threads: introduce util/threadnames, refactor thread naming

This work is prerequisite to attaching thread names to log lines and deadlock
debug utilities. This code allows setting of an "internal" threadname per
thread on platforms where thread_local is available.

This commit also moves RenameThread() out of a more general module and adds a
numeric suffix to disambiguate between threads with the same name. It
explicitly names a few main threads using the new util::ThreadRename().

1 files changed, 6 insertions, 5 deletions

diff --git a/src/httpserver.cpp b/src/httpserver.cpp
index 5d9c3d2c1a..63639fa3e0 100644
--- a/src/httpserver.cpp
+++ b/src/httpserver.cpp
@@ -6,6 +6,7 @@
 
 #include <chainparamsbase.h>
 #include <compat.h>
+#include <util/threadnames.h>
 #include <util/system.h>
 #include <util/strencodings.h>
 #include <netbase.h>
@@ -17,7 +18,7 @@
 #include <memory>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
+#include <string>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -284,7 +285,7 @@ static void http_reject_request_cb(struct evhttp_request* req, void*)
 /** Event dispatcher thread */
 static bool ThreadHTTP(struct event_base* base)
 {
-    RenameThread("bitcoin-http");
+    util::ThreadRename("http");
     LogPrint(BCLog::HTTP, "Entering http event loop\n");
     event_base_dispatch(base);
     // Event loop will be interrupted by InterruptHTTPServer()
@@ -335,9 +336,9 @@ static bool HTTPBindAddresses(struct evhttp* http)
 }
 
 /** Simple wrapper to set thread name and run work queue */
-static void HTTPWorkQueueRun(WorkQueue<HTTPClosure>* queue)
+static void HTTPWorkQueueRun(WorkQueue<HTTPClosure>* queue, int worker_num)
 {
-    RenameThread("bitcoin-httpworker");
+    util::ThreadRename(strprintf("httpworker.%i", worker_num));
     queue->Run();
 }
 
@@ -430,7 +431,7 @@ void StartHTTPServer()
     threadHTTP = std::thread(ThreadHTTP, eventBase);
 
     for (int i = 0; i < rpcThreads; i++) {
-        g_thread_http_workers.emplace_back(HTTPWorkQueueRun, workQueue);
+        g_thread_http_workers.emplace_back(HTTPWorkQueueRun, workQueue, i);
     }
 }