1 files changed, 120 insertions, 0 deletions
diff --git a/lib/spack/external/pytest-fallback/py/_process/forkedfunc.py b/lib/spack/external/pytest-fallback/py/_process/forkedfunc.py
new file mode 100644
index 0000000000..1c28530688
--- /dev/null
+++ b/lib/spack/external/pytest-fallback/py/_process/forkedfunc.py
@@ -0,0 +1,120 @@
+
+"""
+    ForkedFunc provides a way to run a function in a forked process
+    and get at its return value, stdout and stderr output as well
+    as signals and exitstatusus.
+"""
+
+import py
+import os
+import sys
+import marshal
+
+
+def get_unbuffered_io(fd, filename):
+    f = open(str(filename), "w")
+    if fd != f.fileno():
+        os.dup2(f.fileno(), fd)
+    class AutoFlush:
+        def write(self, data):
+            f.write(data)
+            f.flush()
+        def __getattr__(self, name):
+            return getattr(f, name)
+    return AutoFlush()
+
+
+class ForkedFunc:
+    EXITSTATUS_EXCEPTION = 3
+
+
+    def __init__(self, fun, args=None, kwargs=None, nice_level=0,
+                 child_on_start=None, child_on_exit=None):
+        if args is None:
+            args = []
+        if kwargs is None:
+            kwargs = {}
+        self.fun = fun
+        self.args = args
+        self.kwargs = kwargs
+        self.tempdir = tempdir = py.path.local.mkdtemp()
+        self.RETVAL = tempdir.ensure('retval')
+        self.STDOUT = tempdir.ensure('stdout')
+        self.STDERR = tempdir.ensure('stderr')
+
+        pid = os.fork()
+        if pid:  # in parent process
+            self.pid = pid
+        else:  # in child process
+            self.pid = None
+            self._child(nice_level, child_on_start, child_on_exit)
+
+    def _child(self, nice_level, child_on_start, child_on_exit):
+        # right now we need to call a function, but first we need to
+        # map all IO that might happen
+        sys.stdout = stdout = get_unbuffered_io(1, self.STDOUT)
+        sys.stderr = stderr = get_unbuffered_io(2, self.STDERR)
+        retvalf = self.RETVAL.open("wb")
+        EXITSTATUS = 0
+        try:
+            if nice_level:
+                os.nice(nice_level)
+            try:
+                if child_on_start is not None:
+                    child_on_start()
+                retval = self.fun(*self.args, **self.kwargs)
+                retvalf.write(marshal.dumps(retval))
+                if child_on_exit is not None:
+                    child_on_exit()
+            except:
+                excinfo = py.code.ExceptionInfo()
+                stderr.write(str(excinfo._getreprcrash()))
+                EXITSTATUS = self.EXITSTATUS_EXCEPTION
+        finally:
+            stdout.close()
+            stderr.close()
+            retvalf.close()
+        os.close(1)
+        os.close(2)
+        os._exit(EXITSTATUS)
+
+    def waitfinish(self, waiter=os.waitpid):
+        pid, systemstatus = waiter(self.pid, 0)
+        if systemstatus:
+            if os.WIFSIGNALED(systemstatus):
+                exitstatus = os.WTERMSIG(systemstatus) + 128
+            else:
+                exitstatus = os.WEXITSTATUS(systemstatus)
+        else:
+            exitstatus = 0
+        signal = systemstatus & 0x7f
+        if not exitstatus and not signal:
+            retval = self.RETVAL.open('rb')
+            try:
+                retval_data = retval.read()
+            finally:
+                retval.close()
+            retval = marshal.loads(retval_data)
+        else:
+            retval = None
+        stdout = self.STDOUT.read()
+        stderr = self.STDERR.read()
+        self._removetemp()
+        return Result(exitstatus, signal, retval, stdout, stderr)
+
+    def _removetemp(self):
+        if self.tempdir.check():
+            self.tempdir.remove()
+
+    def __del__(self):
+        if self.pid is not None:  # only clean up in main process
+            self._removetemp()
+
+
+class Result(object):
+    def __init__(self, exitstatus, signal, retval, stdout, stderr):
+        self.exitstatus = exitstatus
+        self.signal = signal
+        self.retval = retval
+        self.out = stdout
+        self.err = stderr