Implement thread name on windows, cleanup thread naming internals

src/ctx.cpp

@@ -426,14 +426,10 @@ void zmq::thread_ctx_t::start_thread (thread_t &thread_,
                                      _thread_affinity_cpus);
 
     char namebuf[16] = "";
-#ifdef ZMQ_HAVE_WINDOWS
-    LIBZMQ_UNUSED (name_);
-#else
     snprintf (namebuf, sizeof (namebuf), "%s%sZMQbg%s%s",
               _thread_name_prefix.empty () ? "" : _thread_name_prefix.c_str (),
               _thread_name_prefix.empty () ? "" : "/", name_ ? "/" : "",
               name_ ? name_ : "");
-#endif
     thread_.start (tfn_, arg_, namebuf);
 }
 

src/io_thread.cpp

@@ -57,10 +57,8 @@ zmq::io_thread_t::~io_thread_t ()
 void zmq::io_thread_t::start ()
 {
     char name[16] = "";
-#ifndef ZMQ_HAVE_WINDOWS
     snprintf (name, sizeof (name), "IO/%u",
               get_tid () - zmq::ctx_t::reaper_tid - 1);
-#endif
     //  Start the underlying I/O thread.
     _poller->start (name);
 }

src/thread.cpp

@@ -47,6 +47,7 @@ static unsigned int __stdcall thread_routine (void *arg_)
 #endif
 {
     zmq::thread_t *self = (zmq::thread_t *) arg_;
+    self->applyThreadName ();
     self->_tfn (self->_arg);
     return 0;
 }
@@ -54,9 +55,10 @@ static unsigned int __stdcall thread_routine (void *arg_)
 
 void zmq::thread_t::start (thread_fn *tfn_, void *arg_, const char *name_)
 {
-    LIBZMQ_UNUSED (name_);
     _tfn = tfn_;
     _arg = arg_;
+    if (name_)
+        strncpy (_name, name_, sizeof (_name));
 #if defined _WIN32_WCE
     _descriptor =
       (HANDLE) CreateThread (NULL, 0, &::thread_routine, this, 0, NULL);
@@ -92,10 +94,48 @@ void zmq::thread_t::setSchedulingParameters (
     LIBZMQ_UNUSED (affinity_cpus_);
 }
 
-void zmq::thread_t::setThreadName (const char *name_)
+void zmq::thread_t::
+  applySchedulingParameters () // to be called in secondary thread context
 {
     // not implemented
-    LIBZMQ_UNUSED (name_);
+}
+
+namespace
+{
+#pragma pack(push, 8)
+struct thread_info_t
+{
+    DWORD _type;
+    LPCSTR _name;
+    DWORD _thread_id;
+    DWORD _flags;
+};
+#pragma pack(pop)
+}
+
+void zmq::thread_t::
+  applyThreadName () // to be called in secondary thread context
+{
+    if (!_name[0])
+        return;
+
+    thread_info_t thread_info;
+    thread_info._type = 0x1000;
+    thread_info._name = _name;
+    thread_info._thread_id = -1;
+    thread_info._flags = 0;
+
+#pragma warning(push)
+#pragma warning(disable : 6320 6322)
+    __try {
+        DWORD MS_VC_EXCEPTION = 0x406D1388;
+        RaiseException (MS_VC_EXCEPTION, 0,
+                        sizeof (thread_info) / sizeof (ULONG_PTR),
+                        (ULONG_PTR *) &thread_info);
+    }
+    __except (EXCEPTION_CONTINUE_EXECUTION) {
+    }
+#pragma warning(pop)
 }
 
 #elif defined ZMQ_HAVE_VXWORKS
@@ -154,10 +194,10 @@ void zmq::thread_t::
     }
 }
 
-void zmq::thread_t::setThreadName (const char *name_)
+void zmq::thread_t::
+  applyThreadName () // to be called in secondary thread context
 {
     // not implemented
-    LIBZMQ_UNUSED (name_);
 }
 
 #else
@@ -181,7 +221,7 @@ static void *thread_routine (void *arg_)
 #endif
     zmq::thread_t *self = (zmq::thread_t *) arg_;
     self->applySchedulingParameters ();
-    self->setThreadName (self->_name.c_str ());
+    self->applyThreadName ();
     self->_tfn (self->_arg);
     return NULL;
 }
@@ -191,7 +231,8 @@ void zmq::thread_t::start (thread_fn *tfn_, void *arg_, const char *name_)
 {
     _tfn = tfn_;
     _arg = arg_;
-    _name = name_;
+    if (name_)
+        strncpy (_name, name_, sizeof (_name));
     int rc = pthread_create (&_descriptor, NULL, thread_routine, this);
     posix_assert (rc);
     _started = true;
@@ -301,7 +342,8 @@ void zmq::thread_t::
 #endif
 }
 
-void zmq::thread_t::setThreadName (const char *name_)
+void zmq::thread_t::
+  applyThreadName () // to be called in secondary thread context
 {
     /* The thread name is a cosmetic string, added to ease debugging of
  * multi-threaded applications. It is not a big issue if this value
@@ -310,7 +352,7 @@ void zmq::thread_t::setThreadName (const char *name_)
  * "int rc" is retained where available, to help debuggers stepping
  * through code to see its value - but otherwise it is ignored.
  */
-    if (!name_)
+    if (!_name[0])
         return;
 
         /* Fails with permission denied on Android 5/6 */
@@ -319,19 +361,19 @@ void zmq::thread_t::setThreadName (const char *name_)
 #endif
 
 #if defined(ZMQ_HAVE_PTHREAD_SETNAME_1)
-    int rc = pthread_setname_np (name_);
+    int rc = pthread_setname_np (_name);
     if (rc)
         return;
 #elif defined(ZMQ_HAVE_PTHREAD_SETNAME_2)
-    int rc = pthread_setname_np (pthread_self (), name_);
+    int rc = pthread_setname_np (pthread_self (), _name);
     if (rc)
         return;
 #elif defined(ZMQ_HAVE_PTHREAD_SETNAME_3)
-    int rc = pthread_setname_np (pthread_self (), name_, NULL);
+    int rc = pthread_setname_np (pthread_self (), _name, NULL);
     if (rc)
         return;
 #elif defined(ZMQ_HAVE_PTHREAD_SET_NAME)
-    pthread_set_name_np (pthread_self (), name_);
+    pthread_set_name_np (pthread_self (), _name);
 #endif
 }
 

src/thread.hpp

@@ -37,7 +37,7 @@
 #include <pthread.h>
 #endif
 #include <set>
-#include <string>
+#include <cstring>
 
 namespace zmq
 {
@@ -56,11 +56,11 @@ class thread_t
     inline thread_t () :
         _tfn (NULL),
         _arg (NULL),
-        _name (""),
         _started (false),
         _thread_priority (ZMQ_THREAD_PRIORITY_DFLT),
         _thread_sched_policy (ZMQ_THREAD_SCHED_POLICY_DFLT)
     {
+        memset (_name, 0, sizeof (_name));
     }
 
 #ifdef ZMQ_HAVE_VXWORKS
@@ -74,6 +74,8 @@ class thread_t
 
     //  Creates OS thread. 'tfn' is main thread function. It'll be passed
     //  'arg' as an argument.
+    //  Name is 16 characters max including terminating NUL. Thread naming is
+    //  implemented only for pthread, and windows when a debugger is attached.
     void start (thread_fn *tfn_, void *arg_, const char *name_);
 
     //  Returns whether the thread was started, i.e. start was called.
@@ -92,16 +94,13 @@ class thread_t
                                   int scheduling_policy_,
                                   const std::set<int> &affinity_cpus_);
 
-    // Sets the thread name, 16 characters max including terminating NUL.
-    // Only implemented for pthread. Has no effect on other platforms.
-    void setThreadName (const char *name_);
-
     //  These are internal members. They should be private, however then
     //  they would not be accessible from the main C routine of the thread.
     void applySchedulingParameters ();
+    void applyThreadName ();
     thread_fn *_tfn;
     void *_arg;
-    std::string _name;
+    char _name[16];
 
   private:
     bool _started;

src/windows.hpp

@@ -95,3 +95,10 @@ static inline int poll (struct pollfd *pfd, unsigned long nfds, int timeout)
 #define AI_NUMERICSERV 0x0400
 #endif
 #endif
+
+//  In MSVC prior to v14, snprintf is not available
+//  The closest implementation is the _snprintf_s function
+#if defined(_MSC_VER) && _MSC_VER < 1900
+#define snprintf(buffer_, count_, format_, ...)                                \
+    _snprintf_s (buffer_, count_, _TRUNCATE, format_, __VA_ARGS__)
+#endif

tests/test_security_curve.cpp

@@ -48,10 +48,6 @@
 
 char error_message_buffer[256];
 
-#if defined(_MSC_VER) && _MSC_VER < 1900
-#define snprintf _snprintf
-#endif
-
 void *handler;
 void *zap_thread;
 void *server;

tests/testutil.hpp

@@ -96,6 +96,13 @@ enum
 };
 #endif
 
+//  In MSVC prior to v14, snprintf is not available
+//  The closest implementation is the _snprintf_s function
+#if defined _MSC_VER && _MSC_VER < 1900
+#define snprintf(buffer_, count_, format_, ...)                                \
+    _snprintf_s (buffer_, count_, _TRUNCATE, format_, __VA_ARGS__)
+#endif
+
 #define LIBZMQ_UNUSED(object) (void) object
 
 //  Bounce a message from client to server and back

tests/testutil_unity.hpp

@@ -35,10 +35,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <unity.h>
 
-#if defined(_MSC_VER) && _MSC_VER <= 1800
-#define snprintf _snprintf
-#endif
-
 // Internal helper functions that are not intended to be directly called from
 // tests. They must be declared in the header since they are used by macros.