refactor: Rearrange initialize_cuda() for better err check, no warn (#4726)

Sonar was complaining that initialize_cuda() contained a loop that would
only iterate once. Upon looking, this was true, but mainly because we
just didn't adequately check errors. Fix up, which should both make the
code more robust and also silence the Sonar complaint.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

src/libOpenImageIO/oiio_gpu.cpp

@@ -99,6 +99,8 @@ initialize_cuda()
 {
     std::lock_guard lock(compute_mutex);
 
+    cuda_supported = false;
+
     // Environment OPENIMAGEIO_CUDA=0 trumps everything else, turns off
     // Cuda functionality. We don't even initialize in this case.
     std::string env = Sysutil::getenv("OPENIMAGEIO_CUDA");
@@ -112,34 +114,35 @@ initialize_cuda()
     if (!checkCudaErrors(cudaGetDeviceCount(&deviceCount))) {
         return;
     }
+    OIIO::debugfmt("Number of CUDA devices: {}\n", deviceCount);
 
     // Initialize CUDA
-    if (!CUDA_CHECK(cudaFree(0))) {
+    bool ok = CUDA_CHECK(cudaFree(0)) && CUDA_CHECK(cudaSetDevice(0))
+              && CUDA_CHECK(cudaStreamCreate(&cuda_stream));
+    if (!ok) {
         cuda_geterror();  // clear the error
         return;
     }
 
-    CUDA_CHECK(cudaSetDevice(0));
-    CUDA_CHECK(cudaStreamCreate(&cuda_stream));
-
-    OIIO::debugfmt("Number of CUDA devices: {}\n", deviceCount);
     for (int dev = 0; dev < deviceCount; ++dev) {
         cudaDeviceProp deviceProp;
-        CUDA_CHECK(cudaGetDeviceProperties(&deviceProp, dev));
-        CUDA_CHECK(cudaDriverGetVersion(&cuda_driver_version));
-        CUDA_CHECK(cudaRuntimeGetVersion(&cuda_runtime_version));
-        cuda_device_name   = ustring(deviceProp.name);
-        cuda_compatibility = 100 * deviceProp.major + deviceProp.minor;
-        cuda_total_memory  = deviceProp.totalGlobalMem;
-        OIIO::debugfmt(
-            "CUDA device \"{}\": driver {}, runtime {}, Cuda compat {}\n",
-            deviceProp.name, cuda_driver_version, cuda_runtime_version,
-            cuda_compatibility);
-        OIIO::debugfmt(" total mem {:g} MB\n",
-                       cuda_total_memory / (1024.0 * 1024.0));
-        break;  // only inventory the first Cuda device. FIXME?
+        bool ok = CUDA_CHECK(cudaGetDeviceProperties(&deviceProp, dev))
+                  && CUDA_CHECK(cudaDriverGetVersion(&cuda_driver_version))
+                  && CUDA_CHECK(cudaRuntimeGetVersion(&cuda_runtime_version));
+        if (ok) {
+            cuda_device_name   = ustring(deviceProp.name);
+            cuda_compatibility = 100 * deviceProp.major + deviceProp.minor;
+            cuda_total_memory  = deviceProp.totalGlobalMem;
+            OIIO::debugfmt(
+                "CUDA device \"{}\": driver {}, runtime {}, Cuda compat {}\n",
+                deviceProp.name, cuda_driver_version, cuda_runtime_version,
+                cuda_compatibility);
+            OIIO::debugfmt(" total mem {:g} MB\n",
+                           cuda_total_memory / (1024.0 * 1024.0));
+            cuda_supported = true;
+            break;  // only inventory the first Cuda device. FIXME?
+        }
     }
-    cuda_supported = true;
 }
 
 #endif /* defined(OIIO_USE_CUDA) */