Set names of worker threads

This adds some configury so that gdb can set the names of worker
threads.  This makes them show up more nicely when debugging gdb
itself.

2019-11-26  Tom Tromey  <tom@tromey.com>

	* gdbsupport/thread-pool.c (thread_pool::set_thread_count): Set
	name of worker thread.
	* gdbsupport/common.m4 (GDB_AC_COMMON): Check for
	pthread_setname_np.
	* configure, config.in: Rebuild.

gdb/gdbserver/ChangeLog
2019-11-26  Tom Tromey  <tom@tromey.com>

	* configure, config.in: Rebuild.

Change-Id: I60473d65ae9ae14d8c56ddde39684240c16aaf35

8 files changed, 45 insertions, 9 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0c5aab2..94a8bdc 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2019-11-26  Tom Tromey  <tom@tromey.com>
 
+	* gdbsupport/thread-pool.c (thread_pool::set_thread_count): Set
+	name of worker thread.
+	* gdbsupport/common.m4 (GDB_AC_COMMON): Check for
+	pthread_setname_np.
+	* configure, config.in: Rebuild.
+
+2019-11-26  Tom Tromey  <tom@tromey.com>
+
 	* python/python.c (class gdbpy_gil): New.
 	(struct gdbpy_event): Add constructor, destructor, operator().
 	(gdbpy_post_event): Use run_on_main_thread.
diff --git a/gdb/config.in b/gdb/config.in
index 61e63e2..1caf764 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -342,6 +342,9 @@
 /* Have PTHREAD_PRIO_INHERIT. */
 #undef HAVE_PTHREAD_PRIO_INHERIT
 
+/* Define to 1 if you have the `pthread_setname_np' function. */
+#undef HAVE_PTHREAD_SETNAME_NP
+
 /* Define to 1 if you have the `pthread_sigmask' function. */
 #undef HAVE_PTHREAD_SIGMASK
 
diff --git a/gdb/configure b/gdb/configure
index dd936d2..6b64619 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -14333,12 +14333,13 @@ $as_echo "$gdb_cv_cxx_std_thread" >&6; }
 
     # This check must be here, while LIBS includes any necessary
     # threading library.
-    for ac_func in pthread_sigmask
+    for ac_func in pthread_sigmask pthread_setname_np
 do :
-  ac_fn_cxx_check_func "$LINENO" "pthread_sigmask" "ac_cv_func_pthread_sigmask"
-if test "x$ac_cv_func_pthread_sigmask" = xyes; then :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_cxx_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_PTHREAD_SIGMASK 1
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
 _ACEOF
 
 fi
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 00b0a0d..de6c311 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,9 @@
 2019-11-26  Tom Tromey  <tom@tromey.com>
 
+	* configure, config.in: Rebuild.
+
+2019-11-26  Tom Tromey  <tom@tromey.com>
+
 	* remote-utils.c (block_unblock_async_io): Use gdb_sigmask.
 	* linux-low.c (linux_wait_for_event_filtered, linux_async): Use
 	gdb_sigmask.
diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in
index 3027ffa..14cf709 100644
--- a/gdb/gdbserver/config.in
+++ b/gdb/gdbserver/config.in
@@ -195,6 +195,9 @@
 /* Have PTHREAD_PRIO_INHERIT. */
 #undef HAVE_PTHREAD_PRIO_INHERIT
 
+/* Define to 1 if you have the `pthread_setname_np' function. */
+#undef HAVE_PTHREAD_SETNAME_NP
+
 /* Define to 1 if you have the `pthread_sigmask' function. */
 #undef HAVE_PTHREAD_SIGMASK
 
diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure
index 8d34a6c..da17f8c 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -7725,12 +7725,13 @@ $as_echo "$gdb_cv_cxx_std_thread" >&6; }
 
     # This check must be here, while LIBS includes any necessary
     # threading library.
-    for ac_func in pthread_sigmask
+    for ac_func in pthread_sigmask pthread_setname_np
 do :
-  ac_fn_cxx_check_func "$LINENO" "pthread_sigmask" "ac_cv_func_pthread_sigmask"
-if test "x$ac_cv_func_pthread_sigmask" = xyes; then :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_cxx_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_PTHREAD_SIGMASK 1
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
 _ACEOF
 
 fi
diff --git a/gdb/gdbsupport/common.m4 b/gdb/gdbsupport/common.m4
index e993b20..4f2bb52 100644
--- a/gdb/gdbsupport/common.m4
+++ b/gdb/gdbsupport/common.m4
@@ -57,7 +57,7 @@ AC_DEFUN([GDB_AC_COMMON], [
 
     # This check must be here, while LIBS includes any necessary
     # threading library.
-    AC_CHECK_FUNCS([pthread_sigmask])
+    AC_CHECK_FUNCS([pthread_sigmask pthread_setname_np])
 
     LIBS="$save_LIBS"
     CXXFLAGS="$save_CXXFLAGS"
diff --git a/gdb/gdbsupport/thread-pool.c b/gdb/gdbsupport/thread-pool.c
index 8282ea3..d19ae02 100644
--- a/gdb/gdbsupport/thread-pool.c
+++ b/gdb/gdbsupport/thread-pool.c
@@ -26,6 +26,19 @@
 #include "gdbsupport/block-signals.h"
 #include <algorithm>
 
+/* On the off chance that we have the pthread library on a Windows
+   host, but std::thread is not using it, avoid calling
+   pthread_setname_np on Windows.  */
+#ifndef _WIN32
+#ifdef HAVE_PTHREAD_SETNAME_NP
+#define USE_PTHREAD_SETNAME_NP
+#endif
+#endif
+
+#ifdef USE_PTHREAD_SETNAME_NP
+#include <pthread.h>
+#endif
+
 namespace gdb
 {
 
@@ -62,6 +75,9 @@ thread_pool::set_thread_count (size_t num_threads)
       for (size_t i = m_thread_count; i < num_threads; ++i)
 	{
 	  std::thread thread (&thread_pool::thread_function, this);
+#ifdef USE_PTHREAD_SETNAME_NP
+	  pthread_setname_np (thread.native_handle (), "gdb worker");
+#endif
 	  thread.detach ();
 	}
     }