perf

Classes
class	zth::Load< T >
	Measure the load of some activity. More...
class	zth::EventRate< T, Bins, Count >
	Measure the rate of some event in Hz. More...

Functions
void	zth::perf_start (zth_perf_done_callback_t *f) noexcept
	Starts recording perf events.
void	zth::perf_stop () noexcept
	Stops recording perf events.
void	zth::perf_mark (char const *m, Timestamp const &t) noexcept
	Put a string marker into the perf output.
void	zth::perf_async_handle (zth_perf_async_handle_t *handle) noexcept
	Returns the handle of the current thread's perf buffer.
void	zth::perf_mark_async (char const *marker, zth_perf_async_handle_t *handle) noexcept
	Async-/thread-safe zth::perf_mark().
void	zth::perf_log (char const *fmt,...) noexcept
	Put a formatted log string into the perf output.
void	zth::perf_log (Timestamp const &t, char const *fmt,...) noexcept
	Put a formatted log string into the perf output.
void	zth::perf_logv (char const *fmt, va_list args, Timestamp const &t) noexcept
	Put a formatted log string into the perf output.
void	zth::perf_dump (zth_perf_dump_callback_t *f) noexcept
	Passes collected perf data to f.
void	zth::perf_run (zth_perf_dump_callback_t *f) noexcept
	Setup the system to automatically perform perf event recording, dumping, and resuming.
void	zth::perf_abort () noexcept
	Abort a zth::perf_run().
void	zth::perf_run_dump (char const *path) noexcept
	Like zth::perf_run(), but dump the contents to file immediately.

Detailed Description

This module allows generating a VCD file which tracks scheduling behavior of the application.

Function Documentation

perf_abort()

void zth::perf_abort ( )

noexcept

Abort a zth::perf_run().

Definition at line 700 of file perf.cpp.

perf_async_handle()

void zth::perf_async_handle ( zth_perf_async_handle_t *  handle )

noexcept

Returns the handle of the current thread's perf buffer.

See also

perf_mark_async()

Definition at line 408 of file perf.cpp.

perf_dump()

void zth::perf_dump ( zth_perf_dump_callback_t *  f )

noexcept

Passes collected perf data to f.

The data (pointer to a buffer and its length) passed to f can be converted to VCD later on. Write the data to file or stdout, for example, for later processing.

The internal buffer is erased afterwards.

Typical workflow:

• Call zth::perf_start() when event collection is required.
• Wait till the callback to zth::perf_start() is invoked.
• Call zth::perf_dump() to convert the buffer to be sent to the PC.
• On the PC (offline), process the buffer into VCD.

Definition at line 572 of file perf.cpp.

perf_log() [1/2]

void zth::perf_log ( char const *  fmt,   ...  )

noexcept

Put a formatted log string into the perf output.

Examples

5_perf.cpp.

Definition at line 443 of file perf.cpp.

perf_log() [2/2]

void zth::perf_log ( Timestamp const &  t, char const *  fmt,   ...  )

noexcept

Put a formatted log string into the perf output.

Definition at line 455 of file perf.cpp.

perf_logv()

void zth::perf_logv ( char const *  fmt, va_list  args, Timestamp const &  t = Timestamp()  )

noexcept

Put a formatted log string into the perf output.

Definition at line 467 of file perf.cpp.

perf_mark()

void zth::perf_mark ( char const *  marker, Timestamp const &  t = Timestamp()  )

noexcept

Put a string marker into the perf output.

Examples

5_perf.cpp.

Definition at line 394 of file perf.cpp.

perf_mark_async()

void zth::perf_mark_async ( char const *  marker, zth_perf_async_handle_t *  handle  )

noexcept

Async-/thread-safe zth::perf_mark().

This function performs zth::perf_mark() on another thread's perf event buffer, of which its handle is retrieved by the owner thread using zth::perf_async_handle().

Definition at line 424 of file perf.cpp.

perf_run()

void zth::perf_run ( zth_perf_dump_callback_t *  f )

noexcept

Setup the system to automatically perform perf event recording, dumping, and resuming.

Typical workflow:

• Make sure Config::DoPerfEvent is set (optionally via environment).
• Call perf_run().
• When the buffer is full, the callback function is called, as if zth::perf_dump() was invoked.
• The buffer is cleared and recording is resumed automatically.

This gives a continuous flow of zth::perf_dump() callbacks, with data later/offline to be converted to VCD.

Definition at line 685 of file perf.cpp.

perf_run_dump()

void zth::perf_run_dump ( char const *  path = nullptr )

noexcept

Like zth::perf_run(), but dump the contents to file immediately.

Definition at line 744 of file perf.cpp.

perf_start()

void zth::perf_start ( zth_perf_done_callback_t *  f )

noexcept

Starts recording perf events.

Recording can only be started when perf is enabled.

Definition at line 263 of file perf.cpp.

perf_stop()

void zth::perf_stop ( )

noexcept

Stops recording perf events.

Recording is automatically stopped when the buffer is full.

Definition at line 276 of file perf.cpp.