From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 2 Apr 2011 02:35:20 +0000 (-0400)
Subject: reorganize the __libc structure for threaded performance issues
X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=952987a0cb9b1973fdf23e05f8ddc6fe3c98fd68;hp=4ae5e811f8d291a0df1418e1aae583161c142952

reorganize the __libc structure for threaded performance issues

we want to keep atomically updated fields (locks and thread count) and
really anything writable far away from frequently-needed function
pointers. stuff some rarely-needed function pointers in between to
pad, hopefully up to a cache line boundary.
---

diff --git a/src/internal/libc.h b/src/internal/libc.h
index c83fcafe..60a25eff 100644
--- a/src/internal/libc.h
+++ b/src/internal/libc.h
@@ -5,20 +5,20 @@
 #include <stdio.h>
 
 struct __libc {
-	void (*lock)(volatile int *);
+	int *(*errno_location)(void);
 	void (*cancelpt)(int);
+	void (*lock)(volatile int *);
+	void (*lockfile)(FILE *);
+	void (**tsd_keys)(void *);
+	void (*sigtimer)();
 	int (*atexit)(void (*)(void));
 	void (*fini)(void);
 	void (*ldso_fini)(void);
-	int *(*errno_location)(void);
 	volatile int threads_minus_1;
+	int ofl_lock;
 	int (*rsyscall)(int, long, long, long, long, long, long);
-	void (**tsd_keys)(void *);
 	void (*fork_handler)(int);
 	FILE *ofl_head;
-	int ofl_lock;
-	void (*lockfile)(FILE *);
-	void (*sigtimer)();
 };