Google Map crashes in IOS7

Question

We are developing an Hybrid app and we are using google map API in our application. When we are trying to load 2000 data markers in the map, it got crashed. Map is not get c

Answer 1

Having experienced similar problems with Google Maps I tried to isolate a minimal test case. I wanted to see if this was perhaps a more general memory management issue.

This code that just stores random data in an array crashes Safari on IOS 7 on an iPad mini, 16GB:

function randomString(length, chars) {
    var result = '';
    for (var i = length; i > 0; --i) result += chars[Math.round(Math.random() * (chars.length - 1))];
    return result;
}

var arr = []
for (var i=0;i<5000;i++) {
    // one character is two bytes in JavaScript, so 512 chars is 1Kb:
    o = randomString(512, '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ');
    arr.push(o);
}

You can try this test with your own browser by going http://vici.org/memtest.html . The script on that page will try to claim 50Mb of memory, in steps of 1Mb. The script shows a running counter so you will see how well your browser performs and when it crashes (if it does). The script stores the results for each ip / user agent combination in a database to be able to draw some conclusions.

On average, IOS 6 (n=12) allows a script to claim about 12Mb. IOS 7 (n=47) allows a script to claim around 15 Mb. These are not hard limits. For both sets the standard devation was quite high, ~12 Mb. In the Xcode emulator Safari doesn't even crash at all (claiming the full 50Mb, probably because it has access to more RAM).

So we may conclude that the issue is not caused by IOS 7 leaving less memory for Safari. The problem seems to be, as was suggested by Philipp Kühn, that -in some specific cases? - Safari consumes significantly more memory than it did in IOS 6. One clue about the cause can be found at https://discussions.apple.com/message/23837361#23837361 where a page with 200 divs and the following CSS

div {
  -webkit-backface-visibility: hidden;
}

crashes safari.

It appears that using the Leaflet library circumvents the maps issue (see https://code.google.com/p/gmaps-api-issues/issues/detail?id= and https://github.com/Leaflet/Leaflet/pull/2149) however Leaflet circumvented the low memory crashes not by changes on the css but on the javascript level. Leaflet now circumvents statements like

context = this

This would suggest Safari doesn't clean up unused objects. As long as Apple doesn't fix Safari, perhaps Google could do changes similar to what the Leaflet guys have done?

In the mean time Apple has release IOS7.1 which doesn't fully solve the crashes but certainly makes them occur les often.