1 /*
2 * Copyright (C) 2016-2020 Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11
12
13 /* *************************************
14 * Includes
15 ***************************************/
16 #include <stdlib.h> /* malloc, free */
17 #include <string.h> /* memset */
18 #undef NDEBUG /* assert must not be disabled */
19 #include <assert.h> /* assert */
20
21 #include "timefn.h" /* UTIL_time_t, UTIL_getTime */
22 #include "benchfn.h"
23
24
25 /* *************************************
26 * Constants
27 ***************************************/
28 #define TIMELOOP_MICROSEC SEC_TO_MICRO /* 1 second */
29 #define TIMELOOP_NANOSEC (1*1000000000ULL) /* 1 second */
30
31 #define KB *(1 <<10)
32 #define MB *(1 <<20)
33 #define GB *(1U<<30)
34
35
36 /* *************************************
37 * Debug errors
38 ***************************************/
39 #if defined(DEBUG) && (DEBUG >= 1)
40 # include <stdio.h> /* fprintf */
41 # define DISPLAY(...) fprintf(stderr, __VA_ARGS__)
42 # define DEBUGOUTPUT(...) { if (DEBUG) DISPLAY(__VA_ARGS__); }
43 #else
44 # define DEBUGOUTPUT(...)
45 #endif
46
47
48 /* error without displaying */
49 #define RETURN_QUIET_ERROR(retValue, ...) { \
50 DEBUGOUTPUT("%s: %i: \n", __FILE__, __LINE__); \
51 DEBUGOUTPUT("Error : "); \
52 DEBUGOUTPUT(__VA_ARGS__); \
53 DEBUGOUTPUT(" \n"); \
54 return retValue; \
55 }
56
57
58 /* *************************************
59 * Benchmarking an arbitrary function
60 ***************************************/
61
BMK_isSuccessful_runOutcome(BMK_runOutcome_t outcome)62 int BMK_isSuccessful_runOutcome(BMK_runOutcome_t outcome)
63 {
64 return outcome.error_tag_never_ever_use_directly == 0;
65 }
66
67 /* warning : this function will stop program execution if outcome is invalid !
68 * check outcome validity first, using BMK_isValid_runResult() */
BMK_extract_runTime(BMK_runOutcome_t outcome)69 BMK_runTime_t BMK_extract_runTime(BMK_runOutcome_t outcome)
70 {
71 assert(outcome.error_tag_never_ever_use_directly == 0);
72 return outcome.internal_never_ever_use_directly;
73 }
74
BMK_extract_errorResult(BMK_runOutcome_t outcome)75 size_t BMK_extract_errorResult(BMK_runOutcome_t outcome)
76 {
77 assert(outcome.error_tag_never_ever_use_directly != 0);
78 return outcome.error_result_never_ever_use_directly;
79 }
80
BMK_runOutcome_error(size_t errorResult)81 static BMK_runOutcome_t BMK_runOutcome_error(size_t errorResult)
82 {
83 BMK_runOutcome_t b;
84 memset(&b, 0, sizeof(b));
85 b.error_tag_never_ever_use_directly = 1;
86 b.error_result_never_ever_use_directly = errorResult;
87 return b;
88 }
89
BMK_setValid_runTime(BMK_runTime_t runTime)90 static BMK_runOutcome_t BMK_setValid_runTime(BMK_runTime_t runTime)
91 {
92 BMK_runOutcome_t outcome;
93 outcome.error_tag_never_ever_use_directly = 0;
94 outcome.internal_never_ever_use_directly = runTime;
95 return outcome;
96 }
97
98
99 /* initFn will be measured once, benchFn will be measured `nbLoops` times */
100 /* initFn is optional, provide NULL if none */
101 /* benchFn must return a size_t value that errorFn can interpret */
102 /* takes # of blocks and list of size & stuff for each. */
103 /* can report result of benchFn for each block into blockResult. */
104 /* blockResult is optional, provide NULL if this information is not required */
105 /* note : time per loop can be reported as zero if run time < timer resolution */
BMK_benchFunction(BMK_benchParams_t p,unsigned nbLoops)106 BMK_runOutcome_t BMK_benchFunction(BMK_benchParams_t p,
107 unsigned nbLoops)
108 {
109 /* init */
110 { size_t i;
111 for (i = 0; i < p.blockCount; i++) {
112 memset(p.dstBuffers[i], 0xE5, p.dstCapacities[i]); /* warm up and erase result buffer */
113 } }
114
115 /* benchmark */
116 { UTIL_time_t const clockStart = UTIL_getTime();
117 size_t dstSize = 0;
118 unsigned loopNb, blockNb;
119 nbLoops += !nbLoops; /* minimum nbLoops is 1 */
120 if (p.initFn != NULL) p.initFn(p.initPayload);
121 for (loopNb = 0; loopNb < nbLoops; loopNb++) {
122 for (blockNb = 0; blockNb < p.blockCount; blockNb++) {
123 size_t const res = p.benchFn(p.srcBuffers[blockNb], p.srcSizes[blockNb],
124 p.dstBuffers[blockNb], p.dstCapacities[blockNb],
125 p.benchPayload);
126 if (loopNb == 0) {
127 if (p.blockResults != NULL) p.blockResults[blockNb] = res;
128 if ((p.errorFn != NULL) && (p.errorFn(res))) {
129 RETURN_QUIET_ERROR(BMK_runOutcome_error(res),
130 "Function benchmark failed on block %u (of size %u) with error %i",
131 blockNb, (unsigned)p.srcSizes[blockNb], (int)res);
132 }
133 dstSize += res;
134 } }
135 } /* for (loopNb = 0; loopNb < nbLoops; loopNb++) */
136
137 { PTime const totalTime = UTIL_clockSpanNano(clockStart);
138 BMK_runTime_t rt;
139 rt.nanoSecPerRun = (double)totalTime / nbLoops;
140 rt.sumOfReturn = dstSize;
141 return BMK_setValid_runTime(rt);
142 } }
143 }
144
145
146 /* ==== Benchmarking any function, providing intermediate results ==== */
147
148 struct BMK_timedFnState_s {
149 PTime timeSpent_ns;
150 PTime timeBudget_ns;
151 PTime runBudget_ns;
152 BMK_runTime_t fastestRun;
153 unsigned nbLoops;
154 UTIL_time_t coolTime;
155 }; /* typedef'd to BMK_timedFnState_t within bench.h */
156
BMK_createTimedFnState(unsigned total_ms,unsigned run_ms)157 BMK_timedFnState_t* BMK_createTimedFnState(unsigned total_ms, unsigned run_ms)
158 {
159 BMK_timedFnState_t* const r = (BMK_timedFnState_t*)malloc(sizeof(*r));
160 if (r == NULL) return NULL; /* malloc() error */
161 BMK_resetTimedFnState(r, total_ms, run_ms);
162 return r;
163 }
164
BMK_freeTimedFnState(BMK_timedFnState_t * state)165 void BMK_freeTimedFnState(BMK_timedFnState_t* state) { free(state); }
166
167 BMK_timedFnState_t*
BMK_initStatic_timedFnState(void * buffer,size_t size,unsigned total_ms,unsigned run_ms)168 BMK_initStatic_timedFnState(void* buffer, size_t size, unsigned total_ms, unsigned run_ms)
169 {
170 typedef char check_size[ 2 * (sizeof(BMK_timedFnState_shell) >= sizeof(struct BMK_timedFnState_s)) - 1]; /* static assert : a compilation failure indicates that BMK_timedFnState_shell is not large enough */
171 typedef struct { check_size c; BMK_timedFnState_t tfs; } tfs_align; /* force tfs to be aligned at its next best position */
172 size_t const tfs_alignment = offsetof(tfs_align, tfs); /* provides the minimal alignment restriction for BMK_timedFnState_t */
173 BMK_timedFnState_t* const r = (BMK_timedFnState_t*)buffer;
174 if (buffer == NULL) return NULL;
175 if (size < sizeof(struct BMK_timedFnState_s)) return NULL;
176 if ((size_t)buffer % tfs_alignment) return NULL; /* buffer must be properly aligned */
177 BMK_resetTimedFnState(r, total_ms, run_ms);
178 return r;
179 }
180
BMK_resetTimedFnState(BMK_timedFnState_t * timedFnState,unsigned total_ms,unsigned run_ms)181 void BMK_resetTimedFnState(BMK_timedFnState_t* timedFnState, unsigned total_ms, unsigned run_ms)
182 {
183 if (!total_ms) total_ms = 1 ;
184 if (!run_ms) run_ms = 1;
185 if (run_ms > total_ms) run_ms = total_ms;
186 timedFnState->timeSpent_ns = 0;
187 timedFnState->timeBudget_ns = (PTime)total_ms * TIMELOOP_NANOSEC / 1000;
188 timedFnState->runBudget_ns = (PTime)run_ms * TIMELOOP_NANOSEC / 1000;
189 timedFnState->fastestRun.nanoSecPerRun = (double)TIMELOOP_NANOSEC * 2000000000; /* hopefully large enough : must be larger than any potential measurement */
190 timedFnState->fastestRun.sumOfReturn = (size_t)(-1LL);
191 timedFnState->nbLoops = 1;
192 timedFnState->coolTime = UTIL_getTime();
193 }
194
195 /* Tells if nb of seconds set in timedFnState for all runs is spent.
196 * note : this function will return 1 if BMK_benchFunctionTimed() has actually errored. */
BMK_isCompleted_TimedFn(const BMK_timedFnState_t * timedFnState)197 int BMK_isCompleted_TimedFn(const BMK_timedFnState_t* timedFnState)
198 {
199 return (timedFnState->timeSpent_ns >= timedFnState->timeBudget_ns);
200 }
201
202
203 #undef MIN
204 #define MIN(a,b) ( (a) < (b) ? (a) : (b) )
205
206 #define MINUSABLETIME (TIMELOOP_NANOSEC / 2) /* 0.5 seconds */
207
BMK_benchTimedFn(BMK_timedFnState_t * cont,BMK_benchParams_t p)208 BMK_runOutcome_t BMK_benchTimedFn(BMK_timedFnState_t* cont,
209 BMK_benchParams_t p)
210 {
211 PTime const runBudget_ns = cont->runBudget_ns;
212 PTime const runTimeMin_ns = runBudget_ns / 2;
213 BMK_runTime_t bestRunTime = cont->fastestRun;
214
215 for (;;) {
216 BMK_runOutcome_t const runResult = BMK_benchFunction(p, cont->nbLoops);
217
218 if (!BMK_isSuccessful_runOutcome(runResult)) { /* error : move out */
219 return runResult;
220 }
221
222 { BMK_runTime_t const newRunTime = BMK_extract_runTime(runResult);
223 double const loopDuration_ns = newRunTime.nanoSecPerRun * cont->nbLoops;
224
225 cont->timeSpent_ns += (unsigned long long)loopDuration_ns;
226
227 /* estimate nbLoops for next run to last approximately 1 second */
228 if (loopDuration_ns > (runBudget_ns / 50)) {
229 double const fastestRun_ns = MIN(bestRunTime.nanoSecPerRun, newRunTime.nanoSecPerRun);
230 cont->nbLoops = (unsigned)(runBudget_ns / fastestRun_ns) + 1;
231 } else {
232 /* previous run was too short : blindly increase workload by x multiplier */
233 const unsigned multiplier = 10;
234 assert(cont->nbLoops < ((unsigned)-1) / multiplier); /* avoid overflow */
235 cont->nbLoops *= multiplier;
236 }
237
238 if (loopDuration_ns < runTimeMin_ns) {
239 /* When benchmark run time is too small : don't report results.
240 * increased risks of rounding errors */
241 continue;
242 }
243
244 if (newRunTime.nanoSecPerRun < bestRunTime.nanoSecPerRun) {
245 bestRunTime = newRunTime;
246 }
247 }
248 break;
249 } /* while (!completed) */
250
251 return BMK_setValid_runTime(bestRunTime);
252 }
253