blob: e555bbe6ae32337d0b8def43238bb947531fa6dd [file] [log] [blame]
* Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
* All rights reserved.
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
/* benchfn :
* benchmark any function on a set of input
* providing result in nanoSecPerRun
* or detecting and returning an error
#if defined (__cplusplus)
extern "C" {
#ifndef BENCH_FN_H_23876
#define BENCH_FN_H_23876
/* === Dependencies === */
#include <stddef.h> /* size_t */
/* ==== Benchmark any function, iterated on a set of blocks ==== */
/* BMK_runTime_t: valid result return type */
typedef struct {
double nanoSecPerRun; /* time per iteration (over all blocks) */
size_t sumOfReturn; /* sum of return values */
} BMK_runTime_t;
/* BMK_runOutcome_t:
* type expressing the outcome of a benchmark run by BMK_benchFunction(),
* which can be either valid or invalid.
* benchmark outcome can be invalid if errorFn is provided.
* BMK_runOutcome_t must be considered "opaque" : never access its members directly.
* Instead, use its assigned methods :
* BMK_isSuccessful_runOutcome, BMK_extract_runTime, BMK_extract_errorResult.
* The structure is only described here to allow its allocation on stack. */
typedef struct {
BMK_runTime_t internal_never_ever_use_directly;
size_t error_result_never_ever_use_directly;
int error_tag_never_ever_use_directly;
} BMK_runOutcome_t;
/* prototypes for benchmarked functions */
typedef size_t (*BMK_benchFn_t)(const void* src, size_t srcSize, void* dst, size_t dstCapacity, void* customPayload);
typedef size_t (*BMK_initFn_t)(void* initPayload);
typedef unsigned (*BMK_errorFn_t)(size_t);
/* BMK_benchFunction() parameters are provided via the following structure.
* A structure is preferable for readability,
* as the number of parameters required is fairly large.
* No initializer is provided, because it doesn't make sense to provide some "default" :
* all parameters must be specified by the caller.
* optional parameters are labelled explicitly, and accept value NULL when not used */
typedef struct {
BMK_benchFn_t benchFn; /* the function to benchmark, over the set of blocks */
void* benchPayload; /* pass custom parameters to benchFn :
* (*benchFn)(srcBuffers[i], srcSizes[i], dstBuffers[i], dstCapacities[i], benchPayload) */
BMK_initFn_t initFn; /* (*initFn)(initPayload) is run once per run, at the beginning. */
void* initPayload; /* Both arguments can be NULL, in which case nothing is run. */
BMK_errorFn_t errorFn; /* errorFn will check each return value of benchFn over each block, to determine if it failed or not.
* errorFn can be NULL, in which case no check is performed.
* errorFn must return 0 when benchFn was successful, and >= 1 if it detects an error.
* Execution is stopped as soon as an error is detected.
* the triggering return value can be retrieved using BMK_extract_errorResult(). */
size_t blockCount; /* number of blocks to operate benchFn on.
* It's also the size of all array parameters :
* srcBuffers, srcSizes, dstBuffers, dstCapacities, blockResults */
const void *const * srcBuffers; /* read-only array of buffers to be operated on by benchFn */
const size_t* srcSizes; /* read-only array containing sizes of srcBuffers */
void *const * dstBuffers; /* array of buffers to be written into by benchFn. This array is not optional, it must be provided even if unused by benchfn. */
const size_t* dstCapacities; /* read-only array containing capacities of dstBuffers. This array must be present. */
size_t* blockResults; /* Optional: store the return value of benchFn for each block. Use NULL if this result is not requested. */
} BMK_benchParams_t;
/* BMK_benchFunction() :
* This function benchmarks benchFn and initFn, providing a result.
* params : see description of BMK_benchParams_t above.
* nbLoops: defines number of times benchFn is run over the full set of blocks.
* Minimum value is 1. A 0 is interpreted as a 1.
* @return: can express either an error or a successful result.
* Use BMK_isSuccessful_runOutcome() to check if benchmark was successful.
* If yes, extract the result with BMK_extract_runTime(),
* it will contain :
* .sumOfReturn : the sum of all return values of benchFn through all of blocks
* .nanoSecPerRun : time per run of benchFn + (time for initFn / nbLoops)
* .sumOfReturn is generally intended for functions which return a # of bytes written into dstBuffer,
* in which case, this value will be the total amount of bytes written into dstBuffer.
* blockResults : when provided (!= NULL), and when benchmark is successful,
* params.blockResults contains all return values of `benchFn` over all blocks.
* when provided (!= NULL), and when benchmark failed,
* params.blockResults contains return values of `benchFn` over all blocks preceding and including the failed block.
BMK_runOutcome_t BMK_benchFunction(BMK_benchParams_t params, unsigned nbLoops);
/* check first if the benchmark was successful or not */
int BMK_isSuccessful_runOutcome(BMK_runOutcome_t outcome);
/* If the benchmark was successful, extract the result.
* note : this function will abort() program execution if benchmark failed !
* always check if benchmark was successful first !
BMK_runTime_t BMK_extract_runTime(BMK_runOutcome_t outcome);
/* when benchmark failed, it means one invocation of `benchFn` failed.
* The failure was detected by `errorFn`, operating on return values of `benchFn`.
* Returns the faulty return value.
* note : this function will abort() program execution if benchmark did not failed.
* always check if benchmark failed first !
size_t BMK_extract_errorResult(BMK_runOutcome_t outcome);
/* ==== Benchmark any function, returning intermediate results ==== */
/* state information tracking benchmark session */
typedef struct BMK_timedFnState_s BMK_timedFnState_t;
/* BMK_benchTimedFn() :
* Similar to BMK_benchFunction(), most arguments being identical.
* Automatically determines `nbLoops` so that each result is regularly produced at interval of about run_ms.
* Note : minimum `nbLoops` is 1, therefore a run may last more than run_ms, and possibly even more than total_ms.
* Usage - initialize timedFnState, select benchmark duration (total_ms) and each measurement duration (run_ms)
* call BMK_benchTimedFn() repetitively, each measurement is supposed to last about run_ms
* Check if total time budget is spent or exceeded, using BMK_isCompleted_TimedFn()
BMK_runOutcome_t BMK_benchTimedFn(BMK_timedFnState_t* timedFnState,
BMK_benchParams_t params);
/* Tells if duration of all benchmark runs has exceeded total_ms
int BMK_isCompleted_TimedFn(const BMK_timedFnState_t* timedFnState);
/* BMK_createTimedFnState() and BMK_resetTimedFnState() :
* Create/Set BMK_timedFnState_t for next benchmark session,
* which shall last a minimum of total_ms milliseconds,
* producing intermediate results, paced at interval of (approximately) run_ms.
BMK_timedFnState_t* BMK_createTimedFnState(unsigned total_ms, unsigned run_ms);
void BMK_resetTimedFnState(BMK_timedFnState_t* timedFnState, unsigned total_ms, unsigned run_ms);
void BMK_freeTimedFnState(BMK_timedFnState_t* state);
/* BMK_timedFnState_shell and BMK_initStatic_timedFnState() :
* Makes it possible to statically allocate a BMK_timedFnState_t on stack.
* BMK_timedFnState_shell is only there to allocate space,
* never ever access its members.
* BMK_timedFnState_t() actually accepts any buffer.
* It will check if provided buffer is large enough and is correctly aligned,
* and will return NULL if conditions are not respected.
typedef union {
char never_access_space[BMK_TIMEDFNSTATE_SIZE];
long long alignment_enforcer; /* must be aligned on 8-bytes boundaries */
} BMK_timedFnState_shell;
BMK_timedFnState_t* BMK_initStatic_timedFnState(void* buffer, size_t size, unsigned total_ms, unsigned run_ms);
#endif /* BENCH_FN_H_23876 */
#if defined (__cplusplus)