runtime: avoid repeated findmoduledatap calls
Currently almost every function that deals with a *_func has to first
look up the *moduledata for the module containing the function's entry
point. This means we almost always do at least two identical module
lookups whenever we deal with a *_func (one to get the *_func and
another to get something from its module data) and sometimes several
more.
Fix this by making findfunc return a new funcInfo type that embeds
*_func, but also includes the *moduledata, and making all of the
functions that currently take a *_func instead take a funcInfo and use
the already-found *moduledata.
This transformation is trivial for the most part, since the *_func
type is usually inferred. The annoying part is that we can no longer
use nil to indicate failure, so this introduces a funcInfo.valid()
method and replaces nil checks with calls to valid.
Change-Id: I9b8075ef1c31185c1943596d96dec45c7ab5100f
Reviewed-on: https://go-review.googlesource.com/37331
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go
index 39ef8a2..f72b068 100644
--- a/src/runtime/traceback.go
+++ b/src/runtime/traceback.go
@@ -92,14 +92,14 @@
if fn == nil {
// Defer of nil function. Args don't matter.
frame.pc = 0
- frame.fn = nil
+ frame.fn = funcInfo{}
frame.argp = 0
frame.arglen = 0
frame.argmap = nil
} else {
frame.pc = fn.fn
f := findfunc(frame.pc)
- if f == nil {
+ if !f.valid() {
print("runtime: unknown pc in defer ", hex(frame.pc), "\n")
throw("unknown pc")
}
@@ -186,7 +186,7 @@
}
f := findfunc(frame.pc)
- if f == nil {
+ if !f.valid() {
if callback != nil {
print("runtime: unknown pc ", hex(frame.pc), "\n")
throw("unknown pc")
@@ -230,10 +230,10 @@
frame.fp += sys.RegSize
}
}
- var flr *_func
+ var flr funcInfo
if topofstack(f) {
frame.lr = 0
- flr = nil
+ flr = funcInfo{}
} else if usesLR && f.entry == jmpdeferPC {
// jmpdefer modifies SP/LR/PC non-atomically.
// If a profiling interrupt arrives during jmpdefer,
@@ -259,7 +259,7 @@
}
}
flr = findfunc(frame.lr)
- if flr == nil {
+ if !flr.valid() {
// This happens if you get a profiling interrupt at just the wrong time.
// In that context it is okay to stop early.
// But if callback is set, we're doing a garbage collection and must
@@ -403,7 +403,7 @@
waspanic = f.entry == sigpanicPC
// Do not unwind past the bottom of the stack.
- if flr == nil {
+ if !flr.valid() {
break
}
@@ -426,7 +426,7 @@
}
f = findfunc(frame.pc)
frame.fn = f
- if f == nil {
+ if !f.valid() {
frame.pc = x
} else if funcspdelta(f, frame.pc, &cache) == 0 {
frame.lr = x
@@ -521,7 +521,7 @@
// call, ctxt must be nil (getArgInfo will retrieve what it needs from
// the active stack frame). If this is a deferred call, ctxt must be
// the function object that was deferred.
-func getArgInfo(frame *stkframe, f *_func, needArgMap bool, ctxt *funcval) (arglen uintptr, argmap *bitvector) {
+func getArgInfo(frame *stkframe, f funcInfo, needArgMap bool, ctxt *funcval) (arglen uintptr, argmap *bitvector) {
arglen = uintptr(f.args)
if needArgMap && f.args == _ArgsSizeUnknown {
// Extract argument bitmaps for reflect stubs from the calls they made to reflect.
@@ -593,7 +593,7 @@
// Show what created goroutine, except main goroutine (goid 1).
pc := gp.gopc
f := findfunc(pc)
- if f != nil && showframe(f, gp, false) && gp.goid != 1 {
+ if f.valid() && showframe(f, gp, false) && gp.goid != 1 {
print("created by ", funcname(f), "\n")
tracepc := pc // back up to CALL instruction for funcline.
if pc > f.entry {
@@ -673,7 +673,7 @@
return gentraceback(^uintptr(0), ^uintptr(0), 0, gp, skip, &pcbuf[0], len(pcbuf), nil, nil, 0)
}
-func showframe(f *_func, gp *g, firstFrame bool) bool {
+func showframe(f funcInfo, gp *g, firstFrame bool) bool {
g := getg()
if g.m.throwing > 0 && gp != nil && (gp == g.m.curg || gp == g.m.caughtsig.ptr()) {
return true
@@ -690,7 +690,7 @@
return true
}
- return level > 1 || f != nil && contains(name, ".") && (!hasprefix(name, "runtime.") || isExportedRuntime(name))
+ return level > 1 || f.valid() && contains(name, ".") && (!hasprefix(name, "runtime.") || isExportedRuntime(name))
}
// isExportedRuntime reports whether name is an exported runtime function.
@@ -781,7 +781,7 @@
}
// Does f mark the top of a goroutine stack?
-func topofstack(f *_func) bool {
+func topofstack(f funcInfo) bool {
pc := f.entry
return pc == goexitPC ||
pc == mstartPC ||
