[Fuchsia] Give VMOs names

runtime/vm/scavenger.cc

Index: runtime/vm/scavenger.cc
diff --git a/runtime/vm/scavenger.cc b/runtime/vm/scavenger.cc
index 2309e6ca2aa3bb5c5b08cdf062cc4556206060b5..cac038ffd168e78e3f6b6408bbfa81c43f6c9547 100644
--- a/runtime/vm/scavenger.cc
+++ b/runtime/vm/scavenger.cc
@@ -273,7 +273,7 @@ void SemiSpace::InitOnce() {
 }
 
 
-SemiSpace* SemiSpace::New(intptr_t size_in_words) {
+SemiSpace* SemiSpace::New(intptr_t size_in_words, const char* name) {
   {
     MutexLocker locker(mutex_);
     // TODO(koda): Cache one entry per size.
@@ -288,7 +288,8 @@ SemiSpace* SemiSpace::New(intptr_t size_in_words) {
   } else {
     intptr_t size_in_bytes = size_in_words << kWordSizeLog2;
     VirtualMemory* reserved = VirtualMemory::Reserve(size_in_bytes);
-    if ((reserved == NULL) || !reserved->Commit(false)) {  // Not executable.
+    const bool kExecutable = false;

[siva, 2017/06/09 21:25:46]

Ditto comment about moving the call to Heap::RegionName here.

[zra, 2017/06/09 21:47:35]

VirtualMemory and SemiSpace don't have back pointers to the Heap object to get
the isolate name. I thought it would be simpler to pass the string instead of
passing the Heap or adding back pointers.

+    if ((reserved == NULL) || !reserved->Commit(kExecutable, name)) {
       // TODO(koda): If cache_ is not empty, we could try to delete it.
       delete reserved;
       return NULL;
@@ -346,7 +347,11 @@ Scavenger::Scavenger(Heap* heap,
   const intptr_t initial_semi_capacity_in_words =
       max_semi_capacity_in_words /
       (FLAG_new_gen_growth_factor * FLAG_new_gen_growth_factor);
-  to_ = SemiSpace::New(initial_semi_capacity_in_words);
+
+  const intptr_t kVmNameSize = 128;
+  char vm_name[kVmNameSize];
+  heap_->RegionName(Heap::kNew, vm_name, kVmNameSize);
+  to_ = SemiSpace::New(initial_semi_capacity_in_words, vm_name);
   if (to_ == NULL) {
     OUT_OF_MEMORY();
   }
@@ -390,7 +395,11 @@ SemiSpace* Scavenger::Prologue(Isolate* isolate, bool invoke_api_callbacks) {
   // Flip the two semi-spaces so that to_ is always the space for allocating
   // objects.
   SemiSpace* from = to_;
-  to_ = SemiSpace::New(NewSizeInWords(from->size_in_words()));
+
+  const intptr_t kVmNameSize = 128;
+  char vm_name[kVmNameSize];
+  heap_->RegionName(Heap::kNew, vm_name, kVmNameSize);
+  to_ = SemiSpace::New(NewSizeInWords(from->size_in_words()), vm_name);
   if (to_ == NULL) {
     // TODO(koda): We could try to recover (collect old space, wait for another
     // isolate to finish scavenge, etc.).