VkCalibratedTimestampInfoKHR - Structure specifying the input parameters of a calibrated timestamp query

Valid Usage (Implicit)

See Also

VK_EXT_calibrated_timestamps, VK_KHR_calibrated_timestamps, StructureType, TimeDomainKHR, getCalibratedTimestampsEXT, getCalibratedTimestampsKHR

vkGetPhysicalDeviceCalibrateableTimeDomainsKHR - Query calibrateable time domains

Description

If pTimeDomains is NULL, then the number of calibrateable time domains supported for the given physicalDevice is returned in pTimeDomainCount. Otherwise, pTimeDomainCount must point to a variable set by the user to the number of elements in the pTimeDomains array, and on return the variable is overwritten with the number of values actually written to pTimeDomains. If the value of pTimeDomainCount is less than the number of calibrateable time domains supported, at most pTimeDomainCount values will be written to pTimeDomains, and INCOMPLETE will be returned instead of SUCCESS, to indicate that not all the available time domains were returned.

Valid Usage (Implicit)

• physicalDevice must be a valid PhysicalDevice handle

• pTimeDomainCount must be a valid pointer to a uint32_t value
• If the value referenced by pTimeDomainCount is not 0, and pTimeDomains is not NULL, pTimeDomains must be a valid pointer to an array of pTimeDomainCount TimeDomainKHR values

Return Codes

Success

• SUCCESS
• INCOMPLETE

Failure

• ERROR_OUT_OF_HOST_MEMORY
• ERROR_OUT_OF_DEVICE_MEMORY

See Also

VK_EXT_calibrated_timestamps, VK_KHR_calibrated_timestamps, PhysicalDevice, TimeDomainKHR

vkGetCalibratedTimestampsKHR - Query calibrated timestamps

Description

Note

The maximum deviation may vary between calls to getCalibratedTimestampsKHR even for the same set of time domains due to implementation and platform specific reasons. It is the application’s responsibility to assess whether the returned maximum deviation makes the timestamp values suitable for any particular purpose and can choose to re-issue the timestamp calibration call pursuing a lower deviation value.

Calibrated timestamp values can be extrapolated to estimate future coinciding timestamp values, however, depending on the nature of the time domains and other properties of the platform extrapolating values over a sufficiently long period of time may no longer be accurate enough to fit any particular purpose, so applications are expected to re-calibrate the timestamps on a regular basis.

Valid Usage

• The timeDomain value of each CalibratedTimestampInfoEXT in pTimestampInfos must be unique

Valid Usage (Implicit)

• device must be a valid Device handle

• pTimestampInfos must be a valid pointer to an array of timestampCount valid CalibratedTimestampInfoKHR structures
• pTimestamps must be a valid pointer to an array of timestampCount uint64_t values
• pMaxDeviation must be a valid pointer to a uint64_t value
• timestampCount must be greater than 0

Return Codes

Success

• SUCCESS

Failure

• ERROR_OUT_OF_HOST_MEMORY
• ERROR_OUT_OF_DEVICE_MEMORY

See Also

VK_EXT_calibrated_timestamps, VK_KHR_calibrated_timestamps, CalibratedTimestampInfoKHR, Device

VkTimeDomainKHR - Supported time domains

Description

Note

An implementation supporting VK_KHR_calibrated_timestamps or VK_EXT_calibrated_timestamps will use the same time domain for all its Queue so that timestamp values reported for TIME_DOMAIN_DEVICE_KHR can be matched to any timestamp captured through cmdWriteTimestamp or cmdWriteTimestamp2 .

struct timespec tv;
clock_gettime(CLOCK_MONOTONIC, &tv);
return tv.tv_nsec + tv.tv_sec*1000000000ull;

struct timespec tv;
clock_gettime(CLOCK_MONOTONIC_RAW, &tv);
return tv.tv_nsec + tv.tv_sec*1000000000ull;

LARGE_INTEGER counter;
QueryPerformanceCounter(&counter);
return counter.QuadPart;

See Also

VK_EXT_calibrated_timestamps, VK_KHR_calibrated_timestamps, CalibratedTimestampInfoKHR, getPhysicalDeviceCalibrateableTimeDomainsEXT, getPhysicalDeviceCalibrateableTimeDomainsKHR