Handle eintr in kqueue/epoll better related to timers

[Jarred-Sumner]

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

[robobun]

^{Updated 2:32 AM PT - Dec 19th, 2024}

✅ @Jarred-Sumner, your commit cd2249d has passed in #8221! 🎉

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🧪   try this PR locally:

bunx bun-pr 15875

[dlagno]

Since you use this function thrice in the same repeating pattern I suggest wrapping that repeating logic inside e.g.

pub export fn Bun__updateTimeoutAfterEINTR(this: *VirtualMachine, timeout: **timespec) bool {
    if (timeout_update_ctx && timeout && timeout.* && !this.timer.getTimeout(timeout.*)) {
        timeout.* = NULL;
    }
    return !(timeout_update_ctx && timeout && timeout.* && timeout.*->tv_sec == 0 && timeout.*->tv_nsec == 0);
}

This would simplify callsites e.g.

        if (UNLIKELY(rc == -1 && errno == EINTR)) {
            if (Bun__updateTimeoutAfterEINTR(timeout_update_ctx, timeout)) {
                continue;
            }
            loop->num_ready_polls = 0;
            break;
        }