add get_available_backends, add display & equality comparison for enum and update example

Author: Jason Ramapuram

examples/unified.rs

@@ -21,22 +21,33 @@ fn test_backend(){
 
 #[allow(unused_must_use)]
 fn main() {
-  println!("There are {} available backends", get_backend_count().unwrap());
-  let err = set_backend(AfBackend::AF_BACKEND_CPU);
-  match err {
-    Ok(_)  => test_backend(),
-    Err(e) => println!("CPU backend not available: {}", e),
-  };
-
-  let err = set_backend(AfBackend::AF_BACKEND_CUDA);
-  match err {
-    Ok(_)  => test_backend(),
-    Err(e) => println!("CUDA backend not available: {}", e),
-  };
-
-  let err = set_backend(AfBackend::AF_BACKEND_OPENCL);
-  match err {
-    Ok(_)  => test_backend(),
-    Err(e) => println!("OpenCL backend not available: {}", e),
-  };
+  println!("There are {:?} available backends", get_backend_count().unwrap());
+  let available = get_available_backends().unwrap();
+
+  if available.contains(&AfBackend::AF_BACKEND_CPU){
+    println!("Evaluating CPU Backend...");
+    let err = set_backend(AfBackend::AF_BACKEND_CPU);
+      match err {
+        Ok(_)  => test_backend(),
+        Err(e) => println!("CPU backend error: {}", e),
+    };
+  }
+
+  if available.contains(&AfBackend::AF_BACKEND_CUDA){
+    println!("Evaluating CUDA Backend...");
+    let err = set_backend(AfBackend::AF_BACKEND_CUDA);
+      match err {
+        Ok(_)  => test_backend(),
+        Err(e) => println!("CUDA backend error: {}", e),
+    };
+  }
+
+  if available.contains(&AfBackend::AF_BACKEND_OPENCL){
+    println!("Evaluating OpenCL Backend...");
+    let err = set_backend(AfBackend::AF_BACKEND_OPENCL);
+      match err {
+        Ok(_)  => test_backend(),
+        Err(e) => println!("OpenCL backend error: {}", e),
+    };
+  }
 }

src/defines.rs

@@ -48,7 +48,7 @@ pub enum AfError {
 }
 
 #[repr(C)]
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum AfBackend {
     /// Default backend order: OpenCL -> CUDA -> CPU
     AF_BACKEND_DEFAULT = 0,
@@ -60,6 +60,18 @@ pub enum AfBackend {
     AF_BACKEND_OPENCL  = 3
 }
 
+impl Display for AfBackend {
+    fn fmt(&self, f: &mut Formatter) -> Result<(), FmtError> {
+        let text = match *self {
+            AfBackend::AF_BACKEND_OPENCL  => "OpenCL",
+            AfBackend::AF_BACKEND_CUDA    => "Cuda",
+            AfBackend::AF_BACKEND_CPU     => "CPU",
+            AfBackend::AF_BACKEND_DEFAULT => "Default",
+        };
+        write!(f, "{}", text)
+    }
+}
+
 impl Display for AfError {
     fn fmt(&self, f: &mut Formatter) -> Result<(), FmtError> {
         write!(f, "{}", self.description())

src/device/mod.rs

@@ -12,6 +12,7 @@ extern {
     fn af_set_device(device: c_int) -> c_int;
     fn af_set_backend(bknd: uint8_t) -> c_int;
     fn af_get_backend_count(num_backends: *mut c_uint) -> c_int;
+    fn af_get_available_backends(backends: *mut c_int) -> c_int;
     fn af_get_device(device: *mut c_int) -> c_int;
     fn af_sync(device: c_int) -> c_int;
 }
@@ -160,3 +161,23 @@ pub fn get_backend_count() -> Result<u32, AfError> {
         }
     }
 }
+
+
+/// Get the available backends
+#[allow(unused_mut)]
+pub fn get_available_backends() -> Result<Vec<AfBackend>, AfError> {
+    unsafe {
+        let mut temp: i32 = 0;
+        let err_val = af_get_available_backends(&mut temp as *mut c_int);
+        match err_val {
+            0 => {
+                let mut b = Vec::new();
+                if temp & 0b0100 == 0b0100 { b.push(AfBackend::AF_BACKEND_OPENCL); }
+                if temp & 0b0010 == 0b0010 { b.push(AfBackend::AF_BACKEND_CUDA); }
+                if temp & 0b0001 == 0b0001 { b.push(AfBackend::AF_BACKEND_CPU); }
+                Ok(b)
+            },
+            _ => Err(AfError::from(err_val)),
+        }
+    }
+}

src/lib.rs

@@ -34,7 +34,9 @@ pub use data::{reorder, shift, moddims, flat, flip};
 pub use data::{select, selectl, selectr, replace, replace_scalar};
 mod data;
 
-pub use device::{get_version, info, device_count, is_double_available, set_device, get_device, sync, get_backend_count, set_backend};
+pub use device::{get_version, info, device_count, is_double_available
+	, set_device, get_device, sync, get_backend_count, set_backend
+	, get_available_backends};
 mod device;
 
 pub use defines::{Aftype, AfError, AfBackend, ColorMap, YCCStd};