Fixed duplicate services and constistency in naming

ctru-rs/examples/buttons.rs

@@ -8,7 +8,7 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let console = Console::init(gfx.top_screen.borrow_mut());
 
     println!("Hi there! Try pressing a button");

ctru-rs/examples/file-explorer.rs

@@ -14,10 +14,10 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
 
     #[cfg(all(feature = "romfs", romfs_exists))]
-    let _romfs = ctru::romfs::RomFS::new().unwrap();
+    let _romfs = ctru::romfs::RomFS::init().unwrap();
 
     FileExplorer::init(&apt, &hid, &gfx).run();
 }

ctru-rs/examples/futures-basic.rs

@@ -13,7 +13,7 @@ use futures::StreamExt;
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
     let _console = Console::init(gfx.top_screen.borrow_mut());

ctru-rs/examples/futures-tokio.rs

@@ -6,7 +6,7 @@ use std::time::Duration;
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
     let _console = Console::init(gfx.top_screen.borrow_mut());

ctru-rs/examples/gfx-wide-mode.rs

@@ -7,7 +7,7 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let mut console = Console::init(gfx.top_screen.borrow_mut());
 
     println!("Press A to enable/disable wide screen mode.");

ctru-rs/examples/graphics-bitmap.rs

@@ -19,7 +19,7 @@ static IMAGE: &[u8] = include_bytes!("assets/ferris.rgb");
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
     let _console = Console::init(gfx.top_screen.borrow_mut());

ctru-rs/examples/hashmaps.rs

@@ -12,7 +12,7 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let _console = Console::init(gfx.top_screen.borrow_mut());
 
     let mut map = std::collections::HashMap::new();

ctru-rs/examples/hello-both-screens.rs

@@ -8,7 +8,7 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
 
     // Start a console on the top screen
     let top_screen = Console::init(gfx.top_screen.borrow_mut());

ctru-rs/examples/hello-world.rs

@@ -7,7 +7,7 @@ use std::io::BufWriter;
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtain GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
     let _console = Console::init(gfx.top_screen.borrow_mut());

ctru-rs/examples/network-sockets.rs

@@ -10,7 +10,7 @@ use std::time::Duration;
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let _console = Console::init(gfx.top_screen.borrow_mut());
     let hid = Hid::init().unwrap();
     let apt = Apt::init().unwrap();

ctru-rs/examples/romfs.rs

@@ -5,7 +5,7 @@ use ctru::services::hid::{Hid, KeyPad};
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
     let _console = Console::init(gfx.top_screen.borrow_mut());
@@ -15,7 +15,7 @@ fn main() {
         // This never fails as `ctru-rs` examples inherit all of the `ctru` features,
         // but it might if a normal user application wasn't setup correctly
         if #[cfg(all(feature = "romfs", romfs_exists))] {
-            let _romfs = ctru::romfs::RomFS::new().unwrap();
+            let _romfs = ctru::romfs::RomFS::init().unwrap();
 
             let f = std::fs::read_to_string("romfs:/test-file.txt").unwrap();
             println!("Contents of test-file.txt: \n{f}\n");

ctru-rs/examples/thread-basic.rs

@@ -11,7 +11,7 @@ fn main() {
     ctru::init();
     let apt = Apt::init().unwrap();
     let hid = Hid::init().unwrap();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let _console = Console::init(gfx.top_screen.borrow_mut());
 
     let prio = thread::current().priority();

ctru-rs/examples/thread-locals.rs

@@ -10,7 +10,7 @@ std::thread_local! {
 
 fn main() {
     ctru::init();
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     gfx.top_screen.borrow_mut().set_wide_mode(true);
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");

ctru-rs/examples/time-rtc.rs

@@ -6,7 +6,7 @@ use ctru::services::hid::{Hid, KeyPad};
 fn main() {
     ctru::init();
 
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().expect("Couldn't obtaint GFX controller");
     let hid = Hid::init().expect("Couldn't obtain HID controller");
     let apt = Apt::init().expect("Couldn't obtain APT controller");
 

ctru-rs/src/error.rs

@@ -9,6 +9,7 @@ pub type Result<T> = ::std::result::Result<T, Error>;
 #[non_exhaustive]
 pub enum Error {
     Os(ctru_sys::Result),
+    ServiceAlreadyActive(&'static str),
 }
 
 impl From<ctru_sys::Result> for Error {
@@ -28,6 +29,7 @@ impl fmt::Debug for Error {
                 .field("summary", &R_SUMMARY(err))
                 .field("level", &R_LEVEL(err))
                 .finish(),
+            Error::ServiceAlreadyActive(service) => write!(f, "Service {service} already active"),
         }
     }
 }
@@ -39,6 +41,7 @@ impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
             Error::Os(err) => write!(f, "libctru result code: 0x{:08X}", err),
+            Error::ServiceAlreadyActive(service) => write!(f, "Service {service} already active"),
         }
     }
 }

ctru-rs/src/gfx.rs

@@ -1,10 +1,11 @@
 //! LCD screens manipulation helper
 
 use std::cell::RefCell;
-use std::default::Default;
 use std::marker::PhantomData;
 use std::ops::Drop;
+use std::sync::atomic::{AtomicBool, Ordering};
 
+use crate::error::{Error, Result};
 use crate::services::gspgpu::{self, FramebufferFormat};
 
 /// Trait implemented by TopScreen and BottomScreen for common methods
@@ -73,23 +74,37 @@ pub struct Gfx {
     pub bottom_screen: RefCell<BottomScreen>,
 }
 
+static GFX_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl Gfx {
     /// Initialize the Gfx module with the chosen framebuffer formats for the top and bottom
     /// screens
     ///
-    /// Use `Gfx::default()` instead of this function to initialize the module with default parameters
+    /// Use `Gfx::init_default()` instead of this function to initialize the module with default parameters
-    pub fn new(
+    pub fn init(
         top_fb_fmt: FramebufferFormat,
         bottom_fb_fmt: FramebufferFormat,
         use_vram_buffers: bool,
-    ) -> Self {
+    ) -> Result<Self> {
+        match GFX_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
+            Ok(_) => {
                 unsafe {
                     ctru_sys::gfxInit(top_fb_fmt.into(), bottom_fb_fmt.into(), use_vram_buffers);
                 }
-        Gfx {
+
+                Ok(Gfx {
                     top_screen: RefCell::new(TopScreen),
                     bottom_screen: RefCell::new(BottomScreen),
+                })
+            }
+            Err(_) => Err(Error::ServiceAlreadyActive("Gfx")),
+        }
     }
+
+    /// Creates a new Gfx instance with default init values
+    /// It's the same as calling: `Gfx::init(FramebufferFormat::Bgr8, FramebufferFormat::Bgr8, false)
+    pub fn init_default() -> Result<Self> {
+        Gfx::init(FramebufferFormat::Bgr8, FramebufferFormat::Bgr8, false)
     }
 
     /// Flushes the current framebuffers
@@ -197,18 +212,21 @@ impl From<Side> for ctru_sys::gfx3dSide_t {
     }
 }
 
-impl Default for Gfx {
-    fn default() -> Self {
-        unsafe { ctru_sys::gfxInitDefault() };
-        Gfx {
-            top_screen: RefCell::new(TopScreen),
-            bottom_screen: RefCell::new(BottomScreen),
-        }
-    }
-}
-
 impl Drop for Gfx {
     fn drop(&mut self) {
         unsafe { ctru_sys::gfxExit() };
+
+        GFX_ACTIVE.store(false, Ordering::Release);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn gfx_duplicate() {
+        // We don't need to build a `Gfx` because the test runner has one already
+        assert!(Gfx::init_default().is_err());
     }
 }

ctru-rs/src/lib.rs

@@ -38,15 +38,34 @@ pub fn init() {
         // Only for panics in the main thread
         if main_thread == thread::current().id() && console::Console::exists() {
             println!("\nPress SELECT to exit the software");
-            let hid = services::hid::Hid::init().unwrap();
+
+            // The use of unsafe functions here is basically obligatory.
+            // To have memory safety when using the `Hid` struct, we must not make more
+            // than one available at the same time, so no drop/service ownership issues arise.
+            // The problem here is that the `panic_hook` is run _before_ the app cleanup,
+            // so an `Hid` stuct may still be alive and thus make the `panic_hook` panic.
+            // If that were to happen, the system would have to reboot to properly close the app.
+            // 
+            // Using `hidInit` is safe when another instance is open, and we can do safe operations afterwards.
+            // The only (probably) unsafe part of this system is the `hidExit`, since in a multithreaded
+            // environment some other threads may still be doing operations on the service
+            // before the cleanup, though the time window would be almost nonexistent, and it would only
+            // really be a problem in preemptive threads.
+            //
+            // TL;DR : This code is bad.
+            unsafe {
+                ctru_sys::hidInit();
 
                 loop {
-                hid.scan_input();
+                    ctru_sys::hidScanInput();
-                if hid.keys_down().contains(services::hid::KeyPad::KEY_SELECT) {
+                    let keys = services::hid::KeyPad::from_bits_truncate(ctru_sys::hidKeysDown());
+                    if keys.contains(services::hid::KeyPad::KEY_SELECT) {
+                        ctru_sys::hidExit();
                         break;
                     }
                 }
             }
+        }
     });
     std::panic::set_hook(new_hook);
 }

ctru-rs/src/romfs.rs

@@ -11,12 +11,19 @@
 //! ```
 
 use std::ffi::CStr;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
 
 #[non_exhaustive]
 pub struct RomFS;
 
+static ROMFS_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl RomFS {
-    pub fn new() -> crate::Result<Self> {
+    pub fn init() -> crate::Result<Self> {
+        match ROMFS_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
+            Ok(_) => {
                 let mount_name = CStr::from_bytes_with_nul(b"romfs\0").unwrap();
                 let result = unsafe { ctru_sys::romfsMountSelf(mount_name.as_ptr()) };
 
@@ -26,11 +33,28 @@ impl RomFS {
                     Ok(Self)
                 }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("RomFS")),
+        }
+    }
 }
 
 impl Drop for RomFS {
     fn drop(&mut self) {
         let mount_name = CStr::from_bytes_with_nul(b"romfs\0").unwrap();
         unsafe { ctru_sys::romfsUnmount(mount_name.as_ptr()) };
+
+        ROMFS_ACTIVE.store(false, Ordering::Release);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn romfs_duplicate() {
+        let _romfs = RomFS::init().unwrap();
+
+        assert!(RomFS::init().is_err());
     }
 }

ctru-rs/src/services/apt.rs

@@ -1,15 +1,25 @@
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
+
+#[non_exhaustive]
 pub struct Apt(());
 
+static APT_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl Apt {
-    pub fn init() -> crate::Result<Apt> {
+    pub fn init() -> crate::Result<Self> {
-        unsafe {
+        match APT_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
-            let r = ctru_sys::aptInit();
+            Ok(_) => {
+                let r = unsafe { ctru_sys::aptInit() };
                 if r < 0 {
                     Err(r.into())
                 } else {
-                Ok(Apt(()))
+                    Ok(Self(()))
                 }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("Apt")),
+        }
     }
 
     pub fn main_loop(&self) -> bool {
@@ -17,19 +27,31 @@ impl Apt {
     }
 
     pub fn set_app_cpu_time_limit(&self, percent: u32) -> crate::Result<()> {
-        unsafe {
+        let r = unsafe { ctru_sys::APT_SetAppCpuTimeLimit(percent) };
-            let r = ctru_sys::APT_SetAppCpuTimeLimit(percent);
         if r < 0 {
             Err(r.into())
         } else {
             Ok(())
         }
     }
-    }
 }
 
 impl Drop for Apt {
     fn drop(&mut self) {
         unsafe { ctru_sys::aptExit() };
+
+        APT_ACTIVE.store(false, Ordering::Release);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn gfx_duplicate() {
+        // We don't need to build a `Apt` because the test runner has one already
+        assert!(Apt::init().is_err());
+    }
+}
+

ctru-rs/src/services/fs.rs

@@ -13,9 +13,12 @@ use std::mem;
 use std::path::{Path, PathBuf};
 use std::ptr;
 use std::slice;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 use widestring::{WideCStr, WideCString};
 
+use crate::error::Error;
+
 bitflags! {
     #[derive(Default)]
     struct FsOpen: u32 {
@@ -82,8 +85,11 @@ pub enum ArchiveID {
 /// until an instance of this struct is created.
 ///
 /// The service exits when all instances of this struct go out of scope.
+#[non_exhaustive]
 pub struct Fs(());
 
+static FS_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 /// Handle to an open filesystem archive.
 ///
 /// Archives are automatically closed when they go out of scope.
@@ -96,6 +102,7 @@ pub struct Fs(());
 /// let fs = Fs::init().unwrap();
 /// let sdmc_archive = fs.sdmc().unwrap();
 /// ```
+#[non_exhaustive]
 pub struct Archive {
     id: ArchiveID,
     handle: u64,
@@ -164,6 +171,7 @@ pub struct Archive {
 /// # Ok(())
 /// # }
 /// ```
+#[non_exhaustive]
 pub struct File {
     handle: u32,
     offset: u64,
@@ -175,6 +183,7 @@ pub struct File {
 /// represents known metadata about a file.
 ///
 /// [`metadata`]: fn.metadata.html
+#[non_exhaustive]
 pub struct Metadata {
     attributes: u32,
     size: u64,
@@ -257,6 +266,7 @@ pub struct OpenOptions {
 ///
 /// This Result will return Err if there's some sort of intermittent IO error
 /// during iteration.
+#[non_exhaustive]
 pub struct ReadDir<'a> {
     handle: Dir,
     root: Arc<PathBuf>,
@@ -297,15 +307,18 @@ impl Fs {
     /// ctrulib services are reference counted, so this function may be called
     /// as many times as desired and the service will not exit until all
     /// instances of Fs drop out of scope.
-    pub fn init() -> crate::Result<Fs> {
+    pub fn init() -> crate::Result<Self> {
-        unsafe {
+        match FS_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
-            let r = ctru_sys::fsInit();
+            Ok(_) => {
+                let r = unsafe { ctru_sys::fsInit() };
                 if r < 0 {
                     Err(r.into())
                 } else {
-                Ok(Fs(()))
+                    Ok(Self(()))
                 }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("Fs")),
+        }
     }
 
     /// Returns a handle to the SDMC (memory card) Archive.
@@ -990,6 +1003,8 @@ impl Drop for Fs {
         unsafe {
             ctru_sys::fsExit();
         }
+
+        FS_ACTIVE.store(false, Ordering::Release);
     }
 }
 
@@ -1059,3 +1074,16 @@ impl From<ArchiveID> for ctru_sys::FS_ArchiveID {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn fs_duplicate() {
+        let _fs = Fs::init().unwrap();
+
+        assert!(Fs::init().is_err());
+    }
+}
+

ctru-rs/src/services/hid.rs

@@ -4,6 +4,10 @@
 //! and circle pad information. It also provides information from the sound volume slider,
 //! the accelerometer, and the gyroscope.
 
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
+
 bitflags::bitflags! {
     /// A set of flags corresponding to the button and directional pad
     /// inputs on the 3DS
@@ -44,12 +48,17 @@ bitflags::bitflags! {
 /// when all instances of this struct fall out of scope.
 ///
 /// This service requires no special permissions to use.
+#[non_exhaustive]
 pub struct Hid(());
 
+static HID_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 /// Represents user input to the touchscreen.
+#[non_exhaustive]
 pub struct TouchPosition(ctru_sys::touchPosition);
 
 /// Represents the current position of the 3DS circle pad.
+#[non_exhaustive]
 pub struct CirclePosition(ctru_sys::circlePosition);
 
 /// Initializes the HID service.
@@ -60,14 +69,17 @@ pub struct CirclePosition(ctru_sys::circlePosition);
 /// Since this service requires no special or elevated permissions, errors are
 /// rare in practice.
 impl Hid {
-    pub fn init() -> crate::Result<Hid> {
+    pub fn init() -> crate::Result<Self> {
-        unsafe {
+        match HID_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
-            let r = ctru_sys::hidInit();
+            Ok(_) => {
+                let r = unsafe { ctru_sys::hidInit() };
                 if r < 0 {
                     Err(r.into())
                 } else {
-                Ok(Hid(()))
+                    Ok(Self(()))
+                }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("Hid")),
         }
     }
 
@@ -151,5 +163,18 @@ impl CirclePosition {
 impl Drop for Hid {
     fn drop(&mut self) {
         unsafe { ctru_sys::hidExit() };
+
+        HID_ACTIVE.store(false, Ordering::Release);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn hid_duplicate() {
+        // We don't need to build a `Hid` because the test runner has one already
+        assert!(Hid::init().is_err());
     }
 }

ctru-rs/src/services/ps.rs

@@ -63,8 +63,6 @@ pub fn generate_random_bytes(out: &mut [u8]) -> crate::Result<()> {
 mod tests {
     use std::collections::HashMap;
 
-    use super::*;
-
     #[test]
     fn construct_hash_map() {
         let mut input = vec![

ctru-rs/src/services/soc.rs

@@ -1,21 +1,27 @@
-use ctru_sys::{socExit, socInit};
 use libc::{free, memalign};
 use std::net::Ipv4Addr;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
+use ctru_sys::{socExit, socInit};
 
 /// Soc service. Initializing this service will enable the use of network sockets and utilities
 /// such as those found in `std::net`. The service will be closed when this struct is is dropped.
+#[non_exhaustive]
 pub struct Soc {
     soc_mem: *mut u32,
 }
 
+static SOC_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl Soc {
     /// Initialize the Soc service with a default buffer size of 0x100000 bytes
     ///
     /// # Errors
     ///
     /// This function will return an error if the `Soc` service is already initialized
-    pub fn init() -> crate::Result<Soc> {
+    pub fn init() -> crate::Result<Self> {
-        Soc::init_with_buffer_size(0x100000)
+        Self::init_with_buffer_size(0x100000)
     }
 
     /// Initialize the Soc service with a custom buffer size in bytes. The size should be
@@ -24,8 +30,9 @@ impl Soc {
     /// # Errors
     ///
     /// This function will return an error if the `Soc` service is already initialized
-    pub fn init_with_buffer_size(num_bytes: usize) -> crate::Result<Soc> {
+    pub fn init_with_buffer_size(num_bytes: usize) -> crate::Result<Self> {
-        unsafe {
+        match SOC_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
+            Ok(_) => unsafe {
                 let soc_mem = memalign(0x1000, num_bytes) as *mut u32;
 
                 let r = socInit(soc_mem, num_bytes as u32);
@@ -33,8 +40,10 @@ impl Soc {
                     free(soc_mem as *mut _);
                     Err(r.into())
                 } else {
-                Ok(Soc { soc_mem })
+                    Ok(Self { soc_mem })
                 }
+            },
+            Err(_) => Err(Error::ServiceAlreadyActive("Soc")),
         }
     }
 
@@ -51,5 +60,19 @@ impl Drop for Soc {
             socExit();
             free(self.soc_mem as *mut _);
         }
+
+        SOC_ACTIVE.store(false, Ordering::Release);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn soc_duplicate() {
+        let _soc = Soc::init().unwrap();
+
+        assert!(Soc::init().is_err());
     }
 }

ctru-rs/src/services/sslc.rs

@@ -1,35 +1,58 @@
 // TODO: Implement remaining functions
 
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
+
+#[non_exhaustive]
 pub struct SslC(());
 
+static SSLC_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl SslC {
     /// Initialize sslc
     pub fn init() -> crate::Result<Self> {
-        unsafe {
+        match SSLC_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
-            let r = ctru_sys::sslcInit(0);
+            Ok(_) => {
+                let r = unsafe { ctru_sys::sslcInit(0) };
                 if r < 0 {
                     Err(r.into())
                 } else {
-                Ok(SslC(()))
+                    Ok(Self(()))
                 }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("SslC")),
+        }
     }
 
     /// Fill `buf` with `buf.len()` random bytes
     pub fn generate_random_data(&self, buf: &mut [u8]) -> crate::Result<()> {
-        unsafe {
+        let r = unsafe { ctru_sys::sslcGenerateRandomData(buf.as_ptr() as _, buf.len() as u32) };
-            let r = ctru_sys::sslcGenerateRandomData(buf.as_ptr() as _, buf.len() as u32);
         if r < 0 {
             Err(r.into())
         } else {
             Ok(())
         }
     }
-    }
 }
 
 impl Drop for SslC {
     fn drop(&mut self) {
         unsafe { ctru_sys::sslcExit() };
+
+        SSLC_ACTIVE.store(false, Ordering::Release);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn sslc_duplicate() {
+        let _sslc = SslC::init().unwrap();
+
+        assert!(SslC::init().is_err());
+    }
+}
+

ctru-rs/src/srv.rs

@@ -1,20 +1,44 @@
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use crate::error::Error;
+
+#[non_exhaustive]
 pub struct Srv(());
 
+static SRV_ACTIVE: AtomicBool = AtomicBool::new(false);
+
 impl Srv {
-    pub fn init() -> crate::Result<Srv> {
+    pub fn init() -> crate::Result<Self> {
-        unsafe {
+        match SRV_ACTIVE.compare_exchange(false, true, Ordering::Acquire, Ordering::Relaxed) {
-            let r = ctru_sys::srvInit();
+            Ok(_) => {
+                let r = unsafe { ctru_sys::srvInit() };
                 if r < 0 {
                     Err(r.into())
                 } else {
-                Ok(Srv(()))
+                    Ok(Self(()))
                 }
             }
+            Err(_) => Err(Error::ServiceAlreadyActive("Srv")),
+        }
     }
 }
 
 impl Drop for Srv {
     fn drop(&mut self) {
         unsafe { ctru_sys::srvExit() };
+
+        SRV_ACTIVE.store(false, Ordering::Release);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn srv_duplicate() {
+        let _srv = Srv::init().unwrap();
+
+        assert!(Srv::init().is_err());
     }
 }

ctru-rs/src/test_runner.rs

@@ -17,7 +17,7 @@ use crate::services::Apt;
 pub(crate) fn run(tests: &[&TestDescAndFn]) {
     crate::init();
 
-    let gfx = Gfx::default();
+    let gfx = Gfx::init_default().unwrap();
     let hid = Hid::init().unwrap();
     let apt = Apt::init().unwrap();
 
@@ -115,9 +115,4 @@ mod link_fix {
     extern "C" fn sigemptyset(_arg1: *mut libc::sigset_t) -> ::libc::c_int {
         -1
     }
-
-    #[no_mangle]
-    extern "C" fn sysconf(_name: libc::c_int) -> libc::c_long {
-        -1
-    }
 }