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Merge branch 'perlgov-omnibus-amendments' into blead
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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)
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)
83#endif
84
85/* This is constant on most architectures, a global on OS/2 */
86#ifdef OS2
87PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */
88#endif
89
90#ifdef USE_PERLIO
91
92# if defined(USE_ITHREADS)
93PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */
94# endif
95
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 */
99#endif
100
101#ifdef HAS_MMAP
102PERLVARI(G, mmap_page_size, IV, 0)
103#endif
104
105#if defined(USE_ITHREADS)
106PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */
107PERLVAR(G, env_mutex, perl_RnW1_mutex_t) /* Mutex for accessing ENV */
108PERLVAR(G, locale_mutex, perl_mutex) /* Mutex related to locale handling */
109# ifndef USE_THREAD_SAFE_LOCALE
110PERLVAR(G, lc_numeric_mutex, perl_mutex) /* Mutex for switching LC_NUMERIC */
111# endif
112#endif
113
114#ifdef USE_POSIX_2008_LOCALE
115PERLVAR(G, C_locale_obj, locale_t)
116#endif
117
118PERLVARI(G, watch_pvx, char *, NULL)
119
120/*
121=for apidoc AmnU|Perl_check_t *|PL_check
122
123Array, indexed by opcode, of functions that will be called for the "check"
124phase of optree building during compilation of Perl code. For most (but
125not all) types of op, once the op has been initially built and populated
126with child ops it will be filtered through the check function referenced
127by the appropriate element of this array. The new op is passed in as the
128sole argument to the check function, and the check function returns the
129completed op. The check function may (as the name suggests) check the op
130for validity and signal errors. It may also initialise or modify parts of
131the ops, or perform more radical surgery such as adding or removing child
132ops, or even throw the op away and return a different op in its place.
133
134This array of function pointers is a convenient place to hook into the
135compilation process. An XS module can put its own custom check function
136in place of any of the standard ones, to influence the compilation of a
137particular type of op. However, a custom check function must never fully
138replace a standard check function (or even a custom check function from
139another module). A module modifying checking must instead B<wrap> the
140preexisting check function. A custom check function must be selective
141about when to apply its custom behaviour. In the usual case where
142it decides not to do anything special with an op, it must chain the
143preexisting op function. Check functions are thus linked in a chain,
144with the core's base checker at the end.
145
146For thread safety, modules should not write directly to this array.
147Instead, use the function L</wrap_op_checker>.
148
149=for apidoc Amn|enum perl_phase|PL_phase
150
151A value that indicates the current Perl interpreter's phase. Possible values
152include C<PERL_PHASE_CONSTRUCT>, C<PERL_PHASE_START>, C<PERL_PHASE_CHECK>,
153C<PERL_PHASE_INIT>, C<PERL_PHASE_RUN>, C<PERL_PHASE_END>, and
154C<PERL_PHASE_DESTRUCT>.
155
156For example, the following determines whether the interpreter is in
157global destruction:
158
159 if (PL_phase == PERL_PHASE_DESTRUCT) {
160 // we are in global destruction
161 }
162
163C<PL_phase> was introduced in Perl 5.14; in prior perls you can use
164C<PL_dirty> (boolean) to determine whether the interpreter is in global
165destruction. (Use of C<PL_dirty> is discouraged since 5.14.)
166
167=cut
168*/
169
170#if defined(USE_ITHREADS)
171PERLVAR(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
178PERLVAR(G, my_ctx_mutex, perl_mutex)
179# endif
180PERLVARI(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) */
185PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */
186
187/*
188=for apidoc AmnUx|Perl_keyword_plugin_t|PL_keyword_plugin
189
190Function pointer, pointing at a function used to handle extended keywords.
191The function should be declared as
192
193 int keyword_plugin_function(pTHX_
194 char *keyword_ptr, STRLEN keyword_len,
195 OP **op_ptr)
196
197The function is called from the tokeniser, whenever a possible keyword
198is seen. C<keyword_ptr> points at the word in the parser's input
199buffer, and C<keyword_len> gives its length; it is not null-terminated.
200The function is expected to examine the word, and possibly other state
201such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it
202as an extended keyword. If it does not, the function should return
203C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue.
204
205If the function wants to handle the keyword, it first must
206parse anything following the keyword that is part of the syntax
207introduced by the keyword. See L</Lexer interface> for details.
208
209When a keyword is being handled, the plugin function must build
210a tree of C<OP> structures, representing the code that was parsed.
211The root of the tree must be stored in C<*op_ptr>. The function then
212returns a constant indicating the syntactic role of the construct that
213it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or
214C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement
215construct cannot be used inside an expression (except via C<do BLOCK>
216and similar), and an expression is not a complete statement (it requires
217at least a terminating semicolon).
218
219When a keyword is handled, the plugin function may also have
220(compile-time) side effects. It may modify C<%^H>, define functions, and
221so on. Typically, if side effects are the main purpose of a handler,
222it does not wish to generate any ops to be included in the normal
223compilation. In this case it is still required to supply an op tree,
224but it suffices to generate a single null op.
225
226That's how the C<*PL_keyword_plugin> function needs to behave overall.
227Conventionally, however, one does not completely replace the existing
228handler function. Instead, take a copy of C<PL_keyword_plugin> before
229assigning your own function pointer to it. Your handler function should
230look for keywords that it is interested in and handle those. Where it
231is not interested, it should call the saved plugin function, passing on
232the arguments it received. Thus C<PL_keyword_plugin> actually points
233at a chain of handler functions, all of which have an opportunity to
234handle keywords, and only the last function in the chain (built into
235the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
236
237For thread safety, modules should not set this variable directly.
238Instead, use the function L</wrap_keyword_plugin>.
239
240=cut
241*/
242
243#if defined(USE_ITHREADS)
244PERLVAR(G, keyword_plugin_mutex, perl_mutex) /* Mutex for PL_keyword_plugin */
245#endif
246PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
247
248PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */
249PERLVARI(G, op_seq, UV, 0) /* dump.c */
250
251#ifdef USE_ITHREADS
252PERLVAR(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
260PERLVAR(G, sv_placeholder, SV)
261
262#if defined(MYMALLOC) && defined(USE_ITHREADS)
263PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */
264#endif
265
266PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */
267PERLVARA(G, hash_seed_w, PERL_HASH_SEED_WORDS, __PERL_HASH_WORD_TYPE) /* perl.c and hv.h */
268#if defined(PERL_HASH_STATE_BYTES)
269PERLVARA(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)
272PERLVARA(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
279PERLVAR(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 */
284PERLVARI(G, user_def_props, HV *, NULL)
285
286#if defined(USE_ITHREADS)
287PERLVAR(G, user_def_props_aTHX, PerlInterpreter *) /* aTHX that user_def_props
288 was defined in */
289PERLVAR(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 */
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 */