libgo: Update to Go 1.3 release.

From-SVN: r212837

1 files changed, 33 insertions, 8 deletions

diff --git a/libgo/runtime/runtime.c b/libgo/runtime/runtime.c
index 1678a45..33fe1e7 100644
--- a/libgo/runtime/runtime.c
+++ b/libgo/runtime/runtime.c
@@ -8,8 +8,20 @@
 #include "config.h"
 
 #include "runtime.h"
+#include "arch.h"
 #include "array.h"
 
+enum {
+	maxround = sizeof(uintptr),
+};
+
+// Keep a cached value to make gotraceback fast,
+// since we call it on every call to gentraceback.
+// The cached value is a uint32 in which the low bit
+// is the "crash" setting and the top 31 bits are the
+// gotraceback value.
+static uint32 traceback_cache = ~(uint32)0;
+
 // The GOTRACEBACK environment variable controls the
 // behavior of a Go program that is crashing and exiting.
 //	GOTRACEBACK=0   suppress all tracebacks
@@ -20,18 +32,28 @@ int32
 runtime_gotraceback(bool *crash)
 {
 	const byte *p;
+	uint32 x;
 
 	if(crash != nil)
 		*crash = false;
-	p = runtime_getenv("GOTRACEBACK");
-	if(p == nil || p[0] == '\0')
-		return 1;	// default is on
-	if(runtime_strcmp((const char *)p, "crash") == 0) {
-		if(crash != nil)
-			*crash = true;
-		return 2;	// extra information
+	if(runtime_m()->traceback != 0)
+		return runtime_m()->traceback;
+	x = runtime_atomicload(&traceback_cache);
+	if(x == ~(uint32)0) {
+		p = runtime_getenv("GOTRACEBACK");
+		if(p == nil)
+			p = (const byte*)"";
+		if(p[0] == '\0')
+			x = 1<<1;
+		else if(runtime_strcmp((const char *)p, "crash") == 0)
+			x = (2<<1) | 1;
+		else
+			x = runtime_atoi(p)<<1;	
+		runtime_atomicstore(&traceback_cache, x);
 	}
-	return runtime_atoi(p);
+	if(crash != nil)
+		*crash = x&1;
+	return x>>1;
 }
 
 static int32	argc;
@@ -90,6 +112,8 @@ runtime_goenvs_unix(void)
 	syscall_Envs.__values = (void*)s;
 	syscall_Envs.__count = n;
 	syscall_Envs.__capacity = n;
+
+	traceback_cache = ~(uint32)0;
 }
 
 int32
@@ -275,6 +299,7 @@ static struct {
 	{"allocfreetrace", &runtime_debug.allocfreetrace},
 	{"efence", &runtime_debug.efence},
 	{"gctrace", &runtime_debug.gctrace},
+	{"gcdead", &runtime_debug.gcdead},
 	{"scheddetail", &runtime_debug.scheddetail},
 	{"schedtrace", &runtime_debug.schedtrace},
 };