2 * Copyright (c) 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 /* This file implements a simple form of coverage instrumentation. Points in
21 * source code that are of interest must be explicitly annotated with
22 * COVERAGE_INC. The coverage counters may be logged at any time with
25 * This form of coverage instrumentation is intended to be so lightweight that
26 * it can be enabled in production builds. It is obviously not a substitute
27 * for traditional coverage instrumentation with e.g. "gcov", but it is still
28 * a useful debugging tool. */
30 #include "ovs-thread.h"
33 /* Makes coverage_run run every 5000 ms (5 seconds).
34 * If this value is redefined, the new value must
35 * divide 60000 (1 minute). */
36 #define COVERAGE_RUN_INTERVAL 5000
37 BUILD_ASSERT_DECL(60000 % COVERAGE_RUN_INTERVAL == 0);
39 #define COVERAGE_CLEAR_INTERVAL 1000
40 BUILD_ASSERT_DECL(COVERAGE_RUN_INTERVAL % COVERAGE_CLEAR_INTERVAL == 0);
42 /* Defines the moving average array length. */
43 #define MIN_AVG_LEN (60000/COVERAGE_RUN_INTERVAL)
46 /* A coverage counter. */
47 struct coverage_counter {
48 const char *const name; /* Textual name. */
49 unsigned int (*const count)(void); /* Gets, zeros this thread's count. */
50 unsigned long long int total; /* Total count. */
51 unsigned long long int last_total;
52 /* The moving average arrays. */
53 unsigned int min[MIN_AVG_LEN];
54 unsigned int hr[HR_AVG_LEN];
57 /* Defines COUNTER. There must be exactly one such definition at file scope
58 * within a program. */
59 #if USE_LINKER_SECTIONS
60 #define COVERAGE_DEFINE(COUNTER) \
61 DEFINE_STATIC_PER_THREAD_DATA(unsigned int, \
62 counter_##COUNTER, 0); \
63 static unsigned int COUNTER##_count(void) \
65 unsigned int *countp = counter_##COUNTER##_get(); \
66 unsigned int count = *countp; \
70 static inline void COUNTER##_add(unsigned int n) \
72 *counter_##COUNTER##_get() += n; \
74 extern struct coverage_counter counter_##COUNTER; \
75 struct coverage_counter counter_##COUNTER \
76 = { #COUNTER, COUNTER##_count, 0, 0, {0}, {0} }; \
77 extern struct coverage_counter *counter_ptr_##COUNTER; \
78 struct coverage_counter *counter_ptr_##COUNTER \
79 __attribute__((section("coverage"))) = &counter_##COUNTER
81 #define COVERAGE_DEFINE(COUNTER) \
82 DECLARE_EXTERN_PER_THREAD_DATA(unsigned int, \
84 static inline void COUNTER##_add(unsigned int n) \
86 *counter_##COUNTER##_get() += n; \
88 extern struct coverage_counter counter_##COUNTER
91 /* Adds 1 to COUNTER. */
92 #define COVERAGE_INC(COUNTER) COVERAGE_ADD(COUNTER, 1)
94 /* Adds AMOUNT to COUNTER. */
95 #define COVERAGE_ADD(COUNTER, AMOUNT) COUNTER##_add(AMOUNT)
97 void coverage_init(void);
98 void coverage_log(void);
99 void coverage_clear(void);
100 void coverage_run(void);
102 /* Implementation detail. */
103 #define COVERAGE_DEFINE__(COUNTER) \
105 #endif /* coverage.h */