mongo/jstests/slowWeekly/query_yield2.js

var currentOp;
var N;
var i;
var t;
var q;
var len;
var num;
var start;
var insertTime;

load( "jstests/libs/slow_weekly_util.js" );
testServer = new SlowWeeklyMongod( "query_yield2" );
db = testServer.getDB( "test" );

t = db.query_yield2;
t.drop();

N = 200;
i = 0;

q = function() { var x=this.n; for ( var i=0; i<25000; i++ ) { x = x * 2; } return false; }

print( "Shell ==== Creating test.query_yield2 collection ..." );
print( "Shell ==== Adding documents until a time-wasting query takes over 2 seconds to complete" );
while ( true ){
    function fill() {
        for ( ; i < N; ++i ) {
            t.insert( { _id : i , n : 1 } )
        }
    }
    function timeQuery() {
        return Date.timeFunc( 
            function() {
                assert.eq( 0 , t.find( q ).itcount() );
            }
        );
    }
    print( "Shell ==== Adding document IDs from " + i + " to " + (N - 1) );
    fill();
    print( "Shell ==== Running warm-up query 1" );
    timeQuery();
    print( "Shell ==== Running warm-up query 2" );
    timeQuery();
    print( "Shell ==== Running timed query ..." );
    time = timeQuery();
    print( "Shell ==== Query across " + N + " documents took " + time + " ms" );
    if ( time > 2000 ) {
        print( "Shell ==== Reached desired 2000 ms mark (at " + time + " ms), proceding to next step" );
        break;
    }
    N *= 2;
    print( "Shell ==== Did not reach 2000 ms, increasing fill point to " + N + " documents" );
}

print( "Shell ==== Testing db.currentOp to make sure nothing is in progress" );
print( "Shell ==== Dump of db.currentOp:" );
currentOp = db.currentOp();
print( tojson( currentOp ) );
len = currentOp.inprog.length;
if ( len ) {
    print( "Shell ==== This test is broken: db.currentOp().inprog.length is " + len );
    throw "query_yield2.js test is broken";
}
print( "Shell ==== The test is working so far: db.currentOp().inprog.length is " + len );

print( "Shell ==== Starting parallel shell to test if slow query will yield to write" );
join = startParallelShell( "print( 0 == db.query_yield2.find( function(){ var x=this.n; for ( var i=0; i<50000; i++ ){ x = x * 2; } return false; } ).itcount() ); " )

print( "Shell ==== Waiting until db.currentOp().inprog becomes non-empty" );
assert.soon( 
    function(){
        currentOp = db.currentOp();
        len = currentOp.inprog.length;
        if ( len ) {
            print( "Shell ==== Wait satisfied: db.currentOp().inprog.length is " + len );
            print( "Shell ==== Dump of db.currentOp:" );
            print( tojson( currentOp ) );
            print( "Shell ==== Checking if this currentOp is the query we are waiting for" );
            if ( currentOp.inprog[0].ns == "test.query_yield2" && currentOp.inprog[0].query["$where"] ) {
                print( "Shell ==== Yes, we found the query we are waiting for" );
                return true;
            }
            if ( currentOp.inprog[0].ns == "" && currentOp.inprog[0].query["whatsmyuri"] ) {
                print( "Shell ==== No, we found a \"whatsmyuri\" query, waiting some more" );
                return false;
            }
            print( "Shell ==== No, we found something other than our query or a \"whatsmyuri\", waiting some more" );
            return false;
        }
        return len > 0;
    } , "Wait failed, db.currentOp().inprog never became non-empty" , 2000 , 1 
);

print( "Shell ==== Now that we have seen db.currentOp().inprog show that our query is running, we start the real test" );
num = 0;
start = new Date();
while ( ( (new Date()).getTime() - start ) < ( time * 2 ) ) {
    if ( num == 0 ) {
        print( "Shell ==== Starting loop " + num + ", inserting 1 document" );
    }
    insertTime = Date.timeFunc( function() { t.insert( { x : 1 } ); db.getLastError(); } );
    currentOp = db.currentOp();
    len = currentOp.inprog.length;
    print( "Shell ==== Time to insert document " + num + " was " + insertTime + " ms, db.currentOp().inprog.length is " + len );
    if ( num++ == 0 ) {
        if ( len != 1 ) {
            print( "Shell ==== TEST FAILED!  db.currentOp().inprog.length is " + len );
            print( "Shell ==== Dump of db.currentOp:" );
            print( tojson( currentOp ) );
            throw "TEST FAILED!";
        }
    }
    assert.gt( 200, insertTime, "Insert took too long (" + insertTime + " ms), should be less than 200 ms" );
    if ( currentOp.inprog.length == 0 ) {
        break;
    }
}

print( "Shell ==== Finished inserting documents, reader also finished" );
print( "Shell ==== Waiting for parallel shell to exit" );
join();

currentOp = db.currentOp();
len = currentOp.inprog.length;
if ( len != 0 ) {
    print( "Shell ==== Final sanity check FAILED!  db.currentOp().inprog.length is " + len );
    print( "Shell ==== Dump of db.currentOp:" );
    print( tojson( currentOp ) );
    throw "TEST FAILED!";
}
print( "Shell ==== Test completed successfully, shutting down server" );
testServer.stop();