alloc_observe.install

1/// Installs a borrowed sink and context as the active observation target,2/// returning an active session handle. If an enabled sink is already installed,3/// the function returns AlreadyInstalled. In disabled builds, installation4/// succeeds inertly. The caller must guarantee that sink storage and context5/// pointers remain valid and stationary, because registered producers on other6/// threads may deliver callbacks before install returns. The function must be7/// called outside existing callbacks and suppression scopes. Callers must8/// serialize session lifecycles externally, ensuring that prior session9/// teardown completes fully before a new session is installed.10pub fn install(sink: *const Sink) error{AlreadyInstalled}!Session {11    if (comptime !enabled) {12        return .{};13    }14    std.debug.assert(callback_depth == 0);15    lockProducerRegistry();16    defer producer_registry_lock.unlock();17    const address = @intFromPtr(sink);18    std.debug.assert(address != 0);19    const producer_id_floor = next_producer_id.load(.acquire);20    if (active_sink.cmpxchgStrong(21        0,22        address,23        .acq_rel,24        .acquire,25    ) != null) {26        return error.AlreadyInstalled;27    }28    return .{29        .sink = sink,30        .active = true,31        .producer_id_floor = producer_id_floor,32    };33}

1/// Installs a borrowed sink and context as the active observation target,2/// returning an active session handle. If an enabled sink is already installed,3/// the function returns AlreadyInstalled. In disabled builds, installation4/// succeeds inertly. The caller must guarantee that sink storage and context5/// pointers remain valid and stationary, because registered producers on other6/// threads may deliver callbacks before install returns. The function must be7/// called outside existing callbacks and suppression scopes. Callers must8/// serialize session lifecycles externally, ensuring that prior session9/// teardown completes fully before a new session is installed.10pub const install = protocol.install;