Yarn: Add Thread helper class
Contains static methods that abstract OS-specific thread / cpu queries and control.
Bug: b/139010488
Change-Id: Idab47624598c3585d7741058ba62974faadc191d
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/34810
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
diff --git a/src/Yarn/Thread.cpp b/src/Yarn/Thread.cpp
new file mode 100644
index 0000000..83c56b2
--- /dev/null
+++ b/src/Yarn/Thread.cpp
@@ -0,0 +1,100 @@
+// Copyright 2019 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "Thread.hpp"
+
+#include <cstdarg>
+
+#if defined(_WIN32)
+# ifndef WIN32_LEAN_AND_MEAN
+# define WIN32_LEAN_AND_MEAN
+# endif
+# include <windows.h>
+#elif defined(__APPLE__)
+# include <pthread.h>
+# include <mach/thread_act.h>
+# include <unistd.h>
+#else
+# include <pthread.h>
+# include <unistd.h>
+#endif
+
+namespace yarn {
+
+#if defined(_WIN32)
+
+void Thread::setName(const char* fmt, ...)
+{
+ static auto setThreadDescription = reinterpret_cast<HRESULT(WINAPI*)(HANDLE, PCWSTR)>(GetProcAddress(GetModuleHandle("kernelbase.dll"), "SetThreadDescription"));
+ if (setThreadDescription == nullptr)
+ {
+ return;
+ }
+
+ char name[1024];
+ va_list vararg;
+ va_start(vararg, fmt);
+ vsnprintf(name, sizeof(name), fmt, vararg);
+ va_end(vararg);
+
+ wchar_t wname[1024];
+ mbstowcs(wname, name, 1024);
+ setThreadDescription(GetCurrentThread(), wname);
+}
+
+unsigned int Thread::numLogicalCPUs()
+{
+ DWORD_PTR processAffinityMask = 1;
+ DWORD_PTR systemAffinityMask = 1;
+
+ GetProcessAffinityMask(GetCurrentProcess(), &processAffinityMask, &systemAffinityMask);
+
+ auto count = 0;
+ while (processAffinityMask > 0)
+ {
+ if (processAffinityMask & 1)
+ {
+ count++;
+ }
+
+ processAffinityMask >>= 1;
+ }
+ return count;
+}
+
+#else
+
+void Thread::setName(const char* fmt, ...)
+{
+ char name[1024];
+ va_list vararg;
+ va_start(vararg, fmt);
+ vsnprintf(name, sizeof(name), fmt, vararg);
+ va_end(vararg);
+
+#if defined(__APPLE__)
+ pthread_setname_np(name);
+#else
+ pthread_setname_np(pthread_self(), name);
+#endif
+}
+
+unsigned int Thread::numLogicalCPUs()
+{
+ return sysconf(_SC_NPROCESSORS_ONLN);
+}
+
+#endif
+
+} // namespace yarn
diff --git a/src/Yarn/Thread.hpp b/src/Yarn/Thread.hpp
new file mode 100644
index 0000000..878cb8e
--- /dev/null
+++ b/src/Yarn/Thread.hpp
@@ -0,0 +1,38 @@
+// Copyright 2019 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef yarn_thread_hpp
+#define yarn_thread_hpp
+
+#include <bitset>
+
+namespace yarn {
+
+// Thread contains static methods that abstract OS-specific thread / cpu
+// queries and control.
+class Thread
+{
+public:
+ // setName() sets the name of the currently executing thread for displaying
+ // in a debugger.
+ static void setName(const char* fmt, ...);
+
+ // numLogicalCPUs() returns the number of available logical CPU cores for
+ // the system.
+ static unsigned int numLogicalCPUs();
+};
+
+} // namespace yarn
+
+#endif // yarn_thread_hpp
