Edit File: perlvars.h
/* perlvars.h * * Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, * by Larry Wall and others * * You may distribute under the terms of either the GNU General Public * License or the Artistic License, as specified in the README file. * */ /* =head1 Global Variables These variables are global to an entire process. They are shared between all interpreters and all threads in a process. Any variables not documented here may be changed or removed without notice, so don't use them! If you feel you really do need to use an unlisted variable, first send email to L<perl5-porters@perl.org|mailto:perl5-porters@perl.org>. It may be that someone there will point out a way to accomplish what you need without using an internal variable. But if not, you should get a go-ahead to document and then use the variable. =cut */ /* Don't forget to re-run regen/embed.pl to propagate changes! */ /* This file describes the "global" variables used by perl * This used to be in perl.h directly but we want to abstract out into * distinct files which are per-thread, per-interpreter or really global, * and how they're initialized. * * The 'G' prefix is only needed for vars that need appropriate #defines * generated in embed*.h. Such symbols are also used to generate * the appropriate export list for win32. */ /* global state */ #if defined(USE_ITHREADS) PERLVAR(G, op_mutex, perl_mutex) /* Mutex for op refcounting */ #endif PERLVARI(G, curinterp, PerlInterpreter *, NULL) /* currently running interpreter * (initial parent interpreter under * useithreads) */ #if defined(USE_ITHREADS) PERLVAR(G, thr_key, perl_key) /* key to retrieve per-thread struct */ #endif /* XXX does anyone even use this? */ PERLVARI(G, do_undump, bool, FALSE) /* -u or dump seen? */ #ifndef PERL_USE_SAFE_PUTENV PERLVARI(G, use_safe_putenv, bool, TRUE) #endif #if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS) PERLVARI(G, sig_handlers_initted, int, 0) #endif #ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS PERLVARA(G, sig_ignoring, SIG_SIZE, int) /* which signals we are ignoring */ #endif #ifdef FAKE_DEFAULT_SIGNAL_HANDLERS PERLVARA(G, sig_defaulting, SIG_SIZE, int) #endif /* XXX signals are process-wide anyway, so we * ignore the implications of this for threading */ #ifndef HAS_SIGACTION PERLVARI(G, sig_trapped, int, 0) #endif #ifndef PERL_MICRO /* If Perl has to ignore SIGPFE, this is its saved state. * See perl.h macros PERL_FPU_INIT and PERL_FPU_{PRE,POST}_EXEC. */ PERLVAR(G, sigfpe_saved, Sighandler_t) PERLVARI(G, csighandlerp, Sighandler_t, Perl_csighandler) /* Pointer to C-level sighandler */ #endif /* This is constant on most architectures, a global on OS/2 */ #ifdef OS2 PERLVARI(G, sh_path, char *, SH_PATH) /* full path of shell */ #endif #ifdef USE_PERLIO # if defined(USE_ITHREADS) PERLVAR(G, perlio_mutex, perl_mutex) /* Mutex for perlio fd refcounts */ # endif PERLVARI(G, perlio_fd_refcnt, int *, 0) /* Pointer to array of fd refcounts. */ PERLVARI(G, perlio_fd_refcnt_size, int, 0) /* Size of the array */ PERLVARI(G, perlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */ #endif #ifdef HAS_MMAP PERLVARI(G, mmap_page_size, IV, 0) #endif #if defined(USE_ITHREADS) PERLVAR(G, hints_mutex, perl_mutex) /* Mutex for refcounted he refcounting */ PERLVAR(G, locale_mutex, perl_mutex) /* Mutex for setlocale() changing */ # ifdef HAS_NEWLOCALE PERLVAR(G, C_locale_obj, locale_t) # endif #endif #ifdef DEBUGGING PERLVARI(G, watch_pvx, char *, NULL) #endif /* =for apidoc AmU|Perl_check_t *|PL_check Array, indexed by opcode, of functions that will be called for the "check" phase of optree building during compilation of Perl code. For most (but not all) types of op, once the op has been initially built and populated with child ops it will be filtered through the check function referenced by the appropriate element of this array. The new op is passed in as the sole argument to the check function, and the check function returns the completed op. The check function may (as the name suggests) check the op for validity and signal errors. It may also initialise or modify parts of the ops, or perform more radical surgery such as adding or removing child ops, or even throw the op away and return a different op in its place. This array of function pointers is a convenient place to hook into the compilation process. An XS module can put its own custom check function in place of any of the standard ones, to influence the compilation of a particular type of op. However, a custom check function must never fully replace a standard check function (or even a custom check function from another module). A module modifying checking must instead B<wrap> the preexisting check function. A custom check function must be selective about when to apply its custom behaviour. In the usual case where it decides not to do anything special with an op, it must chain the preexisting op function. Check functions are thus linked in a chain, with the core's base checker at the end. For thread safety, modules should not write directly to this array. Instead, use the function L</wrap_op_checker>. =cut */ #if defined(USE_ITHREADS) PERLVAR(G, check_mutex, perl_mutex) /* Mutex for PL_check */ #endif #ifdef PERL_GLOBAL_STRUCT PERLVAR(G, ppaddr, Perl_ppaddr_t *) /* or opcode.h */ PERLVAR(G, check, Perl_check_t *) /* or opcode.h */ PERLVARA(G, fold_locale, 256, unsigned char) /* or perl.h */ #endif #ifdef PERL_NEED_APPCTX PERLVAR(G, appctx, void*) /* the application context */ #endif #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE) PERLVAR(G, timesbase, struct tms) #endif /* allocate a unique index to every module that calls MY_CXT_INIT */ #ifdef PERL_IMPLICIT_CONTEXT # ifdef USE_ITHREADS PERLVAR(G, my_ctx_mutex, perl_mutex) # endif PERLVARI(G, my_cxt_index, int, 0) #endif /* this is currently set without MUTEX protection, so keep it a type which * can be set atomically (ie not a bit field) */ PERLVARI(G, veto_cleanup, int, FALSE) /* exit without cleanup */ /* =for apidoc AmUx|Perl_keyword_plugin_t|PL_keyword_plugin Function pointer, pointing at a function used to handle extended keywords. The function should be declared as int keyword_plugin_function(pTHX_ char *keyword_ptr, STRLEN keyword_len, OP **op_ptr) The function is called from the tokeniser, whenever a possible keyword is seen. C<keyword_ptr> points at the word in the parser's input buffer, and C<keyword_len> gives its length; it is not null-terminated. The function is expected to examine the word, and possibly other state such as L<%^H|perlvar/%^H>, to decide whether it wants to handle it as an extended keyword. If it does not, the function should return C<KEYWORD_PLUGIN_DECLINE>, and the normal parser process will continue. If the function wants to handle the keyword, it first must parse anything following the keyword that is part of the syntax introduced by the keyword. See L</Lexer interface> for details. When a keyword is being handled, the plugin function must build a tree of C<OP> structures, representing the code that was parsed. The root of the tree must be stored in C<*op_ptr>. The function then returns a constant indicating the syntactic role of the construct that it has parsed: C<KEYWORD_PLUGIN_STMT> if it is a complete statement, or C<KEYWORD_PLUGIN_EXPR> if it is an expression. Note that a statement construct cannot be used inside an expression (except via C<do BLOCK> and similar), and an expression is not a complete statement (it requires at least a terminating semicolon). When a keyword is handled, the plugin function may also have (compile-time) side effects. It may modify C<%^H>, define functions, and so on. Typically, if side effects are the main purpose of a handler, it does not wish to generate any ops to be included in the normal compilation. In this case it is still required to supply an op tree, but it suffices to generate a single null op. That's how the C<*PL_keyword_plugin> function needs to behave overall. Conventionally, however, one does not completely replace the existing handler function. Instead, take a copy of C<PL_keyword_plugin> before assigning your own function pointer to it. Your handler function should look for keywords that it is interested in and handle those. Where it is not interested, it should call the saved plugin function, passing on the arguments it received. Thus C<PL_keyword_plugin> actually points at a chain of handler functions, all of which have an opportunity to handle keywords, and only the last function in the chain (built into the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>. =cut */ PERLVARI(G, keyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard) PERLVARI(G, op_sequence, HV *, NULL) /* dump.c */ PERLVARI(G, op_seq, UV, 0) /* dump.c */ #ifdef USE_ITHREADS PERLVAR(G, dollarzero_mutex, perl_mutex) /* Modifying $0 */ #endif /* Restricted hashes placeholder value. In theory, the contents are never used, only the address. In practice, &PL_sv_placeholder is returned by some APIs, and the calling code is checking SvOK(). */ PERLVAR(G, sv_placeholder, SV) #if defined(MYMALLOC) && defined(USE_ITHREADS) PERLVAR(G, malloc_mutex, perl_mutex) /* Mutex for malloc */ #endif PERLVARI(G, hash_seed_set, bool, FALSE) /* perl.c */ PERLVARA(G, hash_seed, PERL_HASH_SEED_BYTES, unsigned char) /* perl.c and hv.h */ /* The path separator can vary depending on whether we're running under DCL or * a Unix shell. */ #ifdef __VMS PERLVAR(G, perllib_sep, char) #endif
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