gist it, but gist.github.com appears down. The following reproduces the failure - likely could reduce the proxy logic some but it hopefully will reproduce the failure (and not due to another stupid mistake on my part!)import Timer from 'timer';
class MyClass {
myTimer;
}
const handler = {
construct(target, argArray, newTarget) {
return new Proxy(Reflect.construct(target, argArray, newTarget), handler);
},
get(target, propertyKey, receiver) {
const value = Reflect.get(target, propertyKey, receiver);
if (propertyKey == 'prototype') return value;
const proxy = new Proxy(value, handler);
return proxy;
},
};
// choose one of the following sections - the first fails with Proxy, the second works without it
const ProxyMyClass = new Proxy(MyClass, handler);
const myProxyInstance = new ProxyMyClass();
// const myProxyInstance = new MyClass();
myProxyInstance.myTimer = Timer.set(() => {
myProxyInstance.myTimer = undefined;
trace('long time expired\n');
}, 300);
Timer.set(() => {
trace('short timer expired\n');
if (myProxyInstance.myTimer) Timer.clear(myProxyInstance.myTimer);
}, 100);
Timer.set(() => {
trace('done\n');
}, 2000);Imagine you have a class with many objects inside it. You want to mock it, so you use a generic mocking service to do it:NewClass = mock(OldClass) (or newObject = mock(new OldClass()). That class that wraps the initial proxy, and as the handler executes it continues to proxy what it finds (get/construct/access).
No worries - I'll find a way around this. My issue - not Moddable's. Thanks for the help.
Array.prototype.push. Internally to XS there are actually two kinds of host functions – a host object and a host primitive. The host primitive is more compact and less standard. As part of preparing the ROM image, the XS linker converts host objects to host primitives. That step is skipped when strip is disabled (which is why turning off strip allows your Proxy to work). In most places, XS automatically and invisibly promotes a host primitive to a host object when needed (fxToInstance). The special case to do that promotion isn't in the Proxy constructor, so it fails. We'll add that. Just FYI, a more focused workaround is to use Object.assign which promotes the host primitive to a host object: new Proxy(Object.assign([].push), {}).
Thanks! Since I can't tell which objects are host, I'd have to do that on every object, property, etc., which I'd prefer not to do. But it sounds like you found the fix?
I have @unmockable working now and it's resolved my issue with Timer - so I'm all good there! Getting close to have preload working on all modules (one big module left to go). Dependency injection and Mocking are working now (major rework to Mock, a bit of refactoring to Dependency Injection). Hopefully a few more days and I'll see what the new slot footprint looks like.
Mind if I ask a couple performance/memory questions?
1) If I have a method that needs to return an object, is there much benefit in slots/memory/fragmentation if I return a native object (return { prop: value }) vs. use a class to contain the object (return newClass(value); where the class provides the prop property)?
2) Is it correct that if I have an object that is not preloaded with six properties, it will consume 7 slots (1 for the object, and 6 for the properties, or a total of 112 bytes)?
3) Likewise, if I have an array of 100 elements, it takes 100 slots? (And if the array has objects, we multiple the above with this ... or in this case, 100 elements * 6 slots = 600 slots = 9.6K?)
4) Would using CDV to encapsulate heavy usage objects (arrays of objects with many properties) drop the slot count to one per CDV buffer?
xsuse example.
just pulled the public branch and did the "make install" for linux, got hit with the following errors.
make install -f simulator.mk
make[1]: Entering directory '/home/loki/Projects/moddable/build/makefiles/lin'
simulator debug : cc main.c
/home/loki/Projects/moddable/build/simulator/lin/main.c: In function ‘onApplicationOpen’:
/home/loki/Projects/moddable/build/simulator/lin/main.c:434:99: warning: ‘.xsa'’ directive output may be truncated writing 5 bytes into a region of size between 3 and 8193 [-Wformat-truncation=]
434 | snprintf(cmd, sizeof(cmd), "/bin/cp -p \'%s\' \'%s.xsa\'", path, gxConfigPath);
| ^~
/home/loki/Projects/moddable/build/simulator/lin/main.c:434:49: note: ‘snprintf’ output between 21 and 8211 bytes into a destination of size 8208
434 | snprintf(cmd, sizeof(cmd), "/bin/cp -p \'%s\' \'%s.xsa\'", path, gxConfigPath);
| ^~~~~~~~~~~~~~~~~~
/home/loki/Projects/moddable/build/simulator/lin/main.c:427:99: warning: ‘.so'’ directive output may be truncated writing 4 bytes into a region of size between 3 and 8193 [-Wformat-truncation=]
427 | snprintf(cmd, sizeof(cmd), "/bin/cp -p \'%s\' \'%s.so\'", path, gxConfigPath);
| ^~~
/home/loki/Projects/moddable/build/simulator/lin/main.c:427:49: note: ‘snprintf’ output between 20 and 8210 bytes into a destination of size 8208
427 | snprintf(cmd, sizeof(cmd), "/bin/cp -p \'%s\' \'%s.so\'", path, gxConfigPath);
| ^~~~~~~~~~~~~~~~~~~
Assembler messages:
Fatal error: can't create /home/loki/Projects/moddable/build/tmp/lin/debug/simulator/main.o: No such file or directory
make[1]: [simulator.mk:59: /home/loki/Projects/moddable/build/tmp/lin/debug/simulator/main.o] Error 1
make[1]: Leaving directory '/home/loki/Projects/moddable/build/makefiles/lin'
make: [makefile:66: install] Error 2
@cmidgley – a fix the issue you ran into, being unable to create a Proxy for a host function primitive, will be pushed in a couple days. Meanwhile, if you want to give it a try before that, in xsProxy.c after line 780 add these lines:
#ifdef mxHostFunctionPrimitive
if ((mxArgc > 0) && (mxArgv(0)->kind == XS_HOST_FUNCTION_KIND))
fxToInstance(the, mxArgv(0));
if ((mxArgc > 1) && (mxArgv(1)->kind == XS_HOST_FUNCTION_KIND))
fxToInstance(the, mxArgv(1));
#endifThere's a corresponding change for Proxy.revocable, but it doesn't sound like you are using that (yet!).
Using Instrumentation to get live info on slots - I'm finding the doc and the first example are wrong, as the numbers are not correct (for example, doc says 11 is SlotHeapSize yet it is actually 14 on ESP32). I see in xsuse it scans to find the correct number - that's how I got to 14. What's the story here?
Also, the type definition for it is very difficult to use. The type InstrumentationOffset is not exported, and really only limits a numeric value and enforces it to be 1-16 (even though different numbers are used). And you can't use the actual names as they are only types and not exported constants. Same issue with WiFi (and perhaps others) on their type definitions. Just an FYI for now, but I think the fix (if instrumentation numbers are static and don't need to be scanned) is to export constants from the .js file and declare them in the .d.ts file (perhaps using a enum, not sure yet). If instrumentation numbers are dynamic, I've got no good ideas for typing ... maybe a dictionary lookup method in .js that does the scan and return the correct number for the instrumentation?
xsuse on macOS, ESP8266, and ESP32. All results look reasonable. Here's the start of output from ESP32:Boolean: 0 bytes
Number: 0 bytes
String `String in ROM`: 0 bytes
String `fromCharCode(32)`: 12 chunk bytes = 12 bytes
String `String in ` + 'RAM': 24 chunk bytes = 24 bytes
Object {}: 1 slots = 16 bytes
Object {x: 1}: 2 slots = 32 bytes
Object {x: 1, y: 2}: 3 slots = 48 bytes
Object {x: 1, y: 2, z: 3}: 4 slots = 64 bytes
Date: 2 slots = 32 bytes
BigInt 1n: 12 chunk bytes = 12 bytes
BigInt 100000000001n: 16 chunk bytes = 16 bytes
Function () => {}: 7 slots = 112 bytes
...Sorry if I was unclear - xsuse works fine, and that's how I figured out the numbers. The documentation, TypeScript file and the other example are all wrong (or at least not portable, as they are wrong on ESP32).
I do see how to find the base of instrumentation to get slots and instrumentation that follows (and I have that working). I found that before that, System Free Memory, was also offset wrong... Just wondering how I should approach accessing any of the instrumentation - for example, is the base of instrumentation (1) always correct until a particular index, and then we have to scan backwards from the end to find the rest? How would I find System Free Memory or Timers, for example?
@phoddie As you know, I've been working on out-of-memory issues, focused on getting preload working. I got much of Instrumentation working (still don't have all the indexes right, see prior comment) and found I needed to use another WeakMap.
I'm now crashing in xsMapSet.js with an exception here. Spent the last two days trying to debug why and finally got a small fragment showing the crash - it's due to preload being used on a class that gets put into a WeakMap. See this gist for the files that recreate the failure. This is a blocking issue for me as I can't run without preload but crash with it. Hopefully there is a simple solution, but it's beyond me to figure out.