qemu/job.c
Kevin Wolf 5d43e86e11 job: Add job_sleep_ns()
There is nothing block layer specific about block_job_sleep_ns(), so
move the function to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00

374 lines
10 KiB
C

/*
* Background jobs (long-running operations)
*
* Copyright (c) 2011 IBM Corp.
* Copyright (c) 2012, 2018 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qapi/error.h"
#include "qemu/job.h"
#include "qemu/id.h"
#include "qemu/main-loop.h"
#include "trace-root.h"
static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs);
/* Job State Transition Table */
bool JobSTT[JOB_STATUS__MAX][JOB_STATUS__MAX] = {
/* U, C, R, P, Y, S, W, D, X, E, N */
/* U: */ [JOB_STATUS_UNDEFINED] = {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
/* C: */ [JOB_STATUS_CREATED] = {0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1},
/* R: */ [JOB_STATUS_RUNNING] = {0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0},
/* P: */ [JOB_STATUS_PAUSED] = {0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0},
/* Y: */ [JOB_STATUS_READY] = {0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 0},
/* S: */ [JOB_STATUS_STANDBY] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
/* W: */ [JOB_STATUS_WAITING] = {0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0},
/* D: */ [JOB_STATUS_PENDING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
/* X: */ [JOB_STATUS_ABORTING] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0},
/* E: */ [JOB_STATUS_CONCLUDED] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
/* N: */ [JOB_STATUS_NULL] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
};
bool JobVerbTable[JOB_VERB__MAX][JOB_STATUS__MAX] = {
/* U, C, R, P, Y, S, W, D, X, E, N */
[JOB_VERB_CANCEL] = {0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0},
[JOB_VERB_PAUSE] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
[JOB_VERB_RESUME] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
[JOB_VERB_SET_SPEED] = {0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0},
[JOB_VERB_COMPLETE] = {0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},
[JOB_VERB_FINALIZE] = {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0},
[JOB_VERB_DISMISS] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0},
};
/* Right now, this mutex is only needed to synchronize accesses to job->busy
* and job->sleep_timer, such as concurrent calls to job_do_yield and
* job_enter. */
static QemuMutex job_mutex;
static void job_lock(void)
{
qemu_mutex_lock(&job_mutex);
}
static void job_unlock(void)
{
qemu_mutex_unlock(&job_mutex);
}
static void __attribute__((__constructor__)) job_init(void)
{
qemu_mutex_init(&job_mutex);
}
/* TODO Make static once the whole state machine is in job.c */
void job_state_transition(Job *job, JobStatus s1)
{
JobStatus s0 = job->status;
assert(s1 >= 0 && s1 <= JOB_STATUS__MAX);
trace_job_state_transition(job, /* TODO re-enable: job->ret */ 0,
JobSTT[s0][s1] ? "allowed" : "disallowed",
JobStatus_str(s0), JobStatus_str(s1));
assert(JobSTT[s0][s1]);
job->status = s1;
}
int job_apply_verb(Job *job, JobVerb verb, Error **errp)
{
JobStatus s0 = job->status;
assert(verb >= 0 && verb <= JOB_VERB__MAX);
trace_job_apply_verb(job, JobStatus_str(s0), JobVerb_str(verb),
JobVerbTable[verb][s0] ? "allowed" : "prohibited");
if (JobVerbTable[verb][s0]) {
return 0;
}
error_setg(errp, "Job '%s' in state '%s' cannot accept command verb '%s'",
job->id, JobStatus_str(s0), JobVerb_str(verb));
return -EPERM;
}
JobType job_type(const Job *job)
{
return job->driver->job_type;
}
const char *job_type_str(const Job *job)
{
return JobType_str(job_type(job));
}
bool job_is_cancelled(Job *job)
{
return job->cancelled;
}
bool job_started(Job *job)
{
return job->co;
}
bool job_should_pause(Job *job)
{
return job->pause_count > 0;
}
Job *job_next(Job *job)
{
if (!job) {
return QLIST_FIRST(&jobs);
}
return QLIST_NEXT(job, job_list);
}
Job *job_get(const char *id)
{
Job *job;
QLIST_FOREACH(job, &jobs, job_list) {
if (job->id && !strcmp(id, job->id)) {
return job;
}
}
return NULL;
}
static void job_sleep_timer_cb(void *opaque)
{
Job *job = opaque;
job_enter(job);
}
void *job_create(const char *job_id, const JobDriver *driver, AioContext *ctx,
Error **errp)
{
Job *job;
if (job_id) {
if (!id_wellformed(job_id)) {
error_setg(errp, "Invalid job ID '%s'", job_id);
return NULL;
}
if (job_get(job_id)) {
error_setg(errp, "Job ID '%s' already in use", job_id);
return NULL;
}
}
job = g_malloc0(driver->instance_size);
job->driver = driver;
job->id = g_strdup(job_id);
job->refcnt = 1;
job->aio_context = ctx;
job->busy = false;
job->paused = true;
job->pause_count = 1;
job_state_transition(job, JOB_STATUS_CREATED);
aio_timer_init(qemu_get_aio_context(), &job->sleep_timer,
QEMU_CLOCK_REALTIME, SCALE_NS,
job_sleep_timer_cb, job);
QLIST_INSERT_HEAD(&jobs, job, job_list);
return job;
}
void job_ref(Job *job)
{
++job->refcnt;
}
void job_unref(Job *job)
{
if (--job->refcnt == 0) {
assert(job->status == JOB_STATUS_NULL);
assert(!timer_pending(&job->sleep_timer));
if (job->driver->free) {
job->driver->free(job);
}
QLIST_REMOVE(job, job_list);
g_free(job->id);
g_free(job);
}
}
void job_enter_cond(Job *job, bool(*fn)(Job *job))
{
if (!job_started(job)) {
return;
}
if (job->deferred_to_main_loop) {
return;
}
job_lock();
if (job->busy) {
job_unlock();
return;
}
if (fn && !fn(job)) {
job_unlock();
return;
}
assert(!job->deferred_to_main_loop);
timer_del(&job->sleep_timer);
job->busy = true;
job_unlock();
aio_co_wake(job->co);
}
void job_enter(Job *job)
{
job_enter_cond(job, NULL);
}
/* Yield, and schedule a timer to reenter the coroutine after @ns nanoseconds.
* Reentering the job coroutine with block_job_enter() before the timer has
* expired is allowed and cancels the timer.
*
* If @ns is (uint64_t) -1, no timer is scheduled and block_job_enter() must be
* called explicitly. */
void coroutine_fn job_do_yield(Job *job, uint64_t ns)
{
job_lock();
if (ns != -1) {
timer_mod(&job->sleep_timer, ns);
}
job->busy = false;
job_unlock();
qemu_coroutine_yield();
/* Set by job_enter_cond() before re-entering the coroutine. */
assert(job->busy);
}
void coroutine_fn job_pause_point(Job *job)
{
assert(job && job_started(job));
if (!job_should_pause(job)) {
return;
}
if (job_is_cancelled(job)) {
return;
}
if (job->driver->pause) {
job->driver->pause(job);
}
if (job_should_pause(job) && !job_is_cancelled(job)) {
JobStatus status = job->status;
job_state_transition(job, status == JOB_STATUS_READY
? JOB_STATUS_STANDBY
: JOB_STATUS_PAUSED);
job->paused = true;
job_do_yield(job, -1);
job->paused = false;
job_state_transition(job, status);
}
if (job->driver->resume) {
job->driver->resume(job);
}
}
void coroutine_fn job_sleep_ns(Job *job, int64_t ns)
{
assert(job->busy);
/* Check cancellation *before* setting busy = false, too! */
if (job_is_cancelled(job)) {
return;
}
if (!job_should_pause(job)) {
job_do_yield(job, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + ns);
}
job_pause_point(job);
}
/**
* All jobs must allow a pause point before entering their job proper. This
* ensures that jobs can be paused prior to being started, then resumed later.
*/
static void coroutine_fn job_co_entry(void *opaque)
{
Job *job = opaque;
assert(job && job->driver && job->driver->start);
job_pause_point(job);
job->driver->start(job);
}
void job_start(Job *job)
{
assert(job && !job_started(job) && job->paused &&
job->driver && job->driver->start);
job->co = qemu_coroutine_create(job_co_entry, job);
job->pause_count--;
job->busy = true;
job->paused = false;
job_state_transition(job, JOB_STATUS_RUNNING);
aio_co_enter(job->aio_context, job->co);
}
typedef struct {
Job *job;
JobDeferToMainLoopFn *fn;
void *opaque;
} JobDeferToMainLoopData;
static void job_defer_to_main_loop_bh(void *opaque)
{
JobDeferToMainLoopData *data = opaque;
Job *job = data->job;
AioContext *aio_context = job->aio_context;
aio_context_acquire(aio_context);
data->fn(data->job, data->opaque);
aio_context_release(aio_context);
g_free(data);
}
void job_defer_to_main_loop(Job *job, JobDeferToMainLoopFn *fn, void *opaque)
{
JobDeferToMainLoopData *data = g_malloc(sizeof(*data));
data->job = job;
data->fn = fn;
data->opaque = opaque;
job->deferred_to_main_loop = true;
aio_bh_schedule_oneshot(qemu_get_aio_context(),
job_defer_to_main_loop_bh, data);
}