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Perl_my_cxt_init: fix potential race condition
[perl5.git] / perlvars.h
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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. */
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75PERLVAR(G, sigfpe_saved, Sighandler_t)
76PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler)
77 /* Pointer to C-level sighandler */
2f42fcb0 78#endif
5c1546dc 79
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80/* This is constant on most architectures, a global on OS/2 */
81#ifdef OS2
115ff745 82PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */
50acdf95 83#endif
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84
85#ifdef USE_PERLIO
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86
87# if defined(USE_ITHREADS)
115ff745 88PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
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89# endif
90
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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 */
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94#endif
95
96#ifdef HAS_MMAP
115ff745 97PERLVARI(G, mmap_page_size, IV, 0)
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98#endif
99
eeb6b841 100#if defined(USE_ITHREADS)
115ff745 101PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
69c5e0db 102# if ! defined(USE_THREAD_SAFE_LOCALE) || defined(TS_W32_BROKEN_LOCALECONV)
929e1213 103PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */
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104# endif
105# ifndef USE_THREAD_SAFE_LOCALE
49d7d366 106PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */
423a80b7 107# endif
5acc3fa5 108#endif
6ebbc862 109
39e69e77 110#ifdef USE_POSIX_2008_LOCALE
5acc3fa5 111PERLVAR(G, C_locale_obj, locale_t)
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112#endif
113
114#ifdef DEBUGGING
0c5ea019 115PERLVARI(G, watch_pvx, char *, NULL)
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116#endif
117
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118/*
119=for apidoc AmU|Perl_check_t *|PL_check
120
121Array, indexed by opcode, of functions that will be called for the "check"
122phase of optree building during compilation of Perl code. For most (but
123not all) types of op, once the op has been initially built and populated
124with child ops it will be filtered through the check function referenced
125by the appropriate element of this array. The new op is passed in as the
126sole argument to the check function, and the check function returns the
127completed op. The check function may (as the name suggests) check the op
128for validity and signal errors. It may also initialise or modify parts of
129the ops, or perform more radical surgery such as adding or removing child
130ops, or even throw the op away and return a different op in its place.
131
132This array of function pointers is a convenient place to hook into the
133compilation process. An XS module can put its own custom check function
134in place of any of the standard ones, to influence the compilation of a
135particular type of op. However, a custom check function must never fully
136replace a standard check function (or even a custom check function from
137another module). A module modifying checking must instead B<wrap> the
138preexisting check function. A custom check function must be selective
139about when to apply its custom behaviour. In the usual case where
140it decides not to do anything special with an op, it must chain the
141preexisting op function. Check functions are thus linked in a chain,
142with the core's base checker at the end.
143
144For thread safety, modules should not write directly to this array.
145Instead, use the function L</wrap_op_checker>.
146
147=cut
148*/
149
150#if defined(USE_ITHREADS)
151PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */
152#endif
27da23d5 153#ifdef PERL_GLOBAL_STRUCT
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154PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */
155PERLVAR(G, check, Perl_check_t *) /* or opcode.h */
156PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */
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157#endif
158
159#ifdef PERL_NEED_APPCTX
115ff745 160PERLVAR(G, appctx, void*) /* the application context */
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161#endif
162
27da23d5 163#if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
115ff745 164PERLVAR(G, timesbase, struct tms)
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165#endif
166
f16dd614 167/* allocate a unique index to every module that calls MY_CXT_INIT */
27da23d5 168
f16dd614 169#ifdef PERL_IMPLICIT_CONTEXT
97aff369 170# ifdef USE_ITHREADS
115ff745 171PERLVAR(G, my_ctx_mutex, perl_mutex)
97aff369 172# endif
115ff745 173PERLVARI(G, my_cxt_index, int, 0)
f16dd614 174#endif
71ad1b0c 175
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176/* this is currently set without MUTEX protection, so keep it a type which
177 * can be set atomically (ie not a bit field) */
115ff745 178PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */
c301d606 179
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180/*
181=for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin
182
183Function pointer, pointing at a function used to handle extended keywords.
184The function should be declared as
185
186 int keyword_plugin_function(pTHX_
187 char *keyword_ptr, STRLEN keyword_len,
188 OP **op_ptr)
189
190The function is called from the tokeniser, whenever a possible keyword
191is seen. C<keyword_ptr> points at the word in the parser's input
192buffer, and C<keyword_len> gives its length; it is not null-terminated.
193The function is expected to examine the word, and possibly other state
194such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
195as an extended keyword. If it does not, the function should return
196C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
197
198If the function wants to handle the keyword, it first must
199parse anything following the keyword that is part of the syntax
f0e67a1d 200introduced by the keyword. See L</Lexer interface> for details.
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201
202When a keyword is being handled, the plugin function must build
203a tree of C<OP> structures, representing the code that was parsed.
204The root of the tree must be stored in C<*op_ptr>. The function then
364f83bf 205returns a constant indicating the syntactic role of the construct that
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206it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
207C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
208construct cannot be used inside an expression (except via C<do BLOCK>
209and similar), and an expression is not a complete statement (it requires
210at least a terminating semicolon).
211
212When a keyword is handled, the plugin function may also have
213(compile-time) side effects. It may modify C<%^H>, define functions, and
214so on. Typically, if side effects are the main purpose of a handler,
215it does not wish to generate any ops to be included in the normal
216compilation. In this case it is still required to supply an op tree,
217but it suffices to generate a single null op.
218
219That's how the C<*PL_keyword_plugin> function needs to behave overall.
220Conventionally, however, one does not completely replace the existing
221handler function. Instead, take a copy of C<PL_keyword_plugin> before
222assigning your own function pointer to it. Your handler function should
223look for keywords that it is interested in and handle those. Where it
224is not interested, it should call the saved plugin function, passing on
225the arguments it received. Thus C<PL_keyword_plugin> actually points
226at a chain of handler functions, all of which have an opportunity to
227handle keywords, and only the last function in the chain (built into
228the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
229
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230For thread safety, modules should not set this variable directly.
231Instead, use the function L</wrap_keyword_plugin>.
232
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233=cut
234*/
235
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236#if defined(USE_ITHREADS)
237PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */
238#endif
115ff745 239PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
eeb6b841 240
5c64bffd 241PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */
115ff745 242PERLVARI(G, op_seq, UV, 0) /* dump.c */
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243
244#ifdef USE_ITHREADS
115ff745 245PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */
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246#endif
247
248/* Restricted hashes placeholder value.
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249 In theory, the contents are never used, only the address.
250 In practice, &PL_sv_placeholder is returned by some APIs, and the calling
251 code is checking SvOK(). */
252
115ff745 253PERLVAR(G, sv_placeholder, SV)
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254
255#if defined(MYMALLOC) && defined(USE_ITHREADS)
115ff745 256PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */
eeb6b841 257#endif
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258
259PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */
6a5b4183 260PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */
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261#if defined(PERL_HASH_STATE_BYTES)
262PERLVARA(G, hash_state, PERL_HASH_STATE_BYTES, unsigned char) /* perl.c and hv.h */
263#endif
264#if defined(PERL_USE_SINGLE_CHAR_HASH_CACHE)
265PERLVARA(G, hash_chars, (1+256) * sizeof(U32), unsigned char) /* perl.c and hv.h */
266#endif
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267
268/* The path separator can vary depending on whether we're running under DCL or
269 * a Unix shell.
270 */
271#ifdef __VMS
272PERLVAR(G, perllib_sep, char)
273#endif
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274
275PERLVAR(G, AboveLatin1, SV *)
276PERLVAR(G, Assigned_invlist, SV *)
277PERLVAR(G, GCB_invlist, SV *)
278PERLVAR(G, HasMultiCharFold, SV *)
3601832e 279PERLVAR(G, InMultiCharFold, SV *)
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280PERLVAR(G, Latin1, SV *)
281PERLVAR(G, LB_invlist, SV *)
712f802a 282PERLVAR(G, NonFinalFold, SV *)
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283PERLVAR(G, SB_invlist, SV *)
284PERLVAR(G, SCX_invlist, SV *)
285PERLVAR(G, UpperLatin1, SV *) /* Code points 128 - 255 */
286
ac7b6cfc 287/* List of characters that participate in any fold defined by Unicode */
de8dfdba 288PERLVAR(G, in_some_fold, SV *)
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289
290PERLVAR(G, utf8_idcont, SV *)
291PERLVAR(G, utf8_idstart, SV *)
292PERLVAR(G, utf8_perl_idcont, SV *)
293PERLVAR(G, utf8_perl_idstart, SV *)
294PERLVAR(G, utf8_xidcont, SV *)
295PERLVAR(G, utf8_xidstart, SV *)
296PERLVAR(G, WB_invlist, SV *)
297PERLVARA(G, XPosix_ptrs, POSIX_CC_COUNT, SV *)
a74bb78e 298PERLVARA(G, Posix_ptrs, POSIX_CC_COUNT, SV *)
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299PERLVAR(G, utf8_toupper, SV *)
300PERLVAR(G, utf8_totitle, SV *)
301PERLVAR(G, utf8_tolower, SV *)
302PERLVAR(G, utf8_tofold, SV *)
303PERLVAR(G, utf8_tosimplefold, SV *)
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304PERLVAR(G, utf8_charname_begin, SV *)
305PERLVAR(G, utf8_charname_continue, SV *)
7258295b 306PERLVAR(G, utf8_mark, SV *)
6009fde9 307PERLVARI(G, InBitmap, SV *, NULL)
a2aeff50 308PERLVAR(G, CCC_non0_non230, SV *)
b74fe592 309
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310/* Definitions of user-defined \p{} properties, as the subs that define them
311 * are only called once */
312PERLVARI(G, user_def_props, HV *, NULL)
313
8310e7fa 314#if defined(USE_ITHREADS)
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315PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props
316 was defined in */
317PERLVAR(G, user_prop_mutex, perl_mutex) /* Mutex for manipulating
318 PL_user_defined_properties */
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319#endif
320
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321/* Everything that folds to a given character, for case insensitivity regex
322 * matching */
323PERLVAR(G, utf8_foldclosures, SV *)
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324
325/* these record the best way to to perform certain IO operations while
326 * atomically setting FD_CLOEXEC. On the first call, a probe is done
327 * and the result recorded for use by subsequent calls.
328 * In theory these variables aren't thread-safe, but the worst that can
329 * happen is that two treads will both do an initial probe
330 */
331PERLVARI(G, strategy_dup, int, 0) /* doio.c */
332PERLVARI(G, strategy_dup2, int, 0) /* doio.c */
333PERLVARI(G, strategy_open, int, 0) /* doio.c */
334PERLVARI(G, strategy_open3, int, 0) /* doio.c */
335PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */
336PERLVARI(G, strategy_socket, int, 0) /* doio.c */
337PERLVARI(G, strategy_accept, int, 0) /* doio.c */
338PERLVARI(G, strategy_pipe, int, 0) /* doio.c */
339PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */