mongodb/jstests/noPassthrough/yield_during_writes.js

// Ensure that multi-update and multi-remove operations yield regularly.
// @tags: [requires_profiling]
(function() {
'use strict';

function countOpYields(coll, op) {
    const profileEntry = coll.getDB()
                             .system.profile.find({ns: coll.getFullName()})
                             .sort({$natural: -1})
                             .limit(1)
                             .next();
    assert.eq(profileEntry.op, op);
    return profileEntry.numYield;
}

const nDocsToInsert = 300;
const worksPerYield = 50;

// Start a mongod that will yield every 50 work cycles.
const mongod = MongoRunner.runMongod({
    setParameter: `internalQueryExecYieldIterations=${worksPerYield}`,
    profile: 2,
});
assert.neq(null, mongod, 'mongod was unable to start up');

const coll = mongod.getDB('test').yield_during_writes;
coll.drop();

for (let i = 0; i < nDocsToInsert; i++) {
    assert.commandWorked(coll.insert({_id: i}));
}

// A multi-update doing a collection scan should yield about nDocsToInsert / worksPerYield
// times.
assert.commandWorked(coll.update({}, {$inc: {counter: 1}}, {multi: true}));
assert.gt(countOpYields(coll, 'update'), (nDocsToInsert / worksPerYield) - 2);

// Likewise, a multi-remove should also yield approximately every worksPerYield documents.
assert.commandWorked(coll.remove({}, {multi: true}));
assert.gt(countOpYields(coll, 'remove'), (nDocsToInsert / worksPerYield) - 2);

MongoRunner.stopMongod(mongod);
})();