Set thread names to be visible in debuggers

base/threading/platform_thread_android.cc

Index: base/threading/platform_thread_android.cc
diff --git a/base/threading/platform_thread_android.cc b/base/threading/platform_thread_android.cc
index 0dbb1913d0e08af10fb86330a66dc75b41edd40f..bd0b4b33db74a137fa1dd0508f39586362857d5a 100644
--- a/base/threading/platform_thread_android.cc
+++ b/base/threading/platform_thread_android.cc
@@ -5,6 +5,7 @@
 #include "base/threading/platform_thread.h"
 
 #include <errno.h>
+#include <sys/prctl.h>
 #include <sys/resource.h>
 
 #include "base/android/jni_android.h"
@@ -77,6 +78,18 @@ void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
 void PlatformThread::SetName(const char* name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
   tracked_objects::ThreadData::InitializeThreadContext(name);
+
+  // Like linux, on android we can get the thread names to show up in the
+  // debugger by setting the process name for the LWP.
+  // We don't want to do this for the main thread because that would rename
+  // the process, causing tools like killall to stop working.
+  if (PlatformThread::CurrentId() == getpid())
+    return;
+
+  // Set the name for the LWP (which gets truncated to 15 characters).
+  int err = prctl(PR_SET_NAME, name);
+  if (err < 0 && errno != EPERM)
+    DPLOG(ERROR) << "prctl(PR_SET_NAME)";
 }