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_RnW1_mutex_t) /* Mutex for accessing ENV */ 108 PERLVAR(G, locale_mutex, perl_mutex) /* Mutex related to locale handling */ 109 # ifndef USE_THREAD_SAFE_LOCALE 110 PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */ 111 # endif 112 #endif 113 114 #ifdef USE_POSIX_2008_LOCALE 115 PERLVAR(G, C_locale_obj, locale_t) 116 #endif 117 118 PERLVARI(G, watch_pvx, char *, NULL) 119 120 /* 121 =for apidoc AmnU|Perl_check_t *|PL_check 122 123 Array, indexed by opcode, of functions that will be called for the "check" 124 phase of optree building during compilation of Perl code. For most (but 125 not all) types of op, once the op has been initially built and populated 126 with child ops it will be filtered through the check function referenced 127 by the appropriate element of this array. The new op is passed in as the 128 sole argument to the check function, and the check function returns the 129 completed op. The check function may (as the name suggests) check the op 130 for validity and signal errors. It may also initialise or modify parts of 131 the ops, or perform more radical surgery such as adding or removing child 132 ops, or even throw the op away and return a different op in its place. 133 134 This array of function pointers is a convenient place to hook into the 135 compilation process. An XS module can put its own custom check function 136 in place of any of the standard ones, to influence the compilation of a 137 particular type of op. However, a custom check function must never fully 138 replace a standard check function (or even a custom check function from 139 another module). A module modifying checking must instead B<wrap> the 140 preexisting check function. A custom check function must be selective 141 about when to apply its custom behaviour. In the usual case where 142 it decides not to do anything special with an op, it must chain the 143 preexisting op function. Check functions are thus linked in a chain, 144 with the core's base checker at the end. 145 146 For thread safety, modules should not write directly to this array. 147 Instead, use the function L</wrap_op_checker>. 148 149 =for apidoc Amn|enum perl_phase|PL_phase 150 151 A value that indicates the current Perl interpreter's phase. Possible values 152 include C<PERL_PHASE_CONSTRUCT>, C<PERL_PHASE_START>, C<PERL_PHASE_CHECK>, 153 C<PERL_PHASE_INIT>, C<PERL_PHASE_RUN>, C<PERL_PHASE_END>, and 154 C<PERL_PHASE_DESTRUCT>. 155 156 For example, the following determines whether the interpreter is in 157 global destruction: 158 159 if (PL_phase == PERL_PHASE_DESTRUCT) { 160 // we are in global destruction 161 } 162 163 C<PL_phase> was introduced in Perl 5.14; in prior perls you can use 164 C<PL_dirty> (boolean) to determine whether the interpreter is in global 165 destruction. (Use of C<PL_dirty> is discouraged since 5.14.) 166 167 =cut 168 */ 169 170 #if defined(USE_ITHREADS) 171 PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */ 172 #endif 173 174 /* allocate a unique index to every module that calls MY_CXT_INIT */ 175 176 #ifdef MULTIPLICITY 177 # ifdef USE_ITHREADS 178 PERLVAR(G, my_ctx_mutex, perl_mutex) 179 # endif 180 PERLVARI(G, my_cxt_index, int, 0) 181 #endif 182 183 /* this is currently set without MUTEX protection, so keep it a type which 184 * can be set atomically (ie not a bit field) */ 185 PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */ 186 187 /* 188 =for apidoc AmnUx|Perl_keyword_plugin_t|PL_keyword_plugin 189 190 Function pointer, pointing at a function used to handle extended keywords. 191 The function should be declared as 192 193 int keyword_plugin_function(pTHX_ 194 char *keyword_ptr, STRLEN keyword_len, 195 OP **op_ptr) 196 197 The function is called from the tokeniser, whenever a possible keyword 198 is seen. C<keyword_ptr> points at the word in the parser's input 199 buffer, and C<keyword_len> gives its length; it is not null-terminated. 200 The function is expected to examine the word, and possibly other state 201 such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it 202 as an extended keyword. If it does not, the function should return 203 C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue. 204 205 If the function wants to handle the keyword, it first must 206 parse anything following the keyword that is part of the syntax 207 introduced by the keyword. See L</Lexer interface> for details. 208 209 When a keyword is being handled, the plugin function must build 210 a tree of C<OP> structures, representing the code that was parsed. 211 The root of the tree must be stored in C<*op_ptr>. The function then 212 returns a constant indicating the syntactic role of the construct that 213 it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or 214 C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement 215 construct cannot be used inside an expression (except via C<do BLOCK> 216 and similar), and an expression is not a complete statement (it requires 217 at least a terminating semicolon). 218 219 When a keyword is handled, the plugin function may also have 220 (compile-time) side effects. It may modify C<%^H>, define functions, and 221 so on. Typically, if side effects are the main purpose of a handler, 222 it does not wish to generate any ops to be included in the normal 223 compilation. In this case it is still required to supply an op tree, 224 but it suffices to generate a single null op. 225 226 That's how the C<*PL_keyword_plugin> function needs to behave overall. 227 Conventionally, however, one does not completely replace the existing 228 handler function. Instead, take a copy of C<PL_keyword_plugin> before 229 assigning your own function pointer to it. Your handler function should 230 look for keywords that it is interested in and handle those. Where it 231 is not interested, it should call the saved plugin function, passing on 232 the arguments it received. Thus C<PL_keyword_plugin> actually points 233 at a chain of handler functions, all of which have an opportunity to 234 handle keywords, and only the last function in the chain (built into 235 the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>. 236 237 For thread safety, modules should not set this variable directly. 238 Instead, use the function L</wrap_keyword_plugin>. 239 240 =cut 241 */ 242 243 #if defined(USE_ITHREADS) 244 PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */ 245 #endif 246 PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard) 247 248 PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */ 249 PERLVARI(G, op_seq, UV, 0) /* dump.c */ 250 251 #ifdef USE_ITHREADS 252 PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */ 253 #endif 254 255 /* Restricted hashes placeholder value. 256 In theory, the contents are never used, only the address. 257 In practice, &PL_sv_placeholder is returned by some APIs, and the calling 258 code is checking SvOK(). */ 259 260 PERLVAR(G, sv_placeholder, SV) 261 262 #if defined(MYMALLOC) && defined(USE_ITHREADS) 263 PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */ 264 #endif 265 266 PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */ 267 PERLVARA(G, hash_seed_w, PERL_HASH_SEED_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 268 #if defined(PERL_HASH_STATE_BYTES) 269 PERLVARA(G, hash_state_w, PERL_HASH_STATE_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */ 270 #endif 271 #if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE) 272 PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */ 273 #endif 274 275 /* The path separator can vary depending on whether we're running under DCL or 276 * a Unix shell. 277 */ 278 #ifdef __VMS 279 PERLVAR(G, perllib_sep, char) 280 #endif 281 282 /* Definitions of user-defined \p{} properties, as the subs that define them 283 * are only called once */ 284 PERLVARI(G, user_def_props, HV *, NULL) 285 286 #if defined(USE_ITHREADS) 287 PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props 288 was defined in */ 289 PERLVAR(G, user_prop_mutex, perl_mutex) /* Mutex for manipulating 290 PL_user_defined_properties */ 291 #endif 292 293 /* these record the best way to perform certain IO operations while 294 * atomically setting FD_CLOEXEC. On the first call, a probe is done 295 * and the result recorded for use by subsequent calls. 296 * In theory these variables aren't thread-safe, but the worst that can 297 * happen is that two treads will both do an initial probe 298 */ 299 PERLVARI(G, strategy_dup, int, 0) /* doio.c */ 300 PERLVARI(G, strategy_dup2, int, 0) /* doio.c */ 301 PERLVARI(G, strategy_open, int, 0) /* doio.c */ 302 PERLVARI(G, strategy_open3, int, 0) /* doio.c */ 303 PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */ 304 PERLVARI(G, strategy_socket, int, 0) /* doio.c */ 305 PERLVARI(G, strategy_accept, int, 0) /* doio.c */ 306 PERLVARI(G, strategy_pipe, int, 0) /* doio.c */ 307 PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */ 308