Summary

When all-smi is embedded as a library in a Windows GUI application (one built with #![windows_subsystem = "windows"], so it has no attached console), a console window flashes briefly whenever all-smi spawns a child process. The reporter sees it on startup via AllSmi::new(), and because all-smi shells out to vendor tools on every collection, the flash can recur during ongoing monitoring, not only at startup. The fix is to set the Windows CREATE_NO_WINDOW process creation flag on the child processes all-smi spawns.

Background

On Windows, spawning a console subprocess from a GUI (windowless) process causes the OS to allocate a console for the child, which appears as a brief flashing window. Rust's std::process::Command does not set any creation flags by default, so every child inherits this behavior unless CREATE_NO_WINDOW (0x08000000) is supplied via std::os::windows::process::CommandExt::creation_flags.

all-smi spawns vendor CLIs (for example nvidia-smi) to detect and query hardware. The central spawn helper is run_command_with_timeout in src/utils/command_timeout.rs:91, which builds a bare Command (line 97) with no creation flags. The NVIDIA reader reaches it through this path: src/device/readers/nvidia.rs invokes nvidia-smi via that helper (see the fallback paths around lines 769 and 854). Other readers and utilities spawn processes directly with Command::new as well (for example src/utils/system.rs, src/device/process_list.rs, src/device/readers/gaudi.rs, src/device/readers/google_tpu.rs). A repository-wide search finds no use of creation_flags or CREATE_NO_WINDOW anywhere, so no spawn site currently suppresses the console window.

Proposed Solution

Apply the CREATE_NO_WINDOW creation flag to every child process all-smi spawns on Windows. Centralizing this in the shared spawn helper covers the common path; the remaining direct Command::new call sites need the same treatment so no detection path leaks a console window.

A Windows-only extension trait or a small wrapper helper keeps the platform code isolated, for example:

#[cfg(windows)]
use std::os::windows::process::CommandExt;

#[cfg(windows)]
const CREATE_NO_WINDOW: u32 = 0x0800_0000;

#[cfg(windows)]
cmd.creation_flags(CREATE_NO_WINDOW);

guarded so non-Windows builds are unaffected.

Implementation Notes

• Set the flag on the Command built in run_command_with_timeout (src/utils/command_timeout.rs:97). This covers run_command_fast_fail and every reader that routes through it, including the NVIDIA nvidia-smi paths in src/device/readers/nvidia.rs.
• Audit the direct Command::new call sites and apply the same flag: src/utils/runtime_environment.rs, src/utils/system.rs, src/network/client.rs, src/device/readers/tpu_info_runner.rs, src/device/readers/gaudi.rs, src/device/readers/google_tpu.rs, src/device/process_list.rs, src/device/process_utils.rs, src/device/hlsmi/process.rs, src/device/cpu_linux.rs, src/device/cpu_macos.rs. A shared helper that constructs the Command would prevent future sites from regressing.
• Keep all Windows-specific code behind #[cfg(windows)] (or #[cfg(target_os = "windows")]) so Unix and macOS builds compile unchanged. The CommandExt import and creation_flags call exist only on Windows.
• The Windows-relevant spawn paths in practice are the NVIDIA reader, the Intel GPU Windows reader, the AMD Windows reader, and the Windows CPU/temperature utilities; verify each no longer flashes a console.

Acceptance Criteria

• Building the reporter's minimal example (#![windows_subsystem = "windows"] calling all_smi::AllSmi::new()) shows no flashing console window on startup.
• No console window flashes during subsequent metric collection on Windows GUI applications.
• Non-Windows builds (Linux, macOS) compile and behave identically, with no new warnings.

Original Suggestion

Title: [bug] Terminal window flashing when detecting gpu on Windows

When using all-smi as a library for my GUI program I have come across an issue where there is a terminal window flashing for a split second on startup. This seems to only be a problem in apps that have the console disabled.

Minimal reproducible example (Windows OS only):

#![windows_subsystem = "windows"]

fn main() {
    let _smi = all_smi::AllSmi::new().unwrap();
}