Warn if a thread attaches without a name and blow up if a thread detaches while running.

Also don't crash if a thread attaches without a name. Doing so is allowed, even
if it's not a good idea.

Change-Id: If5796af689e9221ce21f443023b0d793a8be15b0

4 files changed, 19 insertions, 13 deletions

diff --git a/src/runtime.cc b/src/runtime.cc
index f6311bb..7e0eab5 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -818,11 +818,15 @@ void Runtime::BlockSignals() {
 
 void Runtime::AttachCurrentThread(const char* thread_name, bool as_daemon, Object* thread_group) {
   Thread::Attach(thread_name, as_daemon, thread_group);
+  if (thread_name == NULL) {
+    LOG(WARNING) << *Thread::Current() << " attached without supplying a name";
+  }
 }
 
 void Runtime::DetachCurrentThread() {
-  // TODO: check we're not calling DetachCurrentThread from a call stack that
-  // includes managed frames. (It's only valid if the stack is all-native.)
+  if (Thread::Current()->GetTopOfStack().GetSP() != NULL) {
+    LOG(FATAL) << *Thread::Current() << " attempting to detach while still running code";
+  }
   thread_list_->Unregister();
 }
 
diff --git a/src/thread.cc b/src/thread.cc
index dea554f..8bd7bc2 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -415,8 +415,10 @@ Thread* Thread::Attach(const char* thread_name, bool as_daemon, Object* thread_g
     self->CreatePeer(thread_name, as_daemon, thread_group);
   } else {
     // These aren't necessary, but they improve diagnostics for unit tests & command-line tools.
-    self->name_->assign(thread_name);
-    ::art::SetThreadName(thread_name);
+    if (thread_name != NULL) {
+      self->name_->assign(thread_name);
+      ::art::SetThreadName(thread_name);
+    }
   }
 
   self->GetJniEnv()->locals.AssertEmpty();
diff --git a/src/utils.cc b/src/utils.cc
index bdc5925..03b6172 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -740,12 +740,12 @@ bool StartsWith(const std::string& s, const char* prefix) {
   return s.compare(0, strlen(prefix), prefix) == 0;
 }
 
-void SetThreadName(const char* threadName) {
-  ANNOTATE_THREAD_NAME(threadName); // For tsan.
+void SetThreadName(const char* thread_name) {
+  ANNOTATE_THREAD_NAME(thread_name); // For tsan.
 
   int hasAt = 0;
   int hasDot = 0;
-  const char* s = threadName;
+  const char* s = thread_name;
   while (*s) {
     if (*s == '.') {
       hasDot = 1;
@@ -754,11 +754,11 @@ void SetThreadName(const char* threadName) {
     }
     s++;
   }
-  int len = s - threadName;
+  int len = s - thread_name;
   if (len < 15 || hasAt || !hasDot) {
-    s = threadName;
+    s = thread_name;
   } else {
-    s = threadName + len - 15;
+    s = thread_name + len - 15;
   }
 #if defined(HAVE_ANDROID_PTHREAD_SETNAME_NP)
   // pthread_setname_np fails rather than truncating long strings.
@@ -770,11 +770,11 @@ void SetThreadName(const char* threadName) {
     PLOG(WARNING) << "Unable to set the name of current thread to '" << buf << "'";
   }
 #elif defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1060
-  pthread_setname_np(threadName);
+  pthread_setname_np(thread_name);
 #elif defined(HAVE_PRCTL)
   prctl(PR_SET_NAME, (unsigned long) s, 0, 0, 0);  // NOLINT (unsigned long)
 #else
-  UNIMPLEMENTED(WARNING) << threadName;
+  UNIMPLEMENTED(WARNING) << thread_name;
 #endif
 }
 
diff --git a/src/utils.h b/src/utils.h
index 9c18093..b49d764 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -283,7 +283,7 @@ std::string GetSchedulerGroupName(pid_t tid);
 
 // Sets the name of the current thread. The name may be truncated to an
 // implementation-defined limit.
-void SetThreadName(const char* name);
+void SetThreadName(const char* thread_name);
 
 // Find $ANDROID_ROOT, /system, or abort
 const char* GetAndroidRoot();