dumpsys: add --thread option

This displays the thread usage of services in the format
"<threadsUsed>/<threadCount>". This has been useful in lshal to find
deadlocks in binder threads.

Test: atest dumpsys_test
Test: run 'dumpsys --thread' on cuttlefish and verify thread usage
Test: run 'dumpsys --thread SurfaceFlinger' and verify thread usage
Bug: 140639610
Change-Id: I0cd3f86ca47ec911b276d8e8859ef54743ee34cf
diff --git a/cmds/dumpstate/Android.bp b/cmds/dumpstate/Android.bp
index f48f1fb..aff32c3 100644
--- a/cmds/dumpstate/Android.bp
+++ b/cmds/dumpstate/Android.bp
@@ -99,6 +99,7 @@
         "libhidlbase",
         "liblog",
         "libutils",
+        "libbinderdebug",
     ],
     srcs: [
         "DumpstateService.cpp",
diff --git a/cmds/dumpsys/Android.bp b/cmds/dumpsys/Android.bp
index 91aa018..6ab6b7f 100644
--- a/cmds/dumpsys/Android.bp
+++ b/cmds/dumpsys/Android.bp
@@ -32,6 +32,7 @@
         "libutils",
         "liblog",
         "libbinder",
+        "libbinderdebug",
     ],
 
     static_libs: [
diff --git a/cmds/dumpsys/dumpsys.cpp b/cmds/dumpsys/dumpsys.cpp
index a017246..ba1c449 100644
--- a/cmds/dumpsys/dumpsys.cpp
+++ b/cmds/dumpsys/dumpsys.cpp
@@ -25,6 +25,7 @@
 #include <binder/Parcel.h>
 #include <binder/ProcessState.h>
 #include <binder/TextOutput.h>
+#include <binderdebug/BinderDebug.h>
 #include <serviceutils/PriorityDumper.h>
 #include <utils/Log.h>
 #include <utils/Vector.h>
@@ -60,13 +61,15 @@
             "usage: dumpsys\n"
             "         To dump all services.\n"
             "or:\n"
-            "       dumpsys [-t TIMEOUT] [--priority LEVEL] [--pid] [--help | -l | --skip SERVICES "
+            "       dumpsys [-t TIMEOUT] [--priority LEVEL] [--pid] [--thread] [--help | -l | "
+            "--skip SERVICES "
             "| SERVICE [ARGS]]\n"
             "         --help: shows this help\n"
             "         -l: only list services, do not dump them\n"
             "         -t TIMEOUT_SEC: TIMEOUT to use in seconds instead of default 10 seconds\n"
             "         -T TIMEOUT_MS: TIMEOUT to use in milliseconds instead of default 10 seconds\n"
             "         --pid: dump PID instead of usual dump\n"
+            "         --thread: dump thread usage instead of usual dump\n"
             "         --proto: filter services that support dumping data in proto format. Dumps\n"
             "               will be in proto format.\n"
             "         --priority LEVEL: filter services based on specified priority\n"
@@ -125,7 +128,8 @@
     Type type = Type::DUMP;
     int timeoutArgMs = 10000;
     int priorityFlags = IServiceManager::DUMP_FLAG_PRIORITY_ALL;
-    static struct option longOptions[] = {{"pid", no_argument, 0, 0},
+    static struct option longOptions[] = {{"thread", no_argument, 0, 0},
+                                          {"pid", no_argument, 0, 0},
                                           {"priority", required_argument, 0, 0},
                                           {"proto", no_argument, 0, 0},
                                           {"skip", no_argument, 0, 0},
@@ -163,6 +167,8 @@
                 }
             } else if (!strcmp(longOptions[optionIndex].name, "pid")) {
                 type = Type::PID;
+            } else if (!strcmp(longOptions[optionIndex].name, "thread")) {
+                type = Type::THREAD;
             }
             break;
 
@@ -329,6 +335,23 @@
      return OK;
 }
 
+static status_t dumpThreadsToFd(const sp<IBinder>& service, const unique_fd& fd) {
+    pid_t pid;
+    status_t status = service->getDebugPid(&pid);
+    if (status != OK) {
+        return status;
+    }
+    BinderPidInfo pidInfo;
+    status = getBinderPidInfo(BinderDebugContext::BINDER, pid, &pidInfo);
+    if (status != OK) {
+        return status;
+    }
+    WriteStringToFd("Threads in use: " + std::to_string(pidInfo.threadUsage) + "/" +
+                        std::to_string(pidInfo.threadCount) + "\n",
+                    fd.get());
+    return OK;
+}
+
 status_t Dumpsys::startDumpThread(Type type, const String16& serviceName,
                                   const Vector<String16>& args) {
     sp<IBinder> service = sm_->checkService(serviceName);
@@ -359,6 +382,9 @@
         case Type::PID:
             err = dumpPidToFd(service, remote_end);
             break;
+        case Type::THREAD:
+            err = dumpThreadsToFd(service, remote_end);
+            break;
         default:
             std::cerr << "Unknown dump type" << static_cast<int>(type) << std::endl;
             return;
diff --git a/cmds/dumpsys/dumpsys.h b/cmds/dumpsys/dumpsys.h
index 929c55c..349947c 100644
--- a/cmds/dumpsys/dumpsys.h
+++ b/cmds/dumpsys/dumpsys.h
@@ -52,13 +52,14 @@
     static void setServiceArgs(Vector<String16>& args, bool asProto, int priorityFlags);
 
     enum class Type {
-        DUMP,  // dump using `dump` function
-        PID,   // dump pid of server only
+        DUMP,    // dump using `dump` function
+        PID,     // dump pid of server only
+        THREAD,  // dump thread usage of server only
     };
 
     /**
      * Starts a thread to connect to a service and get its dump output. The thread redirects
-     * the output to a pipe. Thread must be stopped by a subsequent callto {@code
+     * the output to a pipe. Thread must be stopped by a subsequent call to {@code
      * stopDumpThread}.
      * @param serviceName
      * @param args list of arguments to pass to service dump method.
diff --git a/cmds/dumpsys/tests/Android.bp b/cmds/dumpsys/tests/Android.bp
index 6854c75..58fec30 100644
--- a/cmds/dumpsys/tests/Android.bp
+++ b/cmds/dumpsys/tests/Android.bp
@@ -19,6 +19,7 @@
         "libbase",
         "libbinder",
         "libutils",
+        "libbinderdebug",
     ],
 
     static_libs: [
@@ -26,6 +27,4 @@
         "libgmock",
         "libserviceutils",
     ],
-
-    clang: true,
 }
diff --git a/cmds/dumpsys/tests/AndroidTest.xml b/cmds/dumpsys/tests/AndroidTest.xml
index 1a8c67f..c2351d9 100644
--- a/cmds/dumpsys/tests/AndroidTest.xml
+++ b/cmds/dumpsys/tests/AndroidTest.xml
@@ -23,4 +23,4 @@
         <option name="native-test-device-path" value="/data/local/tmp" />
         <option name="module-name" value="dumpsys_test" />
     </test>
-</configuration>
\ No newline at end of file
+</configuration>
diff --git a/cmds/dumpsys/tests/dumpsys_test.cpp b/cmds/dumpsys/tests/dumpsys_test.cpp
index 67a77f6..39af7df 100644
--- a/cmds/dumpsys/tests/dumpsys_test.cpp
+++ b/cmds/dumpsys/tests/dumpsys_test.cpp
@@ -16,12 +16,15 @@
 
 #include "../dumpsys.h"
 
+#include <regex>
 #include <vector>
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 #include <android-base/file.h>
+#include <binder/Binder.h>
+#include <binder/ProcessState.h>
 #include <serviceutils/PriorityDumper.h>
 #include <utils/String16.h>
 #include <utils/String8.h>
@@ -222,6 +225,10 @@
         EXPECT_THAT(stdout_, HasSubstr(expected));
     }
 
+    void AssertOutputFormat(const std::string format) {
+        EXPECT_THAT(stdout_, testing::MatchesRegex(format));
+    }
+
     void AssertDumped(const std::string& service, const std::string& dump) {
         EXPECT_THAT(stdout_, HasSubstr("DUMP OF SERVICE " + service + ":\n" + dump));
         EXPECT_THAT(stdout_, HasSubstr("was the duration of dumpsys " + service + ", ending at: "));
@@ -574,6 +581,30 @@
     AssertOutput(std::to_string(getpid()) + "\n");
 }
 
+// Tests 'dumpsys --thread'
+TEST_F(DumpsysTest, ListAllServicesWithThread) {
+    ExpectListServices({"Locksmith", "Valet"});
+    ExpectCheckService("Locksmith");
+    ExpectCheckService("Valet");
+
+    CallMain({"--thread"});
+
+    AssertRunningServices({"Locksmith", "Valet"});
+
+    const std::string format("(.|\n)*((Threads in use: [0-9]+/[0-9]+)?\n-(.|\n)*){2}");
+    AssertOutputFormat(format);
+}
+
+// Tests 'dumpsys --thread service_name'
+TEST_F(DumpsysTest, ListServiceWithThread) {
+    ExpectCheckService("Locksmith");
+
+    CallMain({"--thread", "Locksmith"});
+    // returns an empty string without root enabled
+    const std::string format("(^$|Threads in use: [0-9]/[0-9]+\n)");
+    AssertOutputFormat(format);
+}
+
 TEST_F(DumpsysTest, GetBytesWritten) {
     const char* serviceName = "service2";
     const char* dumpContents = "dump1";
@@ -599,3 +630,13 @@
                         /* as_proto = */ false, elapsedDuration, bytesWritten);
     EXPECT_THAT(status, Eq(INVALID_OPERATION));
 }
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+
+    // start a binder thread pool for testing --thread option
+    android::ProcessState::self()->setThreadPoolMaxThreadCount(8);
+    ProcessState::self()->startThreadPool();
+
+    return RUN_ALL_TESTS();
+}