connect/src/main/java/org/apache/felix/connect/felix/framework/ServiceRegistry.java [286:488]: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - return null; } @SuppressWarnings("unchecked") public S getService(final Bundle bundle, final ServiceReference ref, final boolean isServiceObjects) { // prototype scope is only possible if called from ServiceObjects final boolean isPrototype = isServiceObjects && ref.getProperty(Constants.SERVICE_SCOPE) == Constants.SCOPE_PROTOTYPE; UsageCount usage = null; Object svcObj = null; // Get the service registration. final ServiceRegistrationImpl reg = ((ServiceRegistrationImpl.ServiceReferenceImpl) ref).getRegistration(); // We don't allow cycles when we call out to the service factory. if ( reg.currentThreadMarked() ) { throw new ServiceException( "ServiceFactory.getService() resulted in a cycle.", ServiceException.FACTORY_ERROR, null); } try { reg.markCurrentThread(); // Make sure the service registration is still valid. if (reg.isValid()) { // Get the usage count, or create a new one. If this is a // prototype, the we'll alway create a new one. usage = obtainUsageCount(bundle, ref, null, isPrototype); // Increment the usage count and grab the already retrieved // service object, if one exists. incrementToPositiveValue(usage.m_count); svcObj = usage.getService(); if ( isServiceObjects ) { incrementToPositiveValue(usage.m_serviceObjectsCount); } // If we have a usage count, but no service object, then we haven't // cached the service object yet, so we need to create one. if (usage != null) { ServiceHolder holder = null; // There is a possibility that the holder is unset between the compareAndSet() and the get() // below. If that happens get() returns null and we may have to set a new holder. This is // why the below section is in a loop. while (holder == null) { ServiceHolder h = new ServiceHolder(); if (usage.m_svcHolderRef.compareAndSet(null, h)) { holder = h; try { svcObj = reg.getService(bundle); holder.m_service = svcObj; } finally { holder.m_latch.countDown(); } } else { holder = usage.m_svcHolderRef.get(); if (holder != null) { boolean interrupted = false; do { try { // Need to ensure that the other thread has obtained // the service. holder.m_latch.await(); if (interrupted) { Thread.currentThread().interrupt(); } interrupted = false; } catch (InterruptedException e) { interrupted = true; Thread.interrupted(); } } while (interrupted); svcObj = holder.m_service; } } // if someone concurrently changed the holder, loop again if (holder != usage.m_svcHolderRef.get()) holder = null; } if (svcObj != null && isPrototype) { UsageCount existingUsage = obtainUsageCount(bundle, ref, svcObj, null); if (existingUsage != null && existingUsage != usage) { flushUsageCount(bundle, ref, usage); usage = existingUsage; incrementToPositiveValue(usage.m_count); if ( isServiceObjects ) { incrementToPositiveValue(usage.m_serviceObjectsCount); } } } } } } finally { reg.unmarkCurrentThread(); if (!reg.isValid() || (svcObj == null)) { flushUsageCount(bundle, ref, usage); } } return (S) svcObj; } // Increment the Atomic Long by 1, and ensure the result is at least 1. // This method uses a loop, optimistic algorithm to do this in a threadsafe // way without locks. private void incrementToPositiveValue(AtomicLong al) { boolean success = false; while (!success) { long oldVal = al.get(); long newVal = Math.max(oldVal + 1L, 1L); checkCountOverflow(newVal); success = al.compareAndSet(oldVal, newVal); } } private void checkCountOverflow(long c) { if (c == Long.MAX_VALUE) { throw new ServiceException( "The use count for the service overflowed.", ServiceException.UNSPECIFIED, null); } } public boolean ungetService(final Bundle bundle, final ServiceReference ref, final Object svcObj) { final ServiceRegistrationImpl reg = ((ServiceRegistrationImpl.ServiceReferenceImpl) ref).getRegistration(); if ( reg.currentThreadMarked() ) { throw new IllegalStateException( "ServiceFactory.ungetService() resulted in a cycle."); } try { // Mark the current thread to avoid cycles reg.markCurrentThread(); // Get the usage count. UsageCount usage = obtainUsageCount(bundle, ref, svcObj, null); // If there are no cached services, then just return immediately. if (usage == null) { return false; } // if this is a call from service objects and the service was not fetched from // there, return false if ( svcObj != null ) { if (usage.m_serviceObjectsCount.decrementAndGet() < 0) { return false; } } // If usage count will go to zero, then unget the service // from the registration. long count = usage.m_count.decrementAndGet(); try { if (count <= 0) { ServiceHolder holder = usage.m_svcHolderRef.get(); Object svc = holder != null ? holder.m_service : null; if (svc != null) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - framework/src/main/java/org/apache/felix/framework/ServiceRegistry.java [301:503]: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - return null; } @SuppressWarnings("unchecked") public S getService(final Bundle bundle, final ServiceReference ref, final boolean isServiceObjects) { // prototype scope is only possible if called from ServiceObjects final boolean isPrototype = isServiceObjects && ref.getProperty(Constants.SERVICE_SCOPE) == Constants.SCOPE_PROTOTYPE; UsageCount usage = null; Object svcObj = null; // Get the service registration. final ServiceRegistrationImpl reg = ((ServiceRegistrationImpl.ServiceReferenceImpl) ref).getRegistration(); // We don't allow cycles when we call out to the service factory. if ( reg.currentThreadMarked() ) { throw new ServiceException( "ServiceFactory.getService() resulted in a cycle.", ServiceException.FACTORY_ERROR, null); } try { reg.markCurrentThread(); // Make sure the service registration is still valid. if (reg.isValid()) { // Get the usage count, or create a new one. If this is a // prototype, the we'll alway create a new one. usage = obtainUsageCount(bundle, ref, null, isPrototype); // Increment the usage count and grab the already retrieved // service object, if one exists. incrementToPositiveValue(usage.m_count); svcObj = usage.getService(); if ( isServiceObjects ) { incrementToPositiveValue(usage.m_serviceObjectsCount); } // If we have a usage count, but no service object, then we haven't // cached the service object yet, so we need to create one. if (usage != null) { ServiceHolder holder = null; // There is a possibility that the holder is unset between the compareAndSet() and the get() // below. If that happens get() returns null and we may have to set a new holder. This is // why the below section is in a loop. while (holder == null) { ServiceHolder h = new ServiceHolder(); if (usage.m_svcHolderRef.compareAndSet(null, h)) { holder = h; try { svcObj = reg.getService(bundle); holder.m_service = svcObj; } finally { holder.m_latch.countDown(); } } else { holder = usage.m_svcHolderRef.get(); if (holder != null) { boolean interrupted = false; do { try { // Need to ensure that the other thread has obtained // the service. holder.m_latch.await(); if (interrupted) { Thread.currentThread().interrupt(); } interrupted = false; } catch (InterruptedException e) { interrupted = true; Thread.interrupted(); } } while (interrupted); svcObj = holder.m_service; } } // if someone concurrently changed the holder, loop again if (holder != usage.m_svcHolderRef.get()) holder = null; } if (svcObj != null && isPrototype) { UsageCount existingUsage = obtainUsageCount(bundle, ref, svcObj, null); if (existingUsage != null && existingUsage != usage) { flushUsageCount(bundle, ref, usage); usage = existingUsage; incrementToPositiveValue(usage.m_count); if ( isServiceObjects ) { incrementToPositiveValue(usage.m_serviceObjectsCount); } } } } } } finally { reg.unmarkCurrentThread(); if (!reg.isValid() || (svcObj == null)) { flushUsageCount(bundle, ref, usage); } } return (S) svcObj; } // Increment the Atomic Long by 1, and ensure the result is at least 1. // This method uses a loop, optimistic algorithm to do this in a threadsafe // way without locks. private void incrementToPositiveValue(AtomicLong al) { boolean success = false; while (!success) { long oldVal = al.get(); long newVal = Math.max(oldVal + 1L, 1L); checkCountOverflow(newVal); success = al.compareAndSet(oldVal, newVal); } } private void checkCountOverflow(long c) { if (c == Long.MAX_VALUE) { throw new ServiceException( "The use count for the service overflowed.", ServiceException.UNSPECIFIED, null); } } public boolean ungetService(final Bundle bundle, final ServiceReference ref, final Object svcObj) { final ServiceRegistrationImpl reg = ((ServiceRegistrationImpl.ServiceReferenceImpl) ref).getRegistration(); if ( reg.currentThreadMarked() ) { throw new IllegalStateException( "ServiceFactory.ungetService() resulted in a cycle."); } try { // Mark the current thread to avoid cycles reg.markCurrentThread(); // Get the usage count. UsageCount usage = obtainUsageCount(bundle, ref, svcObj, null); // If there are no cached services, then just return immediately. if (usage == null) { return false; } // if this is a call from service objects and the service was not fetched from // there, return false if ( svcObj != null ) { if (usage.m_serviceObjectsCount.decrementAndGet() < 0) { return false; } } // If usage count will go to zero, then unget the service // from the registration. long count = usage.m_count.decrementAndGet(); try { if (count <= 0) { ServiceHolder holder = usage.m_svcHolderRef.get(); Object svc = holder != null ? holder.m_service : null; if (svc != null) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -