qemu/migration/colo-failover.c
Stefan Hajnoczi d73415a315 qemu/atomic.h: rename atomic_ to qatomic_
clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
2020-09-23 16:07:44 +01:00

87 lines
2.2 KiB
C

/*
* COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
* (a.k.a. Fault Tolerance or Continuous Replication)
*
* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
* Copyright (c) 2016 FUJITSU LIMITED
* Copyright (c) 2016 Intel Corporation
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "migration/colo.h"
#include "migration/failover.h"
#include "qemu/main-loop.h"
#include "migration.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-migration.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "trace.h"
static QEMUBH *failover_bh;
static FailoverStatus failover_state;
static void colo_failover_bh(void *opaque)
{
int old_state;
qemu_bh_delete(failover_bh);
failover_bh = NULL;
old_state = failover_set_state(FAILOVER_STATUS_REQUIRE,
FAILOVER_STATUS_ACTIVE);
if (old_state != FAILOVER_STATUS_REQUIRE) {
error_report("Unknown error for failover, old_state = %s",
FailoverStatus_str(old_state));
return;
}
colo_do_failover();
}
void failover_request_active(Error **errp)
{
if (failover_set_state(FAILOVER_STATUS_NONE,
FAILOVER_STATUS_REQUIRE) != FAILOVER_STATUS_NONE) {
error_setg(errp, "COLO failover is already activated");
return;
}
failover_bh = qemu_bh_new(colo_failover_bh, NULL);
qemu_bh_schedule(failover_bh);
}
void failover_init_state(void)
{
failover_state = FAILOVER_STATUS_NONE;
}
FailoverStatus failover_set_state(FailoverStatus old_state,
FailoverStatus new_state)
{
FailoverStatus old;
old = qatomic_cmpxchg(&failover_state, old_state, new_state);
if (old == old_state) {
trace_colo_failover_set_state(FailoverStatus_str(new_state));
}
return old;
}
FailoverStatus failover_get_state(void)
{
return qatomic_read(&failover_state);
}
void qmp_x_colo_lost_heartbeat(Error **errp)
{
if (get_colo_mode() == COLO_MODE_NONE) {
error_setg(errp, QERR_FEATURE_DISABLED, "colo");
return;
}
failover_request_active(errp);
}