[PATCH 04/12] util: set the name for the 'main' thread

["Daniel P. Berrangé" <berrange@redhat.com>]

The default main thread name is undefined, so use a constructor to
explicitly set it to 'main'. This constructor is marked to run early
as the thread name is intended to be used in error reporting / logs
which may be triggered very early in QEMU execution.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 util/qemu-thread-posix.c | 12 ++++++++++++
 util/qemu-thread-win32.c |  6 ++++++
 2 files changed, 18 insertions(+)

diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 7c985b5d38..121d7ed69b 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -22,6 +22,18 @@
 #include <pthread_np.h>
 #endif
 
+static void __attribute__((__constructor__(QEMU_CONSTRUCTOR_EARLY)))
+qemu_thread_init(void)
+{
+# if defined(CONFIG_PTHREAD_SETNAME_NP_W_TID)
+    pthread_setname_np(pthread_self(), "main");
+# elif defined(CONFIG_PTHREAD_SETNAME_NP_WO_TID)
+    pthread_setname_np("main");
+# elif defined(CONFIG_PTHREAD_SET_NAME_NP)
+    pthread_set_name_np(pthread_self(), "main");
+# endif
+}
+
 static void error_exit(int err, const char *msg)
 {
     fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));
diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
index 9595a5b090..5e6ca0c12f 100644
--- a/util/qemu-thread-win32.c
+++ b/util/qemu-thread-win32.c
@@ -332,6 +332,12 @@ static void set_thread_description(HANDLE h, const char *name)
     SetThreadDescriptionFunc(h, namew);
 }
 
+static void __attribute__((__constructor__(QEMU_CONSTRUCTOR_EARLY)))
+qemu_thread_init(void)
+{
+    set_thread_description(GetCurrentThread(), "main");
+}
+
 void qemu_thread_create(QemuThread *thread, const char *name,
                        void *(*start_routine)(void *),
                        void *arg, int mode)
-- 
2.50.1