[RUNTIME] Fix Metal runtime compile (#241)

src/runtime/metal/metal_common.h

@@ -21,6 +21,7 @@
 #include <mutex>
 #include <string>
 #include <vector>
+#include "../workspace_pool.h"
 
 namespace tvm {
 namespace runtime {

src/runtime/metal/metal_device_api.mm

@@ -12,9 +12,10 @@ namespace tvm {
 namespace runtime {
 namespace metal {
 
-MetalWorkspace* MetalWorkspace::Global() {
-  static MetalWorkspace inst;
-  return &inst;
+const std::shared_ptr<MetalWorkspace>& MetalWorkspace::Global() {
+  static std::shared_ptr<MetalWorkspace> inst =
+      std::make_shared<MetalWorkspace>();
+  return inst;
 }
 
 void MetalWorkspace::GetAttr(
@@ -254,7 +255,7 @@ MetalThreadEntry* MetalThreadEntry::ThreadLocal() {
 
 TVM_REGISTER_GLOBAL("device_api.metal")
 .set_body([](TVMArgs args, TVMRetValue* rv) {
-    DeviceAPI* ptr = MetalWorkspace::Global();
+    DeviceAPI* ptr = MetalWorkspace::Global().get();
     *rv = static_cast<void*>(ptr);
   });
 

src/runtime/metal/metal_module.mm

@@ -69,7 +69,7 @@ class MetalModuleNode final :public runtime::ModuleNode {
   // get a CUfunction from primary context in device_id
   id<MTLComputePipelineState> GetPipelineState(
       size_t device_id, const std::string& func_name) {
-    metal::MetalWorkspace* w = metal::MetalWorkspace::Global();
+    metal::MetalWorkspace* w = metal::MetalWorkspace::Global().get();
     CHECK_LT(device_id, w->devices.size());
     // start lock scope.
     std::lock_guard<std::mutex> lock(mutex_);
@@ -167,7 +167,7 @@ class MetalWrappedFunc {
             size_t num_buffer_args,
             size_t num_pack_args,
             const std::vector<std::string>& thread_axis_tags) {
-    w_ = metal::MetalWorkspace::Global();
+    w_ = metal::MetalWorkspace::Global().get();
     m_ = m;
     sptr_ = sptr;
     func_name_ = func_name;
@@ -255,8 +255,7 @@ Module MetalModuleCreate(
     std::string fmt,
     std::unordered_map<std::string, FunctionInfo> fmap,
     std::string source) {
-  metal::MetalWorkspace* w = metal::MetalWorkspace::Global();
-  w->Init();
+  metal::MetalWorkspace::Global()->Init();
   std::shared_ptr<MetalModuleNode> n =
       std::make_shared<MetalModuleNode>(data, fmt, fmap, source);
   return Module(n);