved, Sighandler_t) 76 77 /* these ptrs to functions are to avoid linkage problems; see 78 * perl-5.8.0-2193-g5c1546dc48 79 */ 80 PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler) 81 PERLVARI(G, csighandler1p, Sighandler1_t, Perl_csighandler1) 82 PERLVARI(G, csighandler3p, Sighandler3_t, Perl_csighandler3) 83 #endif 84 85 /* This is constant on most architectures, a global on OS/2 */ 86 #ifdef OS2 87 PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */ 88 #endif 89 90 #ifdef USE_PERLIO 91 92 # if defined(USE_ITHREADS) 93 PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */ 94 # endif 95 96 PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */ 97 PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */ 98 PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */ 99 #endif 100 101 #ifdef HAS_MMAP 102 PERLVARI(G, mmap_page_size, IV, 0) 103 #endif 104 105 #if defined(USE_ITHREADS) 106 PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */ 107 PERLVAR(G, env_mutex, perl_mutex) /* Mutex for accessing ENV */ 108 # if ! defined(USE_THREAD_SAFE_LOCALE) || defined(TS_W32_BROKEN_LOCALECONV) 109 PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */ 110 # endif 111 # ifndef USE_THREAD_SAFE_LOCALE 112 PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */ 113 # endif 114 #endif 115 116 #ifdef USE_POSIX_2008_LOCALE 117 PERLVAR(G, C_locale_obj, locale_t) 118 #endif 119 120 PERLVARI(G, watch_pvx, char *, NULL) 121 122 /* 123 =for apidoc AmnU|Perl_check_t *|PL_check 124 125 Array, indexed by opcode, of functions that will be called for the "check" 126 phase of optree building during compilation of Perl code. For most (but 127 not all) types of op, once the op has been initially built and populated 128 with child ops it will be filtered through the check function referenced 129 by the appropriate element of this array. The new op is passed in as the 130 sole argument to the check function, and the check function returns the 131 completed op. The check function may (as the name suggests) check the op 132 for validity and signal errors. It may also initialise or modify parts of 133 the ops, or perform more radical surgery such as adding or removing child 134 ops, or even throw the op away and return a different op in its place. 135 136 This array of function pointers is a convenient place to hook into the 137 compilation process. An XS module can put its own custom check function 138 in place of any of the standard ones, to influence the compilation of a 139 particular type of op. However, a custom check function must never fully 140 replace a standard check function (or even a custom check function from 141 another module). A module modifying checking must instead B<wrap> the 142 preexisting check function. A custom check function must be selective 143 about when to apply its custom behaviour. In the usual case where 144 it decides not to do anything special with an op, it must chain the 145 preexisting op function. Check functions are thus linked in a chain, 146 with the core's base checker at the end. 147 148 For thread safety, modules should not write directly to this array. 149 Instead, use the function L</wrap_op_checker>. 150 151 =for apidoc Amn|enum perl_phase|PL_phase 152 153 A value that indicates the current Perl interpreter's phase. Possible values 154 include C<PERL_PHASE_CONSTRUCT>, C<PERL_PHASE_START>, C<PERL_PHASE_CHECK>, 155 C<PERL_PHASE_INIT>, C<PERL_PHASE_RUN>, C<PERL_PHASE_END>, and 156 C<PERL_PHASE_DESTRUCT>. 157 158 For example, the following determines whether the interpreter is in 159 global destruction: 160 161 if (PL_phase == PERL_PHASE_DESTRUCT) { 162 // we are in global destruction 163 } 164 165 C<PL_phase> was introduced in Perl 5.14; in prior perls you can use 166 C<PL_dirty> (boolean) to determine whether the interpreter is in global 167 destruction. (Use of C<PL_dirty> is discouraged since 5.14.) 168 169 =cut 170 */ 171 172 #if defined(USE_ITHREADS) 173 PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */ 174 #endif 175 #ifdef PERL_GLOBAL_STRUCT 176 PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */ 177 PERLVAR(G, check, Perl_check_t *) /* or opcode.h */ 178 PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */ 179 #endif 180 181 #ifdef PERL_NEED_APPCTX 182 PERLVAR(G, appctx, void*) /* the application context */ 183 #endif 184 185 #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE) 186 PERLVAR(G, timesbase, struct tms) 187 #endif 188 189 /* allocate a unique index to every module that calls MY_CXT_INIT */ 190 191 #ifdef PERL_IMPLICIT_CONTEXT 192 # ifdef USE_ITHREADS 193 PERLVAR(G, my_ctx_mutex, perl_mutex) 194 # endif 195 PERLVARI(G, my_cxt_index, int, 0) 196 #endif 197 198 /* this is currently set without MUTEX protection, so keep it a type which 199 * can be set atomically (ie not a bit field) */ 200 PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */ 201 202 /* 203 =for apidoc AmnUx|Perl_keyword_plugin_t|PL_keyword_plugin 204 205 Function pointer, pointing at a function used to handle extended keywords. 206 The function should be declared as 207 208 int keyword_plugin_function(pTHX_ 209 char *keyword_ptr, STRLEN keyword_len, 210 OP **op_ptr) 211 212 The function is called from the tokeniser, whenever a possible keyword 213 is seen. C<keyword_ptr> points at the word in the parser's input 214 buffer, and C<keyword_len> gives its length; it is not null-terminated. 215 The function is expected to examine the word, and possibly other state 216 such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it 217 as an extended keyword. If it does not, the function should return 218 C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue. 219 220 If the function wants to handle the keyword, it first must 221 parse anything following the keyword that is part of the syntax 222 introduced by the keyword. See L</Lexer interface> for details. 223 224 When a keyword is being handled, the plugin function must build 225 a tree of C<OP> structures, representing the code that was parsed. 226 The root of the tree must be stored in C<*op_ptr>. The function then 227 returns a constant indicating the syntactic role of the construct that 228 it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or 229 C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement 230 construct cannot be used inside an expression (except via C<do BLOCK> 231 and similar), and an expression is not a complete statement (it requires 232 at least a terminating semicolon). 233 234 When a keyword is handled, the plugin function may also have 235 (compile-time) side effects. It may modify C<%^H>, define functions, and 236 so on. Typically, if side effects are the main purpose of a handler, 237 it does not wish to generate any ops to be included in the normal 238 compilation. In this case it is still required to supply an op tree, 239 but it suffices to generate a single null op. 240 241 That's how the C<*PL_keyword_plugin> function needs to behave overall. 242 Conventionally, however, one does not completely replace the existing 243 handler function. Instead, take a copy of C<PL_keyword_plugin> before 244 assigning your own function pointer to it. Your handler function should 245 look for keywords that it is interested in and handle those. Where it 246 is not interested, it should call the saved plugin function, passing on 247 the arguments it received. Thus C<PL_keyword_plugin> actually points 248 at a chain of handler functions, all of which have an opportunity to 249 handle keywords, and only the last function in the chain (built into 250 the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>. 251 252 For thread safety, modules should not set this variable directly. 253 Instead, use the function L</wrap_keyword_plugin>. 254 255 =cut 256 */ 257 258 #if defined(USE_ITHREADS) 259 PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */ 260 #endif 261 PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard) 262 263 PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */ 264 PERLVARI(G, op_seq, UV, 0) /* dump.c */ 265 266 #ifdef USE_ITHREADS 267 PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */ 268 #endif 269 270 /* Restricted hashes placeholder value. 271 In theory, the contents are never used, only the address. 272 In practice, &PL_sv_placeholder is returned by some APIs, and the calling 273 code is checking SvOK(). */ 274 275 PERLVAR(G, sv_placeholder, SV) 276 277 #if defined(MYMALLOC) && defined(USE_ITHREADS) 278 PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */ 279 #endif 280 281 PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */ 282 PERLVARA(G, hash_seed_w, PERL_HASH_SEED_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 283 #if defined(PERL_HASH_STATE_BYTES) 284 PERLVARA(G, hash_state_w, PERL_HASH_STATE_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 285 #endif 286 #if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE) 287 PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */ 288 #endif 289 290 /* The path separator can vary depending on whether we're running under DCL or 291 * a Unix shell. 292 */ 293 #ifdef __VMS 294 PERLVAR(G, perllib_sep, char) 295 #endif 296 297 /* Definitions of user-defined \p{} properties, as the subs that define them 298 * are only called once */ 299 PERLVARI(G, user_def_props, HV *, NULL) 300 301 #if defined(USE_ITHREADS) 302 PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props 303 was defined in */ 304 PERLVAR(G, user_prop_mutex, perl_mutex) /* Mutex for manipulating 305 PL_user_defined_properties */ 306 #endif 307 308 /* these record the best way to perform certain IO operations while 309 * atomically setting FD_CLOEXEC. On the first call, a probe is done 310 * and the result recorded for use by subsequent calls. 311 * In theory these variables aren't thread-safe, but the worst that can 312 * happen is that two treads will both do an initial probe 313 */ 314 PERLVARI(G, strategy_dup, int, 0) /* doio.c */ 315 PERLVARI(G, strategy_dup2, int, 0) /* doio.c */ 316 PERLVARI(G, strategy_open, int, 0) /* doio.c */ 317 PERLVARI(G, strategy_open3, int, 0) /* doio.c */ 318 PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */ 319 PERLVARI(G, strategy_socket, int, 0) /* doio.c */ 320 PERLVARI(G, strategy_accept, int, 0) /* doio.c */ 321 PERLVARI(G, strategy_pipe, int, 0) /* doio.c */ 322 PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */ 323 324 #ifdef PERL_IMPLICIT_CONTEXT 325 # ifdef PERL_GLOBAL_STRUCT_PRIVATE 326 /* per-module array of pointers to MY_CXT_KEY constants. 327 * It simulates each module having a static my_cxt_index var on builds 328 * which don't allow static vars */ 329 PERLVARI(G, my_cxt_keys, const char **, NULL) 330 PERLVARI(G, my_cxt_keys_size, int, 0) /* size of PL_my_cxt_keys */ 331 # endif 332 #endif 333