X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=type_decoder.c;h=c097c7fce5b94cb950d3cb03c0fb4e52371a0df2;hp=9ed3339d418593507b61c649f3a8f09fc4a3a127;hb=HEAD;hpb=04383ea876df72b7bd5c19854c30c81abdc0aa0c

diff --git a/type_decoder.c b/type_decoder.c
index 9ed3339..6932cde 100644
--- a/type_decoder.c
+++ b/type_decoder.c
@@ -22,24 +22,37 @@
 #include "libsigrokdecode.h"
 #include <inttypes.h>
 
+/** @cond PRIVATE */
+extern SRD_PRIV GSList *sessions;
+/** @endcond */
+
 typedef struct {
         PyObject_HEAD
 } srd_Decoder;
 
-/* This is only used for nicer srd_dbg() output.
- */
-static const char *output_type_name(unsigned int idx)
+/* This is only used for nicer srd_dbg() output. */
+SRD_PRIV const char *output_type_name(unsigned int idx)
 {
-	static const char names[][16] = {
+	static const char *names[] = {
 		"OUTPUT_ANN",
 		"OUTPUT_PYTHON",
 		"OUTPUT_BINARY",
+		"OUTPUT_LOGIC",
 		"OUTPUT_META",
 		"(invalid)"
 	};
+
 	return names[MIN(idx, G_N_ELEMENTS(names) - 1)];
 }
 
+static void release_annotation(struct srd_proto_data_annotation *pda)
+{
+	if (!pda)
+		return;
+	if (pda->ann_text)
+		g_strfreev(pda->ann_text);
+}
+
 static int convert_annotation(struct srd_decoder_inst *di, PyObject *obj,
 		struct srd_proto_data *pdata)
 {
@@ -48,20 +61,23 @@ static int convert_annotation(struct srd_decoder_inst *di, PyObject *obj,
 	struct srd_proto_data_annotation *pda;
 	int ann_class;
 	char **ann_text;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
 
 	/* Should be a list of [annotation class, [string, ...]]. */
 	if (!PyList_Check(obj)) {
-		srd_err("Protocol decoder %s submitted an annotation that"
-			" is not a list", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted an annotation that is not a list",
+				di->decoder->name);
+		goto err;
 	}
 
 	/* Should have 2 elements. */
 	if (PyList_Size(obj) != 2) {
-		srd_err("Protocol decoder %s submitted annotation list with "
-			"%zd elements instead of 2", di->decoder->name,
-			PyList_Size(obj));
-		return SRD_ERR_PYTHON;
+		ssize_t sz = PyList_Size(obj);
+		srd_err("Protocol decoder %s submitted annotation list with %zd elements instead of 2",
+				di->decoder->name, sz);
+		goto err;
 	}
 
 	/*
@@ -70,36 +86,132 @@ static int convert_annotation(struct srd_decoder_inst *di, PyObject *obj,
 	 */
 	py_tmp = PyList_GetItem(obj, 0);
 	if (!PyLong_Check(py_tmp)) {
-		srd_err("Protocol decoder %s submitted annotation list, but "
-			"first element was not an integer.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted annotation list, but first element was not an integer.",
+				di->decoder->name);
+		goto err;
 	}
 	ann_class = PyLong_AsLong(py_tmp);
 	if (!(pdo = g_slist_nth_data(di->decoder->annotations, ann_class))) {
-		srd_err("Protocol decoder %s submitted data to unregistered "
-			"annotation class %d.", di->decoder->name, ann_class);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted data to unregistered annotation class %d.",
+				di->decoder->name, ann_class);
+		goto err;
 	}
 
 	/* Second element must be a list. */
 	py_tmp = PyList_GetItem(obj, 1);
 	if (!PyList_Check(py_tmp)) {
-		srd_err("Protocol decoder %s submitted annotation list, but "
-			"second element was not a list.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted annotation list, but second element was not a list.",
+				di->decoder->name);
+		goto err;
 	}
 	if (py_strseq_to_char(py_tmp, &ann_text) != SRD_OK) {
-		srd_err("Protocol decoder %s submitted annotation list, but "
-			"second element was malformed.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted annotation list, but second element was malformed.",
+				di->decoder->name);
+		goto err;
 	}
 
-	pda = g_malloc(sizeof(struct srd_proto_data_annotation));
+	pda = pdata->data;
 	pda->ann_class = ann_class;
 	pda->ann_text = ann_text;
-	pdata->data = pda;
+
+	PyGILState_Release(gstate);
 
 	return SRD_OK;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+static void release_logic(struct srd_proto_data_logic *pdl)
+{
+	if (!pdl)
+		return;
+	g_free((void *)pdl->data);
+}
+
+static int convert_logic(struct srd_decoder_inst *di, PyObject *obj,
+		struct srd_proto_data *pdata)
+{
+	struct srd_proto_data_logic *pdl;
+	PyObject *py_tmp;
+	Py_ssize_t size;
+	int logic_group;
+	char *group_name, *buf;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
+	/* Should be a list of [logic group, bytes]. */
+	if (!PyList_Check(obj)) {
+		srd_err("Protocol decoder %s submitted non-list for SRD_OUTPUT_LOGIC.",
+			di->decoder->name);
+		goto err;
+	}
+
+	/* Should have 2 elements. */
+	if (PyList_Size(obj) != 2) {
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_LOGIC list "
+				"with %zd elements instead of 2", di->decoder->name,
+				PyList_Size(obj));
+		goto err;
+	}
+
+	/* The first element should be an integer. */
+	py_tmp = PyList_GetItem(obj, 0);
+	if (!PyLong_Check(py_tmp)) {
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_LOGIC list, "
+			"but first element was not an integer.", di->decoder->name);
+		goto err;
+	}
+	logic_group = PyLong_AsLong(py_tmp);
+	if (!(group_name = g_slist_nth_data(di->decoder->logic_output_channels, logic_group))) {
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_LOGIC with "
+			"unregistered logic group %d.", di->decoder->name, logic_group);
+		goto err;
+	}
+
+	/* Second element should be bytes. */
+	py_tmp = PyList_GetItem(obj, 1);
+	if (!PyBytes_Check(py_tmp)) {
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_LOGIC list, "
+			"but second element was not bytes.", di->decoder->name);
+		goto err;
+	}
+
+	/* Consider an empty set of bytes a bug. */
+	if (PyBytes_Size(py_tmp) == 0) {
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_LOGIC "
+				"with empty data set.", di->decoder->name);
+		goto err;
+	}
+
+	if (PyBytes_AsStringAndSize(py_tmp, &buf, &size) == -1)
+		goto err;
+
+	PyGILState_Release(gstate);
+
+	pdl = pdata->data;
+	pdl->logic_group = logic_group;
+	/* pdl->repeat_count is set by the caller as it depends on the sample range */
+	if (!(pdl->data = g_try_malloc(size)))
+		return SRD_ERR_MALLOC;
+	memcpy((void *)pdl->data, (const void *)buf, size);
+
+	return SRD_OK;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+static void release_binary(struct srd_proto_data_binary *pdb)
+{
+	if (!pdb)
+		return;
+	g_free((void *)pdb->data);
 }
 
 static int convert_binary(struct srd_decoder_inst *di, PyObject *obj,
@@ -110,109 +222,210 @@ static int convert_binary(struct srd_decoder_inst *di, PyObject *obj,
 	Py_ssize_t size;
 	int bin_class;
 	char *class_name, *buf;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
 
 	/* Should be a list of [binary class, bytes]. */
 	if (!PyList_Check(obj)) {
 		srd_err("Protocol decoder %s submitted non-list for SRD_OUTPUT_BINARY.",
 			di->decoder->name);
-		return SRD_ERR_PYTHON;
+		goto err;
 	}
 
 	/* Should have 2 elements. */
 	if (PyList_Size(obj) != 2) {
-		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list "
-				"with %zd elements instead of 2", di->decoder->name,
-				PyList_Size(obj));
-		return SRD_ERR_PYTHON;
+		ssize_t sz = PyList_Size(obj);
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list with %zd elements instead of 2",
+				di->decoder->name, sz);
+		goto err;
 	}
 
 	/* The first element should be an integer. */
 	py_tmp = PyList_GetItem(obj, 0);
 	if (!PyLong_Check(py_tmp)) {
-		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
-			"but first element was not an integer.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, but first element was not an integer.",
+				di->decoder->name);
+		goto err;
 	}
 	bin_class = PyLong_AsLong(py_tmp);
 	if (!(class_name = g_slist_nth_data(di->decoder->binary, bin_class))) {
-		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY with "
-			"unregistered binary class %d.", di->decoder->name, bin_class);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY with unregistered binary class %d.",
+				di->decoder->name, bin_class);
+		goto err;
 	}
 
 	/* Second element should be bytes. */
 	py_tmp = PyList_GetItem(obj, 1);
 	if (!PyBytes_Check(py_tmp)) {
-		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, "
-			"but second element was not bytes.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY list, but second element was not bytes.",
+				di->decoder->name);
+		goto err;
 	}
 
 	/* Consider an empty set of bytes a bug. */
 	if (PyBytes_Size(py_tmp) == 0) {
-		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY "
-				"with empty data set.", di->decoder->name);
-		return SRD_ERR_PYTHON;
+		srd_err("Protocol decoder %s submitted SRD_OUTPUT_BINARY with empty data set.",
+				di->decoder->name);
+		goto err;
 	}
 
-	pdb = g_malloc(sizeof(struct srd_proto_data_binary));
 	if (PyBytes_AsStringAndSize(py_tmp, &buf, &size) == -1)
-		return SRD_ERR_PYTHON;
+		goto err;
+
+	PyGILState_Release(gstate);
+
+	pdb = pdata->data;
 	pdb->bin_class = bin_class;
 	pdb->size = size;
 	if (!(pdb->data = g_try_malloc(pdb->size)))
 		return SRD_ERR_MALLOC;
 	memcpy((void *)pdb->data, (const void *)buf, pdb->size);
-	pdata->data = pdb;
 
 	return SRD_OK;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+static inline struct srd_decoder_inst *srd_sess_inst_find_by_obj(
+	struct srd_session *sess, const GSList *stack, const PyObject *obj)
+{
+	const GSList *l;
+	struct srd_decoder_inst *tmp, *di;
+
+	if (!sess)
+		return NULL;
+
+	di = NULL;
+	for (l = stack ? stack : sess->di_list; di == NULL && l != NULL; l = l->next) {
+		tmp = l->data;
+		if (tmp->py_inst == obj)
+			di = tmp;
+		else if (tmp->next_di)
+			di = srd_sess_inst_find_by_obj(sess, tmp->next_di, obj);
+	}
+
+	return di;
+}
+
+/**
+ * Find a decoder instance by its Python object.
+ *
+ * I.e. find that instance's instantiation of the sigrokdecode.Decoder class.
+ * This will recurse to find the instance anywhere in the stack tree of all
+ * sessions.
+ *
+ * @param stack Pointer to a GSList of struct srd_decoder_inst, indicating the
+ *              stack to search. To start searching at the bottom level of
+ *              decoder instances, pass NULL.
+ * @param obj The Python class instantiation.
+ *
+ * @return Pointer to struct srd_decoder_inst, or NULL if not found.
+ *
+ * @since 0.1.0
+ */
+static inline struct srd_decoder_inst *srd_inst_find_by_obj(
+		const GSList *stack, const PyObject *obj)
+{
+	struct srd_decoder_inst *di;
+	struct srd_session *sess;
+	GSList *l;
+
+	/* Performance shortcut: Handle the most common case first. */
+	sess = sessions->data;
+	di = sess->di_list->data;
+	if (di->py_inst == obj)
+		return di;
+
+	di = NULL;
+	for (l = sessions; di == NULL && l != NULL; l = l->next) {
+		sess = l->data;
+		di = srd_sess_inst_find_by_obj(sess, stack, obj);
+	}
+
+	return di;
 }
 
 static int convert_meta(struct srd_proto_data *pdata, PyObject *obj)
 {
 	long long intvalue;
 	double dvalue;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
 
-	if (pdata->pdo->meta_type == G_VARIANT_TYPE_INT64) {
+	if (g_variant_type_equal(pdata->pdo->meta_type, G_VARIANT_TYPE_INT64)) {
 		if (!PyLong_Check(obj)) {
-			PyErr_Format(PyExc_TypeError, "This output was registered "
-					"as 'int', but something else was passed.");
-			return SRD_ERR_PYTHON;
+			PyErr_Format(PyExc_TypeError,
+				"This output was registered as 'int', but something else was passed.");
+			goto err;
 		}
 		intvalue = PyLong_AsLongLong(obj);
 		if (PyErr_Occurred())
-			return SRD_ERR_PYTHON;
+			goto err;
 		pdata->data = g_variant_new_int64(intvalue);
-	} else if (pdata->pdo->meta_type == G_VARIANT_TYPE_DOUBLE) {
+	} else if (g_variant_type_equal(pdata->pdo->meta_type, G_VARIANT_TYPE_DOUBLE)) {
 		if (!PyFloat_Check(obj)) {
-			PyErr_Format(PyExc_TypeError, "This output was registered "
-					"as 'float', but something else was passed.");
-			return SRD_ERR_PYTHON;
+			PyErr_Format(PyExc_TypeError,
+				"This output was registered as 'float', but something else was passed.");
+			goto err;
 		}
 		dvalue = PyFloat_AsDouble(obj);
 		if (PyErr_Occurred())
-			return SRD_ERR_PYTHON;
+			goto err;
 		pdata->data = g_variant_new_double(dvalue);
 	}
 
+	PyGILState_Release(gstate);
+
 	return SRD_OK;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR_PYTHON;
+}
+
+static void release_meta(GVariant *gvar)
+{
+	if (!gvar)
+		return;
+	g_variant_unref(gvar);
 }
 
+PyDoc_STRVAR(Decoder_put_doc,
+	"Put an annotation for the specified span of samples.\n"
+	"\n"
+	"Arguments: start and end sample number, stream id, annotation data.\n"
+	"Annotation data's layout depends on the output stream type."
+);
+
 static PyObject *Decoder_put(PyObject *self, PyObject *args)
 {
 	GSList *l;
 	PyObject *py_data, *py_res;
 	struct srd_decoder_inst *di, *next_di;
 	struct srd_pd_output *pdo;
-	struct srd_proto_data *pdata;
+	struct srd_proto_data pdata;
+	struct srd_proto_data_annotation pda;
+	struct srd_proto_data_binary pdb;
+	struct srd_proto_data_logic pdl;
 	uint64_t start_sample, end_sample;
 	int output_id;
 	struct srd_pd_callback *cb;
+	PyGILState_STATE gstate;
+
+	py_data = NULL;
+
+	gstate = PyGILState_Ensure();
 
 	if (!(di = srd_inst_find_by_obj(NULL, self))) {
 		/* Shouldn't happen. */
 		srd_dbg("put(): self instance not found.");
-		return NULL;
+		goto err;
 	}
 
 	if (!PyArg_ParseTuple(args, "KKiO", &start_sample, &end_sample,
@@ -222,75 +435,114 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
 		 * Python raise it. This results in a much better trace in
 		 * controller.c on the decode() method call.
 		 */
-		return NULL;
+		goto err;
 	}
 
 	if (!(l = g_slist_nth(di->pd_output, output_id))) {
 		srd_err("Protocol decoder %s submitted invalid output ID %d.",
 			di->decoder->name, output_id);
-		return NULL;
+		goto err;
 	}
 	pdo = l->data;
 
-	srd_spew("Instance %s put %" PRIu64 "-%" PRIu64 " %s on oid %d.",
-		 di->inst_id, start_sample, end_sample,
-		 output_type_name(pdo->output_type), output_id);
+	/* Upon SRD_OUTPUT_PYTHON for stacked PDs, we have a nicer log message later. */
+	if (pdo->output_type != SRD_OUTPUT_PYTHON && di->next_di != NULL) {
+		srd_spew("Instance %s put %" PRIu64 "-%" PRIu64 " %s on "
+			 "oid %d (%s).", di->inst_id, start_sample, end_sample,
+			 output_type_name(pdo->output_type), output_id,
+			 pdo->proto_id);
+	}
 
-	pdata = g_malloc0(sizeof(struct srd_proto_data));
-	pdata->start_sample = start_sample;
-	pdata->end_sample = end_sample;
-	pdata->pdo = pdo;
+	pdata.start_sample = start_sample;
+	pdata.end_sample = end_sample;
+	pdata.pdo = pdo;
+	pdata.data = NULL;
 
 	switch (pdo->output_type) {
 	case SRD_OUTPUT_ANN:
 		/* Annotations are only fed to callbacks. */
 		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+			pdata.data = &pda;
 			/* Convert from PyDict to srd_proto_data_annotation. */
-			if (convert_annotation(di, py_data, pdata) != SRD_OK) {
+			if (convert_annotation(di, py_data, &pdata) != SRD_OK) {
 				/* An error was already logged. */
 				break;
 			}
-			cb->cb(pdata, cb->cb_data);
+			Py_BEGIN_ALLOW_THREADS
+			cb->cb(&pdata, cb->cb_data);
+			Py_END_ALLOW_THREADS
+			release_annotation(pdata.data);
 		}
 		break;
 	case SRD_OUTPUT_PYTHON:
 		for (l = di->next_di; l; l = l->next) {
 			next_di = l->data;
-			srd_spew("Sending %" PRIu64 "-%" PRIu64 " to instance %s",
-				 start_sample, end_sample, next_di->inst_id);
-			if (!(py_res = PyObject_CallMethod(
-				next_di->py_inst, "decode", "KKO", start_sample,
-				end_sample, py_data))) {
+			srd_spew("Instance %s put %" PRIu64 "-%" PRIu64 " %s "
+				 "on oid %d (%s) to instance %s.", di->inst_id,
+				 start_sample,
+				 end_sample, output_type_name(pdo->output_type),
+				 output_id, pdo->proto_id, next_di->inst_id);
+			py_res = PyObject_CallMethod(next_di->py_inst, "decode",
+				"KKO", start_sample, end_sample, py_data);
+			if (!py_res) {
 				srd_exception_catch("Calling %s decode() failed",
 							next_di->inst_id);
 			}
 			Py_XDECREF(py_res);
 		}
 		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
-			/* Frontends aren't really supposed to get Python
-			 * callbacks, but it's useful for testing. */
-			pdata->data = py_data;
-			cb->cb(pdata, cb->cb_data);
+			/*
+			 * Frontends aren't really supposed to get Python
+			 * callbacks, but it's useful for testing.
+			 */
+			pdata.data = py_data;
+			cb->cb(&pdata, cb->cb_data);
 		}
 		break;
 	case SRD_OUTPUT_BINARY:
 		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+			pdata.data = &pdb;
 			/* Convert from PyDict to srd_proto_data_binary. */
-			if (convert_binary(di, py_data, pdata) != SRD_OK) {
+			if (convert_binary(di, py_data, &pdata) != SRD_OK) {
 				/* An error was already logged. */
 				break;
 			}
-			cb->cb(pdata, cb->cb_data);
+			Py_BEGIN_ALLOW_THREADS
+			cb->cb(&pdata, cb->cb_data);
+			Py_END_ALLOW_THREADS
+			release_binary(pdata.data);
+		}
+		break;
+	case SRD_OUTPUT_LOGIC:
+		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
+			pdata.data = &pdl;
+			/* Convert from PyDict to srd_proto_data_logic. */
+			if (convert_logic(di, py_data, &pdata) != SRD_OK) {
+				/* An error was already logged. */
+				break;
+			}
+			if (end_sample <= start_sample) {
+				srd_err("Ignored SRD_OUTPUT_LOGIC with invalid sample range.");
+				break;
+			}
+			pdl.repeat_count = (end_sample - start_sample) - 1;
+			Py_BEGIN_ALLOW_THREADS
+			cb->cb(&pdata, cb->cb_data);
+			Py_END_ALLOW_THREADS
+			release_logic(pdata.data);
 		}
 		break;
 	case SRD_OUTPUT_META:
 		if ((cb = srd_pd_output_callback_find(di->sess, pdo->output_type))) {
 			/* Annotations need converting from PyObject. */
-			if (convert_meta(pdata, py_data) != SRD_OK) {
+			if (convert_meta(&pdata, py_data) != SRD_OK) {
 				/* An exception was already set up. */
 				break;
 			}
-			cb->cb(pdata, cb->cb_data);
+			Py_BEGIN_ALLOW_THREADS
+			cb->cb(&pdata, cb->cb_data);
+			Py_END_ALLOW_THREADS
+			release_meta(pdata.data);
 		}
 		break;
 	default:
@@ -299,13 +551,22 @@ static PyObject *Decoder_put(PyObject *self, PyObject *args)
 		break;
 	}
 
-	g_free(pdata);
+	PyGILState_Release(gstate);
 
 	Py_RETURN_NONE;
+
+err:
+	PyGILState_Release(gstate);
+
+	return NULL;
 }
 
-static PyObject *Decoder_register(PyObject *self, PyObject *args,
-		PyObject *kwargs)
+PyDoc_STRVAR(Decoder_register_doc,
+	"Register a new output stream."
+);
+
+static PyObject *Decoder_register(PyObject *self,
+	PyObject *args, PyObject *kwargs)
 {
 	struct srd_decoder_inst *di;
 	struct srd_pd_output *pdo;
@@ -314,7 +575,13 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 	const GVariantType *meta_type_gv;
 	int output_type;
 	char *proto_id, *meta_name, *meta_descr;
-	char *keywords[] = {"output_type", "proto_id", "meta", NULL};
+	char *keywords[] = { "output_type", "proto_id", "meta", NULL };
+	PyGILState_STATE gstate;
+	gboolean is_meta;
+	GSList *l;
+	struct srd_pd_output *cmp;
+
+	gstate = PyGILState_Ensure();
 
 	meta_type_py = NULL;
 	meta_type_gv = NULL;
@@ -322,32 +589,52 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 
 	if (!(di = srd_inst_find_by_obj(NULL, self))) {
 		PyErr_SetString(PyExc_Exception, "decoder instance not found");
-		return NULL;
+		goto err;
 	}
 
-	/* Default to instance id, which defaults to class id. */
+	/* Default to instance ID, which defaults to class ID. */
 	proto_id = di->inst_id;
 	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "i|s(Oss)", keywords,
 			&output_type, &proto_id,
 			&meta_type_py, &meta_name, &meta_descr)) {
 		/* Let Python raise this exception. */
-		return NULL;
+		goto err;
 	}
 
 	/* Check if the meta value's type is supported. */
-	if (output_type == SRD_OUTPUT_META) {
+	is_meta = output_type == SRD_OUTPUT_META;
+	if (is_meta) {
 		if (meta_type_py == &PyLong_Type)
 			meta_type_gv = G_VARIANT_TYPE_INT64;
 		else if (meta_type_py == &PyFloat_Type)
 			meta_type_gv = G_VARIANT_TYPE_DOUBLE;
 		else {
 			PyErr_Format(PyExc_TypeError, "Unsupported type.");
-			return NULL;
+			goto err;
 		}
 	}
 
-	srd_dbg("Instance %s creating new output type %d for %s.",
-		di->inst_id, output_type, proto_id);
+	pdo = NULL;
+	for (l = di->pd_output; l; l = l->next) {
+		cmp = l->data;
+		if (cmp->output_type != output_type)
+			continue;
+		if (strcmp(cmp->proto_id, proto_id) != 0)
+			continue;
+		if (is_meta && cmp->meta_type != meta_type_gv)
+			continue;
+		if (is_meta && strcmp(cmp->meta_name, meta_name) != 0)
+			continue;
+		if (is_meta && strcmp(cmp->meta_descr, meta_descr) != 0)
+			continue;
+		pdo = cmp;
+		break;
+	}
+	if (pdo) {
+		py_new_output_id = Py_BuildValue("i", pdo->pdo_id);
+		PyGILState_Release(gstate);
+		return py_new_output_id;
+	}
 
 	pdo = g_malloc(sizeof(struct srd_pd_output));
 
@@ -366,7 +653,18 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 	di->pd_output = g_slist_append(di->pd_output, pdo);
 	py_new_output_id = Py_BuildValue("i", pdo->pdo_id);
 
+	PyGILState_Release(gstate);
+
+	srd_dbg("Instance %s creating new output type %s as oid %d (%s).",
+		di->inst_id, output_type_name(output_type), pdo->pdo_id,
+		proto_id);
+
 	return py_new_output_id;
+
+err:
+	PyGILState_Release(gstate);
+
+	return NULL;
 }
 
 static int get_term_type(const char *v)
@@ -384,6 +682,8 @@ static int get_term_type(const char *v)
 		return SRD_TERM_EITHER_EDGE;
 	case 'n':
 		return SRD_TERM_NO_EDGE;
+	default:
+		return -1;
 	}
 
 	return -1;
@@ -405,28 +705,33 @@ static PyObject *get_current_pinvalues(const struct srd_decoder_inst *di)
 	const uint8_t *sample_pos;
 	int byte_offset, bit_offset;
 	PyObject *py_pinvalues;
+	PyGILState_STATE gstate;
 
 	if (!di) {
 		srd_err("Invalid decoder instance.");
 		return NULL;
 	}
 
+	gstate = PyGILState_Ensure();
+
 	py_pinvalues = PyTuple_New(di->dec_num_channels);
 
 	for (i = 0; i < di->dec_num_channels; i++) {
 		/* A channelmap value of -1 means "unused optional channel". */
 		if (di->dec_channelmap[i] == -1) {
 			/* Value of unused channel is 0xff, instead of 0 or 1. */
-			PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(0xff));
+			PyTuple_SetItem(py_pinvalues, i, PyLong_FromUnsignedLong(0xff));
 		} else {
 			sample_pos = di->inbuf + ((di->abs_cur_samplenum - di->abs_start_samplenum) * di->data_unitsize);
 			byte_offset = di->dec_channelmap[i] / 8;
 			bit_offset = di->dec_channelmap[i] % 8;
 			sample = *(sample_pos + byte_offset) & (1 << bit_offset) ? 1 : 0;
-			PyTuple_SetItem(py_pinvalues, i, PyLong_FromLong(sample));
+			PyTuple_SetItem(py_pinvalues, i, PyLong_FromUnsignedLong(sample));
 		}
 	}
 
+	PyGILState_Release(gstate);
+
 	return py_pinvalues;
 }
 
@@ -435,19 +740,22 @@ static PyObject *get_current_pinvalues(const struct srd_decoder_inst *di)
  *
  * If there are no terms in the condition, 'term_list' will be NULL.
  *
+ * @param di The decoder instance to use. Must not be NULL.
  * @param py_dict A Python dict containing terms. Must not be NULL.
  * @param term_list Pointer to a GSList which will be set to the newly
  *                  created list of terms. Must not be NULL.
  *
  * @return SRD_OK upon success, a negative error code otherwise.
  */
-static int create_term_list(PyObject *py_dict, GSList **term_list)
+static int create_term_list(struct srd_decoder_inst *di,
+	PyObject *py_dict, GSList **term_list)
 {
 	Py_ssize_t pos = 0;
 	PyObject *py_key, *py_value;
 	struct srd_term *term;
-	uint64_t num_samples_to_skip;
+	int64_t num_samples_to_skip;
 	char *term_str;
+	PyGILState_STATE gstate;
 
 	if (!py_dict || !term_list)
 		return SRD_ERR_ARG;
@@ -455,42 +763,54 @@ static int create_term_list(PyObject *py_dict, GSList **term_list)
 	/* "Create" an empty GSList of terms. */
 	*term_list = NULL;
 
+	gstate = PyGILState_Ensure();
+
 	/* Iterate over all items in the current dict. */
 	while (PyDict_Next(py_dict, &pos, &py_key, &py_value)) {
 		/* Check whether the current key is a string or a number. */
 		if (PyLong_Check(py_key)) {
 			/* The key is a number. */
-			/* TODO: Check if the number is a valid channel. */
 			/* Get the value string. */
 			if ((py_pydictitem_as_str(py_dict, py_key, &term_str)) != SRD_OK) {
 				srd_err("Failed to get the value.");
-				return SRD_ERR;
+				goto err;
 			}
-			term = g_malloc0(sizeof(struct srd_term));
+			term = g_malloc(sizeof(struct srd_term));
 			term->type = get_term_type(term_str);
 			term->channel = PyLong_AsLong(py_key);
+			if (term->channel < 0 || term->channel >= di->dec_num_channels)
+				term->type = SRD_TERM_ALWAYS_FALSE;
 			g_free(term_str);
 		} else if (PyUnicode_Check(py_key)) {
 			/* The key is a string. */
-			/* TODO: Check if it's "skip". */
+			/* TODO: Check if the key is "skip". */
 			if ((py_pydictitem_as_long(py_dict, py_key, &num_samples_to_skip)) != SRD_OK) {
 				srd_err("Failed to get number of samples to skip.");
-				return SRD_ERR;
+				goto err;
 			}
-			term = g_malloc0(sizeof(struct srd_term));
+			term = g_malloc(sizeof(struct srd_term));
 			term->type = SRD_TERM_SKIP;
 			term->num_samples_to_skip = num_samples_to_skip;
 			term->num_samples_already_skipped = 0;
+			if (num_samples_to_skip < 0)
+				term->type = SRD_TERM_ALWAYS_FALSE;
 		} else {
 			srd_err("Term key is neither a string nor a number.");
-			return SRD_ERR;
+			goto err;
 		}
 
 		/* Add the term to the list of terms. */
 		*term_list = g_slist_append(*term_list, term);
 	}
 
+	PyGILState_Release(gstate);
+
 	return SRD_OK;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR;
 }
 
 /**
@@ -510,14 +830,17 @@ static int set_new_condition_list(PyObject *self, PyObject *args)
 	GSList *term_list;
 	PyObject *py_conditionlist, *py_conds, *py_dict;
 	int i, num_conditions, ret;
+	PyGILState_STATE gstate;
 
 	if (!self || !args)
 		return SRD_ERR_ARG;
 
+	gstate = PyGILState_Ensure();
+
 	/* Get the decoder instance. */
 	if (!(di = srd_inst_find_by_obj(NULL, self))) {
 		PyErr_SetString(PyExc_Exception, "decoder instance not found");
-		return SRD_ERR;
+		goto err;
 	}
 
 	/*
@@ -526,35 +849,43 @@ static int set_new_condition_list(PyObject *self, PyObject *args)
 	 */
 	if (di->want_wait_terminate) {
 		srd_dbg("%s: %s: Skip (want_term).", di->inst_id, __func__);
-		return SRD_ERR;
+		goto err;
 	}
 
-	/* Parse the argument of self.wait() into 'py_conds'. */
-	if (!PyArg_ParseTuple(args, "O", &py_conds)) {
+	/*
+	 * Parse the argument of self.wait() into 'py_conds', and check
+	 * the data type. The argument is optional, None is assumed in
+	 * its absence. None or an empty dict or an empty list mean that
+	 * there is no condition, and the next available sample shall
+	 * get returned to the caller.
+	 */
+	py_conds = Py_None;
+	if (!PyArg_ParseTuple(args, "|O", &py_conds)) {
 		/* Let Python raise this exception. */
-		return SRD_ERR;
+		goto err;
 	}
-
-	/* Check whether 'py_conds' is a dict or a list. */
-	if (PyList_Check(py_conds)) {
+	if (py_conds == Py_None) {
+		/* 'py_conds' is None. */
+		goto ret_9999;
+	} else if (PyList_Check(py_conds)) {
 		/* 'py_conds' is a list. */
 		py_conditionlist = py_conds;
 		num_conditions = PyList_Size(py_conditionlist);
 		if (num_conditions == 0)
-			return 9999; /* The PD invoked self.wait([]). */
-		Py_IncRef(py_conditionlist);
+			goto ret_9999; /* The PD invoked self.wait([]). */
+		Py_INCREF(py_conditionlist);
 	} else if (PyDict_Check(py_conds)) {
 		/* 'py_conds' is a dict. */
 		if (PyDict_Size(py_conds) == 0)
-			return 9999; /* The PD invoked self.wait({}). */
+			goto ret_9999; /* The PD invoked self.wait({}). */
 		/* Make a list and put the dict in there for convenience. */
 		py_conditionlist = PyList_New(1);
-		Py_IncRef(py_conds);
+		Py_INCREF(py_conds);
 		PyList_SetItem(py_conditionlist, 0, py_conds);
 		num_conditions = 1;
 	} else {
 		srd_err("Condition list is neither a list nor a dict.");
-		return SRD_ERR;
+		goto err;
 	}
 
 	/* Free the old condition list. */
@@ -573,7 +904,7 @@ static int set_new_condition_list(PyObject *self, PyObject *args)
 		}
 
 		/* Create the list of terms in this condition. */
-		if ((ret = create_term_list(py_dict, &term_list)) < 0)
+		if ((ret = create_term_list(di, py_dict, &term_list)) < 0)
 			break;
 
 		/* Add the new condition to the PD instance's condition list. */
@@ -582,38 +913,125 @@ static int set_new_condition_list(PyObject *self, PyObject *args)
 
 	Py_DecRef(py_conditionlist);
 
+	PyGILState_Release(gstate);
+
 	return ret;
+
+err:
+	PyGILState_Release(gstate);
+
+	return SRD_ERR;
+
+ret_9999:
+	PyGILState_Release(gstate);
+
+	return 9999;
+}
+
+/**
+ * Create a SKIP condition list for condition-less .wait() calls.
+ *
+ * @param di Decoder instance.
+ * @param count Number of samples to skip.
+ *
+ * @retval SRD_OK The new condition list was set successfully.
+ * @retval SRD_ERR There was an error setting the new condition list.
+ *                 The contents of di->condition_list are undefined.
+ *
+ * This routine is a reduced and specialized version of the @ref
+ * set_new_condition_list() and @ref create_term_list() routines which
+ * gets invoked when .wait() was called without specifications for
+ * conditions. This minor duplication of the SKIP term list creation
+ * simplifies the logic and avoids the creation of expensive Python
+ * objects with "constant" values which the caller did not pass in the
+ * first place. It results in maximum sharing of match handling code
+ * paths.
+ */
+static int set_skip_condition(struct srd_decoder_inst *di, uint64_t count)
+{
+	struct srd_term *term;
+	GSList *term_list;
+
+	condition_list_free(di);
+	term = g_malloc(sizeof(*term));
+	term->type = SRD_TERM_SKIP;
+	term->num_samples_to_skip = count;
+	term->num_samples_already_skipped = 0;
+	term_list = g_slist_append(NULL, term);
+	di->condition_list = g_slist_append(di->condition_list, term_list);
+
+	return SRD_OK;
 }
 
+PyDoc_STRVAR(Decoder_wait_doc,
+	"Wait for one or more conditions to occur.\n"
+	"\n"
+	"Returns the sample data at the next position where the condition\n"
+	"is seen. When the optional condition is missing or empty, the next\n"
+	"sample number is used. The condition can be a dictionary with one\n"
+	"condition's details, or a list of dictionaries specifying multiple\n"
+	"conditions of which at least one condition must be true. Dicts can\n"
+	"contain one or more key/value pairs, all of which must be true for\n"
+	"the dict's condition to be considered true. The key either is a\n"
+	"channel index or a keyword, the value is the operation's parameter.\n"
+	"\n"
+	"Supported parameters for channel number keys: 'h', 'l', 'r', 'f',\n"
+	"or 'e' for level or edge conditions. Other supported keywords:\n"
+	"'skip' to advance over the given number of samples.\n"
+);
+
 static PyObject *Decoder_wait(PyObject *self, PyObject *args)
 {
 	int ret;
+	uint64_t skip_count;
 	unsigned int i;
 	gboolean found_match;
 	struct srd_decoder_inst *di;
-	PyObject *py_pinvalues, *py_matched;
+	PyObject *py_pinvalues, *py_matched, *py_samplenum;
+	PyGILState_STATE gstate;
 
 	if (!self || !args)
 		return NULL;
 
+	gstate = PyGILState_Ensure();
+
 	if (!(di = srd_inst_find_by_obj(NULL, self))) {
 		PyErr_SetString(PyExc_Exception, "decoder instance not found");
+		PyGILState_Release(gstate);
 		Py_RETURN_NONE;
 	}
 
 	ret = set_new_condition_list(self, args);
 	if (ret < 0) {
 		srd_dbg("%s: %s: Aborting wait().", di->inst_id, __func__);
-		return NULL;
+		goto err;
 	}
 	if (ret == 9999) {
-		/* Empty condition list, automatic match. */
-		PyObject_SetAttrString(di->py_inst, "matched", Py_None);
-		/* Leave self.samplenum unchanged (== di->abs_cur_samplenum). */
-		return get_current_pinvalues(di);
+		/*
+		 * Empty condition list, automatic match. Arrange for the
+		 * execution of regular match handling code paths such that
+		 * the next available sample is returned to the caller.
+		 * Make sure to skip one sample when "anywhere within the
+		 * stream", yet make sure to not skip sample number 0.
+		 */
+		if (di->abs_cur_samplenum)
+			skip_count = 1;
+		else if (!di->condition_list)
+			skip_count = 0;
+		else
+			skip_count = 1;
+		ret = set_skip_condition(di, skip_count);
+		if (ret < 0) {
+			srd_dbg("%s: %s: Cannot setup condition-less wait().",
+				di->inst_id, __func__);
+			goto err;
+		}
 	}
 
 	while (1) {
+
+		Py_BEGIN_ALLOW_THREADS
+
 		/* Wait for new samples to process, or termination request. */
 		g_mutex_lock(&di->data_mutex);
 		while (!di->got_new_samples && !di->want_wait_terminate)
@@ -627,28 +1045,36 @@ static PyObject *Decoder_wait(PyObject *self, PyObject *args)
 		 * while the termination request still gets signalled.
 		 */
 		found_match = FALSE;
-		ret = process_samples_until_condition_match(di, &found_match);
+
+		/* Ignore return value for now, should never be negative. */
+		(void)process_samples_until_condition_match(di, &found_match);
+
+		Py_END_ALLOW_THREADS
 
 		/* If there's a match, set self.samplenum etc. and return. */
 		if (found_match) {
 			/* Set self.samplenum to the (absolute) sample number that matched. */
-			PyObject_SetAttrString(di->py_inst, "samplenum",
-				PyLong_FromLong(di->abs_cur_samplenum));
+			py_samplenum = PyLong_FromUnsignedLongLong(di->abs_cur_samplenum);
+			PyObject_SetAttrString(di->py_inst, "samplenum", py_samplenum);
+			Py_DECREF(py_samplenum);
 
 			if (di->match_array && di->match_array->len > 0) {
 				py_matched = PyTuple_New(di->match_array->len);
 				for (i = 0; i < di->match_array->len; i++)
 					PyTuple_SetItem(py_matched, i, PyBool_FromLong(di->match_array->data[i]));
 				PyObject_SetAttrString(di->py_inst, "matched", py_matched);
+				Py_DECREF(py_matched);
 				match_array_free(di);
 			} else {
 				PyObject_SetAttrString(di->py_inst, "matched", Py_None);
 			}
-	
+
 			py_pinvalues = get_current_pinvalues(di);
 
 			g_mutex_unlock(&di->data_mutex);
 
+			PyGILState_Release(gstate);
+
 			return py_pinvalues;
 		}
 
@@ -663,6 +1089,27 @@ static PyObject *Decoder_wait(PyObject *self, PyObject *args)
 		/* Signal the main thread that we handled all samples. */
 		g_cond_signal(&di->handled_all_samples_cond);
 
+		/*
+		 * When EOF was provided externally, communicate the
+		 * Python EOFError exception to .decode() and return
+		 * from the .wait() method call. This is motivated by
+		 * the use of Python context managers, so that .decode()
+		 * methods can "close" incompletely accumulated data
+		 * when the sample data is exhausted.
+		 */
+		if (di->communicate_eof) {
+			/* Advance self.samplenum to the (absolute) last sample number. */
+			py_samplenum = PyLong_FromUnsignedLongLong(di->abs_cur_samplenum);
+			PyObject_SetAttrString(di->py_inst, "samplenum", py_samplenum);
+			Py_DECREF(py_samplenum);
+			/* Raise an EOFError Python exception. */
+			srd_dbg("%s: %s: Raising EOF from wait().",
+				di->inst_id, __func__);
+			g_mutex_unlock(&di->data_mutex);
+			PyErr_SetString(PyExc_EOFError, "samples exhausted");
+			goto err;
+		}
+
 		/*
 		 * When termination of wait() and decode() was requested,
 		 * then exit the loop after releasing the mutex.
@@ -671,15 +1118,30 @@ static PyObject *Decoder_wait(PyObject *self, PyObject *args)
 			srd_dbg("%s: %s: Will return from wait().",
 				di->inst_id, __func__);
 			g_mutex_unlock(&di->data_mutex);
-			return NULL;
+			goto err;
 		}
 
 		g_mutex_unlock(&di->data_mutex);
 	}
 
+	PyGILState_Release(gstate);
+
 	Py_RETURN_NONE;
+
+err:
+	PyGILState_Release(gstate);
+
+	return NULL;
 }
 
+PyDoc_STRVAR(Decoder_has_channel_doc,
+	"Check whether input data is supplied for a given channel.\n"
+	"\n"
+	"Argument: A channel index.\n"
+	"Returns: A boolean, True if the channel is connected,\n"
+	"False if the channel is open (won't see any input data).\n"
+);
+
 /**
  * Return whether the specified channel was supplied to the decoder.
  *
@@ -692,52 +1154,70 @@ static PyObject *Decoder_wait(PyObject *self, PyObject *args)
  */
 static PyObject *Decoder_has_channel(PyObject *self, PyObject *args)
 {
-	int idx, max_idx;
+	int idx, count;
 	struct srd_decoder_inst *di;
-	PyObject *py_channel;
+	PyGILState_STATE gstate;
+	PyObject *bool_ret;
 
 	if (!self || !args)
 		return NULL;
 
+	gstate = PyGILState_Ensure();
+
 	if (!(di = srd_inst_find_by_obj(NULL, self))) {
 		PyErr_SetString(PyExc_Exception, "decoder instance not found");
-		return NULL;
+		goto err;
 	}
 
-	/* Parse the argument of self.has_channel() into 'py_channel'. */
-	if (!PyArg_ParseTuple(args, "O", &py_channel)) {
+	/*
+	 * Get the integer argument of self.has_channel(). Check for
+	 * the range of supported PD input channel numbers.
+	 */
+	if (!PyArg_ParseTuple(args, "i", &idx)) {
 		/* Let Python raise this exception. */
-		return NULL;
+		goto err;
 	}
 
-	if (!PyLong_Check(py_channel)) {
-		PyErr_SetString(PyExc_Exception, "channel index not a number");
-		return NULL;
+	count = g_slist_length(di->decoder->channels) +
+	        g_slist_length(di->decoder->opt_channels);
+	if (idx < 0 || idx >= count) {
+		srd_err("Invalid index %d, PD channel count %d.", idx, count);
+		PyErr_SetString(PyExc_IndexError, "invalid channel index");
+		goto err;
 	}
 
-	idx = PyLong_AsLong(py_channel);
-	max_idx = g_slist_length(di->decoder->channels)
-		+ g_slist_length(di->decoder->opt_channels) - 1;
+	PyGILState_Release(gstate);
 
-	if (idx < 0 || idx > max_idx) {
-		srd_err("Invalid channel index %d/%d.", idx, max_idx);
-		PyErr_SetString(PyExc_Exception, "invalid channel");
-		return NULL;
-	}
+	bool_ret = (di->dec_channelmap[idx] == -1) ? Py_False : Py_True;
+	Py_INCREF(bool_ret);
+	return bool_ret;
 
-	return (di->dec_channelmap[idx] == -1) ? Py_False : Py_True;
+err:
+	PyGILState_Release(gstate);
+
+	return NULL;
 }
 
+PyDoc_STRVAR(Decoder_doc, "sigrok Decoder base class");
+
 static PyMethodDef Decoder_methods[] = {
-	{"put", Decoder_put, METH_VARARGS,
-	 "Accepts a dictionary with the following keys: startsample, endsample, data"},
-	{"register", (PyCFunction)Decoder_register, METH_VARARGS|METH_KEYWORDS,
-			"Register a new output stream"},
-	{"wait", Decoder_wait, METH_VARARGS,
-			"Wait for one or more conditions to occur"},
-	{"has_channel", Decoder_has_channel, METH_VARARGS,
-			"Report whether a channel was supplied"},
-	{NULL, NULL, 0, NULL}
+	{ "put",
+	  Decoder_put, METH_VARARGS,
+	  Decoder_put_doc,
+	},
+	{ "register",
+	  (PyCFunction)(void(*)(void))Decoder_register, METH_VARARGS | METH_KEYWORDS,
+	  Decoder_register_doc,
+	},
+	{ "wait",
+	  Decoder_wait, METH_VARARGS,
+	  Decoder_wait_doc,
+	},
+	{ "has_channel",
+	  Decoder_has_channel, METH_VARARGS,
+	  Decoder_has_channel_doc,
+	},
+	ALL_ZERO,
 };
 
 /**
@@ -751,16 +1231,25 @@ SRD_PRIV PyObject *srd_Decoder_type_new(void)
 {
 	PyType_Spec spec;
 	PyType_Slot slots[] = {
-		{ Py_tp_doc, "sigrok Decoder base class" },
+		{ Py_tp_doc, Decoder_doc },
 		{ Py_tp_methods, Decoder_methods },
 		{ Py_tp_new, (void *)&PyType_GenericNew },
-		{ 0, NULL }
+		ALL_ZERO,
 	};
+	PyObject *py_obj;
+	PyGILState_STATE gstate;
+
+	gstate = PyGILState_Ensure();
+
 	spec.name = "sigrokdecode.Decoder";
 	spec.basicsize = sizeof(srd_Decoder);
 	spec.itemsize = 0;
 	spec.flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE;
 	spec.slots = slots;
 
-	return PyType_FromSpec(&spec);
+	py_obj = PyType_FromSpec(&spec);
+
+	PyGILState_Release(gstate);
+
+	return py_obj;
 }