Frequent parameter update causes runtime error

[hiroMTB]

Issue

When I change a parameter in client.rabbitcontrol.cc, sometimes oF app crashes on macOS and Ubuntu.
This only happens when I have a ofParameter which is frequently updated from oF app.
The crash happens randomly as far as I use it in a normal way.

Location of the issue

parameterserver.cpp L189-L198

ofxRabbitControl/src/rabbitControl/parameterserver.cpp

Lines 186 to 198 in 6ef07ef

	for (auto& p : parameterManager->dirtyParameter) {
	// TODO send COMMAND_UPDATEVALUE
	command_t cmd = COMMAND_UPDATE;
	if (p.second->onlyValueChanged())
	{
	cmd = COMMAND_UPDATEVALUE;
	}
	Packet packet(cmd, p.second);
	sendPacket(packet);
	}

• sometimes p or p->second becomes nullptr
• sometimes iterator(of for loop) fails to increment

How to regenerate issue

1. add following line in example app (ofxRabbitControl/example/src/ofApp.cpp)

void ofApp::update(){
    for(int i=0; i<10000; i++){
        int32Param = ofRandom(0, 100);
        floatParam = ofRandom(0, 10.0f);
    }
}

2. run oF app and connect via client.rabbitcontrol.cc
3. keep moving some of GUI slider or color palette quickly

Environment

A

• macOS 10.15.7
• Xcode 12.4
• oF 0.11.0
• Latest master branch with fake ofFloatColor fix

B

• Ubuntu 20.04
• CLion
• oF 0.11.0
• Latest master branch with fake ofFloatColor fix

[hiroMTB]

a screenshot, just in case

[i-n-g-o]

Some locking was missing.
I pushed some changes, could you try if this works for you?