From 91ff5e401f4f389ada17b7a21fe6c4e4dc6df142 Mon Sep 17 00:00:00 2001
From: Honza Bambas <honzab.moz@firemni.cz>
Date: Wed, 17 Jun 2020 16:14:27 +0000
Subject: [PATCH] Bug 1638925 - Log names of nsINamed runnables, r=froydnj

Differential Revision: https://phabricator.services.mozilla.com/D79620
---
 xpcom/threads/nsThreadUtils.cpp | 20 ++++++++++++++++++++
 xpcom/threads/nsThreadUtils.h   |  4 ++++
 2 files changed, 24 insertions(+)

diff --git a/xpcom/threads/nsThreadUtils.cpp b/xpcom/threads/nsThreadUtils.cpp
index b919360f9673..dbbb43a1e7fa 100644
--- a/xpcom/threads/nsThreadUtils.cpp
+++ b/xpcom/threads/nsThreadUtils.cpp
@@ -39,6 +39,8 @@ static LazyLogModule sEventDispatchAndRunLog("events");
 #endif
 #define LOG1(args) \
   MOZ_LOG(sEventDispatchAndRunLog, mozilla::LogLevel::Error, args)
+#define LOG1_ENABLED() \
+  MOZ_LOG_TEST(sEventDispatchAndRunLog, mozilla::LogLevel::Error)
 
 using namespace mozilla;
 
@@ -619,6 +621,24 @@ LogTaskBase<T>::Run::Run(T* aEvent, bool aWillRunAgain)
   LOG1(("EXEC %p", mEvent));
 }
 
+template <>
+LogTaskBase<nsIRunnable>::Run::Run(nsIRunnable* aEvent, bool aWillRunAgain)
+    : mEvent(aEvent), mWillRunAgain(aWillRunAgain) {
+  if (!LOG1_ENABLED()) {
+    return;
+  }
+
+  nsCOMPtr<nsINamed> named(do_QueryInterface(aEvent));
+  if (!named) {
+    LOG1(("EXEC %p", mEvent));
+    return;
+  }
+
+  nsAutoCString name;
+  named->GetName(name);
+  LOG1(("EXEC %p [%s]", aEvent, name.BeginReading()));
+}
+
 template <typename T>
 LogTaskBase<T>::Run::~Run() {
   LOG1((mWillRunAgain ? "INTERRUPTED %p" : "DONE %p", mEvent));
diff --git a/xpcom/threads/nsThreadUtils.h b/xpcom/threads/nsThreadUtils.h
index f3d9f0bf4d55..ece90506097d 100644
--- a/xpcom/threads/nsThreadUtils.h
+++ b/xpcom/threads/nsThreadUtils.h
@@ -1905,6 +1905,10 @@ class LogTaskBase {
   };
 };
 
+// Specialized constructor; must be explicitly declared.
+template <>
+LogTaskBase<nsIRunnable>::Run::Run(nsIRunnable* aEvent, bool aWillRunAgain);
+
 class MicroTaskRunnable;
 
 typedef LogTaskBase<nsIRunnable> LogRunnable;