kernel/device_manager/id_generator.cpp

10 	whenever someone messes with the generator.
12 	Whenever a generator is searched for, generator_lock is held.
18 	sGeneratorLock instead of a generator specific lock during
70 static mutex sLock = MUTEX_INITIALIZER("id generator");
73 /*!	Create new generator.
81 	id_generator* generator = new(std::nothrow) id_generator(name);
82 	if (generator == NULL)
85 	if (generator->name == NULL) {
86 		delete generator;
90 	sGenerators.Add(generator);
91 	return generator;
97 create_id_internal(id_generator* generator)
101 	TRACE(("create_id_internal(name: %s)\n", generator->name));
108 		if ((generator->alloc_map[id / 8] & (1 << (id & 7))) == 0) {
111 			generator->alloc_map[id / 8] |= 1 << (id & 7);
112 			generator->num_ids++;
122 /*!	Gets a generator by name, and acquires a reference to it.
132 		id_generator* generator = iterator.Next();
134 		if (!strcmp(generator->name, name)) {
136 			generator->ref_count++;
137 			return generator;
145 /*! Decrease ref_count, deleting generator if not used anymore */
147 release_generator(id_generator *generator)
149 	TRACE(("release_generator(name: %s)\n", generator->name));
153 	if (--generator->ref_count == 0) {
154 		// no one messes with generator
155 		if (generator->num_ids == 0) {
156 			TRACE(("  Destroy %s\n", generator->name));
157 			// no IDs is allocated - destroy generator
158 			sGenerators.Remove(generator);
159 			delete generator;
183 	// find generator, create new if not there
186 	id_generator* generator = get_generator(name);
187 	if (generator == NULL)
188 		generator = create_generator(name);
192 	if (generator == NULL)
196 	int32 id = create_id_internal(generator);
198 	release_generator(generator);
211 	// find generator
214 	id_generator* generator = get_generator(name);
218 	if (generator == NULL) {
227 	if ((generator->alloc_map[id / 8] & (1 << (id & 7))) == 0) {
228 		dprintf("id %" B_PRIu32 " of generator %s wasn't allocated\n", id,
229 			generator->name);
231 		release_generator(generator);
235 	generator->alloc_map[id / 8] &= ~(1 << (id & 7));
236 	generator->num_ids--;
238 	release_generator(generator);