Add initial context implementation.

APIs: hipInit, hipCtxCreate.
Track TLS default ctx.  Set deviceID now changes the ctx.
Add first context test.

Change-Id: If1cb9989b5a04a36147e25e84904336c7b6f3d88

src/hip_device.cpp

@@ -28,11 +28,11 @@ THE SOFTWARE.
 /**
  * @return  #hipSuccess
  */
-hipError_t hipGetDevice(int *device)
+hipError_t hipGetDevice(int *deviceId)
 {
-    HIP_INIT_API(device);
+    HIP_INIT_API(deviceId);
 
-    *device = tls_defaultDevice;
+    *deviceId = tls_defaultDeviceId;
     return ihipLogStatus(hipSuccess);
 }
 
@@ -130,13 +130,14 @@ hipError_t hipDeviceGetSharedMemConfig ( hipSharedMemConfig * pConfig )
 /**
  * @return #hipSuccess, #hipErrorInvalidDevice
  */
-hipError_t hipSetDevice(int device)
+hipError_t hipSetDevice(int deviceId)
 {
-    HIP_INIT_API(device);
-    if ((device < 0) || (device >= g_deviceCnt)) {
+    HIP_INIT_API(deviceId);
+    if ((deviceId < 0) || (deviceId >= g_deviceCnt)) {
         return ihipLogStatus(hipErrorInvalidDevice);
     } else {
-        tls_defaultDevice = device;
+        tls_defaultDeviceId = deviceId;
+        tls_defaultCtx = ihipGetPrimaryCtx(deviceId);
         return ihipLogStatus(hipSuccess);
     }
 }