solvers.py 文件源码

def grabLicence(self):
            """
            Returns True if a CPLEX licence can be obtained.
            The licence is kept until releaseLicence() is called.
            """
            status = ctypes.c_int()
            # If the config file allows to do so (non null params), try to
            # grab a runtime license.
            if ilm_cplex_license and ilm_cplex_license_signature:
                runtime_status = CPLEX_DLL.lib.CPXsetstaringsol(
                        ilm_cplex_license,
                        ilm_cplex_license_signature)
                # if runtime_status is not zero, running with a runtime
                # license will fail. However, no error is thrown (yet)
                # because the second call might still succeed if the user
                # has another license. Let us forgive bad user
                # configuration:
                if not (runtime_status == 0) and self.msg:
                    print(
                    "CPLEX library failed to load the runtime license" +
                    "the call returned status=%s" % str(runtime_status) +
                    "Please check the pulp config file.")
            self.env = CPLEX_DLL.lib.CPXopenCPLEX(ctypes.byref(status))
            self.hprob = None
            if not(status.value == 0):
                raise PulpSolverError("CPLEX library failed on " +
                                    "CPXopenCPLEX status=" + str(status))