/**
* Run all jobs in the work list (and any children they have) to completion. This method returns
* <code>true</code> if all jobs were successfully completed. If all jobs were successfully
* completed, then the worklist will be empty.
*
* <p>The scheduling of <code>Job</code>s uses two methods to maintain scheduling invariants:
* <code>selectJobFromWorklist</code> selects a <code>SourceJob</code> from <code>worklist</code>
* (a list of jobs that still need to be processed); <code>enforceInvariants</code> is called
* before a pass is performed on a <code>SourceJob</code> and is responsible for ensuring all
* dependencies are satisfied before the pass proceeds, i.e. enforcing any scheduling invariants.
*/
public boolean runToCompletion() {
boolean okay = true;
while (okay && !worklist.isEmpty()) {
SourceJob job = selectJobFromWorklist();
if (Report.should_report(Report.frontend, 1)) {
Report.report(1, "Running job " + job);
}
okay &= runAllPasses(job);
if (job.completed()) {
// the job has finished. Let's remove it from the map so it
// can be garbage collected, and free up the AST.
jobs.put(job.source(), COMPLETED_JOB);
if (Report.should_report(Report.frontend, 1)) {
Report.report(1, "Completed job " + job);
}
} else {
// the job is not yet completed (although, it really
// should be...)
if (Report.should_report(Report.frontend, 1)) {
Report.report(1, "Failed to complete job " + job);
}
worklist.add(job);
}
}
if (Report.should_report(Report.frontend, 1))
Report.report(1, "Finished all passes -- " + (okay ? "okay" : "failed"));
return okay;
}
/**
* Add a new <code>SourceJob</code> for the <code>Source source</code>, with AST <code>ast</code>.
* A new job will be created if needed. If the <code>Source source</code> has already been
* processed, and its job discarded to release resources, then <code>null</code> will be returned.
*/
public SourceJob addJob(Source source, Node ast) {
Object o = jobs.get(source);
SourceJob job = null;
if (o == COMPLETED_JOB) {
// the job has already been completed.
// We don't need to add a job
return null;
} else if (o == null) {
// No appropriate job yet exists, we will create one.
job = this.createSourceJob(source, ast);
// record the job in the map and the worklist.
jobs.put(source, job);
worklist.addLast(job);
if (Report.should_report(Report.frontend, 3)) {
Report.report(3, "Adding job for " + source + " at the " + "request of job " + currentJob);
}
} else {
job = (SourceJob) o;
}
// if the current source job caused this job to load, record the
// dependency.
if (currentJob instanceof SourceJob) {
((SourceJob) currentJob).addDependency(source);
}
return job;
}
/** Flatten complex expressions within the AST */
public Node leave(Node old, Node n, NodeVisitor v) {
if (n == noFlatten) {
noFlatten = null;
return n;
}
if (n instanceof Block) {
List l = (List) stack.removeFirst();
return ((Block) n).statements(l);
} else if (n instanceof Stmt && !(n instanceof LocalDecl)) {
List l = (List) stack.getFirst();
l.add(n);
return n;
} else if (n instanceof Expr
&& !(n instanceof Lit)
&& !(n instanceof Special)
&& !(n instanceof Local)) {
Expr e = (Expr) n;
if (e instanceof Assign) {
return n;
}
// create a local temp, initialized to the value of the complex
// expression
String name = newID();
LocalDecl def =
nf.LocalDecl(
e.position(), Flags.FINAL, nf.CanonicalTypeNode(e.position(), e.type()), name, e);
def = def.localInstance(ts.localInstance(e.position(), Flags.FINAL, e.type(), name));
List l = (List) stack.getFirst();
l.add(def);
// return the local temp instead of the complex expression
Local use = nf.Local(e.position(), name);
use = (Local) use.type(e.type());
use = use.localInstance(ts.localInstance(e.position(), Flags.FINAL, e.type(), name));
return use;
}
return n;
}
/** When entering a BlockStatement, place a new StatementList onto the stack */
public NodeVisitor enter(Node n) {
if (n instanceof Block) {
stack.addFirst(new LinkedList());
}
if (n instanceof Eval) {
// Don't flatten the expression contained in the statement, but
// flatten its subexpressions.
Eval s = (Eval) n;
noFlatten = s.expr();
}
return this;
}
/**
* Before running <code>Pass pass</code> on <code>SourceJob job</code> make sure that all
* appropriate scheduling invariants are satisfied, to ensure that all passes of other jobs that
* <code>job</code> depends on will have already been done.
*/
protected void enforceInvariants(Job job, Pass pass) throws CyclicDependencyException {
SourceJob srcJob = job.sourceJob();
if (srcJob == null) {
return;
}
BarrierPass lastBarrier = srcJob.lastBarrier();
if (lastBarrier != null) {
// make sure that _all_ dependent jobs have completed at least up to
// the last barrier (not just children).
//
// Ideally the invariant should be that only the source jobs that
// job _depends on_ should be brought up to the last barrier.
// This is work to be done in the future...
List allDependentSrcs = new ArrayList(srcJob.dependencies());
Iterator i = allDependentSrcs.iterator();
while (i.hasNext()) {
Source s = (Source) i.next();
Object o = jobs.get(s);
if (o == COMPLETED_JOB) continue;
if (o == null) {
throw new InternalCompilerError("Unknown source " + s);
}
SourceJob sj = (SourceJob) o;
if (sj.pending(lastBarrier.id())) {
// Make the job run up to the last barrier.
// We ignore the return result, since even if the job
// fails, we will keep on going and see
// how far we get...
if (Report.should_report(Report.frontend, 3)) {
Report.report(3, "Running " + sj + " to " + lastBarrier.id() + " for " + srcJob);
}
runToPass(sj, lastBarrier.id());
}
}
}
if (pass instanceof GlobalBarrierPass) {
// need to make sure that _all_ jobs have completed just up to
// this global barrier.
// If we hit a cyclic dependency, ignore it and run the other
// jobs up to that pass. Then try again to run the cyclic
// pass. If we hit the cycle again for the same job, stop.
LinkedList barrierWorklist = new LinkedList(jobs.values());
while (!barrierWorklist.isEmpty()) {
Object o = barrierWorklist.removeFirst();
if (o == COMPLETED_JOB) continue;
SourceJob sj = (SourceJob) o;
if (sj.completed(pass.id()) || sj.nextPass() == sj.passByID(pass.id())) {
// the source job has either done this global pass
// (which is possible if the job was loaded late in the
// game), or is right up to the global barrier.
continue;
}
// Make the job run up to just before the global barrier.
// We ignore the return result, since even if the job
// fails, we will keep on going and see
// how far we get...
Pass beforeGlobal = sj.getPreviousTo(pass.id());
if (Report.should_report(Report.frontend, 3)) {
Report.report(3, "Running " + sj + " to " + beforeGlobal.id() + " for " + srcJob);
}
// Don't use runToPass, since that catches the
// CyclicDependencyException that we should report
// back to the caller.
while (!sj.pendingPasses().isEmpty()) {
Pass p = (Pass) sj.pendingPasses().get(0);
runPass(sj, p);
if (p == beforeGlobal) {
break;
}
}
}
}
}
/**
* Select and remove a <code>SourceJob</code> from the non-empty <code>worklist</code>. Return the
* selected <code>SourceJob</code> which will be scheduled to run all of its remaining passes.
*/
protected SourceJob selectJobFromWorklist() {
return (SourceJob) worklist.remove(0);
}