Add an interface to Space, so Heap no longer needs to be friend of Space.
Also, fix and add comments with respect to utilization.
Change-Id: Ia9d27cc16d2b85ac97a48fee80567829f41224f4
diff --git a/src/heap.cc b/src/heap.cc
index 98552a7..eae772f 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -353,7 +353,7 @@
ptr = space->AllocWithGrowth(size);
if (ptr != NULL) {
//size_t new_footprint = dvmHeapSourceGetIdealFootprint();
- size_t new_footprint = space->MaxAllowedFootprint();
+ size_t new_footprint = space->GetMaxAllowedFootprint();
// TODO: may want to grow a little bit more so that the amount of
// free space is equal to the old free space + the
// utilization slop for the new allocation.
@@ -497,8 +497,8 @@
* 3. Soft footprint: external allocation + spaces footprint + active space footprint
* 4. Overhead: soft footprint excluding active.
*
- * Layout: (Below might be incontiguous, but are lumped together to depict size.)
- * |---for external allocation---|---spaces footprint ("heap1")---|----active space footprint----|
+ * Layout: (The spaces below might not be contiguous, but are lumped together to depict size.)
+ * |----------------------spaces footprint--------- --------------|----active space footprint----|
* |--active space allocated--|
* |--------------------soft footprint (include active)--------------------------------------|
* |----------------soft footprint excluding active---------------|
@@ -520,26 +520,14 @@
max_allowed_footprint = Heap::maximum_size_;
}
- SetSoftLimit(max_allowed_footprint);
+ alloc_space_->SetMaxAllowedFootprint(max_allowed_footprint);
}
-void Heap::SetSoftLimit(size_t soft_limit)
-{
- // Compare against the actual footprint, rather than the
- // max_allowed, because the heap may not have grown all the
- // way to the allowed size yet.
- //
- size_t current_space_size = mspace_footprint(alloc_space_->mspace_);
- if (soft_limit < current_space_size) {
- // Don't let the space grow any more, and impose a soft limit.
- mspace_set_max_allowed_footprint(alloc_space_->mspace_, current_space_size);
- } else {
- // Let the heap grow to the requested max
- mspace_set_max_allowed_footprint(alloc_space_->mspace_, soft_limit);
- }
-}
-
-static const size_t kHeapIdealFree = 1024 * 1024 * 2;
+// kHeapIdealFree is the ideal maximum free size, when we grow the heap for
+// utlization.
+static const size_t kHeapIdealFree = 2 * MB;
+// kHeapMinFree guarantees that you always have at least 512 KB free, when
+// you grow for utilization, regardless of target utilization ratio.
static const size_t kHeapMinFree = kHeapIdealFree / 4;
// Given the current contents of the active space, increase the allowed
diff --git a/src/heap.h b/src/heap.h
index d847a87..c25803f 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -92,8 +92,9 @@
static void SetTargetHeapUtilization(float target) {
target_utilization_ = target;
}
+ // Sets the maximum number of bytes that the heap is allowed to allocate
+ // from the system. Clamps to the appropriate maximum value.
static void SetIdealFootprint(size_t max_allowed_footprint);
- static void SetSoftLimit(size_t soft_limit);
// Blocks the caller until the garbage collector becomes idle.
static void WaitForConcurrentGcToComplete();
diff --git a/src/space.cc b/src/space.cc
index 1852b0d..1b887d8 100644
--- a/src/space.cc
+++ b/src/space.cc
@@ -203,11 +203,29 @@
mspace_walk_free_pages(mspace_, DontNeed, &num_bytes_released);
}
-size_t Space::MaxAllowedFootprint() {
+size_t Space::GetMaxAllowedFootprint() {
DCHECK(mspace_ != NULL);
return mspace_max_allowed_footprint(mspace_);
}
+void Space::SetMaxAllowedFootprint(size_t limit)
+{
+ DCHECK(mspace_ != NULL);
+
+ // Compare against the actual footprint, rather than the
+ // max_allowed, because the heap may not have grown all the
+ // way to the allowed size yet.
+ //
+ size_t current_space_size = mspace_footprint(mspace_);
+ if (limit < current_space_size) {
+ // Don't let the space grow any more.
+ mspace_set_max_allowed_footprint(mspace_, current_space_size);
+ } else {
+ // Let the heap grow to the requested limit.
+ mspace_set_max_allowed_footprint(mspace_, limit);
+ }
+}
+
void Space::Grow(size_t new_size) {
UNIMPLEMENTED(FATAL);
}
diff --git a/src/space.h b/src/space.h
index 83c94a0..758d80c 100644
--- a/src/space.h
+++ b/src/space.h
@@ -36,7 +36,8 @@
void Trim();
- size_t MaxAllowedFootprint();
+ size_t GetMaxAllowedFootprint();
+ void SetMaxAllowedFootprint(size_t limit);
void Grow(size_t num_bytes);
@@ -102,8 +103,6 @@
byte* limit_;
- friend class Heap;
-
DISALLOW_COPY_AND_ASSIGN(Space);
};