commit 76d2c1f066b1c2320d37c703b231d458b5fd224b
author Steven Moreland <smoreland@google.com> Wed May 05 20:28:58 2021 +0000
committer Steven Moreland <smoreland@google.com> Tue May 11 01:26:16 2021 +0000
tree 6e0b0093acf7528c6a20f899affbfc207dbd4812
parent bd5002b57ce855d1467cc647ea788dc9b56502d0

libbinder: RPC fixup retry logic

By always reading from the pipe in the test, we can ensure we only try
to connect to a server once it's started. After this, additional retry
logic is unneeded.

Bug: 185167543
Test: binderRpcTest
Test: binderRpcTest (after introducing 100ms sleep before 'accept4' in
    RpcServer to simulate a server that is busy doing something else or
    busy accepting other calls from other clients)
Change-Id: I9b5b2876aa74e6ef1b6e8edc4c25124c29446b86

libs/binder/tests/binderRpcTest.cpp

diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index db7f67d..b3ce744 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -327,6 +327,8 @@
                     server->iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
                     server->setMaxThreads(numThreads);
 
+                    unsigned int outPort = 0;
+
                     switch (socketType) {
                         case SocketType::UNIX:
                             CHECK(server->setupUnixDomainServer(addr.c_str())) << addr;
@@ -335,47 +337,43 @@
                             CHECK(server->setupVsockServer(vsockPort));
                             break;
                         case SocketType::INET: {
-                            unsigned int outPort = 0;
                             CHECK(server->setupInetServer(0, &outPort));
                             CHECK_NE(0, outPort);
-                            CHECK(android::base::WriteFully(pipe->writeEnd(), &outPort,
-                                                            sizeof(outPort)));
                             break;
                         }
                         default:
                             LOG_ALWAYS_FATAL("Unknown socket type");
                     }
 
+                    CHECK(android::base::WriteFully(pipe->writeEnd(), &outPort, sizeof(outPort)));
+
                     configure(server);
 
                     server->join();
                 }),
         };
 
-        unsigned int inetPort = 0;
+        // always read socket, so that we have waited for the server to start
+        unsigned int outPort = 0;
+        CHECK(android::base::ReadFully(ret.host.getPipe()->readEnd(), &outPort, sizeof(outPort)));
         if (socketType == SocketType::INET) {
-            CHECK(android::base::ReadFully(ret.host.getPipe()->readEnd(), &inetPort,
-                                           sizeof(inetPort)));
-            CHECK_NE(0, inetPort);
+            CHECK_NE(0, outPort);
         }
 
         for (size_t i = 0; i < numSessions; i++) {
             sp<RpcSession> session = RpcSession::make();
-            for (size_t tries = 0; tries < 10; tries++) {
-                usleep(10000);
-                switch (socketType) {
-                    case SocketType::UNIX:
-                        if (session->setupUnixDomainClient(addr.c_str())) goto success;
-                        break;
-                    case SocketType::VSOCK:
-                        if (session->setupVsockClient(VMADDR_CID_LOCAL, vsockPort)) goto success;
-                        break;
-                    case SocketType::INET:
-                        if (session->setupInetClient("127.0.0.1", inetPort)) goto success;
-                        break;
-                    default:
-                        LOG_ALWAYS_FATAL("Unknown socket type");
-                }
+            switch (socketType) {
+                case SocketType::UNIX:
+                    if (session->setupUnixDomainClient(addr.c_str())) goto success;
+                    break;
+                case SocketType::VSOCK:
+                    if (session->setupVsockClient(VMADDR_CID_LOCAL, vsockPort)) goto success;
+                    break;
+                case SocketType::INET:
+                    if (session->setupInetClient("127.0.0.1", outPort)) goto success;
+                    break;
+                default:
+                    LOG_ALWAYS_FATAL("Unknown socket type");
             }
             LOG_ALWAYS_FATAL("Could not connect");
         success: