1 成员变量
/** Master list of jobs. */
final JobStore mJobs; //job list
/** Tracking the standby bucket state of each app */
final StandbyTracker mStandbyTracker;
/**
* Track Services that have currently active or pending jobs. The index is provided by
* {@link JobStatus#getServiceToken()}
*/
final List mActiveServices = new ArrayList<>();
/** List of controllers that will notify this service of updates to jobs. */
final List mControllers;
/**
* Queue of pending jobs. The JobServiceContext class will receive jobs from this list
* when ready to execute them.
*/
final ArrayList mPendingJobs = new ArrayList<>();
/** Need directly for receiving thermal events */
private IThermalService mThermalService;
final JobHandler mHandler;
/**
* Whether to use heartbeats or rolling window for quota management. True will use
* heartbeats, false will use a rolling window.
*/
public boolean USE_HEARTBEATS = DEFAULT_USE_HEARTBEATS; //默认未false
// Max job counts for screen on / off, for each memory trim level.
final MaxJobCountsPerMemoryTrimLevel MAX_JOB_COUNTS_SCREEN_ON =
new MaxJobCountsPerMemoryTrimLevel(
new MaxJobCounts(
8, "max_job_total_on_normal",
6, "max_job_max_bg_on_normal",
2, "max_job_min_bg_on_normal"),
new MaxJobCounts(
8, "max_job_total_on_moderate",
4, "max_job_max_bg_on_moderate",
2, "max_job_min_bg_on_moderate"),
new MaxJobCounts(
5, "max_job_total_on_low",
1, "max_job_max_bg_on_low",
1, "max_job_min_bg_on_low"),
new MaxJobCounts(
5, "max_job_total_on_critical",
1, "max_job_max_bg_on_critical",
1, "max_job_min_bg_on_critical"));
final MaxJobCountsPerMemoryTrimLevel MAX_JOB_COUNTS_SCREEN_OFF =
new MaxJobCountsPerMemoryTrimLevel(
new MaxJobCounts(
10, "max_job_total_off_normal",
6, "max_job_max_bg_off_normal",
2, "max_job_min_bg_off_normal"),
new MaxJobCounts(
10, "max_job_total_off_moderate",
4, "max_job_max_bg_off_moderate",
2, "max_job_min_bg_off_moderate"),
new MaxJobCounts(
5, "max_job_total_off_low",
1, "max_job_max_bg_off_low",
1, "max_job_min_bg_off_low"),
new MaxJobCounts(
5, "max_job_total_off_critical",
1, "max_job_max_bg_off_critical",
1, "max_job_min_bg_off_critical"));
2 mJobs = JobStore.initAndGet(this);
//读取/data/system/job/jobs.xml中的persist的job任务
PERIODIC_TASK
constraints: 满足条件
periodic：job的周期
3 schedule
-> scheduleAsPackage
-> 判断isAppStartModeDisabled,确认是否允许后台执行．
-> 根据jobinfo创建jobStatus
-> startTrackingJobLocked
// If the job is immediately ready to run, then we can just immediately
// put it in the pending list and try to schedule it. This is especially
// important for jobs with a 0 deadline constraint, since they will happen a fair
// amount, we want to handle them as quickly as possible, and semantically we want to
// make sure we have started holding the wake lock for the job before returning to
// the caller.
// If the job is not yet ready to run, there is nothing more to do -- we are
// now just waiting for one of its controllers to change state and schedule
// the job appropriately.
-> isReadyToBeExecutedLocked
-> maybeRunPendingJobsLocked
or -> evaluateControllerStatesLocked
3.1 判断是否可以执行job
/**
* Criteria for moving a job into the pending queue:
* - It's ready.
* - It's not pending.
* - It's not already running on a JSC.
* - Temperture is too high, and don't run job of request network and proity
* - The user that requested the job is running.
* - The job's standby bucket has come due to be runnable.
* - The component is enabled and runnable.
*/
private boolean isReadyToBeExecutedLocked(JobStatus job)
3.2 决定是否实际需要执行
/**
* ** Reconcile jobs in the pending queue against available execution contexts.**
* A controller can force a job into the pending queue even if it's already running, but
* here is where we decide whether to actually execute it.
*/
void maybeRunPendingJobsLocked() {
/**
* Takes jobs from pending queue and runs them on available contexts.
* If no contexts are available, preempts lower priority jobs to
* run higher priority ones.
* Lock on mJobs before calling this function.
*/
assignJobsToContextsLocked//核心逻辑
3.3 assignJobsToContextsLocked
private void assignJobsToContextsInternalLocked() {
if (DEBUG) {
Slog.d(TAG, printPendingQueueLocked());
}
final JobPackageTracker tracker = mService.mJobPackageTracker;
final List pendingJobs = mService.mPendingJobs;//获取pending jobs
final List activeServices = mService.mActiveServices;//获取active jobservicecontext
final List controllers = mService.mControllers;//获取状态控制器
updateMaxCountsLocked();//更新最大counts
// To avoid GC churn, we recycle the arrays.
JobStatus[] contextIdToJobMap = mRecycledAssignContextIdToJobMap;//实际是索引ActiveServices的状态
boolean[] slotChanged = mRecycledSlotChanged;
int[] preferredUidForContext = mRecycledPreferredUidForContext;
// Initialize the work variables and also count running jobs.
mJobCountTracker.reset(
mMaxJobCounts.getMaxTotal(),
mMaxJobCounts.getMaxBg(),
mMaxJobCounts.getMinBg());
for (int i=0; i= nextPending.lastEvaluatedPriority) {
continue;
}
// TODO lastEvaluatedPriority should be evaluateJobPriorityLocked. (double check it)
if (minPriorityForPreemption > nextPending.lastEvaluatedPriority) {
minPriorityForPreemption = nextPending.lastEvaluatedPriority;
selectedContextId = j;
// In this case, we're just going to preempt a low priority job, we're not
// actually starting a job, so don't set startingJob.
}
}
if (selectedContextId != -1) {
contextIdToJobMap[selectedContextId] = nextPending;
slotChanged[selectedContextId] = true;
}
if (startingJob) {
// Increase the counters when we're going to start a job.
mJobCountTracker.onStartingNewJob(isPendingFg);
}
}
if (DEBUG) {
Slog.d(TAG, printContextIdToJobMap(contextIdToJobMap, "running jobs final"));
}
mJobCountTracker.logStatus();
tracker.noteConcurrency(mJobCountTracker.getTotalRunningJobCountToNote(),
mJobCountTracker.getFgRunningJobCountToNote());
for (int i=0; i