theCollection, about 60 objects
theArray, average 80 object

db.theCollection.find({}, { pro:1, id: 1, title: 1, theArray:1 }).forEach(
function(z) {
	z.theArray.forEach(
		function(p){
			print(z.title+' - '+p.title+' # '+p.gwid);
			db.theCollection.update(
				{ 'theArray.gwid': p.gwid},
				{  
					$set: {
						'theArray.$.pro': z.pro
					}
				}
			)
		}
	)
	print(z.id+' - '+z.title+' '+z.theArray.length);
})

2014-05-21T07:56:11.212+0000 [conn209501] SEVERE: Invalid access at address: 0x20039e0e02
2014-05-21T07:56:11.281+0000 [conn209501] SEVERE: Got signal: 11 (Segmentation fault).
Backtrace:0x11bd301 0x11bc6de 0x11bc7cf 0x7f6a571f85b0 0x796892 0x796fbf 0x79773d 0x7979ff 0xc3d34a 0xc48ca6 0xb8f1c9 0xb993e8 0x76b76f 0x117367b 0x7f6a571f0f18 0x7f6a56506e0d 
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo15printStackTraceERSo+0x21) [0x11bd301]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod() [0x11bc6de]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod() [0x11bc7cf]
 /lib64/libpthread.so.0(+0xf5b0) [0x7f6a571f85b0]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZNK5mongo11mutablebson8Document4Impl12writeElementINS_16BSONArrayBuilderEEEvjPT_PKNS_10StringDataE+0x52) [0x796892]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZNK5mongo11mutablebson8Document4Impl13writeChildrenINS_16BSONArrayBuilderEEEvjPT_+0x4f) [0x796fbf]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZNK5mongo11mutablebson8Document4Impl12writeElementINS_14BSONObjBuilderEEEvjPT_PKNS_10StringDataE+0x22d) [0x79773d]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZNK5mongo11mutablebson8Document4Impl13writeChildrenINS_14BSONObjBuilderEEEvjPT_+0x4f) [0x7979ff]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo6updateERKNS_13UpdateRequestEPNS_7OpDebugEPNS_12UpdateDriverEPNS_14CanonicalQueryE+0x115a) [0xc3d34a]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo14UpdateExecutor7executeEv+0x66) [0xc48ca6]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo14receivedUpdateERNS_7MessageERNS_5CurOpE+0x729) [0xb8f1c9]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo16assembleResponseERNS_7MessageERNS_10DbResponseERKNS_11HostAndPortE+0xec8) [0xb993e8]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo16MyMessageHandler7processERNS_7MessageEPNS_21AbstractMessagingPortEPNS_9LastErrorE+0x9f) [0x76b76f]
 /data/mongodb-linux-x86_64-2.6.0/bin/mongod(_ZN5mongo17PortMessageServer17handleIncomingMsgEPv+0x4fb) [0x117367b]
 /lib64/libpthread.so.0(+0x7f18) [0x7f6a571f0f18]
 /lib64/libc.so.6(clone+0x6d) [0x7f6a56506e0d]