From b8ffb574ca3d2a3bc9b85144bdaa778a47fea809 Mon Sep 17 00:00:00 2001 From: Andrew Tridgell Date: Mon, 9 Sep 2013 16:36:22 +1000 Subject: mb12xx: convert to using RingBuffer class --- src/drivers/mb12xx/mb12xx.cpp | 102 ++++++++++++++++-------------------------- 1 file changed, 39 insertions(+), 63 deletions(-) diff --git a/src/drivers/mb12xx/mb12xx.cpp b/src/drivers/mb12xx/mb12xx.cpp index f83416993..fabe10b87 100644 --- a/src/drivers/mb12xx/mb12xx.cpp +++ b/src/drivers/mb12xx/mb12xx.cpp @@ -64,6 +64,7 @@ #include #include +#include #include #include @@ -119,10 +120,7 @@ private: float _min_distance; float _max_distance; work_s _work; - unsigned _num_reports; - volatile unsigned _next_report; - volatile unsigned _oldest_report; - range_finder_report *_reports; + RingBuffer *_reports; bool _sensor_ok; int _measure_ticks; bool _collect_phase; @@ -183,9 +181,6 @@ private: }; -/* helper macro for handling report buffer indices */ -#define INCREMENT(_x, _lim) do { __typeof__(_x) _tmp = _x+1; if (_tmp >= _lim) _tmp = 0; _x = _tmp; } while(0) - /* * Driver 'main' command. */ @@ -195,9 +190,6 @@ MB12XX::MB12XX(int bus, int address) : I2C("MB12xx", RANGE_FINDER_DEVICE_PATH, bus, address, 100000), _min_distance(MB12XX_MIN_DISTANCE), _max_distance(MB12XX_MAX_DISTANCE), - _num_reports(0), - _next_report(0), - _oldest_report(0), _reports(nullptr), _sensor_ok(false), _measure_ticks(0), @@ -221,7 +213,7 @@ MB12XX::~MB12XX() /* free any existing reports */ if (_reports != nullptr) - delete[] _reports; + delete _reports; } int @@ -234,17 +226,15 @@ MB12XX::init() goto out; /* allocate basic report buffers */ - _num_reports = 2; - _reports = new struct range_finder_report[_num_reports]; + _reports = new RingBuffer(2); if (_reports == nullptr) goto out; - _oldest_report = _next_report = 0; - /* get a publish handle on the range finder topic */ - memset(&_reports[0], 0, sizeof(_reports[0])); - _range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &_reports[0]); + struct range_finder_report zero_report; + memset(&zero_report, 0, sizeof(zero_report)); + _range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &zero_report); if (_range_finder_topic < 0) debug("failed to create sensor_range_finder object. Did you start uOrb?"); @@ -354,31 +344,22 @@ MB12XX::ioctl(struct file *filp, int cmd, unsigned long arg) return (1000 / _measure_ticks); case SENSORIOCSQUEUEDEPTH: { - /* add one to account for the sentinel in the ring */ - arg++; - - /* lower bound is mandatory, upper bound is a sanity check */ - if ((arg < 2) || (arg > 100)) - return -EINVAL; - - /* allocate new buffer */ - struct range_finder_report *buf = new struct range_finder_report[arg]; - - if (nullptr == buf) - return -ENOMEM; - - /* reset the measurement state machine with the new buffer, free the old */ - stop(); - delete[] _reports; - _num_reports = arg; - _reports = buf; - start(); - - return OK; + /* lower bound is mandatory, upper bound is a sanity check */ + if ((arg < 1) || (arg > 100)) + return -EINVAL; + + irqstate_t flags = irqsave(); + if (!_reports->resize(arg)) { + irqrestore(flags); + return -ENOMEM; } + irqrestore(flags); + + return OK; + } case SENSORIOCGQUEUEDEPTH: - return _num_reports - 1; + return _reports->size(); case SENSORIOCRESET: /* XXX implement this */ @@ -406,6 +387,7 @@ ssize_t MB12XX::read(struct file *filp, char *buffer, size_t buflen) { unsigned count = buflen / sizeof(struct range_finder_report); + struct range_finder_report *rbuf = reinterpret_cast(buffer); int ret = 0; /* buffer must be large enough */ @@ -421,10 +403,9 @@ MB12XX::read(struct file *filp, char *buffer, size_t buflen) * we are careful to avoid racing with them. */ while (count--) { - if (_oldest_report != _next_report) { - memcpy(buffer, _reports + _oldest_report, sizeof(*_reports)); - ret += sizeof(_reports[0]); - INCREMENT(_oldest_report, _num_reports); + if (_reports->get(*rbuf)) { + ret += sizeof(*rbuf); + rbuf++; } } @@ -433,9 +414,8 @@ MB12XX::read(struct file *filp, char *buffer, size_t buflen) } /* manual measurement - run one conversion */ - /* XXX really it'd be nice to lock against other readers here */ do { - _oldest_report = _next_report = 0; + _reports->flush(); /* trigger a measurement */ if (OK != measure()) { @@ -453,8 +433,9 @@ MB12XX::read(struct file *filp, char *buffer, size_t buflen) } /* state machine will have generated a report, copy it out */ - memcpy(buffer, _reports, sizeof(*_reports)); - ret = sizeof(*_reports); + if (_reports->get(*rbuf)) { + ret = sizeof(*rbuf); + } } while (0); @@ -498,26 +479,25 @@ MB12XX::collect() if (ret < 0) { log("error reading from sensor: %d", ret); + perf_count(_comms_errors); + perf_end(_sample_perf); return ret; } uint16_t distance = val[0] << 8 | val[1]; float si_units = (distance * 1.0f)/ 100.0f; /* cm to m */ + struct range_finder_report report; + /* this should be fairly close to the end of the measurement, so the best approximation of the time */ - _reports[_next_report].timestamp = hrt_absolute_time(); - _reports[_next_report].distance = si_units; - _reports[_next_report].valid = si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0; + report.timestamp = hrt_absolute_time(); + report.distance = si_units; + report.valid = si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0; /* publish it */ - orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &_reports[_next_report]); - - /* post a report to the ring - note, not locked */ - INCREMENT(_next_report, _num_reports); + orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &report); - /* if we are running up against the oldest report, toss it */ - if (_next_report == _oldest_report) { + if (_reports->force(report)) { perf_count(_buffer_overflows); - INCREMENT(_oldest_report, _num_reports); } /* notify anyone waiting for data */ @@ -525,11 +505,8 @@ MB12XX::collect() ret = OK; -out: perf_end(_sample_perf); return ret; - - return ret; } void @@ -537,7 +514,7 @@ MB12XX::start() { /* reset the report ring and state machine */ _collect_phase = false; - _oldest_report = _next_report = 0; + _reports->flush(); /* schedule a cycle to start things */ work_queue(HPWORK, &_work, (worker_t)&MB12XX::cycle_trampoline, this, 1); @@ -626,8 +603,7 @@ MB12XX::print_info() perf_print_counter(_comms_errors); perf_print_counter(_buffer_overflows); printf("poll interval: %u ticks\n", _measure_ticks); - printf("report queue: %u (%u/%u @ %p)\n", - _num_reports, _oldest_report, _next_report, _reports); + _reports->print_info("report queue"); } /** -- cgit v1.2.3