Add thread name for background threads.

Author: interwq

configure.ac

@@ -1470,6 +1470,15 @@ if test "x$abi" != "xpecoff" ; then
   if test "x${je_cv_pthread_atfork}" = "xyes" ; then
     AC_DEFINE([JEMALLOC_HAVE_PTHREAD_ATFORK], [ ])
   fi
+  dnl Check if pthread_setname_np is available with the expected API.
+  JE_COMPILABLE([pthread_setname_np(3)], [
+#include <pthread.h>
+], [
+  pthread_setname_np(pthread_self(), "setname_test");
+], [je_cv_pthread_setname_np])
+  if test "x${je_cv_pthread_setname_np}" = "xyes" ; then
+    AC_DEFINE([JEMALLOC_HAVE_PTHREAD_SETNAME_NP], [ ])
+  fi
 fi
 
 JE_APPEND_VS(CPPFLAGS, -D_REENTRANT)

include/jemalloc/internal/jemalloc_internal_defs.h.in

@@ -98,6 +98,9 @@
 /* Defined if pthread_atfork(3) is available. */
 #undef JEMALLOC_HAVE_PTHREAD_ATFORK
 
+/* Defined if pthread_setname_np(3) is available. */
+#undef JEMALLOC_HAVE_PTHREAD_SETNAME_NP
+
 /*
  * Defined if clock_gettime(CLOCK_MONOTONIC_COARSE, ...) is available.
  */

src/background_thread.c

@@ -499,7 +499,9 @@ static void *
 background_thread_entry(void *ind_arg) {
 	unsigned thread_ind = (unsigned)(uintptr_t)ind_arg;
 	assert(thread_ind < ncpus);
-
+#ifdef JEMALLOC_HAVE_PTHREAD_SETNAME_NP
+	pthread_setname_np(pthread_self(), "jemalloc_bg_thd");
+#endif
 	if (opt_percpu_arena != percpu_arena_disabled) {
 		set_current_thread_affinity((int)thread_ind);
 	}