Create a HostThread abstraction.

This patch moves creates a thread abstraction that represents a
thread running inside the LLDB process.  This is a replacement for
otherwise using lldb::thread_t, and provides a platform agnostic
interface to managing these threads.

Differential Revision: http://reviews.llvm.org/D5198

Reviewed by: Jim Ingham

llvm-svn: 217460

lldb/source/Host/linux/HostThreadLinux.cpp

@@ -0,0 +1,47 @@
+//===-- HostThreadLinux.cpp -------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Core/DataBuffer.h"
+#include "lldb/Host/linux/HostThreadLinux.h"
+#include "Plugins/Process/Linux/ProcFileReader.h"
+
+#include "llvm/ADT/SmallVector.h"
+
+#include <pthread.h>
+
+using namespace lldb_private;
+
+HostThreadLinux::HostThreadLinux()
+    : HostThreadPosix()
+{
+}
+
+HostThreadLinux::HostThreadLinux(lldb::thread_t thread)
+    : HostThreadPosix(thread)
+{
+}
+
+void
+HostThreadLinux::SetName(lldb::thread_t thread, llvm::StringRef name)
+{
+    ::pthread_setname_np(thread, name.data());
+}
+
+void
+HostThreadLinux::GetName(lldb::thread_t thread, llvm::SmallVectorImpl<char> &name)
+{
+    // Read /proc/$TID/comm file.
+    lldb::DataBufferSP buf_sp = ProcFileReader::ReadIntoDataBuffer(thread, "comm");
+    const char *comm_str = (const char *)buf_sp->GetBytes();
+    const char *cr_str = ::strchr(comm_str, '\n');
+    size_t length = cr_str ? (cr_str - comm_str) : strlen(comm_str);
+
+    name.clear();
+    name.append(comm_str, comm_str + length);
+}