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1/* perlvars.h
2 *
663f364b 3 * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
54ca4ee7 4 * by Larry Wall and others
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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
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11/*
12=head1 Global Variables
e8570548 13These variables are global to an entire process. They are shared between
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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.
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21
22=cut
88e1f1a2 23*/
49f531da 24
d7cb65f2 25/* Don't forget to re-run regen/embed.pl to propagate changes! */
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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
22c35a8c 33 * generated in embed*.h. Such symbols are also used to generate
14dd3ad8 34 * the appropriate export list for win32. */
cb68f92d 35
49f531da 36/* global state */
eeb6b841 37#if defined(USE_ITHREADS)
115ff745 38PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */
eeb6b841 39#endif
5c64bffd 40PERLVARI(G, curinterp, PerlInterpreter *, NULL)
43165c05 41 /* currently running interpreter
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42 * (initial parent interpreter under
43 * useithreads) */
3db8f154 44#if defined(USE_ITHREADS)
115ff745 45PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */
ba869deb 46#endif
a0ed51b3 47
43165c05 48/* XXX does anyone even use this? */
115ff745 49PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */
b363f7ed 50
eeb6b841 51#ifndef PERL_USE_SAFE_PUTENV
115ff745 52PERLVARI(G, use_safe_putenv, bool, TRUE)
b363f7ed 53#endif
534825c4 54
eeb6b841 55#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
115ff745 56PERLVARI(G, sig_handlers_initted, int, 0)
534825c4 57#endif
eeb6b841 58#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
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59PERLVARA(G, sig_ignoring, SIG_SIZE, int)
60 /* which signals we are ignoring */
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61#endif
62#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
115ff745 63PERLVARA(G, sig_defaulting, SIG_SIZE, int)
d90a703e 64#endif
5c728af0 65
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66/* XXX signals are process-wide anyway, so we
67 * ignore the implications of this for threading */
68#ifndef HAS_SIGACTION
115ff745 69PERLVARI(G, sig_trapped, int, 0)
428eed4a 70#endif
af419de7 71
2f42fcb0 72#ifndef PERL_MICRO
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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. */
115ff745 75PERLVAR(G, sigfpe_saved, Sighandler_t)
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76
77/* these ptrs to functions are to avoid linkage problems; see
78 * perl-5.8.0-2193-g5c1546dc48
79 */
80PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler)
81PERLVARI(G, csighandler1p, Sighandler1_t, Perl_csighandler1)
82PERLVARI(G, csighandler3p, Sighandler3_t, Perl_csighandler3)
2f42fcb0 83#endif
5c1546dc 84
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85/* This is constant on most architectures, a global on OS/2 */
86#ifdef OS2
115ff745 87PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */
50acdf95 88#endif
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89
90#ifdef USE_PERLIO
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91
92# if defined(USE_ITHREADS)
115ff745 93PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
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94# endif
95
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96PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */
97PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */
98PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */
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99#endif
100
101#ifdef HAS_MMAP
115ff745 102PERLVARI(G, mmap_page_size, IV, 0)
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103#endif
104
eeb6b841 105#if defined(USE_ITHREADS)
115ff745 106PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
69c5e0db 107# if ! defined(USE_THREAD_SAFE_LOCALE) || defined(TS_W32_BROKEN_LOCALECONV)
929e1213 108PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */
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109# endif
110# ifndef USE_THREAD_SAFE_LOCALE
49d7d366 111PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */
423a80b7 112# endif
5acc3fa5 113#endif
6ebbc862 114
39e69e77 115#ifdef USE_POSIX_2008_LOCALE
5acc3fa5 116PERLVAR(G, C_locale_obj, locale_t)
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117#endif
118
0c5ea019 119PERLVARI(G, watch_pvx, char *, NULL)
27da23d5 120
e8570548 121/*
78342678 122=for apidoc AmnU|Perl_check_t *|PL_check
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123
124Array, indexed by opcode, of functions that will be called for the "check"
125phase of optree building during compilation of Perl code. For most (but
126not all) types of op, once the op has been initially built and populated
127with child ops it will be filtered through the check function referenced
128by the appropriate element of this array. The new op is passed in as the
129sole argument to the check function, and the check function returns the
130completed op. The check function may (as the name suggests) check the op
131for validity and signal errors. It may also initialise or modify parts of
132the ops, or perform more radical surgery such as adding or removing child
133ops, or even throw the op away and return a different op in its place.
134
135This array of function pointers is a convenient place to hook into the
136compilation process. An XS module can put its own custom check function
137in place of any of the standard ones, to influence the compilation of a
138particular type of op. However, a custom check function must never fully
139replace a standard check function (or even a custom check function from
140another module). A module modifying checking must instead B<wrap> the
141preexisting check function. A custom check function must be selective
142about when to apply its custom behaviour. In the usual case where
143it decides not to do anything special with an op, it must chain the
144preexisting op function. Check functions are thus linked in a chain,
145with the core's base checker at the end.
146
147For thread safety, modules should not write directly to this array.
148Instead, use the function L</wrap_op_checker>.
149
150=cut
151*/
152
153#if defined(USE_ITHREADS)
154PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */
155#endif
27da23d5 156#ifdef PERL_GLOBAL_STRUCT
115ff745 157PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */
0850138d 158PERLVAR(G, check, Perl_check_t *) /* or opcode.h */
115ff745 159PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */
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160#endif
161
162#ifdef PERL_NEED_APPCTX
115ff745 163PERLVAR(G, appctx, void*) /* the application context */
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164#endif
165
27da23d5 166#if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
115ff745 167PERLVAR(G, timesbase, struct tms)
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168#endif
169
f16dd614 170/* allocate a unique index to every module that calls MY_CXT_INIT */
27da23d5 171
f16dd614 172#ifdef PERL_IMPLICIT_CONTEXT
97aff369 173# ifdef USE_ITHREADS
115ff745 174PERLVAR(G, my_ctx_mutex, perl_mutex)
97aff369 175# endif
115ff745 176PERLVARI(G, my_cxt_index, int, 0)
f16dd614 177#endif
71ad1b0c 178
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179/* this is currently set without MUTEX protection, so keep it a type which
180 * can be set atomically (ie not a bit field) */
115ff745 181PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */
c301d606 182
88e1f1a2 183/*
78342678 184=for apidoc AmnUx|Perl_keyword_plugin_t|PL_keyword_plugin
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185
186Function pointer, pointing at a function used to handle extended keywords.
187The function should be declared as
188
189 int keyword_plugin_function(pTHX_
190 char *keyword_ptr, STRLEN keyword_len,
191 OP **op_ptr)
192
193The function is called from the tokeniser, whenever a possible keyword
194is seen. C<keyword_ptr> points at the word in the parser's input
195buffer, and C<keyword_len> gives its length; it is not null-terminated.
196The function is expected to examine the word, and possibly other state
197such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
198as an extended keyword. If it does not, the function should return
199C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
200
201If the function wants to handle the keyword, it first must
202parse anything following the keyword that is part of the syntax
f0e67a1d 203introduced by the keyword. See L</Lexer interface> for details.
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204
205When a keyword is being handled, the plugin function must build
206a tree of C<OP> structures, representing the code that was parsed.
207The root of the tree must be stored in C<*op_ptr>. The function then
364f83bf 208returns a constant indicating the syntactic role of the construct that
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209it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
210C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
211construct cannot be used inside an expression (except via C<do BLOCK>
212and similar), and an expression is not a complete statement (it requires
213at least a terminating semicolon).
214
215When a keyword is handled, the plugin function may also have
216(compile-time) side effects. It may modify C<%^H>, define functions, and
217so on. Typically, if side effects are the main purpose of a handler,
218it does not wish to generate any ops to be included in the normal
219compilation. In this case it is still required to supply an op tree,
220but it suffices to generate a single null op.
221
222That's how the C<*PL_keyword_plugin> function needs to behave overall.
223Conventionally, however, one does not completely replace the existing
224handler function. Instead, take a copy of C<PL_keyword_plugin> before
225assigning your own function pointer to it. Your handler function should
226look for keywords that it is interested in and handle those. Where it
227is not interested, it should call the saved plugin function, passing on
228the arguments it received. Thus C<PL_keyword_plugin> actually points
229at a chain of handler functions, all of which have an opportunity to
230handle keywords, and only the last function in the chain (built into
231the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
232
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233For thread safety, modules should not set this variable directly.
234Instead, use the function L</wrap_keyword_plugin>.
235
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236=cut
237*/
238
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239#if defined(USE_ITHREADS)
240PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */
241#endif
115ff745 242PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
eeb6b841 243
5c64bffd 244PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */
115ff745 245PERLVARI(G, op_seq, UV, 0) /* dump.c */
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246
247#ifdef USE_ITHREADS
115ff745 248PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */
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249#endif
250
251/* Restricted hashes placeholder value.
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252 In theory, the contents are never used, only the address.
253 In practice, &PL_sv_placeholder is returned by some APIs, and the calling
254 code is checking SvOK(). */
255
115ff745 256PERLVAR(G, sv_placeholder, SV)
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257
258#if defined(MYMALLOC) && defined(USE_ITHREADS)
115ff745 259PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */
eeb6b841 260#endif
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261
262PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */
6a5b4183 263PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */
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264#if defined(PERL_HASH_STATE_BYTES)
265PERLVARA(G, hash_state, PERL_HASH_STATE_BYTES, unsigned char) /* perl.c and hv.h */
266#endif
267#if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE)
268PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */
269#endif
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270
271/* The path separator can vary depending on whether we're running under DCL or
272 * a Unix shell.
273 */
274#ifdef __VMS
275PERLVAR(G, perllib_sep, char)
276#endif
744ebf52 277
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278/* Definitions of user-defined \p{} properties, as the subs that define them
279 * are only called once */
280PERLVARI(G, user_def_props, HV *, NULL)
281
8310e7fa 282#if defined(USE_ITHREADS)
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283PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props
284 was defined in */
285PERLVAR(G, user_prop_mutex, perl_mutex) /* Mutex for manipulating
286 PL_user_defined_properties */
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287#endif
288
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289/* Everything that folds to a given character, for case insensitivity regex
290 * matching */
291PERLVAR(G, utf8_foldclosures, SV *)
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292
293/* these record the best way to 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 */
299PERLVARI(G, strategy_dup, int, 0) /* doio.c */
300PERLVARI(G, strategy_dup2, int, 0) /* doio.c */
301PERLVARI(G, strategy_open, int, 0) /* doio.c */
302PERLVARI(G, strategy_open3, int, 0) /* doio.c */
303PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */
304PERLVARI(G, strategy_socket, int, 0) /* doio.c */
305PERLVARI(G, strategy_accept, int, 0) /* doio.c */
306PERLVARI(G, strategy_pipe, int, 0) /* doio.c */
307PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */
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308
309#ifdef PERL_IMPLICIT_CONTEXT
310# ifdef PERL_GLOBAL_STRUCT_PRIVATE
311/* per-module array of pointers to MY_CXT_KEY constants.
312 * It simulates each module having a static my_cxt_index var on builds
313 * which don't allow static vars */
314PERLVARI(G, my_cxt_keys, const char **, NULL)
315PERLVARI(G, my_cxt_keys_size, int, 0) /* size of PL_my_cxt_keys */
316# endif
317#endif