Re-order perlvars.h to group related variables, and spread mutexes out.

Move variables smaller than pointers into groups, to avoid holes in the
structure for PERL_GLOBAL_STRUCT. Spreading the mutexes out tries to keep them
off the same cache lines, which may help slightly on multi-processor machines.

diff --git a/perlvars.h b/perlvars.h
index a92a0a0..57bd5bd 100644 (file)
--- a/perlvars.h
+++ b/perlvars.h
@@ -24,6 +24,9 @@
  * the appropriate export list for win32. */
 
 /* global state */
+#if defined(USE_ITHREADS)
+PERLVAR(Gop_mutex,     perl_mutex)     /* Mutex for op refcounting */
+#endif
 PERLVAR(Gcurinterp,    PerlInterpreter *)
                                        /* currently running interpreter
                                         * (initial parent interpreter under
@@ -35,43 +38,44 @@ PERLVAR(Gthr_key,   perl_key)       /* key to retrieve per-thread struct */
 /* XXX does anyone even use this? */
 PERLVARI(Gdo_undump,   bool,   FALSE)  /* -u or dump seen? */
 
-#if defined(MYMALLOC) && defined(USE_ITHREADS)
-PERLVAR(Gmalloc_mutex, perl_mutex)     /* Mutex for malloc */
+#ifndef PERL_USE_SAFE_PUTENV
+PERLVARI(Guse_safe_putenv, bool, TRUE)
 #endif
 
-#if defined(USE_ITHREADS)
-PERLVAR(Gop_mutex,     perl_mutex)     /* Mutex for op refcounting */
+#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
+PERLVARI(Gsig_handlers_initted, int, 0)
 #endif
-
-#ifdef USE_ITHREADS
-PERLVAR(Gdollarzero_mutex, perl_mutex) /* Modifying $0 */
+#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
+PERLVARA(Gsig_ignoring, SIG_SIZE, int) /* which signals we are ignoring */
+#endif
+#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
+PERLVARA(Gsig_defaulting, SIG_SIZE, int)
 #endif
 
-
-/* This is constant on most architectures, a global on OS/2 */
-#ifdef OS2
-PERLVARI(Gsh_path, char *, SH_PATH) /* full path of shell */
+/* XXX signals are process-wide anyway, so we
+ * ignore the implications of this for threading */
+#ifndef HAS_SIGACTION
+PERLVARI(Gsig_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(Gsigfpe_saved, Sighandler_t)
-#endif
-
-/* Restricted hashes placeholder value.
- * The contents are never used, only the address. */
-PERLVAR(Gsv_placeholder, SV)
-
-#ifndef PERL_MICRO
 PERLVARI(Gcsighandlerp,        Sighandler_t, Perl_csighandler) /* Pointer to C-level sighandler */
 #endif
 
-#ifndef PERL_USE_SAFE_PUTENV
-PERLVARI(Guse_safe_putenv, bool, TRUE)
+/* This is constant on most architectures, a global on OS/2 */
+#ifdef OS2
+PERLVARI(Gsh_path, char *, SH_PATH) /* full path of shell */
 #endif
 
 #ifdef USE_PERLIO
+
+#  if defined(USE_ITHREADS)
+PERLVAR(Gperlio_mutex, perl_mutex)    /* Mutex for perlio fd refcounts */
+#  endif
+
 PERLVARI(Gperlio_fd_refcnt, int*, 0) /* Pointer to array of fd refcounts.  */
 PERLVARI(Gperlio_fd_refcnt_size, int, 0) /* Size of the array */
 PERLVARI(Gperlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means not set yet */
@@ -81,20 +85,8 @@ PERLVARI(Gperlio_debug_fd, int, 0) /* the fd to write perlio debug into, 0 means
 PERLVARI(Gmmap_page_size, IV, 0)
 #endif
 
-#if defined(FAKE_PERSISTENT_SIGNAL_HANDLERS)||defined(FAKE_DEFAULT_SIGNAL_HANDLERS)
-PERLVARI(Gsig_handlers_initted, int, 0)
-#endif
-#ifdef FAKE_PERSISTENT_SIGNAL_HANDLERS
-PERLVARA(Gsig_ignoring, SIG_SIZE, int) /* which signals we are ignoring */
-#endif
-#ifdef FAKE_DEFAULT_SIGNAL_HANDLERS
-PERLVARA(Gsig_defaulting, SIG_SIZE, int)
-#endif
-
-/* XXX signals are process-wide anyway, so we
- * ignore the implications of this for threading */
-#ifndef HAS_SIGACTION
-PERLVARI(Gsig_trapped, int, 0)
+#if defined(USE_ITHREADS)
+PERLVAR(Ghints_mutex, perl_mutex)    /* Mutex for refcounted he refcounting */
 #endif
 
 #ifdef DEBUGGING
@@ -111,9 +103,6 @@ PERLVARA(Gfold_locale, 256, unsigned char) /* or perl.h */
 PERLVAR(Gappctx, void*) /* the application context */
 #endif
 
-PERLVAR(Gop_sequence, HV*) /* dump.c */
-PERLVARI(Gop_seq, UV, 0) /* dump.c */
-
 #if defined(HAS_TIMES) && defined(PERL_NEED_TIMESBASE)
 PERLVAR(Gtimesbase, struct tms)
 #endif
@@ -127,14 +116,6 @@ PERLVAR(Gmy_ctx_mutex, perl_mutex)
 PERLVARI(Gmy_cxt_index, int, 0)
 #endif
 
-#if defined(USE_ITHREADS)
-PERLVAR(Ghints_mutex, perl_mutex)    /* Mutex for refcounted he refcounting */
-#endif
-
-#if defined(USE_ITHREADS) && defined(USE_PERLIO)
-PERLVAR(Gperlio_mutex, perl_mutex)    /* Mutex for perlio fd refcounts */
-#endif
-
 /* this is currently set without MUTEX protection, so keep it a type which
  * can be set atomically (ie not a bit field) */
 PERLVARI(Gveto_cleanup,        int, FALSE)     /* exit without cleanup */
@@ -193,3 +174,18 @@ the Perl core) will normally return C<KEYWORD_PLUGIN_DECLINE>.
 */
 
 PERLVARI(Gkeyword_plugin, Perl_keyword_plugin_t, Perl_keyword_plugin_standard)
+
+PERLVAR(Gop_sequence, HV*) /* dump.c */
+PERLVARI(Gop_seq, UV, 0) /* dump.c */
+
+#ifdef USE_ITHREADS
+PERLVAR(Gdollarzero_mutex, perl_mutex) /* Modifying $0 */
+#endif
+
+/* Restricted hashes placeholder value.
+ * The contents are never used, only the address. */
+PERLVAR(Gsv_placeholder, SV)
+
+#if defined(MYMALLOC) && defined(USE_ITHREADS)
+PERLVAR(Gmalloc_mutex, perl_mutex)     /* Mutex for malloc */
+#endif