]> sigrok.org Git - libsigrokdecode.git/blobdiff - instance.c
Add srd_inst_initial_pins_set_all() and support code.
[libsigrokdecode.git] / instance.c
index e80afd751469b7fb6d81acac51cdff3591131019..61e0ea895360df67b76375fe1e7bbac868cc0cf6 100644 (file)
@@ -33,6 +33,10 @@ extern SRD_PRIV GSList *sessions;
 /* module_sigrokdecode.c */
 extern SRD_PRIV PyObject *srd_logic_type;
 
+static void srd_inst_join_decode_thread(struct srd_decoder_inst *di);
+static void srd_inst_reset_state(struct srd_decoder_inst *di);
+SRD_PRIV void oldpins_array_free(struct srd_decoder_inst *di);
+
 /** @endcond */
 
 /**
@@ -349,6 +353,13 @@ SRD_API struct srd_decoder_inst *srd_inst_new(struct srd_session *sess,
                di->channel_samples = g_malloc(di->dec_num_channels);
        }
 
+       /* Default to the initial pins being the same as in sample 0. */
+       di->old_pins_array = g_array_sized_new(FALSE, TRUE, sizeof(uint8_t),
+                                               di->dec_num_channels);
+       g_array_set_size(di->old_pins_array, di->dec_num_channels);
+       memset(di->old_pins_array->data, SRD_INITIAL_PIN_SAME_AS_SAMPLE0,
+               di->dec_num_channels);
+
        /* Create a new instance of this decoder class. */
        if (!(di->py_inst = PyObject_CallObject(dec->py_dec, NULL))) {
                if (PyErr_Occurred())
@@ -372,10 +383,20 @@ SRD_API struct srd_decoder_inst *srd_inst_new(struct srd_session *sess,
        di->inbuf = NULL;
        di->inbuflen = 0;
        di->abs_cur_samplenum = 0;
-       di->old_pins_array = NULL;
        di->thread_handle = NULL;
        di->got_new_samples = FALSE;
        di->handled_all_samples = FALSE;
+       di->want_wait_terminate = FALSE;
+
+       /*
+        * Strictly speaking initialization of statically allocated
+        * condition and mutex variables (or variables allocated on the
+        * stack) is not required, but won't harm either. Explicitly
+        * running init() will better match subsequent clear() calls.
+        */
+       g_cond_init(&di->got_new_samples_cond);
+       g_cond_init(&di->handled_all_samples_cond);
+       g_mutex_init(&di->data_mutex);
 
        /* Instance takes input from a frontend by default. */
        sess->di_list = g_slist_append(sess->di_list, di);
@@ -384,6 +405,66 @@ SRD_API struct srd_decoder_inst *srd_inst_new(struct srd_session *sess,
        return di;
 }
 
+static void srd_inst_join_decode_thread(struct srd_decoder_inst *di)
+{
+       if (!di)
+               return;
+       if (!di->thread_handle)
+               return;
+
+       srd_dbg("%s: Joining decoder thread.", di->inst_id);
+
+       /*
+        * Terminate potentially running threads which still
+        * execute the decoder instance's decode() method.
+        */
+       srd_dbg("%s: Raising want_term, sending got_new.", di->inst_id);
+       g_mutex_lock(&di->data_mutex);
+       di->want_wait_terminate = TRUE;
+       g_cond_signal(&di->got_new_samples_cond);
+       g_mutex_unlock(&di->data_mutex);
+
+       srd_dbg("%s: Running join().", di->inst_id);
+       (void)g_thread_join(di->thread_handle);
+       srd_dbg("%s: Call to join() done.", di->inst_id);
+       di->thread_handle = NULL;
+
+       /*
+        * Reset condition and mutex variables, such that next
+        * operations on them will find them in a clean state.
+        */
+       g_cond_clear(&di->got_new_samples_cond);
+       g_cond_init(&di->got_new_samples_cond);
+       g_cond_clear(&di->handled_all_samples_cond);
+       g_cond_init(&di->handled_all_samples_cond);
+       g_mutex_clear(&di->data_mutex);
+       g_mutex_init(&di->data_mutex);
+}
+
+static void srd_inst_reset_state(struct srd_decoder_inst *di)
+{
+       if (!di)
+               return;
+
+       srd_dbg("%s: Resetting decoder state.", di->inst_id);
+
+       /*
+        * Reset internal state of the decoder.
+        */
+       condition_list_free(di);
+       match_array_free(di);
+       di->abs_start_samplenum = 0;
+       di->abs_end_samplenum = 0;
+       di->inbuf = NULL;
+       di->inbuflen = 0;
+       di->abs_cur_samplenum = 0;
+       oldpins_array_free(di);
+       di->got_new_samples = FALSE;
+       di->handled_all_samples = FALSE;
+       di->want_wait_terminate = FALSE;
+       /* Conditions and mutex got reset after joining the thread. */
+}
+
 /**
  * Stack a decoder instance on top of another.
  *
@@ -550,51 +631,62 @@ SRD_PRIV struct srd_decoder_inst *srd_inst_find_by_obj(const GSList *stack,
 /**
  * Set the list of initial (assumed) pin values.
  *
- * If the list already exists, do nothing.
- *
  * @param di Decoder instance to use. Must not be NULL.
+ * @param initial_pins A GArray of uint8_t values. Must not be NULL.
  *
- * @private
+ * @since 0.5.0
  */
-static void set_initial_pin_values(struct srd_decoder_inst *di)
+SRD_API int srd_inst_initial_pins_set_all(struct srd_decoder_inst *di, GArray *initial_pins)
 {
        int i;
        GString *s;
-       PyObject *py_initial_pins;
 
-       if (!di || !di->py_inst) {
+       if (!di) {
                srd_err("Invalid decoder instance.");
-               return;
-       }
-
-       /* Nothing to do if di->old_pins_array is already != NULL. */
-       if (di->old_pins_array) {
-               srd_dbg("Initial pins already set, nothing to do.");
-               return;
+               return SRD_ERR_ARG;
        }
 
-       /* Create an array of old (previous sample) pins, init to 0. */
-       di->old_pins_array = g_array_sized_new(FALSE, TRUE, sizeof(uint8_t), di->dec_num_channels);
-       g_array_set_size(di->old_pins_array, di->dec_num_channels);
+       if (!initial_pins)
+               return SRD_ERR_ARG;
 
-       /* Check if the decoder has set self.initial_pins. */
-       if (!PyObject_HasAttrString(di->py_inst, "initial_pins")) {
-               srd_dbg("Initial pins: all 0 (self.initial_pins not set).");
-               return;
+       if (initial_pins->len != (guint)di->dec_num_channels) {
+               srd_err("Incorrect number of channels (need %d, got %d).",
+                       di->dec_num_channels, initial_pins->len);
+               return SRD_ERR_ARG;
        }
 
-       /* Get self.initial_pins. */
-       py_initial_pins = PyObject_GetAttrString(di->py_inst, "initial_pins");
+       /* Sanity-check initial pin state values. */
+       for (i = 0; i < di->dec_num_channels; i++) {
+               if (initial_pins->data[i] <= 2)
+                       continue;
+               srd_err("Invalid initial channel %d pin state: %d.",
+                       i, initial_pins->data[i]);
+               return SRD_ERR_ARG;
+       }
 
-       /* Fill di->old_pins_array based on self.initial_pins. */
        s = g_string_sized_new(100);
        for (i = 0; i < di->dec_num_channels; i++) {
-               di->old_pins_array->data[i] = PyLong_AsLong(PyList_GetItem(py_initial_pins, i));
+               di->old_pins_array->data[i] = initial_pins->data[i];
                g_string_append_printf(s, "%d, ", di->old_pins_array->data[i]);
        }
        s = g_string_truncate(s, s->len - 2);
        srd_dbg("Initial pins: %s.", s->str);
        g_string_free(s, TRUE);
+
+       return SRD_OK;
+}
+
+SRD_PRIV void oldpins_array_free(struct srd_decoder_inst *di)
+{
+       if (!di)
+               return;
+       if (!di->old_pins_array)
+               return;
+
+       srd_dbg("%s: Releasing initial pin state.", di->inst_id);
+
+       g_array_free(di->old_pins_array, TRUE);
+       di->old_pins_array = NULL;
 }
 
 /** @private */
@@ -616,9 +708,6 @@ SRD_PRIV int srd_inst_start(struct srd_decoder_inst *di)
        }
        Py_DecRef(py_res);
 
-       /* Set the initial pins based on self.initial_pins. */
-       set_initial_pin_values(di);
-
        /* Set self.samplenum to 0. */
        PyObject_SetAttrString(di->py_inst, "samplenum", PyLong_FromLong(0));
 
@@ -752,6 +841,27 @@ static void update_old_pins_array(struct srd_decoder_inst *di,
        }
 }
 
+static void update_old_pins_array_initial_pins(struct srd_decoder_inst *di)
+{
+       uint8_t sample;
+       int i, byte_offset, bit_offset;
+       const uint8_t *sample_pos;
+
+       if (!di || !di->dec_channelmap)
+               return;
+
+       sample_pos = di->inbuf + ((di->abs_cur_samplenum - di->abs_start_samplenum) * di->data_unitsize);
+
+       for (i = 0; i < di->dec_num_channels; i++) {
+               if (di->old_pins_array->data[i] != SRD_INITIAL_PIN_SAME_AS_SAMPLE0)
+                       continue;
+               byte_offset = di->dec_channelmap[i] / 8;
+               bit_offset = di->dec_channelmap[i] % 8;
+               sample = *(sample_pos + byte_offset) & (1 << bit_offset) ? 1 : 0;
+               di->old_pins_array->data[i] = sample;
+       }
+}
+
 static gboolean term_matches(const struct srd_decoder_inst *di,
                struct srd_term *term, const uint8_t *sample_pos)
 {
@@ -836,6 +946,10 @@ static gboolean find_match(struct srd_decoder_inst *di)
        di->match_array = g_array_sized_new(FALSE, TRUE, sizeof(gboolean), num_conditions);
        g_array_set_size(di->match_array, num_conditions);
 
+       /* Sample 0: Set di->old_pins_array for SRD_INITIAL_PIN_SAME_AS_SAMPLE0 pins. */
+       if (di->abs_cur_samplenum == 0)
+               update_old_pins_array_initial_pins(di);
+
        for (i = 0, s = 0; i < num_samples_to_process; i++, s++, (di->abs_cur_samplenum)++) {
 
                sample_pos = di->inbuf + ((di->abs_cur_samplenum - di->abs_start_samplenum) * di->data_unitsize);
@@ -865,6 +979,8 @@ static gboolean find_match(struct srd_decoder_inst *di)
  *
  * This function returns if there is an error, or when a match is found, or
  * when all samples have been processed (whether a match was found or not).
+ * This function immediately terminates when the decoder's wait() method
+ * invocation shall get terminated.
  *
  * @param di The decoder instance to use. Must not be NULL.
  * @param found_match Will be set to TRUE if at least one condition matched,
@@ -880,6 +996,10 @@ SRD_PRIV int process_samples_until_condition_match(struct srd_decoder_inst *di,
        if (!di || !found_match)
                return SRD_ERR_ARG;
 
+       *found_match = FALSE;
+       if (di->want_wait_terminate)
+               return SRD_OK;
+
        /* Check if any of the current condition(s) match. */
        while (TRUE) {
                /* Feed the (next chunk of the) buffer to find_match(). */
@@ -916,20 +1036,74 @@ static gpointer di_thread(gpointer data)
 {
        PyObject *py_res;
        struct srd_decoder_inst *di;
+       int wanted_term;
 
        if (!data)
                return NULL;
 
        di = data;
 
-       /* Call self.decode(). Only returns if the PD throws an exception. */
+       srd_dbg("%s: Starting thread routine for decoder.", di->inst_id);
+
+       /*
+        * Call self.decode(). Only returns if the PD throws an exception.
+        * "Regular" termination of the decode() method is not expected.
+        */
        Py_IncRef(di->py_inst);
-       if (!(py_res = PyObject_CallMethod(di->py_inst, "decode", NULL))) {
+       srd_dbg("%s: Calling decode() method.", di->inst_id);
+       py_res = PyObject_CallMethod(di->py_inst, "decode", NULL);
+       srd_dbg("%s: decode() method terminated.", di->inst_id);
+
+       /*
+        * Make sure to unblock potentially pending srd_inst_decode()
+        * calls in application threads after the decode() method might
+        * have terminated, while it neither has processed sample data
+        * nor has terminated upon request. This happens e.g. when "need
+        * a samplerate to decode" exception is thrown.
+        */
+       g_mutex_lock(&di->data_mutex);
+       wanted_term = di->want_wait_terminate;
+       di->want_wait_terminate = TRUE;
+       di->handled_all_samples = TRUE;
+       g_cond_signal(&di->handled_all_samples_cond);
+       g_mutex_unlock(&di->data_mutex);
+
+       /*
+        * Check for the termination cause of the decode() method.
+        * Though this is mostly for information.
+        */
+       if (!py_res && wanted_term) {
+               /*
+                * Silently ignore errors upon return from decode() calls
+                * when termination was requested. Terminate the thread
+                * which executed this instance's decode() logic.
+                */
+               srd_dbg("%s: Thread done (!res, want_term).", di->inst_id);
+               PyErr_Clear();
+               return NULL;
+       }
+       if (!py_res) {
+               /*
+                * The decode() invocation terminated unexpectedly. Have
+                * the back trace printed, and terminate the thread which
+                * executed the decode() method.
+                */
+               srd_dbg("%s: decode() terminated unrequested.", di->inst_id);
                srd_exception_catch("Protocol decoder instance %s: ", di->inst_id);
-               exit(1); /* TODO: Proper shutdown. This is a hack. */
+               srd_dbg("%s: Thread done (!res, !want_term).", di->inst_id);
                return NULL;
        }
+
+       /*
+        * TODO: By design the decode() method is not supposed to terminate.
+        * Nevertheless we have the thread joined, and srd backend calls to
+        * decode() will re-start another thread transparently.
+        */
+       srd_dbg("%s: decode() terminated (req %d).", di->inst_id, wanted_term);
        Py_DecRef(py_res);
+       PyErr_Clear();
+
+       srd_dbg("%s: Thread done (with res).", di->inst_id);
 
        return NULL;
 }
@@ -1054,9 +1228,12 @@ SRD_PRIV int srd_inst_decode(struct srd_decoder_inst *di,
                Py_DecRef(py_res);
        } else {
                /* If this is the first call, start the worker thread. */
-               if (!di->thread_handle)
-                       di->thread_handle = g_thread_new("di_thread",
+               if (!di->thread_handle) {
+                       srd_dbg("No worker thread for this decoder stack "
+                               "exists yet, creating one: %s.", di->inst_id);
+                       di->thread_handle = g_thread_new(di->inst_id,
                                                         di_thread, di);
+               }
 
                /* Push the new sample chunk to the worker thread. */
                g_mutex_lock(&di->data_mutex);
@@ -1066,6 +1243,7 @@ SRD_PRIV int srd_inst_decode(struct srd_decoder_inst *di,
                di->inbuflen = inbuflen;
                di->got_new_samples = TRUE;
                di->handled_all_samples = FALSE;
+               di->want_wait_terminate = FALSE;
 
                /* Signal the thread that we have new data. */
                g_cond_signal(&di->got_new_samples_cond);
@@ -1073,7 +1251,7 @@ SRD_PRIV int srd_inst_decode(struct srd_decoder_inst *di,
 
                /* When all samples in this chunk were handled, return. */
                g_mutex_lock(&di->data_mutex);
-               while (!di->handled_all_samples)
+               while (!di->handled_all_samples && !di->want_wait_terminate)
                        g_cond_wait(&di->handled_all_samples_cond, &di->data_mutex);
                g_mutex_unlock(&di->data_mutex);
        }
@@ -1089,6 +1267,9 @@ SRD_PRIV void srd_inst_free(struct srd_decoder_inst *di)
 
        srd_dbg("Freeing instance %s", di->inst_id);
 
+       srd_inst_join_decode_thread(di);
+       srd_inst_reset_state(di);
+
        Py_DecRef(di->py_inst);
        g_free(di->inst_id);
        g_free(di->dec_channelmap);