connect/src/main/java/org/apache/felix/connect/felix/framework/ServiceRegistry.java [627:773]: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - UsageCount obtainUsageCount(Bundle bundle, ServiceReference ref, Object svcObj, Boolean isPrototype) { UsageCount usage = null; // This method uses an optimistic concurrency mechanism with a conditional put/replace // on the m_inUseMap. If this fails (because another thread made changes) this thread // retries the operation. This is the purpose of the while loop. boolean success = false; while (!success) { UsageCount[] usages = m_inUseMap.get(bundle); // If we know it's a prototype, then we always need to create a new usage count if (!Boolean.TRUE.equals(isPrototype)) { for (int i = 0; (usages != null) && (i < usages.length); i++) { if (usages[i].m_ref.equals(ref) && ((svcObj == null && !usages[i].m_prototype) || usages[i].getService() == svcObj)) { return usages[i]; } } } // We haven't found an existing usage count object so we need to create on. For this we need to // know whether this is a prototype or not. if (isPrototype == null) { // If this parameter isn't passed in we can't create a usage count. return null; } // Add a new Usage Count. usage = new UsageCount(ref, isPrototype); if (usages == null) { UsageCount[] newUsages = new UsageCount[] { usage }; success = m_inUseMap.putIfAbsent(bundle, newUsages) == null; } else { UsageCount[] newUsages = new UsageCount[usages.length + 1]; System.arraycopy(usages, 0, newUsages, 0, usages.length); newUsages[usages.length] = usage; success = m_inUseMap.replace(bundle, usages, newUsages); } } return usage; } /** * Utility method to flush the specified bundle's usage count for the * specified service reference. This should be called to completely * remove the associated usage count object for the specified service * reference. If the goal is to simply decrement the usage, then get * the usage count and decrement its counter. This method will also * remove the specified bundle from the "in use" map if it has no more * usage counts after removing the usage count for the specified service * reference. * @param bundle The bundle whose usage count should be removed. * @param ref The service reference whose usage count should be removed. **/ void flushUsageCount(Bundle bundle, ServiceReference ref, UsageCount uc) { // This method uses an optimistic concurrency mechanism with conditional modifications // on the m_inUseMap. If this fails (because another thread made changes) this thread // retries the operation. This is the purpose of the while loop. boolean success = false; while (!success) { UsageCount[] usages = m_inUseMap.get(bundle); final UsageCount[] orgUsages = usages; for (int i = 0; (usages != null) && (i < usages.length); i++) { if ((uc == null && usages[i].m_ref.equals(ref)) || (uc == usages[i])) { // If this is the only usage, then point to empty list. if ((usages.length - 1) == 0) { usages = null; } // Otherwise, we need to do some array copying. else { UsageCount[] newUsages = new UsageCount[usages.length - 1]; System.arraycopy(usages, 0, newUsages, 0, i); if (i < newUsages.length) { System.arraycopy( usages, i + 1, newUsages, i, newUsages.length - i); } usages = newUsages; i--; } } } if (usages == orgUsages) return; // no change in map if (orgUsages != null) { if (usages != null) success = m_inUseMap.replace(bundle, orgUsages, usages); else success = m_inUseMap.remove(bundle, orgUsages); } } } public HookRegistry getHookRegistry() { return this.hookRegistry; } static class UsageCount { final ServiceReference m_ref; final boolean m_prototype; final AtomicLong m_count = new AtomicLong(); final AtomicLong m_serviceObjectsCount = new AtomicLong(); final AtomicReference m_svcHolderRef = new AtomicReference(); UsageCount(final ServiceReference ref, final boolean isPrototype) { m_ref = ref; m_prototype = isPrototype; } Object getService() { ServiceHolder sh = m_svcHolderRef.get(); return sh == null ? null : sh.m_service; } } static class ServiceHolder { final CountDownLatch m_latch = new CountDownLatch(1); volatile Object m_service; } public interface ServiceRegistryCallbacks { void serviceChanged(ServiceEvent event, Dictionary oldProps); - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - framework/src/main/java/org/apache/felix/framework/ServiceRegistry.java [646:792]: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - UsageCount obtainUsageCount(Bundle bundle, ServiceReference ref, Object svcObj, Boolean isPrototype) { UsageCount usage = null; // This method uses an optimistic concurrency mechanism with a conditional put/replace // on the m_inUseMap. If this fails (because another thread made changes) this thread // retries the operation. This is the purpose of the while loop. boolean success = false; while (!success) { UsageCount[] usages = m_inUseMap.get(bundle); // If we know it's a prototype, then we always need to create a new usage count if (!Boolean.TRUE.equals(isPrototype)) { for (int i = 0; (usages != null) && (i < usages.length); i++) { if (usages[i].m_ref.equals(ref) && ((svcObj == null && !usages[i].m_prototype) || usages[i].getService() == svcObj)) { return usages[i]; } } } // We haven't found an existing usage count object so we need to create on. For this we need to // know whether this is a prototype or not. if (isPrototype == null) { // If this parameter isn't passed in we can't create a usage count. return null; } // Add a new Usage Count. usage = new UsageCount(ref, isPrototype); if (usages == null) { UsageCount[] newUsages = new UsageCount[] { usage }; success = m_inUseMap.putIfAbsent(bundle, newUsages) == null; } else { UsageCount[] newUsages = new UsageCount[usages.length + 1]; System.arraycopy(usages, 0, newUsages, 0, usages.length); newUsages[usages.length] = usage; success = m_inUseMap.replace(bundle, usages, newUsages); } } return usage; } /** * Utility method to flush the specified bundle's usage count for the * specified service reference. This should be called to completely * remove the associated usage count object for the specified service * reference. If the goal is to simply decrement the usage, then get * the usage count and decrement its counter. This method will also * remove the specified bundle from the "in use" map if it has no more * usage counts after removing the usage count for the specified service * reference. * @param bundle The bundle whose usage count should be removed. * @param ref The service reference whose usage count should be removed. **/ void flushUsageCount(Bundle bundle, ServiceReference ref, UsageCount uc) { // This method uses an optimistic concurrency mechanism with conditional modifications // on the m_inUseMap. If this fails (because another thread made changes) this thread // retries the operation. This is the purpose of the while loop. boolean success = false; while (!success) { UsageCount[] usages = m_inUseMap.get(bundle); final UsageCount[] orgUsages = usages; for (int i = 0; (usages != null) && (i < usages.length); i++) { if ((uc == null && usages[i].m_ref.equals(ref)) || (uc == usages[i])) { // If this is the only usage, then point to empty list. if ((usages.length - 1) == 0) { usages = null; } // Otherwise, we need to do some array copying. else { UsageCount[] newUsages = new UsageCount[usages.length - 1]; System.arraycopy(usages, 0, newUsages, 0, i); if (i < newUsages.length) { System.arraycopy( usages, i + 1, newUsages, i, newUsages.length - i); } usages = newUsages; i--; } } } if (usages == orgUsages) return; // no change in map if (orgUsages != null) { if (usages != null) success = m_inUseMap.replace(bundle, orgUsages, usages); else success = m_inUseMap.remove(bundle, orgUsages); } } } public HookRegistry getHookRegistry() { return this.hookRegistry; } static class UsageCount { final ServiceReference m_ref; final boolean m_prototype; final AtomicLong m_count = new AtomicLong(); final AtomicLong m_serviceObjectsCount = new AtomicLong(); final AtomicReference m_svcHolderRef = new AtomicReference(); UsageCount(final ServiceReference ref, final boolean isPrototype) { m_ref = ref; m_prototype = isPrototype; } Object getService() { ServiceHolder sh = m_svcHolderRef.get(); return sh == null ? null : sh.m_service; } } static class ServiceHolder { final CountDownLatch m_latch = new CountDownLatch(1); volatile Object m_service; } public interface ServiceRegistryCallbacks { void serviceChanged(ServiceEvent event, Dictionary oldProps); - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -