The job API will be handled separately in another serie. Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com> --- include/qemu/job.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)
diff --git a/include/qemu/job.h b/include/qemu/job.h index 41162ed494..c236c43026 100644 --- a/include/qemu/job.h +++ b/include/qemu/job.h @@ -169,12 +169,21 @@ typedef struct Job { * Callbacks and other information about a Job driver. */ struct JobDriver { + + /* Fields initialized in struct definition and never changed. */ + /** Derived Job struct size */ size_t instance_size; /** Enum describing the operation */ JobType job_type; + /* + * I/O API functions. These functions are thread-safe, and therefore + * can run in any thread as long as they have called + * aio_context_acquire/release(). + */ + /** * Mandatory: Entrypoint for the Coroutine. * @@ -201,6 +210,28 @@ struct JobDriver { */ void coroutine_fn (*resume)(Job *job); + /* + * Global state (GS) API. These functions run under the BQL lock. + * + * If a function modifies the graph, it also uses drain and/or + * aio_context_acquire/release to be sure it has unique access. + * aio_context locking is needed together with BQL because of + * the thread-safe I/O API that concurrently runs and accesses + * the graph without the BQL. + * + * It is important to note that not all of these functions are + * necessarily limited to running under the BQL, but they would + * require additional auditing and may small thread-safety changes + * to move them into the I/O API. Often it's not worth doing that + * work since the APIs are only used with the BQL held at the + * moment, so they have been placed in the GS API (for now). + * + * All callers that use these function pointers must + * use this assertion: + * g_assert(qemu_in_main_thread()); + * to catch when they are accidentally called without the BQL. + */ + /** * Called when the job is resumed by the user (i.e. user_paused becomes * false). .user_resume is called before .resume. -- 2.27.0