int rb_read_from_buffer(ring_buffer *buffer, char *dest, int len) {
if (len == 0) return 0;
if (!buffer || len < 0 || len > rb_available_to_read(buffer)) return -1;
// Note that rb_available_to_read also serves as a memory barrier, and so any
// writes to buffer->buf_ptr that precede the update of buffer->write_idx are
// visible to us now.
int read_idx = buffer->read_idx; // No need for sync in reader thread.
if (read_idx + len <= buffer->size) {
memcpy(dest, buffer->buf_ptr + read_idx, len);
} else {
int d = buffer->size - read_idx;
memcpy(dest, buffer->buf_ptr + read_idx, d);
memcpy(dest + d, buffer->buf_ptr, len - d);
}
SYNC_COMPARE_AND_SWAP(&(buffer->read_idx), buffer->read_idx,
(read_idx + len) % buffer->size); // Includes memory barrier.
return 0;
}
void libpd_queued_receive_midi_messages() {
size_t available = rb_available_to_read(midi_receive_buffer);
if (!available) return;
static char temp_buffer[BUFFER_SIZE];
rb_read_from_buffer(midi_receive_buffer, temp_buffer, available);
char *end = temp_buffer + available;
char *buffer = temp_buffer;
while (buffer < end) {
midi_params *p = (midi_params *)buffer;
buffer += S_MIDI_PARAMS;
switch (p->type) {
case LIBPD_NOTEON: {
receive_noteon(p, &buffer);
break;
}
case LIBPD_CONTROLCHANGE: {
receive_controlchange(p, &buffer);
break;
}
case LIBPD_PROGRAMCHANGE: {
receive_programchange(p, &buffer);
break;
}
case LIBPD_PITCHBEND: {
receive_pitchbend(p, &buffer);
break;
}
case LIBPD_AFTERTOUCH: {
receive_aftertouch(p, &buffer);
break;
}
case LIBPD_POLYAFTERTOUCH: {
receive_polyaftertouch(p, &buffer);
break;
}
case LIBPD_MIDIBYTE: {
receive_midibyte(p, &buffer);
break;
}
default:
break;
}
}
}
void libpd_queued_receive_pd_messages() {
size_t available = rb_available_to_read(pd_receive_buffer);
if (!available) return;
static char temp_buffer[BUFFER_SIZE];
rb_read_from_buffer(pd_receive_buffer, temp_buffer, available);
char *end = temp_buffer + available;
char *buffer = temp_buffer;
while (buffer < end) {
pd_params *p = (pd_params *)buffer;
buffer += S_PD_PARAMS;
switch (p->type) {
case LIBPD_PRINT: {
receive_print(p, &buffer);
break;
}
case LIBPD_BANG: {
receive_bang(p, &buffer);
break;
}
case LIBPD_FLOAT: {
receive_float(p, &buffer);
break;
}
case LIBPD_SYMBOL: {
receive_symbol(p, &buffer);
break;
}
case LIBPD_LIST: {
receive_list(p, &buffer);
break;
}
case LIBPD_MESSAGE: {
receive_message(p, &buffer);
break;
}
default:
break;
}
}
}