[Qemu-devel] [RFC PATCH 23/33] job: Add job_event_*()

[Kevin Wolf <kwolf@redhat.com>]

Go through the Job layer in order to send QMP events. For the moment,
these functions only call a notifier in the BlockJob layer that sends
the existing commands.

This uses notifiers rather than JobDriver callbacks because internal
users of jobs won't receive QMP events, but might still be interested
in getting notified for the events.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/blockjob.h |  9 +++++++++
 include/qemu/job.h       | 18 ++++++++++++++++++
 blockjob.c               | 42 ++++++++++++++++++++++++++++--------------
 job.c                    | 19 +++++++++++++++++++
 4 files changed, 74 insertions(+), 14 deletions(-)

diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index a74d5d02fd..b5bcb52219 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -82,6 +82,15 @@ typedef struct BlockJob {
     /** Block other operations when block job is running */
     Error *blocker;
 
+    /** Called when a cancelled job is finalised. */
+    Notifier finalize_cancelled_notifier;
+
+    /** Called when a successfully completed job is finalised. */
+    Notifier finalize_completed_notifier;
+
+    /** Called when the job transitions to PENDING */
+    Notifier pending_notifier;
+
     /** BlockDriverStates that are involved in this block job */
     GSList *nodes;
 
diff --git a/include/qemu/job.h b/include/qemu/job.h
index ab3d49685a..3d9a9a8d77 100644
--- a/include/qemu/job.h
+++ b/include/qemu/job.h
@@ -105,6 +105,15 @@ typedef struct Job {
     /** True if this job should automatically dismiss itself */
     bool auto_dismiss;
 
+    /** Notifiers called when a cancelled job is finalised */
+    NotifierList on_finalize_cancelled;
+
+    /** Notifiers called when a successfully completed job is finalised */
+    NotifierList on_finalize_completed;
+
+    /** Notifiers called when the job transitions to PENDING */
+    NotifierList on_pending;
+
     /** Element of the list of jobs */
     QLIST_ENTRY(Job) job_list;
 } Job;
@@ -182,6 +191,15 @@ void job_ref(Job *job);
  */
 void job_unref(Job *job);
 
+/** To be called when a cancelled job is finalised. */
+void job_event_cancelled(Job *job);
+
+/** To be called when a successfully completed job is finalised. */
+void job_event_completed(Job *job);
+
+/** To be called when the job transitions to PENDING */
+void job_event_pending(Job *job);
+
 /**
  * @job: A job that has not yet been started.
  *
diff --git a/blockjob.c b/blockjob.c
index c49cfdf130..2f36888c0a 100644
--- a/blockjob.c
+++ b/blockjob.c
@@ -36,10 +36,6 @@
 #include "qemu/coroutine.h"
 #include "qemu/timer.h"
 
-static void block_job_event_cancelled(BlockJob *job);
-static void block_job_event_completed(BlockJob *job, const char *msg);
-static void block_job_event_pending(BlockJob *job);
-
 /* Transactional group of block jobs */
 struct BlockJobTxn {
 
@@ -353,13 +349,9 @@ static int block_job_finalize_single(BlockJob *job)
     /* Emit events only if we actually started */
     if (job_started(&job->job)) {
         if (job_is_cancelled(&job->job)) {
-            block_job_event_cancelled(job);
+            job_event_cancelled(&job->job);
         } else {
-            const char *msg = NULL;
-            if (job->ret < 0) {
-                msg = strerror(-job->ret);
-            }
-            block_job_event_completed(job, msg);
+            job_event_completed(&job->job);
         }
     }
 
@@ -505,7 +497,7 @@ static int block_job_transition_to_pending(BlockJob *job)
 {
     job_state_transition(&job->job, JOB_STATUS_PENDING);
     if (!job->job.auto_finalize) {
-        block_job_event_pending(job);
+        job_event_pending(&job->job);
     }
     return 0;
 }
@@ -711,8 +703,10 @@ static void block_job_iostatus_set_err(BlockJob *job, int error)
     }
 }
 
-static void block_job_event_cancelled(BlockJob *job)
+static void block_job_event_cancelled(Notifier *n, void *opaque)
 {
+    BlockJob *job = opaque;
+
     if (block_job_is_internal(job)) {
         return;
     }
@@ -725,12 +719,19 @@ static void block_job_event_cancelled(BlockJob *job)
                                         &error_abort);
 }
 
-static void block_job_event_completed(BlockJob *job, const char *msg)
+static void block_job_event_completed(Notifier *n, void *opaque)
 {
+    BlockJob *job = opaque;
+    const char *msg = NULL;
+
     if (block_job_is_internal(job)) {
         return;
     }
 
+    if (job->ret < 0) {
+        msg = strerror(-job->ret);
+    }
+
     qapi_event_send_block_job_completed(job_type(&job->job),
                                         job->job.id,
                                         job->len,
@@ -741,8 +742,10 @@ static void block_job_event_completed(BlockJob *job, const char *msg)
                                         &error_abort);
 }
 
-static void block_job_event_pending(BlockJob *job)
+static void block_job_event_pending(Notifier *n, void *opaque)
 {
+    BlockJob *job = opaque;
+
     if (block_job_is_internal(job)) {
         return;
     }
@@ -798,6 +801,17 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
     job->cb            = cb;
     job->opaque        = opaque;
 
+    job->finalize_cancelled_notifier.notify = block_job_event_cancelled;
+    job->finalize_completed_notifier.notify = block_job_event_completed;
+    job->pending_notifier.notify = block_job_event_pending;
+
+    notifier_list_add(&job->job.on_finalize_cancelled,
+                      &job->finalize_cancelled_notifier);
+    notifier_list_add(&job->job.on_finalize_completed,
+                      &job->finalize_completed_notifier);
+    notifier_list_add(&job->job.on_pending,
+                      &job->pending_notifier);
+
     error_setg(&job->blocker, "block device is in use by block job: %s",
                job_type_str(&job->job));
     block_job_add_bdrv(job, "main node", bs, 0, BLK_PERM_ALL, &error_abort);
diff --git a/job.c b/job.c
index 98113196af..ab9d6d8a22 100644
--- a/job.c
+++ b/job.c
@@ -216,6 +216,10 @@ void *job_create(const char *job_id, const JobDriver *driver, AioContext *ctx,
     job->auto_finalize = !(flags & JOB_MANUAL_FINALIZE);
     job->auto_dismiss  = !(flags & JOB_MANUAL_DISMISS);
 
+    notifier_list_init(&job->on_finalize_cancelled);
+    notifier_list_init(&job->on_finalize_completed);
+    notifier_list_init(&job->on_pending);
+
     job_state_transition(job, JOB_STATUS_CREATED);
     aio_timer_init(qemu_get_aio_context(), &job->sleep_timer,
                    QEMU_CLOCK_REALTIME, SCALE_NS,
@@ -248,6 +252,21 @@ void job_unref(Job *job)
     }
 }
 
+void job_event_cancelled(Job *job)
+{
+    notifier_list_notify(&job->on_finalize_cancelled, job);
+}
+
+void job_event_completed(Job *job)
+{
+    notifier_list_notify(&job->on_finalize_completed, job);
+}
+
+void job_event_pending(Job *job)
+{
+    notifier_list_notify(&job->on_pending, job);
+}
+
 /*
  * Conditionally enter a job pending a call to fn() while under the job_lock
  * critical section.
-- 
2.13.6