src/lib/graph/query-executor.c

   1 /*
   2  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #define BT_LOG_TAG "LIB/QUERY-EXECUTOR"
  24 #include "lib/logging.h"
  25
  26 #include "common/assert.h"
  27 #include "common/common.h"
  28 #include "lib/assert-pre.h"
  29 #include "lib/assert-post.h"
  30 #include <babeltrace2/graph/query-executor-const.h>
  31 #include <babeltrace2/graph/query-executor.h>
  32 #include <babeltrace2/graph/component-class.h>
  33 #include <babeltrace2/value.h>
  34 #include <babeltrace2/value-const.h>
  35 #include "lib/object.h"
  36 #include "compat/compiler.h"
  37
  38 #include "component-class.h"
  39 #include "query-executor.h"
  40 #include "interrupter.h"
  41 #include "lib/func-status.h"
  42
  43 static
  44 void bt_query_executor_destroy(struct bt_object *obj)
  45 {
  46         struct bt_query_executor *query_exec =
  47                 container_of(obj, struct bt_query_executor, base);
  48
  49         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  50
  51         if (query_exec->interrupters) {
  52                 BT_LOGD_STR("Putting interrupters.");
  53                 g_ptr_array_free(query_exec->interrupters, TRUE);
  54                 query_exec->interrupters = NULL;
  55         }
  56
  57         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  58
  59         g_free(query_exec);
  60 }
  61
  62 struct bt_query_executor *bt_query_executor_create(void)
  63 {
  64         struct bt_query_executor *query_exec;
  65
  66         BT_LOGD_STR("Creating query executor.");
  67         query_exec = g_new0(struct bt_query_executor, 1);
  68         if (!query_exec) {
  69                 BT_LIB_LOGE_APPEND_CAUSE(
  70                         "Failed to allocate one query executor.");
  71                 goto end;
  72         }
  73
  74         query_exec->interrupters = g_ptr_array_new_with_free_func(
  75                 (GDestroyNotify) bt_object_put_no_null_check);
  76         if (!query_exec->interrupters) {
  77                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  78                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  79                 goto end;
  80         }
  81
  82         query_exec->default_interrupter = bt_interrupter_create();
  83         if (!query_exec->default_interrupter) {
  84                 BT_LIB_LOGE_APPEND_CAUSE(
  85                         "Failed to create one interrupter object.");
  86                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  87                 goto end;
  88         }
  89
  90         bt_query_executor_add_interrupter(query_exec,
  91                 query_exec->default_interrupter);
  92         bt_object_init_shared(&query_exec->base,
  93                 bt_query_executor_destroy);
  94         BT_LOGD("Created query executor: addr=%p", query_exec);
  95
  96 end:
  97         return (void *) query_exec;
  98 }
  99
 100 enum bt_query_executor_query_status bt_query_executor_query(
 101                 struct bt_query_executor *query_exec,
 102                 const struct bt_component_class *comp_cls,
 103                 const char *object, const struct bt_value *params,
 104                 enum bt_logging_level log_level,
 105                 const struct bt_value **user_result)
 106 {
 107         typedef enum bt_component_class_query_method_status (*method_t)(void *,
 108                 const void *, const void *, const void *, enum bt_logging_level,
 109                 const void *);
 110
 111         enum bt_query_executor_query_status status;
 112         enum bt_component_class_query_method_status query_status;
 113         method_t method = NULL;
 114
 115         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 116         BT_ASSERT_PRE_NON_NULL(comp_cls, "Component class");
 117         BT_ASSERT_PRE_NON_NULL(object, "Object");
 118         BT_ASSERT_PRE_NON_NULL(user_result, "Result (output)");
 119
 120         /*
 121          * Initial check: is the query executor already interrupted? If
 122          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 123          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 124          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 125          * legitimate error). Since any query operation could return
 126          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 127          * blocking, the caller is responsible for checking the
 128          * interruption state of the query executor when getting this
 129          * status.
 130          */
 131         if (bt_query_executor_is_interrupted(query_exec)) {
 132                 BT_LIB_LOGD("Query executor is interrupted: "
 133                         "not performing the query operation: "
 134                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 135                         "%![params-]+v, log-level=%s",
 136                         query_exec, comp_cls, object, params,
 137                         bt_common_logging_level_string(log_level));
 138                 status = BT_FUNC_STATUS_AGAIN;
 139                 goto end;
 140         }
 141
 142         if (!params) {
 143                 params = bt_value_null;
 144         }
 145
 146         switch (comp_cls->type) {
 147         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 148         {
 149                 struct bt_component_class_source *src_cc = (void *) comp_cls;
 150
 151                 method = (method_t) src_cc->methods.query;
 152                 break;
 153         }
 154         case BT_COMPONENT_CLASS_TYPE_FILTER:
 155         {
 156                 struct bt_component_class_filter *flt_cc = (void *) comp_cls;
 157
 158                 method = (method_t) flt_cc->methods.query;
 159                 break;
 160         }
 161         case BT_COMPONENT_CLASS_TYPE_SINK:
 162         {
 163                 struct bt_component_class_sink *sink_cc = (void *) comp_cls;
 164
 165                 method = (method_t) sink_cc->methods.query;
 166                 break;
 167         }
 168         default:
 169                 abort();
 170         }
 171
 172         if (!method) {
 173                 /* Not an error: nothing to query */
 174                 BT_LIB_LOGD("Component class has no registered query method: "
 175                         "%!+C", comp_cls);
 176                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 177                 goto end;
 178         }
 179
 180         BT_LIB_LOGD("Calling user's query method: "
 181                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 182                 "log-level=%s",
 183                 query_exec, comp_cls, object, params,
 184                 bt_common_logging_level_string(log_level));
 185         *user_result = NULL;
 186         query_status = method((void *) comp_cls, query_exec, object, params,
 187                 log_level, user_result);
 188         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 189                 bt_common_func_status_string(query_status), *user_result);
 190         BT_ASSERT_POST(query_status != BT_FUNC_STATUS_OK || *user_result,
 191                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 192         status = (int) query_status;
 193
 194         if (status < 0) {
 195                 BT_LIB_LOGW_APPEND_CAUSE(
 196                         "Component class's \"query\" method failed: "
 197                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 198                         "%![params-]+v, log-level=%s", query_exec, comp_cls,
 199                         object, params, bt_common_logging_level_string(log_level));
 200                 goto end;
 201         }
 202
 203 end:
 204         return status;
 205 }
 206
 207 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 208                 struct bt_query_executor *query_exec,
 209                 const struct bt_interrupter *intr)
 210 {
 211         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 212         BT_ASSERT_PRE_NON_NULL(intr, "Interrupter");
 213         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 214         bt_object_get_no_null_check(intr);
 215         BT_LIB_LOGD("Added interrupter to query executor: "
 216                 "query-exec-addr=%p, %![intr-]+z",
 217                 query_exec, intr);
 218         return BT_FUNC_STATUS_OK;
 219 }
 220
 221 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 222 {
 223         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 224         return (bt_bool) bt_interrupter_array_any_is_set(
 225                 query_exec->interrupters);
 226 }
 227
 228 void bt_query_executor_interrupt(struct bt_query_executor *query_exec)
 229 {
 230         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 231         bt_interrupter_set(query_exec->default_interrupter);
 232         BT_LIB_LOGI("Interrupted query executor: query-exec-addr=%p",
 233                 query_exec);
 234 }
 235
 236 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 237 {
 238         bt_object_get_ref(query_executor);
 239 }
 240
 241 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 242 {
 243         bt_object_put_ref(query_executor);
 244 }