VM: Precompiled rodata snapshot.

runtime/vm/pages.cc

Index: runtime/vm/pages.cc
diff --git a/runtime/vm/pages.cc b/runtime/vm/pages.cc
index 5d5df0e2d559398f7494b34059206646c3399233..197e40960fb7ad181d6c4f0f874b0e6991cef6a0 100644
--- a/runtime/vm/pages.cc
+++ b/runtime/vm/pages.cc
@@ -1061,7 +1061,9 @@ uword PageSpace::TryAllocateSmiInitializedLocked(intptr_t size,
 }
 
 
-void PageSpace::SetupInstructionsSnapshotPage(void* pointer, uword size) {
+void PageSpace::SetupInstructionsSnapshotPage(void* pointer,
+                                              uword size,
+                                              bool is_executable) {
   // Setup a HeapPage so precompiled Instructions can be traversed.
   // Instructions are contiguous at [pointer, pointer + size). HeapPage
   // expects to find objects at [memory->start() + ObjectStartOffset,
@@ -1070,23 +1072,30 @@ void PageSpace::SetupInstructionsSnapshotPage(void* pointer, uword size) {
   pointer = reinterpret_cast<void*>(reinterpret_cast<uword>(pointer) - offset);
   size += offset;
 
-  ASSERT(Utils::IsAligned(pointer, OS::PreferredCodeAlignment()));
-
   VirtualMemory* memory = VirtualMemory::ForInstructionsSnapshot(pointer, size);

[rmacnak, 2016/01/15 00:57:01]

rename to VirtualMemory::ForExternalPage

[Florian Schneider, 2016/01/15 15:56:01]

Done.

   ASSERT(memory != NULL);
   HeapPage* page = reinterpret_cast<HeapPage*>(malloc(sizeof(HeapPage)));
   page->memory_ = memory;
   page->next_ = NULL;
   page->object_end_ = memory->end();
-  page->executable_ = true;
 
   MutexLocker ml(pages_lock_);
-  if (exec_pages_ == NULL) {
-    exec_pages_ = page;
+  HeapPage** first, **tail;
+  if (is_executable) {
+    ASSERT(Utils::IsAligned(pointer, OS::PreferredCodeAlignment()));
+    page->executable_ = true;
+    first = &exec_pages_;
+    tail = &exec_pages_tail_;
+  } else {
+    first = &pages_;
+    tail = &pages_tail_;
+  }
+  if (*first == NULL) {
+    *first = page;
   } else {
-    exec_pages_tail_->set_next(page);
+    (*tail)->set_next(page);
   }
-  exec_pages_tail_ = page;
+  (*tail) = page;
 }