Source code
Revision control
Copy as Markdown
Other Tools
Test Info: Warnings
- This test gets skipped with pattern: os == 'android'
- Manifest: devtools/shared/heapsnapshot/tests/xpcshell/xpcshell.toml
/* Any copyright is dedicated to the Public Domain.
"use strict";
// Sanity test that we can compute shortest paths.
//
// Because the actual heap graph is too unpredictable and likely to drastically
// change as various implementation bits change, we don't test exact paths
// here. See js/src/jsapi-tests/testUbiNode.cpp for such tests, where we can
// control the specific graph shape and structure and so testing exact paths is
// reliable.
function run_test() {
const path = ChromeUtils.saveHeapSnapshot({ runtime: true });
const snapshot = ChromeUtils.readHeapSnapshot(path);
const dominatorTree = snapshot.computeDominatorTree();
const dominatedByRoot = dominatorTree
.getImmediatelyDominated(dominatorTree.root)
.slice(0, 10);
ok(dominatedByRoot);
ok(dominatedByRoot.length);
const targetSet = new Set(dominatedByRoot);
const shortestPaths = snapshot.computeShortestPaths(
dominatorTree.root,
dominatedByRoot,
2
);
ok(shortestPaths);
ok(shortestPaths instanceof Map);
Assert.strictEqual(shortestPaths.size, targetSet.size);
for (const [target, paths] of shortestPaths) {
ok(targetSet.has(target), "We should only get paths for our targets");
targetSet.delete(target);
ok(
!!paths.length,
"We must have at least one path, since the target is dominated by the root"
);
Assert.lessOrEqual(
paths.length,
2,
"Should not have recorded more paths than the max requested"
);
dumpn("---------------------");
dumpn("Shortest paths for 0x" + target.toString(16) + ":");
for (const pth of paths) {
dumpn(" path =");
for (const part of pth) {
dumpn(
" predecessor: 0x" +
part.predecessor.toString(16) +
"; edge: " +
part.edge
);
}
}
dumpn("---------------------");
for (const path2 of paths) {
ok(!!path2.length, "Cannot have zero length paths");
Assert.strictEqual(
path2[0].predecessor,
dominatorTree.root,
"The first predecessor is always our start node"
);
for (const part of path2) {
ok(part.predecessor, "Each part of a path has a predecessor");
ok(
!!snapshot.describeNode(
{ by: "count", count: true, bytes: true },
part.predecessor
),
"The predecessor is in the heap snapshot"
);
ok("edge" in part, "Each part has an (potentially null) edge property");
}
}
}
Assert.strictEqual(
targetSet.size,
0,
"We found paths for all of our targets"
);
do_test_finished();
}