LeakCanary實(shí)現(xiàn)原理：

首先將Activity用弱引用(WeakReference)包裝并綁定引用隊(duì)列(ReferenceQueue)，系統(tǒng)在gc的時(shí)候會(huì)優(yōu)先回收弱引用，同時(shí)將要回收的引用放到引用隊(duì)列中。所以只要判斷引用隊(duì)列中是否存在目標(biāo)引用，就可以判斷目標(biāo)引用是否存在內(nèi)存泄漏(如果存在則說明沒有內(nèi)存泄漏，反之則說明有內(nèi)存泄漏)。
如何保證GC立即執(zhí)行？

 GcTrigger DEFAULT = new GcTrigger() {
    @Override public void runGc() {
      // Code taken from AOSP FinalizationTest:
      // https://android.googlesource.com/platform/libcore/+/master/support/src/test/java/libcore/
      // java/lang/ref/FinalizationTester.java
      // System.gc() does not garbage collect every time. Runtime.gc() is
      // more likely to perform a gc.
      Runtime.getRuntime().gc();
      enqueueReferences();
      System.runFinalization();
    }

    private void enqueueReferences() {
      // Hack. We don't have a programmatic way to wait for the reference queue daemon to move
      // references to the appropriate queues.
      try {
        Thread.sleep(100);
      } catch (InterruptedException e) {
        throw new AssertionError();
      }
    }
  };

監(jiān)測(cè)實(shí)現(xiàn)流程：

Application初始化 -> 注冊(cè)ActivityLifecycleCallbacks ->在ActivityLifecycleCallbacks的onDestroy()中調(diào)用RefWatcher.watch()->watch()方法中判斷是否存在內(nèi)存泄漏，HeapDumper抓取dump文件并通過HeapAnalyzerService.runAnalysis分析-> 最后通過DisplayLeakService展示內(nèi)存泄漏信息