Remove unnecessary full GCs before snapshot creation.

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "lib/stacktrace.h"
@@ skipping 1464 matching lines @@
     RETURN_NULL_ERROR(isolate_snapshot_buffer);
   }
   if (isolate_snapshot_size == NULL) {
     RETURN_NULL_ERROR(isolate_snapshot_size);
   }
   // Finalize all classes if needed.
   Dart_Handle state = Api::CheckAndFinalizePendingClasses(T);
   if (::Dart_IsError(state)) {
     return state;
   }
-  I->heap()->CollectAllGarbage();
   I->StopBackgroundCompiler();
 
 #if defined(DEBUG)
+  I->heap()->CollectAllGarbage();
   FunctionVisitor check_canonical(T);
   I->heap()->IterateObjects(&check_canonical);
-#endif  // #if defined(DEBUG).
+#endif  // #if defined(DEBUG)
 
   FullSnapshotWriter writer(Snapshot::kCore,
                             vm_isolate_snapshot_buffer,
                             isolate_snapshot_buffer,
                             ApiReallocate,
                             NULL, /* instructions_writer */
                             true /* vm_isolate_is_symbolic */);
   writer.WriteFullSnapshot();
   *vm_isolate_snapshot_size = writer.VmIsolateSnapshotSize();
   *isolate_snapshot_size = writer.IsolateSnapshotSize();
@@ skipping 16 matching lines @@
   Dart_Handle state = Api::CheckAndFinalizePendingClasses(T);
   if (::Dart_IsError(state)) {
     return state;
   }
   Library& lib = Library::Handle(Z);
   if (library == Dart_Null()) {
     lib ^= I->object_store()->root_library();
   } else {
     lib ^= Api::UnwrapHandle(library);
   }
+
+#if defined(DEBUG)
   I->heap()->CollectAllGarbage();
-#if defined(DEBUG)
   FunctionVisitor check_canonical(T);
   I->heap()->IterateObjects(&check_canonical);
-#endif  // #if defined(DEBUG).
+#endif  // #if defined(DEBUG)
+
   ScriptSnapshotWriter writer(buffer, ApiReallocate);
   writer.WriteScriptSnapshot(lib);
   *size = writer.BytesWritten();
   return Api::Success();
 }
 
 
 DART_EXPORT Dart_Handle Dart_CreateScriptSnapshot(uint8_t** buffer,
                                                   intptr_t* size) {
   API_TIMELINE_DURATION;
@@ skipping 4565 matching lines @@
   }
   if (isolate_snapshot_size == NULL) {
     RETURN_NULL_ERROR(isolate_snapshot_size);
   }
   if (assembly_buffer == NULL) {
     RETURN_NULL_ERROR(assembly_buffer);
   }
   if (assembly_size == NULL) {
     RETURN_NULL_ERROR(assembly_size);
   }
-  I->heap()->CollectAllGarbage();
   AssemblyInstructionsWriter instructions_writer(assembly_buffer,
                                                  ApiReallocate,
                                                  2 * MB /* initial_size */);
   FullSnapshotWriter writer(Snapshot::kAppNoJIT,
                             vm_isolate_snapshot_buffer,
                             isolate_snapshot_buffer,
                             ApiReallocate,
                             &instructions_writer,
                             false /* vm_isolate_is_symbolic */);
 
@@ skipping 40 matching lines @@
   }
   if (instructions_blob_size == NULL) {
     RETURN_NULL_ERROR(instructions_blob_size);
   }
   if (rodata_blob_buffer == NULL) {
     RETURN_NULL_ERROR(instructions_blob_buffer);
   }
   if (rodata_blob_size == NULL) {
     RETURN_NULL_ERROR(instructions_blob_size);
   }
-  I->heap()->CollectAllGarbage();
   BlobInstructionsWriter instructions_writer(instructions_blob_buffer,
                                              rodata_blob_buffer,
                                              ApiReallocate,
                                              2 * MB /* initial_size */);
   FullSnapshotWriter writer(Snapshot::kAppNoJIT,
                             vm_isolate_snapshot_buffer,
                             isolate_snapshot_buffer,
                             ApiReallocate,
                             &instructions_writer,
                             false /* vm_isolate_is_symbolic */);
@@ skipping 76 matching lines @@
     RETURN_NULL_ERROR(instructions_blob_buffer);
   }
   if (rodata_blob_size == NULL) {
     RETURN_NULL_ERROR(instructions_blob_size);
   }
   // Finalize all classes if needed.
   Dart_Handle state = Api::CheckAndFinalizePendingClasses(T);
   if (::Dart_IsError(state)) {
     return state;
   }
-  I->heap()->CollectAllGarbage();
   I->StopBackgroundCompiler();
 
   BlobInstructionsWriter instructions_writer(instructions_blob_buffer,
                                              rodata_blob_buffer,
                                              ApiReallocate,
                                              2 * MB /* initial_size */);
   FullSnapshotWriter writer(Snapshot::kAppWithJIT,
                             vm_isolate_snapshot_buffer,
                             isolate_snapshot_buffer,
                             ApiReallocate,
@@ skipping 16 matching lines @@
 
 DART_EXPORT bool Dart_IsPrecompiledRuntime() {
 #if defined(DART_PRECOMPILED_RUNTIME)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace dart