pandad: refactor to consolidate threads, keep only one can_send thread (

commaai#32680)

* single thread

improve comment

* Keep can_send() running in a separate thread

* send send_peripheral_state in pandad_run

* new PandaSafety class
old-commit-hash: a4de873

selfdrive/pandad/SConscript

@@ -3,7 +3,7 @@ Import('env', 'envCython', 'common', 'messaging')
 libs = ['usb-1.0', common, messaging, 'pthread']
 panda = env.Library('panda', ['panda.cc', 'panda_comms.cc', 'spi.cc'])
 
-env.Program('pandad', ['main.cc', 'pandad.cc'], LIBS=[panda] + libs)
+env.Program('pandad', ['main.cc', 'pandad.cc', 'panda_safety.cc'], LIBS=[panda] + libs)
 env.Library('libcan_list_to_can_capnp', ['can_list_to_can_capnp.cc'])
 
 pandad_python = envCython.Program('pandad_api_impl.so', 'pandad_api_impl.pyx', LIBS=["can_list_to_can_capnp", 'capnp', 'kj'] + envCython["LIBS"])

selfdrive/pandad/panda_safety.cc

@@ -0,0 +1,79 @@
+#include "selfdrive/pandad/pandad.h"
+#include "cereal/messaging/messaging.h"
+#include "common/swaglog.h"
+
+void PandaSafety::configureSafetyMode() {
+  bool is_onroad = params_.getBool("IsOnroad");
+
+  if (is_onroad && !safety_configured_) {
+    updateMultiplexingMode();
+
+    auto car_params = fetchCarParams();
+    if (!car_params.empty()) {
+      LOGW("got %lu bytes CarParams", car_params.size());
+      setSafetyMode(car_params);
+      safety_configured_ = true;
+    }
+  } else if (!is_onroad) {
+    initialized_ = false;
+    safety_configured_ = false;
+  }
+}
+
+void PandaSafety::updateMultiplexingMode() {
+  // Initialize to ELM327 without OBD multiplexing for initial fingerprinting
+  if (!initialized_) {
+    prev_obd_multiplexing_ = false;
+    for (int i = 0; i < pandas_.size(); ++i) {
+      pandas_[i]->set_safety_model(cereal::CarParams::SafetyModel::ELM327, 1U);
+    }
+    initialized_ = true;
+  }
+
+  // Switch between multiplexing modes based on the OBD multiplexing request
+  bool obd_multiplexing_requested = params_.getBool("ObdMultiplexingEnabled");
+  if (obd_multiplexing_requested != prev_obd_multiplexing_) {
+    for (int i = 0; i < pandas_.size(); ++i) {
+      const uint16_t safety_param = (i > 0 || !obd_multiplexing_requested) ? 1U : 0U;
+      pandas_[i]->set_safety_model(cereal::CarParams::SafetyModel::ELM327, safety_param);
+    }
+    prev_obd_multiplexing_ = obd_multiplexing_requested;
+    params_.putBool("ObdMultiplexingChanged", true);
+  }
+}
+
+std::string PandaSafety::fetchCarParams() {
+  if (!params_.getBool("FirmwareQueryDone")) {
+    return {};
+  }
+  LOGW("Finished FW query");
+
+  LOGW("Waiting for params to set safety model");
+  if (!params_.getBool("ControlsReady")) {
+    return {};
+  }
+  return params_.get("CarParams");
+}
+
+void PandaSafety::setSafetyMode(const std::string &params_string) {
+  AlignedBuffer aligned_buf;
+  capnp::FlatArrayMessageReader cmsg(aligned_buf.align(params_string.data(), params_string.size()));
+  cereal::CarParams::Reader car_params = cmsg.getRoot<cereal::CarParams>();
+
+  auto safety_configs = car_params.getSafetyConfigs();
+  uint16_t alternative_experience = car_params.getAlternativeExperience();
+
+  for (int i = 0; i < pandas_.size(); ++i) {
+    // Default to SILENT safety model if not specified
+    cereal::CarParams::SafetyModel safety_model = cereal::CarParams::SafetyModel::SILENT;
+    uint16_t safety_param = 0U;
+    if (i < safety_configs.size()) {
+      safety_model = safety_configs[i].getSafetyModel();
+      safety_param = safety_configs[i].getSafetyParam();
+    }
+
+    LOGW("Panda %d: setting safety model: %d, param: %d, alternative experience: %d", i, (int)safety_model, safety_param, alternative_experience);
+    pandas_[i]->set_alternative_experience(alternative_experience);
+    pandas_[i]->set_safety_model(safety_model, safety_param);
+  }
+}