Commit e4370165 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Fam Zheng
Browse files

aio: introduce qemu_get_current_aio_context 



This will be used by BDRV_POLL_WHILE (and thus by bdrv_drain)
to choose how to wait for I/O completion.

Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-12-git-send-email-pbonzini@redhat.com>
Signed-off-by: default avatarFam Zheng <famz@redhat.com>
parent f11672db

include/block/aio.h

+18 −0
Original line number Diff line number Diff line
@@ -452,6 +452,24 @@ static inline bool aio_node_check(AioContext *ctx, bool is_external) 
    return !is_external || !atomic_read(&ctx->external_disable_cnt);

}



/**

 * Return the AioContext whose event loop runs in the current thread.

 *

 * If called from an IOThread this will be the IOThread's AioContext.  If

 * called from another thread it will be the main loop AioContext.

 */

AioContext *qemu_get_current_aio_context(void);



/**

 * @ctx: the aio context

 *

 * Return whether we are running in the I/O thread that manages @ctx.

 */

static inline bool aio_context_in_iothread(AioContext *ctx)

{

    return ctx == qemu_get_current_aio_context();

}



/**

 * aio_context_setup:

 * @ctx: the aio context

iothread.c

+9 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include "qmp-commands.h"

#include "qemu/error-report.h"

#include "qemu/rcu.h"

#include "qemu/main-loop.h"



typedef ObjectClass IOThreadClass;
@@ -28,6 +29,13 @@ typedef ObjectClass IOThreadClass; 
#define IOTHREAD_CLASS(klass) \

   OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)



static __thread IOThread *my_iothread;



AioContext *qemu_get_current_aio_context(void)

{

    return my_iothread ? my_iothread->ctx : qemu_get_aio_context();

}



static void *iothread_run(void *opaque)

{

    IOThread *iothread = opaque;
@@ -35,6 +43,7 @@ static void *iothread_run(void *opaque) 


    rcu_register_thread();



    my_iothread = iothread;

    qemu_mutex_lock(&iothread->init_done_lock);

    iothread->thread_id = qemu_get_thread_id();

    qemu_cond_signal(&iothread->init_done_cond);

stubs/Makefile.objs

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ stub-obj-y += gdbstub.o 
stub-obj-y += get-fd.o

stub-obj-y += get-next-serial.o

stub-obj-y += get-vm-name.o

stub-obj-y += iothread.o

stub-obj-y += iothread-lock.o

stub-obj-y += is-daemonized.o

stub-obj-y += machine-init-done.o

stubs/iothread.c

0 → 100644
+8 −0
Original line number Diff line number Diff line 
#include "qemu/osdep.h"

#include "block/aio.h"

#include "qemu/main-loop.h"



AioContext *qemu_get_current_aio_context(void)

{

    return qemu_get_aio_context();

}