Don't rename main thread at process level

Set only the internal name.

Fixes #17036 for both `bitcoind` and `bitcoin-qt`.

Github-Pull: #17038
Rebased-From: 07e4bdba3bd46c3a15dedb0a2660453c300643dc
Tree-SHA512: ed6f1b95a23c4c7863982ee6972429be5af0702ea93f0f17d32d2ef4b01446b1c0528eeadc45289609eda5c02ea68b3d722b8ecdfdf4fff4b02592c2188cc0a0

src/bitcoind.cpp

@@ -45,7 +45,7 @@ static bool AppInit(int argc, char* argv[])
 
     bool fRet = false;
 
-    util::ThreadRename("init");
+    util::ThreadSetInternalName("init");
 
     //
     // Parameters

src/qt/bitcoin.cpp

@@ -416,7 +416,7 @@ int GuiMain(int argc, char* argv[])
     std::tie(argc, argv) = winArgs.get();
 #endif
     SetupEnvironment();
-    util::ThreadRename("main");
+    util::ThreadSetInternalName("main");
 
     std::unique_ptr<interfaces::Node> node = interfaces::MakeNode();
 

src/util/threadnames.cpp

@@ -60,3 +60,8 @@ void util::ThreadRename(std::string&& name)
     SetThreadName(("b-" + name).c_str());
     SetInternalName(std::move(name));
 }
+
+void util::ThreadSetInternalName(std::string&& name)
+{
+    SetInternalName(std::move(name));
+}

src/util/threadnames.h

@@ -10,8 +10,13 @@
 namespace util {
 //! Rename a thread both in terms of an internal (in-memory) name as well
 //! as its system thread name.
+//! @note Do not call this for the main thread, as this will interfere with
+//! UNIX utilities such as top and killall. Use ThreadSetInternalName instead.
 void ThreadRename(std::string&&);
 
+//! Set the internal (in-memory) name of the current thread only.
+void ThreadSetInternalName(std::string&&);
+
 //! Get the thread's internal (in-memory) name; used e.g. for identification in
 //! logging.
 const std::string& ThreadGetInternalName();