print tid of the stalling thread.

Reviewed By: yfeldblum

Differential Revision: D30914679

fbshipit-source-id: 79a609ed1eda97a97e6eeeb47038a1e746b75e2d

folly/executors/IOThreadPoolDeadlockDetectorObserver.cpp

@@ -17,6 +17,7 @@
 #include <memory>
 #include <folly/concurrency/DeadlockDetector.h>
 #include <folly/executors/IOThreadPoolDeadlockDetectorObserver.h>
+#include <folly/system/ThreadId.h>
 
 namespace folly {
 
@@ -33,8 +34,10 @@ void IOThreadPoolDeadlockDetectorObserver::threadStarted(
   auto eventBase = folly::IOThreadPoolExecutor::getEventBase(h);
   // This Observer only works with IOThreadPoolExecutor class.
   CHECK_NOTNULL(eventBase);
+  auto thid = folly::to<std::string>(folly::getOSThreadID());
+  auto name = name_ + ":" + thid;
   detectors_.wlock()->insert_or_assign(
-      h, deadlockDetectorFactory_->create(eventBase, name_));
+      h, deadlockDetectorFactory_->create(eventBase, name));
 }
 
 void IOThreadPoolDeadlockDetectorObserver::threadStopped(

folly/executors/test/IOThreadPoolDeadlockDetectorObserverTest.cpp

@@ -15,6 +15,9 @@
  */
 
 #include <memory>
+
+#include <fmt/core.h>
+
 #include <folly/concurrency/DeadlockDetector.h>
 #include <folly/executors/IOThreadPoolDeadlockDetectorObserver.h>
 #include <folly/executors/IOThreadPoolExecutor.h>
@@ -39,7 +42,9 @@ class DeadlockDetectorFactoryMock : public DeadlockDetectorFactory {
   std::unique_ptr<DeadlockDetector> create(
       folly::Executor* executor, const std::string& name) override {
     EXPECT_TRUE(executor != nullptr);
-    EXPECT_EQ("TestPool", name);
+    std::string expectedName =
+        fmt::format("TestPool:{}", folly::getOSThreadID());
+    EXPECT_EQ(expectedName, name);
     return std::make_unique<DeadlockDetectorMock>(counter_);
   }