Use snprintf for SurfaceFlinger fence name
snprintf is significantly faster than String8::format
This change saves ~50us per frame on Android Wear
Change-Id: I6ac47c2434662ca561208daae232f02a9f136aaf
diff --git a/include/ui/Fence.h b/include/ui/Fence.h
index b431bd5..23a8658 100644
--- a/include/ui/Fence.h
+++ b/include/ui/Fence.h
@@ -79,6 +79,9 @@
// becomes signaled when both f1 and f2 are signaled (even if f1 or f2 is
// destroyed before it becomes signaled). The name argument specifies the
// human-readable name to associated with the new Fence object.
+ static sp<Fence> merge(const char* name, const sp<Fence>& f1,
+ const sp<Fence>& f2);
+
static sp<Fence> merge(const String8& name, const sp<Fence>& f1,
const sp<Fence>& f2);
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index a1bdf4a..e7bc7dc 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -315,9 +315,10 @@
if (!mSlots[slot].mFence.get()) {
mSlots[slot].mFence = fence;
} else {
+ char fenceName[32] = {};
+ snprintf(fenceName, 32, "%.28s:%d", mName.string(), slot);
sp<Fence> mergedFence = Fence::merge(
- String8::format("%.28s:%d", mName.string(), slot),
- mSlots[slot].mFence, fence);
+ fenceName, mSlots[slot].mFence, fence);
if (!mergedFence.get()) {
CB_LOGE("failed to merge release fences");
// synchronization is broken, the best we can do is hope fences
diff --git a/libs/ui/Fence.cpp b/libs/ui/Fence.cpp
index bf24ffb..7cf8233 100644
--- a/libs/ui/Fence.cpp
+++ b/libs/ui/Fence.cpp
@@ -72,7 +72,7 @@
return err < 0 ? -errno : status_t(NO_ERROR);
}
-sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
+sp<Fence> Fence::merge(const char* name, const sp<Fence>& f1,
const sp<Fence>& f2) {
ATRACE_CALL();
int result;
@@ -80,24 +80,29 @@
// valid fence (e.g. NO_FENCE) we merge the one valid fence with itself so
// that a new fence with the given name is created.
if (f1->isValid() && f2->isValid()) {
- result = sync_merge(name.string(), f1->mFenceFd, f2->mFenceFd);
+ result = sync_merge(name, f1->mFenceFd, f2->mFenceFd);
} else if (f1->isValid()) {
- result = sync_merge(name.string(), f1->mFenceFd, f1->mFenceFd);
+ result = sync_merge(name, f1->mFenceFd, f1->mFenceFd);
} else if (f2->isValid()) {
- result = sync_merge(name.string(), f2->mFenceFd, f2->mFenceFd);
+ result = sync_merge(name, f2->mFenceFd, f2->mFenceFd);
} else {
return NO_FENCE;
}
if (result == -1) {
status_t err = -errno;
ALOGE("merge: sync_merge(\"%s\", %d, %d) returned an error: %s (%d)",
- name.string(), f1->mFenceFd, f2->mFenceFd,
+ name, f1->mFenceFd, f2->mFenceFd,
strerror(-err), err);
return NO_FENCE;
}
return sp<Fence>(new Fence(result));
}
+sp<Fence> Fence::merge(const String8& name, const sp<Fence>& f1,
+ const sp<Fence>& f2) {
+ return merge(name.string(), f1, f2);
+}
+
int Fence::dup() const {
return ::dup(mFenceFd);
}