globals_toctou_soak.tc

globals_toctou_soak.tc — stress the UDP-global receive path (the

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// globals_toctou_soak.tc — stress the UDP-`global` receive path (the
// tc_udp_on_receive TOCTOU that crashed powerwall when globals were defined).
//
// Declaring a `global` opens the multicast RX socket, so EVERY global on the
// LAN drives tc_udp_on_receive -> UdpCall while a busy TaskLoop keeps the VM
// task flipping halted<->running (the race window). Before the fix this
// corrupted the VM frame -> crash within minutes. With the fix: heap flat,
// uptime climbs, no reboot.
//
// Uses a TEST name (tw_soak) — never a production powerwall/sensor name — so it
// can't pollute real receivers on the LAN.

global float tw_soak;
int rx;        // multicast globals received (UdpCall fired)
int loops;     // VM-busy iterations

void UdpCall() { rx = rx + 1; }

void TaskLoop() {
    int i; float x;
    delay(4000);                       // let WiFi come up + join the group
    while (1) {
        // Keep the VM task busy so the main-task RX races it.
        i = 0; x = 0.0;
        while (i < 15000) { x = x + sin((float)i * 0.001); i = i + 1; }
        loops = loops + 1;
        tw_soak = x;                   // broadcast a TEST global (safe name)
        delay(40);
    }
}

void EverySecond() {
    char b[72];
    if (tasm_uptime % 10 == 0) {
        sprintf(b, "soak up=%ds rx=%d loops=%d heap=%dk", tasm_uptime, rx, loops, tasm_heap / 1024);
        addLog(b);
    }
}

int main() {
    rx = 0; loops = 0;
    printStr("globals TOCTOU soak running (rx counts LAN multicast globals)\n");
    return 0;
}