Linux: Name all threads started by calibre at the OS level for nicer debugging

src/calibre/startup.py

@@ -193,6 +193,36 @@ if not _run_once:
     __builtin__.__dict__['icu_upper'] = icu_upper
     __builtin__.__dict__['icu_title'] = title_case
 
+    if islinux:
+        # Name all threads at the OS level created using the threading module, see
+        # http://bugs.python.org/issue15500
+        import ctypes, ctypes.util, threading
+        libpthread_path = ctypes.util.find_library("pthread")
+        if libpthread_path:
+            libpthread = ctypes.CDLL(libpthread_path)
+            if hasattr(libpthread, "pthread_setname_np"):
+                pthread_setname_np = libpthread.pthread_setname_np
+                pthread_setname_np.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
+                pthread_setname_np.restype = ctypes.c_int
+                orig_start = threading.Thread.start
+                def new_start(self):
+                    orig_start(self)
+                    try:
+                        name = self.name
+                        if not name or name.startswith('Thread-'):
+                            name = self.__class__.__name__
+                            if name == 'Thread':
+                                name = self.name
+                        if name:
+                            if isinstance(name, unicode):
+                                name = name.encode('ascii', 'replace')
+                            ident = getattr(self, "ident", None)
+                            if ident is not None:
+                                pthread_setname_np(ident, name[:15])
+                    except Exception:
+                        pass  # Don't care about failure to set name
+                threading.Thread.start = new_start
+
 def test_lopen():
     from calibre.ptempfile import TemporaryDirectory
     from calibre import CurrentDir