python plugin: first cut of generic Python plugin

now independent of Interp
author: Michael Haberler <git@mah.priv.at> 2011-07-21 00:14:12 +0200
committer: Michael Haberler <git@mah.priv.at> 2011-10-28 08:25:52 +0200
commit: 7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4 (patch)
tree: ec1a4b16877b7b42ffa7a85093020d2272f8abf3
parent: 1b14351210a3a5c1e88fee5ff7de035fa16fbb04 (diff)
download: linuxcnc-7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4.tar.gz
linuxcnc-7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4.zip
4 files changed, 386 insertions, 0 deletions
diff --git a/src/emc/pythonplugin/README b/src/emc/pythonplugin/README
new file mode 100644
index 000000000..07834ec6d
--- /dev/null
+++ b/src/emc/pythonplugin/README
@@ -0,0 +1,2 @@
+spun out as separate class since it's used by interp and task
+no reason to keep it an interp method
diff --git a/src/emc/pythonplugin/Submakefile b/src/emc/pythonplugin/Submakefile
new file mode 100644
index 000000000..e3badf91e
--- /dev/null
+++ b/src/emc/pythonplugin/Submakefile
@@ -0,0 +1,38 @@
+PY=python2.6
+BOOST=boost_python
+
+
+INCLUDES += emc/pythonplugin
+
+LIBPPSRCS := $(addprefix emc/pythonplugin/, \
+	python_plugin.cc)
+
+USERSRCS += $(LIBPPSRCS)
+
+TESTSRCS := $(addprefix emc/pythonplugin/, \
+	testpp.cc )
+
+USERSRCS += $(TESTSRCS)
+
+$(call TOOBJSDEPS, $(LIBPPSRCS)) : EXTRAFLAGS=-fPIC -DBOOST_DEBUG_PYTHON -g -O0
+
+
+$(call TOOBJSDEPS, $(TESTSRCS)) : EXTRAFLAGS=-fPIC -DBOOST_DEBUG_PYTHON -g -O0
+
+TARGETS += ../lib/libpyplugin.so emc/pythonplugin/testpp
+
+../lib/libpyplugin.so.0: $(patsubst %.cc,objects/%.o,$(LIBPPSRCS)) ../lib/libemcini.so
+	$(ECHO) Linking $(notdir $@)
+	@mkdir -p ../lib
+	@rm -f $@
+	$(CXX) -g $(LDFLAGS) -Wl,-soname,$(notdir $@) -shared -o $@ $^ -lstdc++ -l$(BOOST) -l$(PY)
+
+
+../include/%.h: ./emc/pythonplugin/%.h
+	cp $^ $@
+../include/%.hh: ./emc/pythonplugin/%.hh
+	cp $^ $@
+
+emc/pythonplugin/testpp: $(call TOOBJS, $(TESTSRCS)) ../lib/libpyplugin.so.0
+	$(ECHO) Linking $(notdir $@)
+	$(CXX) $(LDFLAGS) -o $@ $^ -lstdc++ -l$(BOOST) -l$(PY)
diff --git a/src/emc/pythonplugin/python_plugin.cc b/src/emc/pythonplugin/python_plugin.cc
new file mode 100644
index 000000000..8ca17867d
--- /dev/null
+++ b/src/emc/pythonplugin/python_plugin.cc
@@ -0,0 +1,290 @@
+
+
+#include "python_plugin.hh"
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <exception>
+
+#define MAX_ERRMSG_SIZE 200
+
+#define ERRMSG(fmt, args...)					\
+    do {							\
+        char msgbuf[MAX_ERRMSG_SIZE];				\
+        snprintf(msgbuf, sizeof(msgbuf) -1,  fmt, ##args);	\
+        error_msg = std::string(msgbuf);			\
+    } while(0)
+
+
+#define PYCHK(bad, fmt, ...)					       \
+    do {							       \
+	if (bad) {						       \
+	    fprintf(stderr,fmt, ## __VA_ARGS__);		       \
+	    fprintf(stderr,"\n");				       \
+	    ERRMSG(fmt, ## __VA_ARGS__);			       \
+	    return PLUGIN_ERROR;				       \
+	}							       \
+    } while(0)
+
+#define logPP(fmt, ...)  fprintf(stderr, fmt, ## __VA_ARGS__)
+
+PythonPlugin::PythonPlugin(int loglevel)
+{
+    module_status = PYMOD_NONE;
+    log_level = loglevel;
+}
+
+PythonPlugin::~PythonPlugin()
+{
+    // boost.python dont support PyFinalize()
+}
+
+
+int PythonPlugin::setup(const char *modpath, const char *modname , bool reload_if_changed)
+{
+    reload_on_change = reload_if_changed;
+    PYCHK((modname == NULL), "initialize: no module defined");
+    module = modname; // ???
+    if (modpath) {
+	strcpy(module_path, modpath);
+	strcat(module_path,"/");
+    } else {
+	module_path[0] = '\0';
+    }
+    strcat(module_path, modname);
+    strcat(module_path,".py");
+
+    char path[PATH_MAX];
+    PYCHK(((realpath(module_path, path)) == NULL),
+	  "setup: cant resolve path to '%s'", module_path);
+
+    // record timestamp
+    struct stat st;
+    PYCHK(stat(module_path, &st),
+	  "setup(): stat(%s) returns %s", module_path, strerror(errno));
+    module_mtime = st.st_mtime;
+    Py_SetProgramName(module_path);
+    return PLUGIN_OK;
+}
+
+int PythonPlugin::add_inittab_entry(const char *mod_name, void (*mod_init)())
+{
+    PYCHK(PyImport_AppendInittab( (char *) mod_name , mod_init),
+	  "cant extend inittab with module '%s'", mod_name);
+    modules.push_back(mod_name);
+    return PLUGIN_OK;
+}
+
+int PythonPlugin::initialize(bool reload)
+{
+    std::string msg;
+
+    if (!reload) {
+	Py_Initialize();
+	if (module_path[0]) {
+	    char pathcmd[PATH_MAX];
+	    sprintf(pathcmd, "import sys\nsys.path.append(\"%s\")", module);
+	    PYCHK(PyRun_SimpleString(pathcmd),
+		  "exeception running '%s'", pathcmd);
+	}
+    }
+    try {
+	bp::object module = bp::import("__main__");
+	module_namespace = module.attr("__dict__");
+
+	for(unsigned i = 0; i < modules.size(); i++) {
+	    module_namespace[modules[i]] = bp::import(modules[i].c_str());
+	}
+	// FIXME
+	// the null deallocator avoids destroying the Interp instance on leaving scope or shutdown
+	// bp::scope(interp_module).attr("interp") =
+	// 	interp_ptr(this, interpDeallocFunc);
+	bp::object result = bp::exec_file(module_path,
+					  module_namespace,
+					  module_namespace);
+	module_status = PYMOD_OK;
+    }
+    catch (bp::error_already_set) {
+	python_exception = true;
+	if (PyErr_Occurred()) {
+	    exception_msg = handle_pyerror();
+	} else
+	    exception_msg = "unknown exception";
+	bp::handle_exception();
+	module_status = PYMOD_FAILED;
+	PyErr_Clear();
+    }
+    PYCHK(python_exception, "initialize: module '%s' init failed: \n%s",
+	  module_path, exception_msg.c_str());
+    return PLUGIN_OK;
+}
+
+
+int PythonPlugin::run_string(const char *cmd, bp::object &retval)
+{
+    if (reload_on_change)
+	reload();
+    try {
+	retval = bp::exec(cmd, module_namespace, module_namespace);
+    }
+    catch (bp::error_already_set) {
+	if (PyErr_Occurred()) {
+	   exception_msg = handle_pyerror();
+	} else
+	    exception_msg = "unknown exception";
+	python_exception = true;
+	bp::handle_exception();
+	PyErr_Clear();
+    }
+    PYCHK(python_exception, "run_string(%s): \n%s",
+	  cmd, exception_msg.c_str());
+    return PLUGIN_OK;
+}
+
+int PythonPlugin::call(const char *module, const char *callable,
+		       bp::object tupleargs, bp::object kwargs, bp::object &retval)
+{
+    bp::object function;
+
+    if (reload_on_change)
+	reload();
+    if ((module_status != PYMOD_OK) ||
+	(callable == NULL))
+	return PLUGIN_ERROR;
+
+    try {
+	if (module == NULL) {  // default to function in toplevel module
+	    function = module_namespace[callable];
+	} else {
+	    bp::object submod =  module_namespace[module];
+	    bp::object submod_namespace = submod.attr("__dict__");
+	    function = submod_namespace[callable];
+	}
+	retval = function(tupleargs,kwargs);
+    }
+    catch (bp::error_already_set) {
+	if (PyErr_Occurred()) {
+	   exception_msg = handle_pyerror();
+	} else
+	    exception_msg = "unknown exception";
+	python_exception = true;
+	bp::handle_exception();
+	PyErr_Clear();
+    }
+    PYCHK(python_exception, "call(%s.%s): \n%s",
+	  module, callable, exception_msg.c_str());
+
+    return PLUGIN_OK;
+}
+
+bool PythonPlugin::is_callable(const char *module,
+			   const char *funcname)
+{
+    bool unexpected = false;
+    bool result = false;
+    bp::object function;
+
+    if (reload_on_change)
+	reload();
+    if ((module_status != PYMOD_OK) ||
+	(funcname == NULL)) {
+	return false;
+    }
+    try {
+	if (module == NULL) {  // default to function in toplevel module
+	   function = module_namespace[funcname];
+	} else {
+	    bp::object submod =  module_namespace[module];
+	    bp::object submod_namespace = submod.attr("__dict__");
+	    function = submod_namespace[funcname];
+	}
+	result = PyCallable_Check(function.ptr());
+    }
+    catch (bp::error_already_set) {
+	// KeyError expected if not callable
+	if (!PyErr_ExceptionMatches(PyExc_KeyError)) {
+	    // something else, strange
+	    exception_msg = handle_pyerror();
+	    unexpected = true;
+	}
+	result = false;
+	PyErr_Clear();
+    }
+    if (unexpected)
+	logPP("is_pycallable(%s.%s): unexpected exception:\n%s",module,funcname,exception_msg.c_str());
+
+    if (log_level)
+	logPP("is_pycallable(%s.%s) = %s", module ? module : "",funcname,result ? "TRUE":"FALSE");
+    return result;
+
+
+    return false;
+}
+
+int PythonPlugin::reload()
+{
+    struct stat st;
+    if (module == NULL)
+	return PLUGIN_OK;
+
+    if (stat(module_path, &st)) {
+	logPP("reload: stat(%s) returned %s", module_path, strerror(errno));
+	return PLUGIN_ERROR;
+    }
+    if (st.st_mtime > module_mtime) {
+	module_mtime = st.st_mtime;
+	int status;
+	if ((status = initialize(true)) != PLUGIN_OK) {
+	    // // init_python() set the error text already
+	    // char err_msg[LINELEN+1];
+	    // error_text(status, err_msg, sizeof(err_msg));
+	    // logPP("reload(%s): %s",  module_path, err_msg);
+	    return PLUGIN_ERROR;
+	} else
+	    logPP("reload(): module %s reloaded", module);
+    }
+    return PLUGIN_OK;
+}
+
+int PythonPlugin::plugin_status()
+{
+    return PLUGIN_OK;
+
+}
+
+std::string PythonPlugin::last_exception()
+{
+    return exception_msg;
+}
+
+std::string PythonPlugin::last_errmsg()
+{
+    return error_msg;
+}
+
+
+// decode a Python exception into a string.
+std::string PythonPlugin::handle_pyerror()
+{
+    using namespace boost::python;
+    using namespace boost;
+
+    PyObject *exc,*val,*tb;
+    object formatted_list, formatted;
+    PyErr_Fetch(&exc,&val,&tb);
+    handle<> hexc(exc),hval(allow_null(val)),htb(allow_null(tb));
+    object traceback(import("traceback"));
+    if (!tb) {
+	object format_exception_only(traceback.attr("format_exception_only"));
+	formatted_list = format_exception_only(hexc,hval);
+    } else {
+	object format_exception(traceback.attr("format_exception"));
+	formatted_list = format_exception(hexc,hval,htb);
+    }
+    formatted = str("\n").join(formatted_list);
+    return extract<std::string>(formatted);
+}
diff --git a/src/emc/pythonplugin/python_plugin.hh b/src/emc/pythonplugin/python_plugin.hh
new file mode 100644
index 000000000..70f8a4802
--- /dev/null
+++ b/src/emc/pythonplugin/python_plugin.hh
@@ -0,0 +1,56 @@
+#ifndef PYTHON_PLUGIN_HH
+#define PYTHON_PLUGIN_HH
+
+#include <boost/python.hpp>
+namespace bp = boost::python;
+
+#include <vector>
+#include <string>
+#include <sys/types.h>
+// #include <sys/stat.h>
+
+// PY_EXCEPTION: both exception_msg and error_msg are set
+// PY_ERROR:  error_msg is set
+
+enum py_retcode {PLUGIN_OK=0, PLUGIN_EXCEPTION=1, PLUGIN_ERROR=2, PLUGIN_NOTCALLABLE=3};
+
+enum pymod_stat {PYMOD_NONE=0, PYMOD_FAILED=1,PYMOD_OK=2};
+
+class PythonPlugin {
+
+
+public:
+    PythonPlugin(int loglevel = 0);
+    ~PythonPlugin();
+    int setup(const char *modpath, const char *module, bool reload_if_changed = false);
+    int add_inittab_entry(const char *mod_name, void (*mod_init)());
+    int initialize(bool reload = false);
+    int run_string(const char *cmd, bp::object &retval);
+    int call(const char *module,const char *callable,
+	     bp::object tupleargs, bp::object kwargs, bp::object &retval);
+    bool is_callable(const char *module, const char *funcname);
+    int plugin_status();
+
+    std::string last_exception();
+    std::string last_errmsg();
+
+private:
+    int reload();
+    std::string handle_pyerror();
+
+    std::vector<std::string> modules;
+    bool python_exception;
+    int module_status;
+    bool reload_on_change;   // auto-reload if toplevel module was changed
+    const char *py_dir;      // plugin directory
+    const char *module;   // toplevel module
+    char module_path[PATH_MAX];
+    time_t     module_mtime;  // top level module - last modification time
+    bp::object module_namespace;
+
+    std::string exception_msg;
+    std::string error_msg;
+    int log_level;
+};
+
+#endif
author	Michael Haberler <git@mah.priv.at>	2011-07-21 00:14:12 +0200
committer	Michael Haberler <git@mah.priv.at>	2011-10-28 08:25:52 +0200
commit	7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4 (patch)
tree	ec1a4b16877b7b42ffa7a85093020d2272f8abf3
parent	1b14351210a3a5c1e88fee5ff7de035fa16fbb04 (diff)
download	linuxcnc-7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4.tar.gz linuxcnc-7bb49b0895a8e1de6a53ce3f990b84a1274ebfd4.zip