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runtime: avoid repeated findmoduledatap calls

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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>
This commit is contained in:
Austin Clements 2017-02-20 22:37:07 -05:00
parent 6533cc1ce8
commit 0efc8b2188
20 changed files with 84 additions and 73 deletions
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6
src/runtime/stack.go
View file

@ -569,7 +569,7 @@ func ptrbit(bv *gobitvector, i uintptr) uint8 {
// bv describes the memory starting at address scanp.
// Adjust any pointers contained therein.
func adjustpointers(scanp unsafe.Pointer, cbv *bitvector, adjinfo *adjustinfo, f *_func) {
func adjustpointers(scanp unsafe.Pointer, cbv *bitvector, adjinfo *adjustinfo, f funcInfo) {
bv := gobv(*cbv)
minp := adjinfo.old.lo
maxp := adjinfo.old.hi
@ -589,7 +589,7 @@ func adjustpointers(scanp unsafe.Pointer, cbv *bitvector, adjinfo *adjustinfo, f
pp := (*uintptr)(add(scanp, i*sys.PtrSize))
retry:
p := *pp
if f != nil && 0 < p && p < minLegalPointer && debug.invalidptr != 0 {
if f.valid() && 0 < p && p < minLegalPointer && debug.invalidptr != 0 {
// Looks like a junk value in a pointer slot.
// Live analysis wrong?
getg().m.traceback = 2
@ -713,7 +713,7 @@ func adjustframe(frame *stkframe, arg unsafe.Pointer) bool {
if stackDebug >= 3 {
print(" args\n")
}
adjustpointers(unsafe.Pointer(frame.argp), &bv, adjinfo, nil)
adjustpointers(unsafe.Pointer(frame.argp), &bv, adjinfo, funcInfo{})
}
return true
}