1/*
2 * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24#include "precompiled.hpp"
25#include "jvm.h"
26#include "logging/log.hpp"
27#include "logging/logFileStreamOutput.hpp"
28#include "logging/logOutput.hpp"
29#include "logging/logSelection.hpp"
30#include "logging/logTagSet.hpp"
31#include "memory/allocation.inline.hpp"
32#include "runtime/mutexLocker.hpp"
33#include "runtime/os.inline.hpp"
34
35LogOutput::~LogOutput() {
36 os::free(_config_string);
37}
38
39void LogOutput::describe(outputStream *out) {
40 out->print("%s ", name());
41 out->print_raw(config_string()); // raw printed because length might exceed O_BUFLEN
42
43 bool has_decorator = false;
44 char delimiter = ' ';
45 for (size_t d = 0; d < LogDecorators::Count; d++) {
46 LogDecorators::Decorator decorator = static_cast<LogDecorators::Decorator>(d);
47 if (decorators().is_decorator(decorator)) {
48 has_decorator = true;
49 out->print("%c%s", delimiter, LogDecorators::name(decorator));
50 delimiter = ',';
51 }
52 }
53 if (!has_decorator) {
54 out->print(" none");
55 }
56}
57
58void LogOutput::set_config_string(const char* string) {
59 os::free(_config_string);
60 _config_string = os::strdup(string, mtLogging);
61 _config_string_buffer_size = strlen(_config_string) + 1;
62}
63
64void LogOutput::add_to_config_string(const LogSelection& selection) {
65 if (_config_string_buffer_size < InitialConfigBufferSize) {
66 _config_string_buffer_size = InitialConfigBufferSize;
67 _config_string = REALLOC_C_HEAP_ARRAY(char, _config_string, _config_string_buffer_size, mtLogging);
68 }
69
70 size_t offset = strlen(_config_string);
71 if (offset > 0) {
72 // Add commas in-between tag and level combinations in the config string
73 _config_string[offset++] = ',';
74 }
75
76 for (;;) {
77 int ret = selection.describe(_config_string + offset,
78 _config_string_buffer_size - offset);
79 if (ret == -1) {
80 // Double the buffer size and retry
81 _config_string_buffer_size *= 2;
82 _config_string = REALLOC_C_HEAP_ARRAY(char, _config_string, _config_string_buffer_size, mtLogging);
83 continue;
84 }
85 break;
86 };
87}
88
89
90static int tag_cmp(const void *a, const void *b) {
91 return static_cast<const LogTagType*>(a) - static_cast<const LogTagType*>(b);
92}
93
94static void sort_tags(LogTagType tags[LogTag::MaxTags]) {
95 size_t ntags = 0;
96 while (tags[ntags] != LogTag::__NO_TAG) {
97 ntags++;
98 }
99 qsort(tags, ntags, sizeof(*tags), tag_cmp);
100}
101
102static const size_t MaxSubsets = 1 << LogTag::MaxTags;
103
104// Fill result with all possible subsets of the given tag set. Empty set not included.
105// For example, if tags is {gc, heap} then the result is {{gc}, {heap}, {gc, heap}}.
106// (Arguments with default values are intended exclusively for recursive calls.)
107static void generate_all_subsets_of(LogTagType result[MaxSubsets][LogTag::MaxTags],
108 size_t* result_size,
109 const LogTagType tags[LogTag::MaxTags],
110 LogTagType subset[LogTag::MaxTags] = NULL,
111 const size_t subset_size = 0,
112 const size_t depth = 0) {
113 assert(subset_size <= LogTag::MaxTags, "subset must never have more than MaxTags tags");
114 assert(depth <= LogTag::MaxTags, "recursion depth overflow");
115
116 if (subset == NULL) {
117 assert(*result_size == 0, "outer (non-recursive) call expects result_size to be 0");
118 // Make subset the first element in the result array initially
119 subset = result[0];
120 }
121 assert((void*) subset >= &result[0] && (void*) subset <= &result[MaxSubsets - 1],
122 "subset should always point to element in result");
123
124 if (depth == LogTag::MaxTags || tags[depth] == LogTag::__NO_TAG) {
125 if (subset_size == 0) {
126 // Ignore empty subset
127 return;
128 }
129 if (subset_size != LogTag::MaxTags) {
130 subset[subset_size] = LogTag::__NO_TAG;
131 }
132 assert(*result_size < MaxSubsets, "subsets overflow");
133 *result_size += 1;
134
135 // Bump subset and copy over current state
136 memcpy(result[*result_size], subset, sizeof(*subset) * LogTag::MaxTags);
137 subset = result[*result_size];
138 return;
139 }
140
141 // Recurse, excluding the tag of the current depth
142 generate_all_subsets_of(result, result_size, tags, subset, subset_size, depth + 1);
143 // ... and with it included
144 subset[subset_size] = tags[depth];
145 generate_all_subsets_of(result, result_size, tags, subset, subset_size + 1, depth + 1);
146}
147
148// Generate all possible selections (for the given level) based on the given tag set,
149// and add them to the selections array (growing it as necessary).
150static void add_selections(LogSelection** selections,
151 size_t* n_selections,
152 size_t* selections_cap,
153 const LogTagSet& tagset,
154 LogLevelType level) {
155 LogTagType tags[LogTag::MaxTags] = { LogTag::__NO_TAG };
156 for (size_t i = 0; i < tagset.ntags(); i++) {
157 tags[i] = tagset.tag(i);
158 }
159
160 size_t n_subsets = 0;
161 LogTagType subsets[MaxSubsets][LogTag::MaxTags];
162 generate_all_subsets_of(subsets, &n_subsets, tags);
163
164 for (size_t i = 0; i < n_subsets; i++) {
165 // Always keep tags sorted
166 sort_tags(subsets[i]);
167
168 // Ignore subsets already represented in selections
169 bool unique = true;
170 for (size_t sel = 0; sel < *n_selections; sel++) {
171 if (level == (*selections)[sel].level() && (*selections)[sel].consists_of(subsets[i])) {
172 unique = false;
173 break;
174 }
175 }
176 if (!unique) {
177 continue;
178 }
179
180 LogSelection exact_selection(subsets[i], false, level);
181 LogSelection wildcard_selection(subsets[i], true, level);
182
183 // Check if the two selections match any tag sets
184 bool wildcard_match = false;
185 bool exact_match = false;
186 for (LogTagSet* ts = LogTagSet::first(); ts != NULL; ts = ts->next()) {
187 if (!wildcard_selection.selects(*ts)) {
188 continue;
189 }
190
191 wildcard_match = true;
192 if (exact_selection.selects(*ts)) {
193 exact_match = true;
194 }
195 if (exact_match) {
196 break;
197 }
198 }
199
200 if (!wildcard_match && !exact_match) {
201 continue;
202 }
203
204 // Ensure there's enough room for both wildcard_match and exact_match
205 if (*n_selections + 2 > *selections_cap) {
206 *selections_cap *= 2;
207 *selections = REALLOC_C_HEAP_ARRAY(LogSelection, *selections, *selections_cap, mtLogging);
208 }
209
210 // Add found matching selections to the result array
211 if (exact_match) {
212 (*selections)[(*n_selections)++] = exact_selection;
213 }
214 if (wildcard_match) {
215 (*selections)[(*n_selections)++] = wildcard_selection;
216 }
217 }
218}
219
220void LogOutput::update_config_string(const size_t on_level[LogLevel::Count]) {
221 // Find the most common level (MCL)
222 LogLevelType mcl = LogLevel::Off;
223 size_t max = on_level[LogLevel::Off];
224 for (LogLevelType l = LogLevel::First; l <= LogLevel::Last; l = static_cast<LogLevelType>(l + 1)) {
225 if (on_level[l] > max) {
226 mcl = l;
227 max = on_level[l];
228 }
229 }
230
231 // Always let the first part of each output's config string be "all=<MCL>"
232 {
233 char buf[64];
234 jio_snprintf(buf, sizeof(buf), "all=%s", LogLevel::name(mcl));
235 set_config_string(buf);
236 }
237
238 // If there are no deviating tag sets, we're done
239 size_t deviating_tagsets = LogTagSet::ntagsets() - max;
240 if (deviating_tagsets == 0) {
241 return;
242 }
243
244 size_t n_selections = 0;
245 size_t selections_cap = 4 * MaxSubsets; // Start with some reasonably large initial capacity
246 LogSelection* selections = NEW_C_HEAP_ARRAY(LogSelection, selections_cap, mtLogging);
247
248 size_t n_deviates = 0;
249 const LogTagSet** deviates = NEW_C_HEAP_ARRAY(const LogTagSet*, deviating_tagsets, mtLogging);
250
251 // Generate all possible selections involving the deviating tag sets
252 for (LogTagSet* ts = LogTagSet::first(); ts != NULL; ts = ts->next()) {
253 LogLevelType level = ts->level_for(this);
254 if (level == mcl) {
255 continue;
256 }
257 deviates[n_deviates++] = ts;
258 add_selections(&selections, &n_selections, &selections_cap, *ts, level);
259 }
260
261 // Reduce deviates greedily, using the "best" selection at each step to reduce the number of deviating tag sets
262 while (n_deviates > 0) {
263 size_t prev_deviates = n_deviates;
264 int max_score = 0;
265
266 guarantee(n_selections > 0, "Cannot find maximal selection.");
267 const LogSelection* best_selection = &selections[0];
268 for (size_t i = 0; i < n_selections; i++) {
269
270 // Give the selection a score based on how many deviating tag sets it selects (with correct level)
271 int score = 0;
272 for (size_t d = 0; d < n_deviates; d++) {
273 if (selections[i].selects(*deviates[d]) && deviates[d]->level_for(this) == selections[i].level()) {
274 score++;
275 }
276 }
277
278 // Ignore selections with lower score than the current best even before subtracting mismatched selections
279 if (score < max_score) {
280 continue;
281 }
282
283 // Subtract from the score the number of tag sets it selects with an incorrect level
284 for (LogTagSet* ts = LogTagSet::first(); ts != NULL; ts = ts->next()) {
285 if (selections[i].selects(*ts) && ts->level_for(this) != selections[i].level()) {
286 score--;
287 }
288 }
289
290 // Pick the selection with the best score, or in the case of a tie, the one with fewest tags
291 if (score > max_score ||
292 (score == max_score && selections[i].ntags() < best_selection->ntags())) {
293 max_score = score;
294 best_selection = &selections[i];
295 }
296 }
297
298 add_to_config_string(*best_selection);
299
300 // Remove all deviates that this selection covered
301 for (size_t d = 0; d < n_deviates;) {
302 if (deviates[d]->level_for(this) == best_selection->level() && best_selection->selects(*deviates[d])) {
303 deviates[d] = deviates[--n_deviates];
304 continue;
305 }
306 d++;
307 }
308
309 // Add back any new deviates that this selection added (no array growth since removed > added)
310 for (LogTagSet* ts = LogTagSet::first(); ts != NULL; ts = ts->next()) {
311 if (ts->level_for(this) == best_selection->level() || !best_selection->selects(*ts)) {
312 continue;
313 }
314
315 bool already_added = false;
316 for (size_t dev = 0; dev < n_deviates; dev++) {
317 if (deviates[dev] == ts) {
318 already_added = true;
319 break;
320 }
321 }
322 if (already_added) {
323 continue;
324 }
325
326 deviates[n_deviates++] = ts;
327 }
328
329 // Reset the selections and generate a new ones based on the updated deviating tag sets
330 n_selections = 0;
331 for (size_t d = 0; d < n_deviates; d++) {
332 add_selections(&selections, &n_selections, &selections_cap, *deviates[d], deviates[d]->level_for(this));
333 }
334
335 assert(n_deviates < deviating_tagsets, "deviating tag set array overflow");
336 assert(prev_deviates > n_deviates, "number of deviating tag sets must never grow");
337 }
338 FREE_C_HEAP_ARRAY(LogTagSet*, deviates);
339 FREE_C_HEAP_ARRAY(Selection, selections);
340}
341
342