* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+/**
+ * @file
+ * Software limits helper functions
+ */
+
#include <config.h>
#include <stdio.h>
#include <stdint.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
+#define LOG_PREFIX "sw_limits"
+
+/**
+ * Initialize a software limit instance
+ *
+ * Must be called before any other operations are performed on a struct
+ * sr_sw_limits and should typically be called after the data structure has been
+ * allocated.
+ *
+ * @param limits the software limit instance to initialize
+ */
SR_PRIV void sr_sw_limits_init(struct sr_sw_limits *limits)
{
- limits->limit_samples = 0;
- limits->limit_msec = 0;
+ memset(limits, 0, sizeof(*limits));
}
-SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
+/**
+ * Get software limit configuration
+ *
+ * Retrieve the currently configured software limit for the specified key.
+ * Should be called from the drivers config_get() callback.
+ *
+ * @param limits software limit instance
+ * @param key config item key
+ * @param data config item data
+ * @return SR_ERR_NA if @p key is not a supported limit, SR_OK otherwise
+ */
+SR_PRIV int sr_sw_limits_config_get(const struct sr_sw_limits *limits, uint32_t key,
GVariant **data)
{
switch (key) {
case SR_CONF_LIMIT_SAMPLES:
*data = g_variant_new_uint64(limits->limit_samples);
break;
+ case SR_CONF_LIMIT_FRAMES:
+ *data = g_variant_new_uint64(limits->limit_frames);
+ break;
case SR_CONF_LIMIT_MSEC:
*data = g_variant_new_uint64(limits->limit_msec / 1000);
break;
return SR_OK;
}
+/**
+ * Set software limit configuration
+ *
+ * Configure software limit for the specified key. Should be called from the
+ * drivers config_set() callback.
+ *
+ * @param limits software limit instance
+ * @param key config item key
+ * @param data config item data
+ * @return SR_ERR_NA if @p key is not a supported limit, SR_OK otherwise
+ */
SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
GVariant *data)
{
case SR_CONF_LIMIT_SAMPLES:
limits->limit_samples = g_variant_get_uint64(data);
break;
+ case SR_CONF_LIMIT_FRAMES:
+ limits->limit_frames = g_variant_get_uint64(data);
+ break;
case SR_CONF_LIMIT_MSEC:
limits->limit_msec = g_variant_get_uint64(data) * 1000;
break;
return SR_OK;
}
+/**
+ * Start a new data acquisition session
+ *
+ * Resets the internal accounting for all software limits. Usually should be
+ * called from the drivers acquisition_start() callback.
+ *
+ * @param limits software limits instance
+ */
SR_PRIV void sr_sw_limits_acquisition_start(struct sr_sw_limits *limits)
{
limits->samples_read = 0;
+ limits->frames_read = 0;
limits->start_time = g_get_monotonic_time();
}
+/**
+ * Check if any of the configured software limits has been reached
+ *
+ * Usually should be called at the end of the drivers work function after all
+ * processing has been done.
+ *
+ * @param limits software limits instance
+ * @returns TRUE if any of the software limits has been reached and the driver
+ * should stop data acquisition, otherwise FALSE.
+ */
SR_PRIV gboolean sr_sw_limits_check(struct sr_sw_limits *limits)
{
if (limits->limit_samples) {
- if (limits->samples_read >= limits->limit_samples)
+ if (limits->samples_read >= limits->limit_samples) {
+ sr_dbg("Requested number of samples (%" PRIu64
+ ") reached.", limits->limit_samples);
+ return TRUE;
+ }
+ }
+
+ if (limits->limit_frames) {
+ if (limits->frames_read >= limits->limit_frames) {
+ sr_dbg("Requested number of frames (%" PRIu64
+ ") reached.", limits->limit_frames);
return TRUE;
+ }
}
- if (limits->limit_msec) {
+ if (limits->limit_msec && limits->start_time) {
guint64 now;
now = g_get_monotonic_time();
if (now > limits->start_time &&
- now - limits->start_time > limits->limit_msec)
+ now - limits->start_time > limits->limit_msec) {
+ sr_dbg("Requested sampling time (%" PRIu64
+ "ms) reached.", limits->limit_msec / 1000);
return TRUE;
+ }
}
return FALSE;
}
+/**
+ * Get remaining counts until software limits are reached.
+ *
+ * This routine fills in those C language variables which callers
+ * requested, and provides the remaining value until a specified limit
+ * would be reached.
+ *
+ * The @ref sr_sw_limits_config_get() routine is suitable for rare
+ * configuration calls and interfaces nicely with Glib data types. The
+ * @ref sr_sw_limits_check() routine only provides a weak "exceeded"
+ * result. This @ref sr_sw_limits_get_remain() routine is suitable for
+ * additional checks and more eager limits enforcement in (potentially
+ * tight) acquisition code paths. Hardware compression may result in
+ * rather large "overshoots" when checks are done only late.
+ *
+ * @param[in] limits software limit instance
+ * @param[out] samples remaining samples count until the limit is reached
+ * @param[out] frames remaining frames count until the limit is reached
+ * @param[out] msecs remaining milliseconds until the limit is reached
+ *
+ * @return SR_ERR_* upon error, SR_OK otherwise
+ */
+SR_PRIV int sr_sw_limits_get_remain(const struct sr_sw_limits *limits,
+ uint64_t *samples, uint64_t *frames, uint64_t *msecs,
+ gboolean *exceeded)
+{
+
+ if (!limits)
+ return SR_ERR_ARG;
+
+ if (exceeded)
+ *exceeded = FALSE;
+
+ if (samples) do {
+ *samples = 0;
+ if (!limits->limit_samples)
+ break;
+ if (limits->samples_read >= limits->limit_samples) {
+ if (exceeded)
+ *exceeded = TRUE;
+ break;
+ }
+ *samples = limits->limit_samples - limits->samples_read;
+ } while (0);
+
+ if (frames) do {
+ *frames = 0;
+ if (!limits->limit_frames)
+ break;
+ if (limits->frames_read >= limits->limit_frames) {
+ if (exceeded)
+ *exceeded = TRUE;
+ break;
+ }
+ *frames = limits->limit_frames - limits->frames_read;
+ } while (0);
+
+ if (msecs) do {
+ guint64 now, elapsed, remain;
+
+ *msecs = 0;
+ if (!limits->limit_msec)
+ break;
+ if (!limits->start_time)
+ break;
+ now = g_get_monotonic_time();
+ if (now < limits->start_time)
+ break;
+ elapsed = now - limits->start_time;
+ if (elapsed >= limits->limit_msec) {
+ if (exceeded)
+ *exceeded = TRUE;
+ break;
+ }
+ remain = limits->limit_msec - elapsed;
+ *msecs = remain / 1000;
+ } while (0);
+
+ return SR_OK;
+}
+
+/**
+ * Update the amount of samples that have been read
+ *
+ * Update the amount of samples that have been read in the current data
+ * acquisition run. For each invocation @p samples_read will be accumulated and
+ * once the configured sample limit has been reached sr_sw_limits_check() will
+ * return TRUE.
+ *
+ * @param limits software limits instance
+ * @param samples_read the amount of samples that have been read
+ */
SR_PRIV void sr_sw_limits_update_samples_read(struct sr_sw_limits *limits,
uint64_t samples_read)
{
limits->samples_read += samples_read;
}
+
+/**
+ * Update the amount of frames that have been read
+ *
+ * Update the amount of frames that have been read in the current data
+ * acquisition run. For each invocation @p frames_read will be accumulated and
+ * once the configured frame limit has been reached sr_sw_limits_check() will
+ * return TRUE.
+ *
+ * @param limits software limits instance
+ * @param frames_read the amount of frames that have been read
+ */
+SR_PRIV void sr_sw_limits_update_frames_read(struct sr_sw_limits *limits,
+ uint64_t frames_read)
+{
+ limits->frames_read += frames_read;
+}
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