Add executor pointer to guard and log that plus name

Summary: Add a separate tag to the blocking guards, derived by default from the names available in the executors. This allows more fine-grained information when reporting blocking operations on the executors.

Reviewed By: yfeldblum

Differential Revision: D28265296

fbshipit-source-id: 98d877ab13dc73c0b0b06edbdf15ec0e06f4d74a

folly/Executor.cpp

@@ -46,7 +46,7 @@ void Executor::keepAliveRelease() noexcept {
 }
 
 // Base case of permitting with no termination to avoid nullptr tests
-static ExecutorBlockingList emptyList{nullptr, {false, false, {}}};
+static ExecutorBlockingList emptyList{nullptr, {false, false, nullptr, {}}};
 
 thread_local ExecutorBlockingList* executor_blocking_list = &emptyList;
 
@@ -61,30 +61,40 @@ ExecutorBlockingGuard::ExecutorBlockingGuard(PermitTag) noexcept {
     list_ = *executor_blocking_list;
     list_.prev = executor_blocking_list;
     list_.curr.forbid = false;
-    list_.curr.name = {};
+    // Do not overwrite tag or executor pointer
     executor_blocking_list = &list_;
   }
 }
 
 ExecutorBlockingGuard::ExecutorBlockingGuard(
-    TrackTag, StringPiece name) noexcept {
+    TrackTag, Executor* ex, StringPiece tag) noexcept {
   if (!kIsMobile) {
     list_ = *executor_blocking_list;
     list_.prev = executor_blocking_list;
     list_.curr.forbid = true;
-    list_.curr.name = name;
+    list_.curr.ex = ex;
+    // If no string was provided, maintain the parent string to keep some
+    // information
+    if (!tag.empty()) {
+      list_.curr.tag = tag;
+    }
     executor_blocking_list = &list_;
   }
 }
 
 ExecutorBlockingGuard::ExecutorBlockingGuard(
-    ProhibitTag, StringPiece name) noexcept {
+    ProhibitTag, Executor* ex, StringPiece tag) noexcept {
   if (!kIsMobile) {
     list_ = *executor_blocking_list;
     list_.prev = executor_blocking_list;
     list_.curr.forbid = true;
+    list_.curr.ex = ex;
     list_.curr.allowTerminationOnBlocking = true;
-    list_.curr.name = name;
+    // If no string was provided, maintain the parent string to keep some
+    // information
+    if (!tag.empty()) {
+      list_.curr.tag = tag;
+    }
     executor_blocking_list = &list_;
   }
 }

folly/Executor.h

@@ -307,7 +307,8 @@ Executor::KeepAlive<ExecutorT> getKeepAliveToken(
 struct ExecutorBlockingContext {
   bool forbid;
   bool allowTerminationOnBlocking;
-  StringPiece name;
+  Executor* ex = nullptr;
+  StringPiece tag;
 };
 static_assert(
     std::is_standard_layout<ExecutorBlockingContext>::value,
@@ -331,8 +332,10 @@ class ExecutorBlockingGuard {
   ExecutorBlockingGuard() = delete;
 
   explicit ExecutorBlockingGuard(PermitTag) noexcept;
-  explicit ExecutorBlockingGuard(TrackTag, StringPiece name) noexcept;
-  explicit ExecutorBlockingGuard(ProhibitTag, StringPiece name) noexcept;
+  explicit ExecutorBlockingGuard(
+      TrackTag, Executor* ex, StringPiece tag) noexcept;
+  explicit ExecutorBlockingGuard(
+      ProhibitTag, Executor* ex, StringPiece tag) noexcept;
 
   ExecutorBlockingGuard(ExecutorBlockingGuard&&) = delete;
   ExecutorBlockingGuard(ExecutorBlockingGuard const&) = delete;

folly/executors/CPUThreadPoolExecutor.cpp

@@ -41,8 +41,6 @@ namespace {
 using default_queue = UnboundedBlockingQueue<CPUThreadPoolExecutor::CPUTask>;
 using default_queue_alloc =
     AlignedSysAllocator<default_queue, FixedAlign<alignof(default_queue)>>;
-
-constexpr folly::StringPiece executorName = "CPUThreadPoolExecutor";
 } // namespace
 
 const size_t CPUThreadPoolExecutor::kDefaultMaxQueueSize = 1 << 14;
@@ -268,9 +266,9 @@ void CPUThreadPoolExecutor::threadRun(ThreadPtr thread) {
   this->threadPoolHook_.registerThread();
   folly::Optional<ExecutorBlockingGuard> guard; // optional until C++17
   if (prohibitBlockingOnThreadPools_ == Options::Blocking::prohibit) {
-    guard.emplace(ExecutorBlockingGuard::ProhibitTag{}, executorName);
+    guard.emplace(ExecutorBlockingGuard::ProhibitTag{}, this, namePrefix_);
   } else {
-    guard.emplace(ExecutorBlockingGuard::TrackTag{}, executorName);
+    guard.emplace(ExecutorBlockingGuard::TrackTag{}, this, namePrefix_);
   }
 
   thread->startupBaton.post();

folly/executors/EDFThreadPoolExecutor.cpp

@@ -31,9 +31,6 @@
 #include <folly/ScopeGuard.h>
 
 namespace folly {
-namespace {
-constexpr folly::StringPiece executorName = "EDFThreadPoolExecutor";
-}
 
 class EDFThreadPoolExecutor::Task {
  public:
@@ -336,7 +333,8 @@ folly::Executor::KeepAlive<> EDFThreadPoolExecutor::deadlineExecutor(
 
 void EDFThreadPoolExecutor::threadRun(ThreadPtr thread) {
   this->threadPoolHook_.registerThread();
-  ExecutorBlockingGuard guard{ExecutorBlockingGuard::TrackTag{}, executorName};
+  ExecutorBlockingGuard guard{
+      ExecutorBlockingGuard::TrackTag{}, this, namePrefix_};
 
   thread->startupBaton.post();
   for (;;) {

folly/executors/IOThreadPoolExecutor.cpp

@@ -203,19 +203,23 @@ void IOThreadPoolExecutor::threadRun(ThreadPtr thread) {
 
   ioThread->eventBase->runInEventBaseThread(
       [thread] { thread->startupBaton.post(); });
-  while (ioThread->shouldRun) {
-    ioThread->eventBase->loopForever();
-  }
-  if (isJoin_) {
-    while (ioThread->pendingTasks > 0) {
-      ioThread->eventBase->loopOnce();
+  {
+    ExecutorBlockingGuard guard{
+        ExecutorBlockingGuard::TrackTag{}, this, namePrefix_};
+    while (ioThread->shouldRun) {
+      ioThread->eventBase->loopForever();
+    }
+    if (isJoin_) {
+      while (ioThread->pendingTasks > 0) {
+        ioThread->eventBase->loopOnce();
+      }
+    }
+    idler.reset();
+    if (isWaitForAll_) {
+      // some tasks, like thrift asynchronous calls, create additional
+      // event base hookups, let's wait till all of them complete.
+      ioThread->eventBase->loop();
     }
-  }
-  idler.reset();
-  if (isWaitForAll_) {
-    // some tasks, like thrift asynchronous calls, create additional
-    // event base hookups, let's wait till all of them complete.
-    ioThread->eventBase->loop();
   }
 
   std::lock_guard<std::mutex> guard(ioThread->eventBaseShutdownMutex_);

folly/executors/test/ThreadPoolExecutorTest.cpp

@@ -1033,10 +1033,10 @@ TEST(ThreadPoolExecutorTest, VirtualExecutorTestEDF) {
 template <class TPE>
 static void currentThreadTest(folly::StringPiece executorName) {
   folly::Optional<ExecutorBlockingContext> ctx{};
-  TPE tpe(1);
+  TPE tpe(1, std::make_shared<NamedThreadFactory>(executorName));
   tpe.add([&ctx]() { ctx = getExecutorBlockingContext(); });
   tpe.join();
-  EXPECT_EQ(ctx->name, executorName);
+  EXPECT_EQ(ctx->tag, executorName);
 }
 
 // Test the nesting of the permit guard
@@ -1044,7 +1044,7 @@ template <class TPE>
 static void currentThreadTestDisabled(folly::StringPiece executorName) {
   folly::Optional<ExecutorBlockingContext> ctxPermit{};
   folly::Optional<ExecutorBlockingContext> ctxForbid{};
-  TPE tpe(1);
+  TPE tpe(1, std::make_shared<NamedThreadFactory>(executorName));
   tpe.add([&]() {
     {
       // Nest the guard that permits blocking
@@ -1055,20 +1055,20 @@ static void currentThreadTestDisabled(folly::StringPiece executorName) {
   });
   tpe.join();
   EXPECT_TRUE(!ctxPermit.has_value());
-  EXPECT_EQ(ctxForbid->name, executorName);
+  EXPECT_EQ(ctxForbid->tag, executorName);
 }
 
 TEST(ThreadPoolExecutorTest, CPUCurrentThreadExecutor) {
-  currentThreadTest<CPUThreadPoolExecutor>("CPUThreadPoolExecutor");
-  currentThreadTestDisabled<CPUThreadPoolExecutor>("CPUThreadPoolExecutor");
+  currentThreadTest<CPUThreadPoolExecutor>("CPU-ExecutorName");
+  currentThreadTestDisabled<CPUThreadPoolExecutor>("CPU-ExecutorName");
 }
 
 TEST(ThreadPoolExecutorTest, IOCurrentThreadExecutor) {
-  currentThreadTest<IOThreadPoolExecutor>("EventBase");
-  currentThreadTestDisabled<IOThreadPoolExecutor>("EventBase");
+  currentThreadTest<IOThreadPoolExecutor>("IO-ExecutorName");
+  currentThreadTestDisabled<IOThreadPoolExecutor>("IO-ExecutorName");
 }
 
 TEST(ThreadPoolExecutorTest, EDFCurrentThreadExecutor) {
-  currentThreadTest<EDFThreadPoolExecutor>("EDFThreadPoolExecutor");
-  currentThreadTestDisabled<EDFThreadPoolExecutor>("EDFThreadPoolExecutor");
+  currentThreadTest<EDFThreadPoolExecutor>("EDF-ExecutorName");
+  currentThreadTestDisabled<EDFThreadPoolExecutor>("EDF-ExecutorName");
 }

folly/io/async/EventBase.cpp

@@ -37,7 +37,6 @@
 #include <folly/system/ThreadName.h>
 
 namespace {
-constexpr folly::StringPiece executorName = "EventBase";
 
 class EventBaseBackend : public folly::EventBaseBackendBase {
  public:
@@ -279,7 +278,8 @@ void EventBase::waitUntilRunning() {
 
 // enters the event_base loop -- will only exit when forced to
 bool EventBase::loop() {
-  ExecutorBlockingGuard guard{ExecutorBlockingGuard::TrackTag{}, executorName};
+  // Enforce blocking tracking and if we have a name override any previous one
+  ExecutorBlockingGuard guard{ExecutorBlockingGuard::TrackTag{}, this, name_};
   return loopBody();
 }