[Qemu-devel] [PATCH v2 3/3] Add a 'name' parameter to qemu_thread_create

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

If enabled, set the thread name at creation (on GNU systems with
  pthread_set_np)
Fix up all the callers with a thread name

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 cpus.c                          | 25 ++++++++++++++++++++-----
 hw/block/dataplane/virtio-blk.c |  2 +-
 hw/usb/ccid-card-emulated.c     |  8 ++++----
 include/qemu/thread.h           |  2 +-
 libcacard/vscclient.c           |  2 +-
 migration.c                     |  2 +-
 thread-pool.c                   |  2 +-
 ui/vnc-jobs.c                   |  3 ++-
 util/compatfd.c                 |  3 ++-
 util/qemu-thread-posix.c        |  9 +++++++--
 util/qemu-thread-win32.c        |  2 +-
 11 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/cpus.c b/cpus.c
index ca4c59f..e5bb271 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1117,16 +1117,23 @@ void resume_all_vcpus(void)
     }
 }
 
+/* For temporary buffers for forming a name */
+#define TMP_THREAD_NAME_LEN 16
+
 static void qemu_tcg_init_vcpu(CPUState *cpu)
 {
+    char thread_name[TMP_THREAD_NAME_LEN];
+
     /* share a single thread for all cpus with TCG */
     if (!tcg_cpu_thread) {
         cpu->thread = g_malloc0(sizeof(QemuThread));
         cpu->halt_cond = g_malloc0(sizeof(QemuCond));
         qemu_cond_init(cpu->halt_cond);
         tcg_halt_cond = cpu->halt_cond;
-        qemu_thread_create(cpu->thread, qemu_tcg_cpu_thread_fn, cpu,
-                           QEMU_THREAD_JOINABLE);
+        snprintf(thread_name, TMP_THREAD_NAME_LEN, "CPU %d/TCG",
+                 cpu->cpu_index);
+        qemu_thread_create(cpu->thread, thread_name, qemu_tcg_cpu_thread_fn,
+                           cpu, QEMU_THREAD_JOINABLE);
 #ifdef _WIN32
         cpu->hThread = qemu_thread_get_handle(cpu->thread);
 #endif
@@ -1142,11 +1149,15 @@ static void qemu_tcg_init_vcpu(CPUState *cpu)
 
 static void qemu_kvm_start_vcpu(CPUState *cpu)
 {
+    char thread_name[TMP_THREAD_NAME_LEN];
+
     cpu->thread = g_malloc0(sizeof(QemuThread));
     cpu->halt_cond = g_malloc0(sizeof(QemuCond));
     qemu_cond_init(cpu->halt_cond);
-    qemu_thread_create(cpu->thread, qemu_kvm_cpu_thread_fn, cpu,
-                       QEMU_THREAD_JOINABLE);
+    snprintf(thread_name, TMP_THREAD_NAME_LEN, "CPU %d/KVM",
+             cpu->cpu_index);
+    qemu_thread_create(cpu->thread, thread_name, qemu_kvm_cpu_thread_fn,
+                       cpu, QEMU_THREAD_JOINABLE);
     while (!cpu->created) {
         qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
     }
@@ -1154,10 +1165,14 @@ static void qemu_kvm_start_vcpu(CPUState *cpu)
 
 static void qemu_dummy_start_vcpu(CPUState *cpu)
 {
+    char thread_name[TMP_THREAD_NAME_LEN];
+
     cpu->thread = g_malloc0(sizeof(QemuThread));
     cpu->halt_cond = g_malloc0(sizeof(QemuCond));
     qemu_cond_init(cpu->halt_cond);
-    qemu_thread_create(cpu->thread, qemu_dummy_cpu_thread_fn, cpu,
+    snprintf(thread_name, TMP_THREAD_NAME_LEN, "CPU %d/DUMMY",
+             cpu->cpu_index);
+    qemu_thread_create(cpu->thread, thread_name, qemu_dummy_cpu_thread_fn, cpu,
                        QEMU_THREAD_JOINABLE);
     while (!cpu->created) {
         qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 456d437..980a684 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -358,7 +358,7 @@ static void start_data_plane_bh(void *opaque)
 
     qemu_bh_delete(s->start_bh);
     s->start_bh = NULL;
-    qemu_thread_create(&s->thread, data_plane_thread,
+    qemu_thread_create(&s->thread, "data_plane", data_plane_thread,
                        s, QEMU_THREAD_JOINABLE);
 }
 
diff --git a/hw/usb/ccid-card-emulated.c b/hw/usb/ccid-card-emulated.c
index aa913df..7213c89 100644
--- a/hw/usb/ccid-card-emulated.c
+++ b/hw/usb/ccid-card-emulated.c
@@ -546,10 +546,10 @@ static int emulated_initfn(CCIDCardState *base)
         printf("%s: failed to initialize vcard\n", EMULATED_DEV_NAME);
         return -1;
     }
-    qemu_thread_create(&card->event_thread_id, event_thread, card,
-                       QEMU_THREAD_JOINABLE);
-    qemu_thread_create(&card->apdu_thread_id, handle_apdu_thread, card,
-                       QEMU_THREAD_JOINABLE);
+    qemu_thread_create(&card->event_thread_id, "ccid/event", event_thread,
+                       card, QEMU_THREAD_JOINABLE);
+    qemu_thread_create(&card->apdu_thread_id, "ccid/apdu", handle_apdu_thread,
+                       card, QEMU_THREAD_JOINABLE);
     return 0;
 }
 
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index bf1e110..f7e3b9b 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -52,7 +52,7 @@ void qemu_event_reset(QemuEvent *ev);
 void qemu_event_wait(QemuEvent *ev);
 void qemu_event_destroy(QemuEvent *ev);
 
-void qemu_thread_create(QemuThread *thread,
+void qemu_thread_create(QemuThread *thread, const char *name,
                         void *(*start_routine)(void *),
                         void *arg, int mode);
 void *qemu_thread_join(QemuThread *thread);
diff --git a/libcacard/vscclient.c b/libcacard/vscclient.c
index 24f7088..3477ab3 100644
--- a/libcacard/vscclient.c
+++ b/libcacard/vscclient.c
@@ -269,7 +269,7 @@ on_host_init(VSCMsgHeader *mhHeader, VSCMsgInit *incoming)
     send_msg(VSC_ReaderRemove, VSCARD_MINIMAL_READER_ID, NULL, 0);
     /* launch the event_thread. This will trigger reader adds for all the
      * existing readers */
-    qemu_thread_create(&thread_id, event_thread, NULL, 0);
+    qemu_thread_create(&thread_id, "vsc/event", event_thread, NULL, 0);
     return 0;
 }
 
diff --git a/migration.c b/migration.c
index 7235c23..bddec7e 100644
--- a/migration.c
+++ b/migration.c
@@ -679,6 +679,6 @@ void migrate_fd_connect(MigrationState *s)
     /* Notify before starting migration thread */
     notifier_list_notify(&migration_state_notifiers, s);
 
-    qemu_thread_create(&s->thread, migration_thread, s,
+    qemu_thread_create(&s->thread, "migration", migration_thread, s,
                        QEMU_THREAD_JOINABLE);
 }
diff --git a/thread-pool.c b/thread-pool.c
index 3735fd3..fbdd3ff 100644
--- a/thread-pool.c
+++ b/thread-pool.c
@@ -140,7 +140,7 @@ static void do_spawn_thread(ThreadPool *pool)
     pool->new_threads--;
     pool->pending_threads++;
 
-    qemu_thread_create(&t, worker_thread, pool, QEMU_THREAD_DETACHED);
+    qemu_thread_create(&t, "worker", worker_thread, pool, QEMU_THREAD_DETACHED);
 }
 
 static void spawn_thread_bh_fn(void *opaque)
diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 2d3fce8..3f3c47b 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -333,7 +333,8 @@ void vnc_start_worker_thread(void)
         return ;
 
     q = vnc_queue_init();
-    qemu_thread_create(&q->thread, vnc_worker_thread, q, QEMU_THREAD_DETACHED);
+    qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
+                       QEMU_THREAD_DETACHED);
     queue = q; /* Set global queue */
 }
 
diff --git a/util/compatfd.c b/util/compatfd.c
index 430a41c..341ada6 100644
--- a/util/compatfd.c
+++ b/util/compatfd.c
@@ -88,7 +88,8 @@ static int qemu_signalfd_compat(const sigset_t *mask)
     memcpy(&info->mask, mask, sizeof(*mask));
     info->fd = fds[1];
 
-    qemu_thread_create(&thread, sigwait_compat, info, QEMU_THREAD_DETACHED);
+    qemu_thread_create(&thread, "signalfd_compat", sigwait_compat, info,
+                       QEMU_THREAD_DETACHED);
 
     return fds[0];
 }
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 0fa6c81..45113b4 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -394,8 +394,7 @@ void qemu_event_wait(QemuEvent *ev)
     }
 }
 
-
-void qemu_thread_create(QemuThread *thread,
+void qemu_thread_create(QemuThread *thread, const char *name,
                        void *(*start_routine)(void*),
                        void *arg, int mode)
 {
@@ -421,6 +420,12 @@ void qemu_thread_create(QemuThread *thread,
     if (err)
         error_exit(err, __func__);
 
+#ifdef _GNU_SOURCE
+    if (name_threads) {
+        pthread_setname_np(thread->thread, name);
+    }
+#endif
+
     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 
     pthread_attr_destroy(&attr);
diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
index e42cb77..b9c957b 100644
--- a/util/qemu-thread-win32.c
+++ b/util/qemu-thread-win32.c
@@ -333,7 +333,7 @@ void *qemu_thread_join(QemuThread *thread)
     return ret;
 }
 
-void qemu_thread_create(QemuThread *thread,
+void qemu_thread_create(QemuThread *thread, const char *name,
                        void *(*start_routine)(void *),
                        void *arg, int mode)
 {
-- 
1.8.5.3