{"id":75,"date":"2024-08-24T21:23:52","date_gmt":"2024-08-24T13:23:52","guid":{"rendered":"https:\/\/newstrong.xyz\/?p=75"},"modified":"2024-08-24T21:23:52","modified_gmt":"2024-08-24T13:23:52","slug":"%e7%bb%98%e5%88%b6%e6%b5%81%e7%a8%8b%e4%b8%ad%e7%aa%a5%e8%a7%86handler%e5%90%8c%e6%ad%a5%e5%b1%8f%e9%9a%9c","status":"publish","type":"post","link":"https:\/\/newstrong.top\/index.php\/2024\/08\/24\/%e7%bb%98%e5%88%b6%e6%b5%81%e7%a8%8b%e4%b8%ad%e7%aa%a5%e8%a7%86handler%e5%90%8c%e6%ad%a5%e5%b1%8f%e9%9a%9c\/","title":{"rendered":"\u7ed8\u5236\u6d41\u7a0b\u4e2d\u7aa5\u89c6handler\u540c\u6b65\u5c4f\u969c"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u7ed8\u5236\u6d41\u7a0b\u4e2d\u7aa5\u89c6handler\u540c\u6b65\u5c4f\u969c<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><span style=\"font-family: kai;\">\u4e3a\u4e86\u5f15\u51fa\u4eca\u5929\u7684\u4e3b\u9898\uff0c\u6211\u4eec\u5148\u6765\u770b\u770bui\u7684\u6e32\u67d3\u6d41\u7a0b\u5427\u3002\u5728Android\u7684\u7ed8\u5236\u6d41\u7a0b\u4e2d\uff0cViewRootImpl\u8fd9\u4e2a\u7c7b\u53d1\u6325\u4e86\u975e\u5e38\u91cd\u8981\u7684\u4f5c\u7528\uff0c\u9996\u5148\u6211\u4eec\u770b\u4e00\u4e0b\u8fd9\u4e2a\u7c7b\u4e2d\u6bd4\u8f83\u91cd\u8981\u7684\u4e00\u4e2a\u65b9\u6cd5requestLayout(),&gt;\u4e3a\u4e86\u5f15\u51fa\u4eca\u5929\u7684\u4e3b\u9898\uff0c\u6211\u4eec\u5148\u6765\u770b\u770bui\u7684\u6e32\u67d3\u6d41\u7a0b\u5427\u3002\u5728Android\u7684\u7ed8\u5236\u6d41\u7a0b\u4e2d\uff0cViewRootImpl\u8fd9\u4e2a\u7c7b\u53d1\u6325\u4e86\u975e\u5e38\u91cd\u8981\u7684\u4f5c\u7528\uff0c\u9996\u5148\u6211\u4eec\u770b\u4e00\u4e0b\u8fd9\u4e2a\u7c7b\u4e2d\u6bd4\u8f83\u91cd\u8981\u7684\u4e00\u4e2a\u65b9\u6cd5requestLayout(),<\/span><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">&nbsp;<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>@Override\n public void requestLayout() {\n if (!mHandlingLayoutInLayoutRequest) {\n \/\/\u6821\u9a8c\u4e3b\u7ebf\u7a0b\n checkThread();\n mLayoutRequested = true;\n \/\/\u8c03\u7528\u8fd9\u4e2a\u65b9\u6cd5\u542f\u52a8\u7ed8\u5236\u6d41\u7a0b\n scheduleTraversals();\n }\n }\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code><\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">requestLayout()\u4e2d\u4f1a\u901a\u8fc7checkThread()\u65b9\u6cd5\u68c0\u67e5\u53d1\u8d77\u5e03\u5c40\u8bf7\u6c42\u7684\u7ebf\u7a0b\u662f\u5426\u4e3a\u4e3b\u7ebf\u7a0b\uff08\u6821\u9a8cViewRootImpl\u6784\u9020\u65f6\u8bb0\u5f55\u7684mThread\uff0c \u548c\u5f53\u524d\u7ebf\u7a0b\u662f\u5426\u4e00\u81f4\uff09\uff0c\u4e4b\u540e\uff0c\u5728\u8c03\u7528scheduleTraversals()\u7684\u65f6\u5019 postSyncBarrier\u6dfb\u52a0\u540c\u6b65\u6d88\u606f\u5c4f\u969c<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scss<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>@UnsupportedAppUsage void scheduleTraversals() { if (!mTraversalScheduled) { mTraversalScheduled = true; \/\/1. \u5f80\u4e3b\u7ebf\u7a0b\u7684Handler\u5bf9\u5e94\u7684MessageQueue\u53d1\u9001\u4e00\u4e2a\u540c\u6b65\u5c4f\u969c\u6d88\u606f mTraversalBarrier = mHandler.getLooper().getQueue().postSyncBarrier(); \/\/2.\u5c06mTraversalRunnable\u4fdd\u5b58\u5230Choreographer\u4e2d mChoreographer.postCallback( Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null); if (!mUnbufferedInputDispatch) { scheduleConsumeBatchedInput(); } notifyRendererOfFramePending(); pokeDrawLockIfNeeded(); } } ... \/\/\u5728doTraversal\u65b9\u6cd5\u4e2d\u79fb\u9664\u540c\u6b65\u6d88\u606f\u5c4f\u969c void doTraversal() { if (mTraversalScheduled) { mTraversalScheduled = false; \/\/\u79fb\u9664\u540c\u6b65\u5c4f\u969c mHandler.getLooper().getQueue().removeSyncBarrier(mTraversalBarrier); ... } }<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u4e2a\u65b9\u6cd5\u4e2d\uff0c\u6d89\u53ca\u5230\u4e09\u4e2a\u6bd4\u8f83\u91cd\u8981\u7684\u4fe1\u606f<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>mTraversalRunnable<\/li>\n\n\n\n<li>Choreographer\u7f16\u821e\u8005<\/li>\n\n\n\n<li>\u540c\u6b65\u5c4f\u969c\u6d88\u606f<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><br><p>\u9996\u5148\u770bmTraversalRunnable\uff0c\u5b83\u7684\u4f5c\u7528\u5c31\u662f\u4eceViewRootImpl \u4ece\u4e0a\u5f80\u4e0b\u6267\u884cperformMeasure\u3001performLayout\u3001performDraw\u3002<\/p><br><\/li>\n\n\n\n<li><br><p>Choreographer\u4e3b\u8981\u662f\u4e3a\u4e86\u914d\u5408Vsync\u4fe1\u53f7\uff0c\u7ed9\u4e0a\u5c42app\u7684\u6e32\u67d3\u63d0\u4f9b\u4e00\u4e2a\u7a33\u5b9a\u7684Message\u5904\u7406\u65f6\u673a\uff0c\u4e5f\u5c31\u662fVsync\u4fe1\u53f7\u5230\u6765\u65f6\uff0c\u7cfb\u7edf\u901a\u8fc7\u5bf9Vsync\u4fe1\u53f7\u7684\u8c03\u6574\uff0c\u6765\u63a7\u5236\u6bcf\u4e00\u5e27\u7ed8\u5236\u64cd\u4f5c\u7684\u65f6\u673a\u3002\u5f53Vsync\u4fe1\u53f7\u5230\u6765\u65f6\uff0c<strong>\u4f1a\u5f80\u4e3b\u7ebf\u7a0b\u7684MessageQueue\u4e2d\u63d2\u5165\u4e00\u6761\u5f02\u6b65\u6d88\u606f\uff0c\u7531\u4e8e\u5728scheduleTraversals\u4e2d\u7ed9MessageQueue\u4e2d\u63d2\u5165\u4e86\u540c\u6b65\u5c4f\u969c\u6d88\u606f\uff0c\u90a3\u4e48\u5f53\u6267\u884c\u5230\u540c\u6b65\u5c4f\u969c\u65f6\uff0c\u4f1a\u53d6\u51fa\u5f02\u6b65\u6d88\u606f\u6267\u884c<\/strong>\u3002 \u770b\u4e0bChoreography\u4e2d\u63d2\u5165\u6d88\u606f\u7684\u65b9\u6cd5\u662f\u5982\u4f55\u5b9e\u73b0\u7684\uff1a<\/p><br><\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">java<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>private void postCallbackDelayedInternal(int callbackType, Object action, Object token, long delayMillis) { synchronized (mLock) { ... if (dueTime &lt;= now) { scheduleFrameLocked(now); } else { Message msg = mHandler.obtainMessage(MSG_DO_SCHEDULE_CALLBACK, action); msg.arg1 = callbackType; \/\/\u8bbe\u7f6e\u4e3a\u5f02\u6b65\u6d88\u606f msg.setAsynchronous(true); mHandler.sendMessageAtTime(msg, dueTime); } } }<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7\u4ee5\u4e0a\u7684\u5206\u6790\uff0c\u6211\u4eec\u77e5\u9053\u4e86\uff0c\u5728\u5237\u65b0ui\u7684\u65f6\u5019\u539f\u6765\u4f1a\u6709\u8fd9\u4e48\u591a\u7684\u53c2\u4e0e\u8005\uff0c\u4f46\u662f\u90a3\u4e9b\u4ec0\u4e48\u540c\u6b65\u6d88\u606f\u3001\u5f02\u6b65\u6d88\u606f\u3001\u6d88\u606f\u5c4f\u969c\u53c8\u662f\u4e9b\u4ec0\u4e48\u4e1c\u897f\u5462\uff1f\u63a5\u4e0b\u6765\u6211\u4eec\u5c31\u6765\u7814\u7a76\u4e00\u4e0b\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u4f55\u4e3a\u540c\u6b65\u5c4f\u969c\uff1f<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">message\u5206\u7c7b<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Handler\u7684message\u5206\u4e3a\u4e09\u79cd<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u540c\u6b65\u6d88\u606f<\/li>\n\n\n\n<li>\u5f02\u6b65\u6d88\u606f<\/li>\n\n\n\n<li>\u5c4f\u969c\u6d88\u606f<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u5e38\u6211\u4eec\u4f7f\u7528handler\u53d1\u9001\u6d88\u606f\uff0c\u90fd\u662f\u4f7f\u7528\u9ed8\u8ba4\u7684\u6784\u9020\u51fd\u6570\u6784\u9020handler\uff0c\u7136\u540e\u4f7f\u7528send\u65b9\u6cd5\u53d1\u9001\u3002\u8fd9\u6837\u53d1\u9001\u7684\u6d88\u606f\u90fd\u662f\u666e\u901a\u6d88\u606f\u4e5f\u5c31\u662f\u540c\u6b65\u6d88\u606f\uff0c\u53d1\u51fa\u53bb\u7684\u6d88\u606f\u5c31\u4f1a\u5728MessageQueue\u4e2d\u6392\u961f\u3002\u5f02\u6b65\u6d88\u606f\u6b63\u5e38\u60c5\u51b5\u4e0b\u8ddf\u540c\u6b65\u6d88\u606f\u6ca1\u6709\u533a\u522b\uff0c\u53ea\u6709\u5728\u8bbe\u7f6e\u4e86\u540c\u6b65\u5c4f\u969c\u4e4b\u540e\uff0c\u624d\u4f1a\u51fa\u73b0\u5dee\u5f02\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u540c\u6b65\u5c4f\u969c\u5c31\u662f\u5728\u6d88\u606f\u961f\u5217\u4e2d\u63d2\u5165\u4e00\u4e2a\u5c4f\u969c\uff0c\u63d2\u5165\u4e4b\u540e\uff0c\u6240\u6709\u7684\u540c\u6b65\u6d88\u606f\u90fd\u4f1a\u88ab\u5c4f\u853d\uff0c\u4e0d\u80fd\u88ab\u6267\u884c\uff0c\u4f46\u662f\u5f02\u6b65\u6d88\u606f\u5374\u4e0d\u53d7\u5f71\u54cd\uff0c\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u63d2\u5165\u6d88\u606f\u5c4f\u969c<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b63\u5e38\u63d2\u5165\u6d88\u606f\u4f1a\u8c03\u7528enqueueMessage\u65b9\u6cd5\uff0c<strong>\u540c\u65f6\u5c06handler\u8d4b\u503c\u7ed9message\u7684target<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">less<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>\/\/\u5c06\u6d88\u606f\u63d2\u5165\u6d88\u606f\u961f\u5217 private boolean enqueueMessage(@NonNull MessageQueue queue, @NonNull Message msg, long uptimeMillis) { msg.target = this; msg.workSourceUid = ThreadLocalWorkSource.getUid(); \/\/\u8fdb\u884c\u5224\u65ad\u662f\u5426\u5c06\u6d88\u606f\u8bbe\u7f6e\u4e3a\u5f02\u6b65\u6d88\u606f if (mAsynchronous) { msg.setAsynchronous(true); } return queue.enqueueMessage(msg, uptimeMillis); }<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728MessageQueue\u4e2d\u8fdb\u884c\u5224\u65ad\uff0c\u5982\u679ctarget\u4e3a\u7a7a\u4e5f\u5c31\u662f\u8fd9\u4e2amessage\u6ca1\u6709\u5bf9\u5e94\u7684handler\u5219\u4f1a\u62a5\u5f02\u5e38\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">scss<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>boolean enqueueMessage(Message msg, long when) { if (msg.target == null) { throw new IllegalArgumentException(\"Message must have a target.\"); } if (msg.isInUse()) { throw new IllegalStateException(msg + \" This message is already in use.\"); } ... \/\/ \u5982\u679c\u9700\u8981\u5524\u9192\uff0c\u5219\u5524\u9192 if (needWake) { nativeWake(mPtr); }<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7MessageQueue\u7684postSyncBarrier\u65b9\u6cd5\u63d2\u5165\u5c4f\u969c\uff0cmessage\u7684target\u5c5e\u6027\u4e3anull<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ini<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">`private int postSyncBarrier(long when) {<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">synchronized (this) {<br>final int token = mNextBarrierToken++;<br>\/\/msg\u6ca1\u6709\u4e3atarget\u5c5e\u6027\u8d4b\u503c<br>final Message msg = Message.obtain();<br>&#8230;<br>\/\/\u6839\u636e\u65f6\u95f4\u63d2\u5165\u5230MessageQueue\u4e2d<br>if (when != 0) {<br>while (p != null &amp;&amp; p.when &lt;= when) {<br>prev = p;<br>p = p.next;<br>}<br>}<br>if (prev != null) { \/\/ invariant: p == prev.next<br>msg.next = p;<br>prev.next = msg;<br>} else {<br>msg.next = p;<br>mMessages = msg;<br>}<br>\/\/\u8fd4\u56de\u4e00\u4e2a\u5e8f\u53f7\uff0c\u901a\u8fc7\u5b83\u53ef\u4ee5\u5bf9\u5c4f\u969c\u6d88\u606f\u8fdb\u884c\u64a4\u9500<br>return token;<br>}<br>}`<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ecf\u8fc7\u4ee5\u4e0a\u7684\u64cd\u4f5c\uff0c\u6211\u4eec\u53ef\u4ee5\u603b\u7ed3\u51fa<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5c4f\u969c\u6d88\u606f\u548c\u666e\u901a\u6d88\u606f\u7684\u533a\u522b\u662f\u5c4f\u969c\u6d88\u606f\u6ca1\u6709target\u5c5e\u6027\uff0c\u666e\u901a\u6d88\u606f\u6709target\u5c5e\u6027\u662f\u56e0\u4e3a\u8981\u5c06\u6d88\u606f\u5206\u53d1\u7ed9target\u6307\u5411\u7684handler\u5904\u7406<\/li>\n\n\n\n<li>\u5c4f\u969c\u6d88\u606f\u4f1a\u63d2\u5165\u5230MessageQueue\u4e2d\u5408\u9002\u7684\u4f4d\u7f6e\uff0c\u8fd9\u4e2a\u6d88\u606f\u4ee5\u540e\u7684\u666e\u901a\u6d88\u606f\u5c06\u88ab\u5c4f\u853d<\/li>\n\n\n\n<li>postSyncBarrier\u8fd4\u56de\u4e00\u4e2aint\u7c7b\u578b\u7684\u6570\u503c\uff0c\u901a\u8fc7\u8fd9\u4e2a\u6570\u503c\u53ef\u4ee5\u64a4\u9500\u5c4f\u969c<\/li>\n\n\n\n<li>postSyncBarrier\u65b9\u6cd5\u662f\u79c1\u6709\u7684\uff0c\u5982\u679c\u6211\u4eec\u60f3\u8c03\u7528\u5b83\u5c31\u5f97\u4f7f\u7528\u53cd\u5c04<\/li>\n\n\n\n<li>\u63d2\u5165\u666e\u901a\u6d88\u606f\u4f1a\u5524\u9192\u6d88\u606f\u961f\u5217\uff0c\u4f46\u662f\u63d2\u5165\u5c4f\u969c\u4e0d\u4f1a<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">\u5982\u4f55\u53d1\u9001\u5f02\u6b65\u6d88\u606f<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u5e38\u6211\u4eec\u53d1\u9001\u7684\u90fd\u662f\u666e\u901a\u6d88\u606f\uff0c\u5982\u679c\u60f3\u53d1\u9001\u5f02\u6b65\u6d88\u606f<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u53ef\u4ee5\u5728\u521b\u5efahandler\u65f6\u4f7f\u7528\u5982\u4e0b\u7684\u6784\u9020\u5668\u4e2d\u7684\u4e00\u79cd\uff0c\u540c\u65f6\u5c06async\u53c2\u6570\u8bbe\u7f6e\u4e3atrue\uff0c\u8fd9\u6837\u8fd9\u4e2ahandler\u53d1\u9001\u7684\u6d88\u606f\u5c31\u90fd\u662f\u5f02\u6b65\u6d88\u606f\u4e86\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">less<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">`public Handler(boolean async) {<br>this(null, async);<br>}<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">public Handler(@NonNull Looper looper, @Nullable Callback callback) {<br>this(looper, callback, false);<br>}<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">public Handler(@Nullable Callback callback, boolean async) {<br>&#8230;<br>mLooper = Looper.myLooper();<br>if (mLooper == null) {<br>throw new RuntimeException(<br>&#8220;Can&#8217;t create handler inside thread &#8221; + Thread.currentThread()<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8221; that has not called Looper.prepare()&#8221;);<br>}<br>mQueue = mLooper.mQueue;<br>mCallback = callback;<br>mAsynchronous = async;<br>}`<\/li>\n\n\n\n<li>\u9664\u4e86\u8fd9\u79cd\u65b9\u5f0f\u8fd8\u53ef\u4ee5\u76f4\u63a5\u8bbe\u7f6e\u6d88\u606f\u7684\u7c7b\u578b\u4e3a\u5f02\u6b65\u6d88\u606f<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">typescript<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>public void setAsynchronous(boolean async) { if (async) { flags |= FLAG_ASYNCHRONOUS; } else { flags &amp;= ~FLAG_ASYNCHRONOUS; } }<\/code><\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u6d88\u606f\u5904\u7406\u7684\u8fc7\u7a0b<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">MessageQueue\u662f\u901a\u8fc7next\u65b9\u6cd5\u6765\u904d\u5386\u6d88\u606f\u7684<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">csharp<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>@UnsupportedAppUsage Message next() { for (;;) { nativePollOnce(ptr, nextPollTimeoutMillis); synchronized (this) { Message msg = mMessages; \/\/\u5982\u679cmsg.target\u4e3a\u7a7a\uff0c\u4e5f\u5c31\u662f\u8bf4\u662f\u4e00\u4e2a\u540c\u6b65\u5c4f\u969c\u6d88\u606f\uff0c\u5219\u8fdb\u5165\u8fd9\u4e2a\u5224\u65ad\u91cc\u9762 if (msg != null &amp;&amp; msg.target == null) { \/\/ Stalled by a barrier.  Find the next asynchronous message in the queue. \/\/\u5728\u8fd9\u4e2awhile\u5faa\u73af\u4e2d\uff0c\u627e\u5230\u6700\u8fd1\u7684\u4e00\u4e2a\u5f02\u6b65\u6d88\u606f do { prevMsg = msg; msg = msg.next; } while (msg != null &amp;&amp; !msg.isAsynchronous()); } \/\/\u627e\u5230\u4e86\u5f02\u6b65\u6d88\u606f if (msg != null) { \/\/\u5982\u679c\u6d88\u606f\u7684\u5904\u7406\u65f6\u95f4\u5c0f\u4e8e\u5f53\u524d\u65f6\u95f4 \u5219\u7b49\u5f85 if (now &lt; msg.when) { \/\/ Next message is not ready.  Set a timeout to wake up when it is ready. nextPollTimeoutMillis = (int) Math.min(msg.when - now, Integer.MAX_VALUE); } else { \/\/ Got a message. \/\/\u5904\u7406\u6d88\u606f mBlocked = false; \/\/\u5c06\u5f02\u6b65\u6d88\u606f\u79fb\u9664 if (prevMsg != null) { prevMsg.next = msg.next; } else { mMessages = msg.next; } msg.next = null; if (DEBUG) Log.v(TAG, \"Returning message: \" + msg); msg.markInUse(); \/\/\u8fd4\u56de\u5f02\u6b65\u6d88\u606f return msg; } } else { \/\/ No more messages. \/\/\u6ca1\u6709\u627e\u5230\u5f02\u6b65\u6d88\u606f\u5219\u8fdb\u5165\u963b\u585e\u72b6\u6001\uff0c\u7b49\u5f85\u88ab\u5524\u9192 nextPollTimeoutMillis = -1; } ... }<\/code><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u8fd9\u6bb5\u4ee3\u7801\u4e2d\uff0c\u53ef\u4ee5\u770b\u5230\uff0c\u5904\u7406\u8fc7\u7a0b\u4e2d\u4f1a\u5148\u5224\u65ad\u6b64\u6d88\u606f\u662f\u5426\u4e3a\u5c4f\u969c\u6d88\u606f\uff0c\u5982\u679c\u662f\u5c4f\u969c\u6d88\u606f\uff0c\u5219\u53bb\u5faa\u73af\u904d\u5386\uff0c\u76f4\u5230\u5bfb\u627e\u5230\u5f02\u6b65\u6d88\u606f\u4e3a\u6b62\u3002\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\u8df3\u8fc7\u4e86\u666e\u901a\u6d88\u606f\uff0c\u76f4\u63a5\u6267\u884c\u5f02\u6b65\u6d88\u606f\u3002<strong>\u4e5f\u5c31\u662f\u8bf4\u540c\u6b65\u5c4f\u969c\u4e3ahandler\u6d88\u606f\u673a\u5236\u63d0\u4f9b\u4e86\u4e00\u79cd\u4f18\u5148\u7ea7\u7b56\u7565\uff0c\u5f02\u6b65\u6d88\u606f\u7684\u4f18\u5148\u7ea7\u8981\u9ad8\u4e8e\u540c\u6b65\u6d88\u606f<\/strong>\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u53e6\u5916\u9700\u8981\u6ce8\u610f\u7684\u662f\uff1a<strong>\u540c\u6b65\u5c4f\u969c\u4e0d\u4f1a\u81ea\u52a8\u79fb\u9664\uff0c\u4f7f\u7528\u5b8c\u6210\u4e4b\u540e\u9700\u8981\u624b\u52a8\u79fb\u9664\uff0c\u4e0d\u7136\u4f1a\u9020\u6210\u540c\u6b65\u6d88\u606f\u65e0\u6cd5\u5904\u7406<\/strong>\u3002\u4e5f\u5c31\u662f\u4e0a\u8fb9\u63d0\u5230\u7684\uff0c\u901a\u8fc7removeSyncBarrier(int token)\u65b9\u6cd5\u8fdb\u884c\u79fb\u9664\uff0ctoken\u5c31\u662f\u4e4b\u524d\u6dfb\u52a0\u5c4f\u969c\u65f6\u8fd4\u56de\u7684token\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">arduino<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4ee3\u7801\u89e3\u8bfb<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u590d\u5236\u4ee3\u7801<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><code>public void removeSyncBarrier(int token){}<\/code><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u7ed3\u8bed<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u901a\u8fc7\u4ee5\u4e0a\u7684\u5206\u6790\uff0c\u60f3\u5fc5\u5bf9\u4e8ehandler\u6d88\u606f\u673a\u5236\u4e2d\u7684\u51e0\u79cd\u4e0d\u540c\u7684\u6d88\u606f\u6709\u4e86\u4e00\u4e2a\u66f4\u6df1\u5165\u7684\u4e86\u89e3\u4e86\u5427\uff0c\u5bf9\u4e8e\u7ed8\u5236\u6d41\u7a0b\u4e2d\uff0c\u4e3a\u4ec0\u4e48\u8981\u53d1\u9001\u4e00\u4e2a\u540c\u6b65\u5c4f\u969c\u5e76\u4e14\u53d1\u9001\u5f02\u6b65\u6d88\u606f\uff0c\u5e94\u8be5\u5fc3\u4e2d\u4e5f\u6709\u4e86\u7b54\u6848\uff0c\u4e0d\u9519\uff0c\u5c31\u662f\u4e3a\u4e86\u8ba9\u4fdd\u8bc1\u5728vsync\u4fe1\u53f7\u5230\u6765\u65f6\uff0c\u5f02\u6b65\u4efb\u52a1\u53ef\u4ee5\u4f18\u5148\u6267\u884c\uff0c\u4ece\u800c\u7ed8\u5236\u4efb\u52a1\u53ef\u4ee5\u88ab\u53ca\u65f6\u6267\u884c\uff0c\u907f\u514d\u9020\u6210\u754c\u9762\u5361\u987f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u53c2\u8003\u8d44\u6599\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a title=\"https:\/\/blog.csdn.net\/u013728021\/article\/details\/105033368\/\" href=\"https:\/\/link.juejin.cn?target=https%3A%2F%2Fblog.csdn.net%2Fu013728021%2Farticle%2Fdetails%2F105033368%2F\">blog.csdn.net\/u013728021\/&#8230;<\/a><\/li>\n\n\n\n<li><a title=\"https:\/\/blog.csdn.net\/dongrimaomaoyu\/article\/details\/115017234\" href=\"https:\/\/link.juejin.cn?target=https%3A%2F%2Fblog.csdn.net%2Fdongrimaomaoyu%2Farticle%2Fdetails%2F115017234\">blog.csdn.net\/dongrimaoma&#8230;<\/a><\/li>\n\n\n\n<li><a title=\"https:\/\/www.cnblogs.com\/renhui\/p\/12875589.html\" href=\"https:\/\/link.juejin.cn?target=https%3A%2F%2Fwww.cnblogs.com%2Frenhui%2Fp%2F12875589.html\">www.cnblogs.com\/renhui\/p\/12&#8230;<\/a><\/li>\n\n\n\n<li><a title=\"https:\/\/zhuanlan.zhihu.com\/p\/265859150\" href=\"https:\/\/link.juejin.cn?target=https%3A%2F%2Fzhuanlan.zhihu.com%2Fp%2F265859150\">zhuanlan.zhihu.com\/p\/265859150<\/a><\/li>\n\n\n\n<li><a title=\"https:\/\/www.sohu.com\/a\/462533350_468633\" href=\"https:\/\/link.juejin.cn?target=https%3A%2F%2Fwww.sohu.com%2Fa%2F462533350_468633\">www.sohu.com\/a\/462533350&#8230;<\/a><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">AI \u63d0\u95ee<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6807\u7b7e\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"\/tag\/%E9%9D%A2%E8%AF%95\">\u9762\u8bd5<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f5c\u8005\uff1a\u5934\u9876\u7684\u98ce\\<br>\u94fe\u63a5\uff1a<a href=\"https:\/\/juejin.cn\/post\/6971981915934949390\">https:\/\/juejin.cn\/post\/6971981915934949390<\/a>\\<br>\u6765\u6e90\uff1a\u7a00\u571f\u6398\u91d1\\<br>\u8457\u4f5c\u6743\u5f52\u4f5c\u8005\u6240\u6709\u3002\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u8054\u7cfb\u4f5c\u8005\u83b7\u5f97\u6388\u6743\uff0c\u975e\u5546\u4e1a\u8f6c\u8f7d\u8bf7\u6ce8\u660e\u51fa\u5904\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7ed8\u5236\u6d41\u7a0b\u4e2d\u7aa5\u89c6handler\u540c\u6b65\u5c4f\u969c \u4e3a\u4e86\u5f15\u51fa\u4eca\u5929\u7684\u4e3b\u9898\uff0c\u6211\u4eec\u5148\u6765\u770b\u770bui\u7684\u6e32\u67d3\u6d41\u7a0b\u5427\u3002\u5728Android\u7684\u7ed8\u5236&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":71,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-75","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/posts\/75","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/comments?post=75"}],"version-history":[{"count":0,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/posts\/75\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/media\/71"}],"wp:attachment":[{"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/media?parent=75"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/categories?post=75"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/newstrong.top\/index.php\/wp-json\/wp\/v2\/tags?post=75"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}