SharedPreference

SharedPreferencesImpl

    @Override
    public Editor edit() {
        // TODO: remove the need to call awaitLoadedLocked() when
        // requesting an editor.  will require some work on the
        // Editor, but then we should be able to do:
        //
        //      context.getSharedPreferences(..).edit().putString(..).apply()
        //
        // ... all without blocking.
        synchronized (mLock) {
            awaitLoadedLocked();
        }

        return new EditorImpl();//這裏會新建對象 所以不要頻繁edit
    }

commit同步

      public boolean commit() {
            long startTime = 0;

            if (DEBUG) {
                startTime = System.currentTimeMillis();
            }
            //寫入內存
            MemoryCommitResult mcr = commitToMemory();
            //寫入文件
            SharedPreferencesImpl.this.enqueueDiskWrite(
                mcr, null /* sync write on this thread okay */);
        }

apply異步

 

        public void apply() {
            final long startTime = System.currentTimeMillis();

            final MemoryCommitResult mcr = commitToMemory();

            SharedPreferencesImpl.this.enqueueDiskWrite(mcr, postWriteRunnable);
        }