split base_launch_kernel into make_kernel_cmd / launch_kernel

IPython/zmq/entry_point.py

@@ -2,8 +2,7 b''
 launchers.
 """
 
-# Standard library imports.
-import atexit
+# Standard library imports
 import json
 import os
 import socket
@@ -17,7 +16,7 b' import tempfile'
 from IPython.utils.localinterfaces import LOCALHOST
 from IPython.utils.py3compat import bytes_to_str
 
-# Local imports.
+# Local imports
 from parentpoller import ParentPollerWindows
 
 def write_connection_file(fname=None, shell_port=0, iopub_port=0, stdin_port=0, hb_port=0,
@@ -98,9 +97,7 b' def write_connection_file(fname=None, shell_port=0, iopub_port=0, stdin_port=0, '
     return fname, cfg
     
 
-def base_launch_kernel(code, fname, stdin=None, stdout=None, stderr=None,
-                        executable=None, independent=False, extra_arguments=[],
-                        cwd=None):
+def make_kernel_cmd(code, executable=None, extra_arguments=[], **kw):
     """ Launches a localhost kernel, binding to the specified ports.
 
     Parameters
@@ -108,17 +105,54 b' def base_launch_kernel(code, fname, stdin=None, stdout=None, stderr=None,'
     code : str,
         A string of Python code that imports and executes a kernel entry point.
 
-    stdin, stdout, stderr : optional (default None)
-        Standards streams, as defined in subprocess.Popen.
+    executable : str, optional (default sys.executable)
+        The Python executable to use for the kernel process.
+
+    extra_arguments : list, optional
+        A list of extra arguments to pass when executing the launch code.
+    
+    Returns
+    -------
+    
+    A Popen command list
+    """
+    
+    # Build the kernel launch command.
+    if executable is None:
+        executable = sys.executable
+    arguments = [ executable, '-c', code, '-f', '{connection_file}' ]
+    arguments.extend(extra_arguments)
 
-    fname : unicode, optional
-        The JSON connector file, containing ip/port/hmac key information.
+    # Spawn a kernel.
+    if sys.platform == 'win32':
 
-    key : str, optional
-        The Session key used for HMAC authentication.
+        # If the kernel is running on pythonw and stdout/stderr are not been
+        # re-directed, it will crash when more than 4KB of data is written to
+        # stdout or stderr. This is a bug that has been with Python for a very
+        # long time; see http://bugs.python.org/issue706263.
+        # A cleaner solution to this problem would be to pass os.devnull to
+        # Popen directly. Unfortunately, that does not work.
+        if executable.endswith('pythonw.exe'):
+            arguments.append('--no-stdout')
+            arguments.append('--no-stderr')
 
-    executable : str, optional (default sys.executable)
-        The Python executable to use for the kernel process.
+    return arguments
+
+
+def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,
+                        independent=False,
+                        cwd=None, ipython_kernel=True,
+                        **kw
+                        ):
+    """ Launches a localhost kernel, binding to the specified ports.
+
+    Parameters
+    ----------
+    cmd : Popen list,
+        A string of Python code that imports and executes a kernel entry point.
+
+    stdin, stdout, stderr : optional (default None)
+        Standards streams, as defined in subprocess.Popen.
 
     independent : bool, optional (default False)
         If set, the kernel process is guaranteed to survive if this process
@@ -126,24 +160,18 b' def base_launch_kernel(code, fname, stdin=None, stdout=None, stderr=None,'
         when this process dies. Note that in this case it is still good practice
         to kill kernels manually before exiting.
 
-    extra_arguments : list, optional
-        A list of extra arguments to pass when executing the launch code.
-    
     cwd : path, optional
         The working dir of the kernel process (default: cwd of this process).
 
+    ipython_kernel : bool, optional
+        Whether the kernel is an official IPython one,
+        and should get a bit of special treatment.
+
     Returns
     -------
-    A tuple of form:
-        (kernel_process, shell_port, iopub_port, stdin_port, hb_port)
-    where kernel_process is a Popen object and the ports are integers.
-    """
     
-    # Build the kernel launch command.
-    if executable is None:
-        executable = sys.executable
-    arguments = [ executable, '-c', code, '-f', fname ]
-    arguments.extend(extra_arguments)
+    Popen instance for the kernel subprocess
+    """
 
     # Popen will fail (sometimes with a deadlock) if stdin, stdout, and stderr
     # are invalid. Unfortunately, there is in general no way to detect whether
@@ -167,50 +195,58 b' def base_launch_kernel(code, fname, stdin=None, stdout=None, stderr=None,'
 
     # Spawn a kernel.
     if sys.platform == 'win32':
+        
         # Create a Win32 event for interrupting the kernel.
         interrupt_event = ParentPollerWindows.create_interrupt_event()
-        arguments += [ '--interrupt=%i'%interrupt_event ]
-
-        # If the kernel is running on pythonw and stdout/stderr are not been
-        # re-directed, it will crash when more than 4KB of data is written to
-        # stdout or stderr. This is a bug that has been with Python for a very
-        # long time; see http://bugs.python.org/issue706263.
-        # A cleaner solution to this problem would be to pass os.devnull to
-        # Popen directly. Unfortunately, that does not work.
-        if executable.endswith('pythonw.exe'):
-            if stdout is None:
-                arguments.append('--no-stdout')
-            if stderr is None:
-                arguments.append('--no-stderr')
+        if ipython_kernel:
+            cmd += [ '--interrupt=%i' % interrupt_event ]
+
+            # If the kernel is running on pythonw and stdout/stderr are not been
+            # re-directed, it will crash when more than 4KB of data is written to
+            # stdout or stderr. This is a bug that has been with Python for a very
+            # long time; see http://bugs.python.org/issue706263.
+            # A cleaner solution to this problem would be to pass os.devnull to
+            # Popen directly. Unfortunately, that does not work.
+            if cmd[0].endswith('pythonw.exe'):
+                if stdout is None:
+                    cmd.append('--no-stdout')
+                if stderr is None:
+                    cmd.append('--no-stderr')
 
         # Launch the kernel process.
         if independent:
-            proc = Popen(arguments,
+            proc = Popen(cmd,
                          creationflags=512, # CREATE_NEW_PROCESS_GROUP
                          stdin=_stdin, stdout=_stdout, stderr=_stderr)
         else:
-            try:
-                from _winapi import DuplicateHandle, GetCurrentProcess, \
-                    DUPLICATE_SAME_ACCESS
-            except:
-                from _subprocess import DuplicateHandle, GetCurrentProcess, \
-                    DUPLICATE_SAME_ACCESS
-            pid = GetCurrentProcess()
-            handle = DuplicateHandle(pid, pid, pid, 0,
-                                     True, # Inheritable by new processes.
-                                     DUPLICATE_SAME_ACCESS)
-            proc = Popen(arguments + ['--parent=%i'%int(handle)],
-                         stdin=_stdin, stdout=_stdout, stderr=_stderr)
+            if ipython_kernel:
+                try:
+                    from _winapi import DuplicateHandle, GetCurrentProcess, \
+                        DUPLICATE_SAME_ACCESS
+                except:
+                    from _subprocess import DuplicateHandle, GetCurrentProcess, \
+                        DUPLICATE_SAME_ACCESS
+                pid = GetCurrentProcess()
+                handle = DuplicateHandle(pid, pid, pid, 0,
+                                         True, # Inheritable by new processes.
+                                         DUPLICATE_SAME_ACCESS)
+                cmd +=[ '--parent=%i' % handle ]
+            
+            
+            proc = Popen(cmd,
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
 
         # Attach the interrupt event to the Popen objet so it can be used later.
         proc.win32_interrupt_event = interrupt_event
 
     else:
         if independent:
-            proc = Popen(arguments, preexec_fn=lambda: os.setsid(),
+            proc = Popen(cmd, preexec_fn=lambda: os.setsid(),
                          stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
         else:
-            proc = Popen(arguments + ['--parent=1'],
+            if ipython_kernel:
+                cmd += ['--parent=1']
+            proc = Popen(cmd,
                          stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd)
 
     # Clean up pipes created to work around Popen bug.