diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 39befbe..b66e89e 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -539,7 +539,7 @@
         return UNEXPECTED_NULL;
     }
 
-    size_t binderThreadPoolMaxCount = ProcessState::self()->getThreadPoolMaxThreadCount();
+    size_t binderThreadPoolMaxCount = ProcessState::self()->getThreadPoolMaxTotalThreadCount();
     if (binderThreadPoolMaxCount <= 1) {
         ALOGE("%s: ProcessState thread pool max count is %zu. RPC is disabled for this service "
               "because RPC requires the service to support multithreading.",
diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index d453ac7..d536219 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -638,7 +638,9 @@
 void IPCThreadState::joinThreadPool(bool isMain)
 {
     LOG_THREADPOOL("**** THREAD %p (PID %d) IS JOINING THE THREAD POOL\n", (void*)pthread_self(), getpid());
-
+    pthread_mutex_lock(&mProcess->mThreadCountLock);
+    mProcess->mCurrentThreads++;
+    pthread_mutex_unlock(&mProcess->mThreadCountLock);
     mOut.writeInt32(isMain ? BC_ENTER_LOOPER : BC_REGISTER_LOOPER);
 
     mIsLooper = true;
@@ -666,6 +668,13 @@
     mOut.writeInt32(BC_EXIT_LOOPER);
     mIsLooper = false;
     talkWithDriver(false);
+    pthread_mutex_lock(&mProcess->mThreadCountLock);
+    LOG_ALWAYS_FATAL_IF(mProcess->mCurrentThreads == 0,
+                        "Threadpool thread count = 0. Thread cannot exist and exit in empty "
+                        "threadpool\n"
+                        "Misconfiguration. Increase threadpool max threads configuration\n");
+    mProcess->mCurrentThreads--;
+    pthread_mutex_unlock(&mProcess->mThreadCountLock);
 }
 
 status_t IPCThreadState::setupPolling(int* fd)
@@ -677,6 +686,9 @@
     mOut.writeInt32(BC_ENTER_LOOPER);
     flushCommands();
     *fd = mProcess->mDriverFD;
+    pthread_mutex_lock(&mProcess->mThreadCountLock);
+    mProcess->mCurrentThreads++;
+    pthread_mutex_unlock(&mProcess->mThreadCountLock);
     return 0;
 }
 
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index c4cf3e6..90b59d0 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -182,7 +182,6 @@
             ALOGW("Extra binder thread started, but 0 threads requested. Do not use "
                   "*startThreadPool when zero threads are requested.");
         }
-
         mThreadPoolStarted = true;
         spawnPooledThread(true);
     }
@@ -386,6 +385,7 @@
         ALOGV("Spawning new pooled thread, name=%s\n", name.string());
         sp<Thread> t = sp<PoolThread>::make(isMain);
         t->run(name.string());
+        mKernelStartedThreads++;
     }
 }
 
@@ -402,12 +402,20 @@
     return result;
 }
 
-size_t ProcessState::getThreadPoolMaxThreadCount() const {
+size_t ProcessState::getThreadPoolMaxTotalThreadCount() const {
     // may actually be one more than this, if join is called
-    if (mThreadPoolStarted) return mMaxThreads;
+    if (mThreadPoolStarted) {
+        return mCurrentThreads < mKernelStartedThreads
+                ? mMaxThreads
+                : mMaxThreads + mCurrentThreads - mKernelStartedThreads;
+    }
     // must not be initialized or maybe has poll thread setup, we
     // currently don't track this in libbinder
-    return 0;
+    LOG_ALWAYS_FATAL_IF(mKernelStartedThreads != 0,
+                        "Expecting 0 kernel started threads but have"
+                        " %zu",
+                        mKernelStartedThreads);
+    return mCurrentThreads;
 }
 
 #define DRIVER_FEATURES_PATH "/dev/binderfs/features/"
@@ -493,6 +501,8 @@
         mExecutingThreadsCount(0),
         mWaitingForThreads(0),
         mMaxThreads(DEFAULT_MAX_BINDER_THREADS),
+        mCurrentThreads(0),
+        mKernelStartedThreads(0),
         mStarvationStartTimeMs(0),
         mForked(false),
         mThreadPoolStarted(false),
diff --git a/libs/binder/include/binder/ProcessState.h b/libs/binder/include/binder/ProcessState.h
index 5820802..e17a76c 100644
--- a/libs/binder/include/binder/ProcessState.h
+++ b/libs/binder/include/binder/ProcessState.h
@@ -84,11 +84,11 @@
     void setCallRestriction(CallRestriction restriction);
 
     /**
-     * Get the max number of threads that the kernel can start.
-     *
-     * Note: this is the lower bound. Additional threads may be started.
+     * Get the max number of threads that have joined the thread pool.
+     * This includes kernel started threads, user joined threads and polling
+     * threads if used.
      */
-    size_t getThreadPoolMaxThreadCount() const;
+    size_t getThreadPoolMaxTotalThreadCount() const;
 
     enum class DriverFeature {
         ONEWAY_SPAM_DETECTION,
@@ -133,8 +133,12 @@
     size_t mExecutingThreadsCount;
     // Number of threads calling IPCThreadState::blockUntilThreadAvailable()
     size_t mWaitingForThreads;
-    // Maximum number for binder threads allowed for this process.
+    // Maximum number of lazy threads to be started in the threadpool by the kernel.
     size_t mMaxThreads;
+    // Current number of threads inside the thread pool.
+    size_t mCurrentThreads;
+    // Current number of pooled threads inside the thread pool.
+    size_t mKernelStartedThreads;
     // Time when thread pool was emptied
     int64_t mStarvationStartTimeMs;
 
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index 57a1fda..a0f12cf 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -82,6 +82,7 @@
 static constexpr int kSchedPolicy = SCHED_RR;
 static constexpr int kSchedPriority = 7;
 static constexpr int kSchedPriorityMore = 8;
+static constexpr int kKernelThreads = 15;
 
 static String16 binderLibTestServiceName = String16("test.binderLib");
 
@@ -115,6 +116,12 @@
     BINDER_LIB_TEST_ECHO_VECTOR,
     BINDER_LIB_TEST_REJECT_OBJECTS,
     BINDER_LIB_TEST_CAN_GET_SID,
+    BINDER_LIB_TEST_GET_MAX_THREAD_COUNT,
+    BINDER_LIB_TEST_SET_MAX_THREAD_COUNT,
+    BINDER_LIB_TEST_LOCK_UNLOCK,
+    BINDER_LIB_TEST_PROCESS_LOCK,
+    BINDER_LIB_TEST_UNLOCK_AFTER_MS,
+    BINDER_LIB_TEST_PROCESS_TEMPORARY_LOCK
 };
 
 pid_t start_server_process(int arg2, bool usePoll = false)
@@ -1232,6 +1239,76 @@
     EXPECT_EQ(sm->unregisterForNotifications(String16("RogerRafa"), cb), OK);
 }
 
+TEST_F(BinderLibTest, ThreadPoolAvailableThreads) {
+    Parcel data, reply;
+    sp<IBinder> server = addServer();
+    ASSERT_TRUE(server != nullptr);
+    EXPECT_THAT(server->transact(BINDER_LIB_TEST_GET_MAX_THREAD_COUNT, data, &reply),
+                StatusEq(NO_ERROR));
+    int32_t replyi = reply.readInt32();
+    // Expect 16 threads: kKernelThreads = 15 + Pool thread == 16
+    EXPECT_TRUE(replyi == kKernelThreads || replyi == kKernelThreads + 1);
+    EXPECT_THAT(server->transact(BINDER_LIB_TEST_PROCESS_LOCK, data, &reply), NO_ERROR);
+
+    /*
+     * This will use all threads in the pool expect the main pool thread.
+     * The service should run fine without locking, and the thread count should
+     * not exceed 16 (15 Max + pool thread).
+     */
+    std::vector<std::thread> ts;
+    for (size_t i = 0; i < kKernelThreads - 1; i++) {
+        ts.push_back(std::thread([&] {
+            EXPECT_THAT(server->transact(BINDER_LIB_TEST_LOCK_UNLOCK, data, &reply), NO_ERROR);
+        }));
+    }
+
+    data.writeInt32(1);
+    // Give a chance for all threads to be used
+    EXPECT_THAT(server->transact(BINDER_LIB_TEST_UNLOCK_AFTER_MS, data, &reply), NO_ERROR);
+
+    for (auto &t : ts) {
+        t.join();
+    }
+
+    EXPECT_THAT(server->transact(BINDER_LIB_TEST_GET_MAX_THREAD_COUNT, data, &reply),
+                StatusEq(NO_ERROR));
+    replyi = reply.readInt32();
+    // No more than 16 threads should exist.
+    EXPECT_EQ(replyi, kKernelThreads + 1);
+}
+
+size_t epochMillis() {
+    using std::chrono::duration_cast;
+    using std::chrono::milliseconds;
+    using std::chrono::seconds;
+    using std::chrono::system_clock;
+    return duration_cast<milliseconds>(system_clock::now().time_since_epoch()).count();
+}
+
+TEST_F(BinderLibTest, HangingServices) {
+    Parcel data, reply;
+    sp<IBinder> server = addServer();
+    ASSERT_TRUE(server != nullptr);
+    int32_t delay = 1000; // ms
+    data.writeInt32(delay);
+    EXPECT_THAT(server->transact(BINDER_LIB_TEST_PROCESS_TEMPORARY_LOCK, data, &reply), NO_ERROR);
+    std::vector<std::thread> ts;
+    size_t epochMsBefore = epochMillis();
+    for (size_t i = 0; i < kKernelThreads + 1; i++) {
+        ts.push_back(std::thread([&] {
+            EXPECT_THAT(server->transact(BINDER_LIB_TEST_LOCK_UNLOCK, data, &reply), NO_ERROR);
+        }));
+    }
+
+    for (auto &t : ts) {
+        t.join();
+    }
+    size_t epochMsAfter = epochMillis();
+
+    // deadlock occurred and threads only finished after 1s passed.
+    EXPECT_GE(epochMsAfter, epochMsBefore + delay);
+}
+
 class BinderLibRpcTestBase : public BinderLibTest {
 public:
     void SetUp() override {
@@ -1638,11 +1715,41 @@
             case BINDER_LIB_TEST_CAN_GET_SID: {
                 return IPCThreadState::self()->getCallingSid() == nullptr ? BAD_VALUE : NO_ERROR;
             }
+            case BINDER_LIB_TEST_GET_MAX_THREAD_COUNT: {
+                reply->writeInt32(ProcessState::self()->getThreadPoolMaxTotalThreadCount());
+                return NO_ERROR;
+            }
+            case BINDER_LIB_TEST_PROCESS_LOCK: {
+                blockMutex.lock();
+                return NO_ERROR;
+            }
+            case BINDER_LIB_TEST_LOCK_UNLOCK: {
+                std::lock_guard<std::mutex> _l(blockMutex);
+                return NO_ERROR;
+            }
+            case BINDER_LIB_TEST_UNLOCK_AFTER_MS: {
+                int32_t ms = data.readInt32();
+                return unlockInMs(ms);
+            }
+            case BINDER_LIB_TEST_PROCESS_TEMPORARY_LOCK: {
+                blockMutex.lock();
+                std::thread t([&] {
+                    unlockInMs(data.readInt32());
+                }); // start local thread to unlock in 1s
+                t.detach();
+                return NO_ERROR;
+            }
             default:
                 return UNKNOWN_TRANSACTION;
         };
     }
 
+    status_t unlockInMs(int32_t ms) {
+        usleep(ms * 1000);
+        blockMutex.unlock();
+        return NO_ERROR;
+    }
+
 private:
     int32_t m_id;
     int32_t m_nextServerId;
@@ -1653,6 +1760,7 @@
     sp<IBinder> m_strongRef;
     sp<IBinder> m_callback;
     bool m_exitOnDestroy;
+    std::mutex blockMutex;
 };
 
 int run_server(int index, int readypipefd, bool usePoll)
@@ -1754,6 +1862,7 @@
              }
         }
     } else {
+        ProcessState::self()->setThreadPoolMaxThreadCount(kKernelThreads);
         ProcessState::self()->startThreadPool();
         IPCThreadState::self()->joinThreadPool();
     }