Remove method verification results right after compiling a method

This saves memory since it allows the code arrays from methods
compiled in future methods to use the ram we just freed from the
verification results.

GmsCore.apk:
Before: dex2oat took 77.383s (threads: 2) arena alloc=6MB java alloc=30MB native alloc=77MB free=13KB
After:  dex2oat took 72.180s (threads: 2) arena alloc=6MB java alloc=30MB native alloc=60MB free=13KB

Bug: 18596910
Change-Id: I5d6df380e4fe58751a2b304202083f4d30b33b7c
(cherry picked from commit 25fda92083d5b93b38cc1f6b12ac6a44d992d6a4)
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index ab9f41a..e427471 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -23,6 +23,10 @@
 #include <vector>
 #include <unistd.h>
 
+#ifndef __APPLE__
+#include <malloc.h>  // For mallinfo
+#endif
+
 #include "base/stl_util.h"
 #include "base/timing_logger.h"
 #include "class_linker.h"
@@ -497,6 +501,7 @@
                                 TimingLogger* timings) {
   DCHECK(!Runtime::Current()->IsStarted());
   std::unique_ptr<ThreadPool> thread_pool(new ThreadPool("Compiler driver thread pool", thread_count_ - 1));
+  VLOG(compiler) << "Before precompile " << GetMemoryUsageString();
   PreCompile(class_loader, dex_files, thread_pool.get(), timings);
   Compile(class_loader, dex_files, thread_pool.get(), timings);
   if (dump_stats_) {
@@ -593,20 +598,25 @@
 void CompilerDriver::PreCompile(jobject class_loader, const std::vector<const DexFile*>& dex_files,
                                 ThreadPool* thread_pool, TimingLogger* timings) {
   LoadImageClasses(timings);
+  VLOG(compiler) << "LoadImageClasses: " << GetMemoryUsageString();
 
   Resolve(class_loader, dex_files, thread_pool, timings);
+  VLOG(compiler) << "Resolve: " << GetMemoryUsageString();
 
   if (!compiler_options_->IsVerificationEnabled()) {
-    LOG(INFO) << "Verify none mode specified, skipping verification.";
+    VLOG(compiler) << "Verify none mode specified, skipping verification.";
     SetVerified(class_loader, dex_files, thread_pool, timings);
     return;
   }
 
   Verify(class_loader, dex_files, thread_pool, timings);
+  VLOG(compiler) << "Verify: " << GetMemoryUsageString();
 
   InitializeClasses(class_loader, dex_files, thread_pool, timings);
+  VLOG(compiler) << "InitializeClasses: " << GetMemoryUsageString();
 
   UpdateImageClasses(timings);
+  VLOG(compiler) << "UpdateImageClasses: " << GetMemoryUsageString();
 }
 
 bool CompilerDriver::IsImageClass(const char* descriptor) const {
@@ -2002,6 +2012,7 @@
     CHECK(dex_file != nullptr);
     CompileDexFile(class_loader, *dex_file, dex_files, thread_pool, timings);
   }
+  VLOG(compiler) << "Compile: " << GetMemoryUsageString();
 }
 
 void CompilerDriver::CompileClass(const ParallelCompilationManager* manager, size_t class_def_index) {
@@ -2128,6 +2139,7 @@
                                    bool compilation_enabled) {
   CompiledMethod* compiled_method = nullptr;
   uint64_t start_ns = kTimeCompileMethod ? NanoTime() : 0;
+  MethodReference method_ref(&dex_file, method_idx);
 
   if ((access_flags & kAccNative) != 0) {
     // Are we interpreting only and have support for generic JNI down calls?
@@ -2141,7 +2153,6 @@
   } else if ((access_flags & kAccAbstract) != 0) {
     // Abstract methods don't have code.
   } else {
-    MethodReference method_ref(&dex_file, method_idx);
     bool compile = compilation_enabled &&
                    verification_results_->IsCandidateForCompilation(method_ref, access_flags);
     if (compile) {
@@ -2178,16 +2189,18 @@
     // When compiling with PIC, there should be zero non-relative linker patches
     CHECK(!compile_pic || non_relative_linker_patch_count == 0u);
 
-    MethodReference ref(&dex_file, method_idx);
-    DCHECK(GetCompiledMethod(ref) == nullptr) << PrettyMethod(method_idx, dex_file);
+    DCHECK(GetCompiledMethod(method_ref) == nullptr) << PrettyMethod(method_idx, dex_file);
     {
       MutexLock mu(self, compiled_methods_lock_);
-      compiled_methods_.Put(ref, compiled_method);
+      compiled_methods_.Put(method_ref, compiled_method);
       non_relative_linker_patch_count_ += non_relative_linker_patch_count;
     }
-    DCHECK(GetCompiledMethod(ref) != nullptr) << PrettyMethod(method_idx, dex_file);
+    DCHECK(GetCompiledMethod(method_ref) != nullptr) << PrettyMethod(method_idx, dex_file);
   }
 
+  // Done compiling, delete the verified method to reduce native memory usage.
+  verification_results_->RemoveVerifiedMethod(method_ref);
+
   if (self->IsExceptionPending()) {
     ScopedObjectAccess soa(self);
     LOG(FATAL) << "Unexpected exception compiling: " << PrettyMethod(method_idx, dex_file) << "\n"
@@ -2337,4 +2350,21 @@
   }
   return !compile;
 }
+
+std::string CompilerDriver::GetMemoryUsageString() const {
+  std::ostringstream oss;
+  const ArenaPool* arena_pool = GetArenaPool();
+  gc::Heap* heap = Runtime::Current()->GetHeap();
+  oss << "arena alloc=" << PrettySize(arena_pool->GetBytesAllocated());
+  oss << " java alloc=" << PrettySize(heap->GetBytesAllocated());
+#ifdef HAVE_MALLOC_H
+  struct mallinfo info = mallinfo();
+  const size_t allocated_space = static_cast<size_t>(info.uordblks);
+  const size_t free_space = static_cast<size_t>(info.fordblks);
+  oss << " native alloc=" << PrettySize(allocated_space) << " free="
+      << PrettySize(free_space);
+#endif
+  return oss.str();
+}
+
 }  // namespace art