libretro.api.perf¶

Performance counter and SIMD feature detection types.

Corresponds to retro_perf_callback, retro_perf_counter, and the RETRO_SIMD_* constants in libretro.h.

See also

PerfDriver: The Protocol that uses these types to expose performance counting functionality to the Core.
libretro.drivers.perf: libretro.py’s included PerfDriver implementations.

Module Attributes

`retro_perf_tick_t`	A performance counter tick value.
`retro_time_t`	A timestamp in microseconds.
`retro_perf_get_time_usec_t`	Return the current system time in microseconds.
`retro_perf_get_counter_t`	Return the number of ticks elapsed since some unspecified epoch.
`retro_get_cpu_features_t`	Return a bitmask of detected CPU features.
`retro_perf_log_t`	Log or display the state of every registered performance counter.
`retro_perf_register_t`	Register a performance counter with the frontend.
`retro_perf_start_t`	Start timing a registered performance counter.
`retro_perf_stop_t`	Stop timing a registered performance counter.

Classes

`CpuFeatures`	SIMD instruction set flags reported by the host CPU.
`retro_perf_callback`	Provides functions for performance profiling and CPU feature detection.
`retro_perf_counter`	A named performance counter for profiling hot code paths within a `Core`.

class CpuFeatures[source]¶

Bases: IntFlag

SIMD instruction set flags reported by the host CPU.

Corresponds to the RETRO_SIMD_* constants in libretro.h.

>>> from libretro.api import CpuFeatures
>>> CpuFeatures.SSE
<CpuFeatures.SSE: 1>

SSE = 1¶

SSE2 = 2¶

VMX = 4¶

VMX128 = 8¶

AVX = 16¶

NEON = 32¶

SSE3 = 64¶

SSSE3 = 128¶

MMX = 256¶

MMXEXT = 512¶

SSE4 = 1024¶

SSE42 = 2048¶

AVX2 = 4096¶

VFPU = 8192¶

PS = 16384¶

AES = 32768¶

VFPV3 = 65536¶

VFPV4 = 131072¶

POPCNT = 262144¶

MOVBE = 524288¶

CMOV = 1048576¶

ASIMD = 2097152¶

__new__(value)¶

other in self¶: Returns True if self has at least the same flags set as other.

iter(self)¶: Returns flags in definition order.

len(self)¶: Return the number of members (no aliases)

classmethod self[name]¶: Return the member matching name.

__init__()¶

class retro_perf_counter[source]¶

Bases: Structure

A named performance counter for profiling hot code paths within a Core.

Corresponds to retro_perf_counter in libretro.h.

>>> from libretro.api import retro_perf_counter
>>> c = retro_perf_counter()
>>> c.registered
False

ident¶: Human-readable identifier for this counter.

start¶: Tick value at the most recent start of measurement.

total¶: Total accumulated ticks for this counter.

call_cnt¶: Number of times this counter has been started.

registered¶: Whether this counter has been registered with the frontend.

__deepcopy__(_)[source]¶: Return a deep copy of this object, including all strings. Intended for use with copy.deepcopy().

__init__(*args, **kwargs)¶

classmethod __new__(*args, **kwargs)¶

retro_perf_get_time_usec_t¶

Return the current system time in microseconds.

Registered by the frontend and called by the core. The frontend should use the most accurate timer available on the platform.

Returns:: The current time, in microseconds.

Corresponds to retro_perf_get_time_usec_t in libretro.h.

retro_perf_get_counter_t¶

Return the number of ticks elapsed since some unspecified epoch.

Registered by the frontend and called by the core. The exact meaning of a tick depends on the platform (typically nanoseconds or CPU cycles).

Returns:: The current tick count.

Corresponds to retro_perf_get_counter_t in libretro.h.

retro_get_cpu_features_t¶

Return a bitmask of detected CPU features.

Registered by the frontend and called by the core to dispatch CPU-specific code paths at runtime.

Returns:: A bitmask of CpuFeatures flags.

Corresponds to retro_get_cpu_features_t in libretro.h.

retro_perf_log_t¶

Log or display the state of every registered performance counter.

Registered by the frontend and called by the core. The exact presentation is up to the frontend.

Corresponds to retro_perf_log_t in libretro.h.

retro_perf_register_t¶

Registered by the frontend and called by the core once per counter, before the counter is started or stopped.

Parameters:: counter – Pointer to a retro_perf_counter to register. Its ident field must be set; all other fields must be zero or False.

Corresponds to retro_perf_register_t in libretro.h.

retro_perf_start_t¶

Start timing a registered performance counter.

Registered by the frontend and called by the core right before the code being measured.

Parameters:: counter – Pointer to a retro_perf_counter that has been registered with retro_perf_register_t.

Corresponds to retro_perf_start_t in libretro.h.

retro_perf_stop_t¶

Stop timing a registered performance counter.

Registered by the frontend and called by the core right after the code being measured; the elapsed time is added to the counter’s total.

Parameters:: counter – Pointer to the same retro_perf_counter that was previously passed to retro_perf_start_t.

Corresponds to retro_perf_stop_t in libretro.h.

class retro_perf_callback[source]¶

Bases: Structure

Provides functions for performance profiling and CPU feature detection.

Corresponds to retro_perf_callback in libretro.h.

__init__(*args, **kwargs)¶

classmethod __new__(*args, **kwargs)¶

get_time_usec¶: Returns the current time in microseconds.

get_cpu_features¶: Returns a bitmask of CpuFeatures.

get_perf_counter¶: Returns the current performance counter tick value.

perf_register¶: Registers a performance counter.

perf_start¶: Starts a performance counter.

perf_stop¶: Stops a performance counter.

perf_log¶: Logs all registered performance counters.

__deepcopy__(_)[source]¶

Return a deep copy of this object. Intended for use with copy.deepcopy().

>>> import copy
>>> from libretro.api import retro_perf_callback
>>> copy.deepcopy(retro_perf_callback()).get_time_usec is None
True

retro_time_t¶: A timestamp in microseconds.

retro_perf_tick_t¶: A performance counter tick value.