Add 'debug-threads' suboption to --name

Add flag storage to qemu-thread-* to store the namethreads flag

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

include/qemu/thread.h

@@ -59,5 +59,6 @@ void *qemu_thread_join(QemuThread *thread);
 void qemu_thread_get_self(QemuThread *thread);
 bool qemu_thread_is_self(QemuThread *thread);
 void qemu_thread_exit(void *retval);
+void qemu_thread_naming(bool enable);
 
 #endif

qemu-options.hx

@@ -328,9 +328,11 @@ possible drivers and properties, use @code{-device help} and
 ETEXI
 
 DEF("name", HAS_ARG, QEMU_OPTION_name,
-    "-name string1[,process=string2]\n"
+    "-name string1[,process=string2][,debug-threads=on|off]\n"
     "                set the name of the guest\n"
-    "                string1 sets the window title and string2 the process name (on Linux)\n",
+    "                string1 sets the window title and string2 the process name (on Linux)\n"
+    "                When debug-threads is enabled, individual threads are given a separate name (on Linux)\n"
+    "                NOTE: The thread names are for debugging and not a stable API.\n",
     QEMU_ARCH_ALL)
 STEXI
 @item -name @var{name}
@@ -339,6 +341,7 @@ Sets the @var{name} of the guest.
 This name will be displayed in the SDL window caption.
 The @var{name} will also be used for the VNC server.
 Also optionally set the top visible process name in Linux.
+Naming of individual threads can also be enabled on Linux to aid debugging.
 ETEXI
 
 DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,

util/qemu-thread-posix.c

@@ -27,6 +27,13 @@
 #include "qemu/thread.h"
 #include "qemu/atomic.h"
 
+static bool name_threads;
+
+void qemu_thread_naming(bool enable)
+{
+    name_threads = enable;
+}
+
 static void error_exit(int err, const char *msg)
 {
     fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));

util/qemu-thread-win32.c

@@ -16,6 +16,14 @@
 #include <assert.h>
 #include <limits.h>
 
+static bool name_threads;
+
+void qemu_thread_naming(bool enable)
+{
+    /* But note we don't actually name them on Windows yet */
+    name_threads = enable;
+}
+
 static void error_exit(int err, const char *msg)
 {
     char *pstr;

vl.c

@@ -495,6 +495,12 @@ static QemuOptsList qemu_name_opts = {
             .name = "process",
             .type = QEMU_OPT_STRING,
             .help = "Sets the name of the QEMU process, as shown in top etc",
+        }, {
+            .name = "debug-threads",
+            .type = QEMU_OPT_BOOL,
+            .help = "When enabled, name the individual threads; defaults off.\n"
+                    "NOTE: The thread names are for debugging and not a\n"
+                    "stable API.",
         },
         { /* End of list */ }
     },
@@ -954,6 +960,9 @@ static void parse_name(QemuOpts *opts)
 {
     const char *proc_name;
 
+    if (qemu_opt_get(opts, "debug-threads")) {
+        qemu_thread_naming(qemu_opt_get_bool(opts, "debug-threads", false));
+    }
     qemu_name = qemu_opt_get(opts, "guest");
 
     proc_name = qemu_opt_get(opts, "process");