Lag spikes or crash when the the screen's refresh rate is too fast

[kamitojaeger]

This issue has been tested by me and one of my friend.

Here's how to reproduce this bug:

1. have a 4 * 4 screen link to a computer
2. run the code below
3. lag spikes happen
4. right click the computer -> game crash

you can also reproduce the lagSpike by deleting the "yield()" without adding "sleep()" to the code. Lag spikes would also happen, and would stop due to [too long without yielding]

---

local gpu = peripheral.wrap("tm_gpu_0")

local start = os.epoch("utc")
local function yield()
    if (os.epoch("utc") - start > 1000) then
        os.queueEvent("yield")
        os.pullEvent("yield")
        start = os.epoch("utc")
    end
end
gpu.setSize(64,64,4,4,16)
gpu.refreshSize()
gpu.fill(0x006400)
gpu.filledRectangle(197, 1, 60, 256, 0x006400)
gpu.line(64,1,64,256,0x32cd32)
gpu.line(196,1,196,256,0x32cd32)
gpu.line(65,192,196,194,0x32cd32)
gpu.line(65,128,196,128,0x32cd32)
gpu.line(65,64,196,64,0x32cd32)
gpu.drawText(10,3,"512m",0x00ff00,0x008000,2)
gpu.drawText(10,64,"384m",0x00ff00,0x008000,2)
gpu.drawText(10,128,"256m",0x00ff00,0x008000,2)
gpu.drawText(10,194,"128m",0x00ff00,0x008000,2)
gpu.drawText(200,30,"VS",0x00ff00,0x006400,2)
gpu.drawText(200,91,"Entity",0x00ff00,0x006400,2)
gpu.drawText(200,155,"VS-E",0x00ff00,0x006400,2)
gpu.drawText(200,221,"SRC",0x00ff00,0x006400,2)
gpu.refreshSize()
gpu.sync()

local function regularLines()

    gpu.line(64,1,64,256,0x32cd32)
    gpu.line(196,1,196,256,0x32cd32)
    gpu.line(65,192,196,194,0x32cd32)
    gpu.line(65,128,196,128,0x32cd32)
    gpu.line(65,64,196,64,0x32cd32)

end

while true do
    for i = 65, 195 do
        if i == 65 then
            gpu.line(65,1,65,256,0x32cd32)
        else
            gpu.line(i,1,i,256,0x32cd32)
            gpu.line(i-1,1,i-1,256,0x006400)
            regularLines()
        end
        gpu.sync()
        yield()
    end
end

---

Here's my crash logs. Hope this issue can be fixed soon : D

debug.log latest.log minecraft.log