JP5458147B2 - Event notification method, program, and apparatus - Google Patents

Description

  The present invention relates to a technique for notifying an OSGi bundle (event listener) of an event.

  A software module called a bundle operates on the OSGi framework compliant with the OSGi specification. The bundle has a status of INSTALLED, RESOLVE, STARTING, ACTIVE, STOPPING, or UNINSTALLED, and the status changes depending on events such as installation, activation, and stop of the bundle.

  As shown in FIG. 6, the bundles A and B that want to receive event notifications are as follows: (1) By registering each event listener a and b in the OSGi framework, (2) Status in other bundles Y When a change occurs, (3) an event notification based on the status change can be received through the individual event listeners a and b by the notification unit of the OSGi framework.

  When a status change occurs, event notification is performed for all event listeners registered in the OSGi framework, but the priority differs depending on the type of event listener.

  According to Non-Patent Document 1, there are two types of event listeners that detect a status change: Synchronous Bundle Listener and Bundle Listener. First, the event listener of Synchronous Bundle Listener is called (synchronous execution of event notification), then , The event listener for BundleListener is called. In the case of FIG. 6, the event listener a is called before the event listener b, and the bundle Y event is notified to the bundle A before the bundle B.

  Therefore, since the priority of event notification is higher in the event listener of Synchronous BundleLister than the event listener of BundleLister, the event listener may be registered as SynchronousBundleListener for the bundle to receive event notification first.

“OSGi Service Platform Core Specification”, OSGi Alliance, Release 4, Version 4.3, April 2011, <URL: http: // www. osgi. org / Download / Release4V43>

  However, when there are a plurality of event listeners registered as Synchronous Bundle Listeners, the calling order between the plurality of event listeners depends on the implementation of the OSGi framework and has the following problems.

  For example, when using the OSGi framework on a device with limited resources, it is necessary to manage the consumed resources for each bundle. One resource to be managed is heap memory consumption. Here, the Management Agent that manages the heap memory consumption for each bundle is defined as a memory management MA.

  The memory management MA plays a role of performing life cycle control of bundles operating on the OSGi framework and management of resource consumption, and is composed of one or more bundles.

  In Java (registered trademark), it is possible to describe code (static initializer) that is executed only once when a class is loaded, and heap memory may be consumed in this process. Therefore, the memory management MA needs to prepare for starting the management before the class included in the bundle is loaded (before the bundle consumes the heap memory).

  In the OSGi framework, a class loader (bundle class loader) is generated for each bundle, and classes included in the bundle are loaded from the bundle class loader. Therefore, since the memory management MA manages the heap memory consumption for each bundle, it is necessary to start the management immediately after the bundle class loader is generated.

  According to the OSGi specification, since the bundle class loader is generated after the bundle state becomes RESOLVED, the memory management MA registers an event listener for SynchronousBundleListener and detects a RESOLVED event for the bundle. It is conceivable to make the above preparation.

  Here, as with the memory management MA, it is assumed that there is a bundle X that registers an event listener of the Synchronous BundleLister and performs processing in response to the RESOLVED event of the bundle.

  In the OSGi specification, as described above, the calling order of a plurality of Synchronous Bundle Listeners is indefinite. Therefore, a Bundle Event notification (event notification) when the bundle state of a certain bundle Y becomes RESOLVED is a Synchronous Bundle Listener registered by the memory management MA. There is a possibility that the event listener of the Synchronous BundleLister registered by the bundle X will be called earlier than the event listener of.

  In this case, the bundle Y consumes the heap memory by some processing by the bundle X before the memory management MA starts managing the heap memory consumption for each bundle. In this case, the bundle Y consumes the heap memory before the memory management MA starts managing the heap memory consumption consumed by the bundle Y, and thus the memory management expected in the memory management MA cannot be realized. It will be.

  In other words, even if there is a bundle that wants to receive an event notification by changing the bundle status before any bundle, such as the bundle of the memory management MA, when another bundle registers an event listener as a Synchronous Bundle Listener. Since the calling order is indefinite, there is no guarantee that the event listener registered by the bundle will receive the event notification with the highest priority.

  The present invention has been made in view of the above, and an object of the present invention is to guarantee the order of event notification to event listeners registered as Synchronous BundleListers in units of bundles.

The event notification method according to claim 1, wherein an event notification method for notifying an event listener of a Synchronous Bundle Listener is a first step of reading out and holding an identifier of a bundle that receives event notification preferentially from a property file by a computer. A second step of holding in the event notification target list the identifiers of all bundles that called the addBundleLister method of the BundleContext interface when registering the event listener with the OSGi framework, and when the status of the bundle changes, The bundle identifier that matches the bundle identifier read from the property file among the bundle identifiers held in the event notification target list Possess a third step of preferentially event notification to the event listener, and the bundle of preferentially receiving an event notification, characterized in that it is a bundle of performing resource management of other bundles .

According to the present invention, in an event notification method for notifying an event listener of a Synchronous BundleLister, an identifier of a bundle that receives event notification preferentially is read from the property file and stored, and the event listener is registered in the OSGi framework. In the event notification target list, the identifiers of all bundles that have called the addBundleLister method of the BundleContext interface are stored in the event notification target list, and when the bundle status changes, the bundle identifiers stored in the event notification target list In order to preferentially notify the event listener of the bundle identifier that matches the read bundle identifier, Syncron The event notification sequence of the event listener is registered as usBundleListener can be guaranteed by the bundle units. Further, since the bundle that receives the event notification preferentially is a bundle that performs resource management of other bundles, it is possible to eliminate omission of management of resources due to uncertain priority.

The event notification method according to claim 2 is the event notification method according to claim 1, wherein there are a plurality of bundles that receive the event notification preferentially, and the priority order of the plurality of bundle identifiers is set in the first step . Further, in the third step , event notification is performed to each event listener of the plurality of matching bundle identifiers based on the priority order.

  According to the present invention, there are a plurality of bundles that receive event notification preferentially, and the event notification is performed to each event listener of the plurality of matching bundle identifiers based on the priority order of the plurality of bundle identifiers. It is possible to guarantee an event notification order between bundles that receive event notifications preferentially.

Event notification method of claim 3, wherein, in the event notification method according to claim 2, wherein preferentially event notified by the bundle priority of the uppermost of the plurality of bundles, performs resource management of other bundles It is a bundle.

  According to the present invention, the bundle with the highest priority among the plurality of bundles that are preferentially notified of events is a bundle that performs resource management of other bundles, and therefore, management of resources due to uncertain priority. Leakage can be eliminated.

The event notification device according to claim 4, wherein an event notification device that performs event notification to an event listener of a Synchronous BundleListener, first holding means that reads and holds an identifier of a bundle that receives event notification preferentially from a property file; and A second holding means for holding in the event notification target list all the identifiers of bundles that have called the addBundleLister method of the BundleContext interface when registering the event listener with the OSGi framework, and the event when the status of the bundle is changed. Among the bundle identifiers held in the notification target list, the event identifier of the bundle identifier that matches the bundle identifier read from the property file Preferentially possess a notification unit for performing an event notification, the by, the bundle preferentially receive event notification, characterized in that it is a bundle of performing resource management of the other bundles.

According to the present invention, in an event notification device that notifies an event listener of a Synchronous BundleLister, an identifier of a bundle that receives the event notification is read from the property file and stored, and the event listener is registered in the OSGi framework. In the event notification target list, the identifiers of all bundles that have called the addBundleLister method of the BundleContext interface are stored in the event notification target list, and when the bundle status changes, the bundle identifiers stored in the event notification target list In order to preferentially notify the event listener of the bundle identifier that matches the read bundle identifier, Syncron The event notification sequence of the event listener is registered as usBundleListener can be guaranteed by the bundle units. Further, since the bundle that receives the event notification preferentially is a bundle that performs resource management of other bundles, it is possible to eliminate omission of management of resources due to uncertain priority.

The event notification device according to claim 5 is the event notification device according to claim 4 , wherein a plurality of bundles receive the event notification preferentially, and the first holding unit includes a priority order of a plurality of bundle identifiers. And the notification means performs event notification to each event listener of the matching bundle identifier based on the priority.

  According to the present invention, there are a plurality of bundles that receive event notification preferentially, and the event notification is performed to each event listener of the plurality of matching bundle identifiers based on the priority order of the plurality of bundle identifiers. It is possible to guarantee an event notification order between bundles that receive event notifications preferentially.

The event notification device according to claim 6 is the event notification device according to claim 5 , wherein the bundle with the highest priority among the plurality of bundles to which the event notification is preferentially performed performs resource management of other bundles. It is a bundle.

According to the present invention, the bundle with the highest priority among the plurality of bundles that are preferentially notified of events is a bundle that performs resource management of other bundles, and therefore, management of resources due to uncertain priority. Leakage can be eliminated.
An event notification program according to a seventh aspect causes a computer to execute the event notification method according to any one of the first to third aspects.

  According to the present invention, the order of event notification to an event listener registered as a Synchronous Bundle Listener can be guaranteed in bundle units.

It is a figure which shows the functional block structure of an event notification apparatus. It is a figure which shows the example of a setting of Bundle SymbolName of a priority bundle. It is a figure which shows the processing flow of an event notification apparatus. It is a figure which shows the example of a setting of Bundle SymbolName of a priority bundle. It is a figure which shows the processing flow of an event notification apparatus. It is a figure explaining the mechanism notified of an event.

  Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the present embodiment.

[First Embodiment]
In the first embodiment, a method for preferentially notifying an event listener registered by a specific bundle among a plurality of event listeners registered as a Synchronous BundleLister will be described.

  FIG. 1 is a diagram illustrating a functional block configuration of the event notification device according to the first embodiment. The event notification device 100 operates on the OSGi framework, and includes a setting unit 11, a first determination unit 13, a first acquisition / holding unit 14, a second determination unit 15, and a second acquisition / holding unit 16. A collation unit 17 and a notification unit 18.

  Such an event notification device 100 can be realized by a computer having a storage unit such as a memory and a calculation / control unit such as a CPU, and its operation processing is executed by a program. Hereinafter, each functional unit will be described.

  The setting unit 11 has a function of setting a bundle symbolic name (bundle identifier) of a bundle (hereinafter referred to as a priority bundle) that receives an event notification preferentially to the Java system property file 12 included in the JVM (Java Virtual Machine).

  For example, the setting is made as shown in FIG. “Prioritized.listener” is a key for designating a priority bundle, and “com.acme.bundleA” indicates a Bundle SymbolicName.

  The use of the Java system property file 12 is an example, and any property file that is read when the OSGi framework is activated can be used arbitrarily. The Java system property file 12 is stored in a memory managed by the JVM, and is used as appropriate by being read from the memory.

  The first determination unit 13 has a function of determining whether or not the bundle bundle name of the priority bundle is set in the Java system property file 12 read when the OSGi framework is activated.

  The first acquisition / holding unit 14 has a function of acquiring and holding the bundle symbolic name of the priority bundle from the Java system property file 12.

  When the BundleContext # addBundleListener (BundleListener) is called when registering the event listener in the OSGi, the second determination unit 15 uses the BundleList listener of the type BundleListener (BundleListener) and the BundleList listener of the type BundleListener (BundleListener). It has a function of determining whether or not it is a mold.

  Note that BundleContext # addBundleListener (BundleListener) refers to the BundleContext interface's addBundleListener method, such as SynchronousBundleListener, which registers the event listener based on the bundle status change. Non-patent document 1).

  When the determination result in the second determination unit 15 is the Synchronous BundleLister type, the second acquisition / holding unit 16 acquires the bundle notification name from all bundles that have called BundleContext # addBundleListener (BundleListener) and lists the event target bundles. It has the function to hold in.

  Note that since the OSGi framework knows the bundle of the caller of BundleContext # addBundleListener (BundleListener), it can acquire the Bundle SymbolicName from that bundle.

  In order to determine whether each Bundle Symbolic Name in the event notification target bundle list is a Bundle Symbolic Name of the priority bundle, the collation unit 17 holds each Bundle Symbolic Name in the event notification target bundle list corresponding to “prioritized.listener”. It has a function to collate with the bundle symbolic name.

  The notification unit 18 has a function of performing event notification preferentially to the event listener of the matching bundle symbolic name that matches the collation result in the collation unit 17.

  Next, the operation of the event notification device 100 will be described. FIG. 3 is a diagram illustrating a processing flow of the event notification device 100. However, it is assumed that the bundle bundle's BundleLabelName has already been set in the Java system property file 12.

  First, when the OSGi framework is activated (step S101), the Java system property file 12 is read (step S102), and the bundle symbol Name of the priority bundle is set in the read Java system property file 12 by the first determination unit 13. Whether or not (Yes) or not (No) is determined (step S103).

  If the determination result in step S103 is Yes, then, the first acquisition / holding unit 14 reads out and holds the Bundle Symbolic Name of the set priority bundle from the Java system property file 12 (step S104). ). If the determination result in step S103 is No, the process proceeds to step S105 without performing step S104.

  Next, when an event listener is registered in the OSGi framework (step S105), when the BundleContext # addBundleListener (BundleListener) is called by the second determination unit 15 when the event listener is registered, the BundleContext # addBundleListener (BundleList) (Bundle) It is determined using the instanceof operator whether or not the type of the BundleLister (type of the event listener) registered in (SynchronousBundleListener type) (Yes) or not (No) (step S106).

  If the determination result in step S106 is Yes, then the second acquisition / holding unit 16 acquires the Bundle SymbolicName from all the bundles that have called BundleContext # addBundleLister (BundleListener), and holds them in the event notification target bundle list. (Step S107). In addition, when the determination result of step S106 is No, it progresses to step S111 mentioned later.

  If a bundle status change occurs (step S108), the collation unit 17 collates the Bundle Symbolic Name in the event notification target bundle list retained in step S107 with the Bundle Symbolic Name retained in step S104 (step S108). S109).

  Thereafter, the notification unit 18 selects a bundle symbolic name event listener (that is, a Synchronous Bundle Listener that is matched with the collation result of step S109 in the event notification target bundle list and that is set to receive event notifications preferentially. An event notification is preferentially given to the event listener (step S110).

  On the other hand, for event listeners of BundleLabelName that do not match (that is, event listeners of bundles that are SynchronousBundleListeners but are not set to receive event notifications preferentially), existing event notifications defined in the OSGi specification Processing is performed (step S111).

  Thereby, the event listener of the Synchronous BundleLister registered by the bundle having the BundleLabelName set in the Java system property file 12 read at the time of starting the framework is notified of the event before the other SynchronousBundleListener.

  Finally, since there may be a plurality of various event lists registered in addition to such preferentially processed event listeners, there is an event listener that has not yet been notified of events after step S110 or step S111. It is determined whether or not (Yes) or not (No) (step S112). If the determination result is Yes, the process returns to step S109 to notify the remaining event listeners of the event. On the other hand, if the determination result is No, the process ends.

  According to the present embodiment, in the event notification device 100 that performs event notification to the event listener of the Synchronous BundleLister, the first acquisition / holding unit 14 reads and holds the identifier of the bundle that receives the event notification preferentially from the property file. The second acquisition / holding unit 16 holds, in the event notification target list, the identifiers of all bundles that have called the bundlebundleListener method of the BundleContext interface when registering the event listener in the OSGi framework. Bundle identification that matches the bundle identifier read from the above property file among the bundle identifiers held in the event notification target list Since for the event listener performs preferentially event notification, it is possible to guarantee an event notification sequence of the event listener is registered as SynchronousBundleListener bundle units.

[Second Embodiment]
In the second embodiment, a description will be given of a method for realizing priority event notification between a plurality of priority bundles when there are a plurality of priority bundles.

  The functional configuration of the event notification device 100 according to the present embodiment is the same as that of the first embodiment shown in FIG. Hereinafter, differences from the functions described in the first embodiment will be described.

  The setting unit 11 has a function of setting each Bundle Symbolic Name of a plurality of priority bundles in the Java system property file 12 and setting the priority order among these priority bundles in association with each Bundle Symbolic Name.

  For example, the setting is made as shown in FIG. In FIG. 4A, each numerical value specified after each Bundle SymbolicName means the priority of event notification. A numerical value is designated by an integer of 1 or more, and a bundle whose numerical value is set low is notified of an event preferentially. Instead of the numerical method, the priorities may be designated in alphabetical order, or the priorities may be designated in the description order of Bundle SymbolicName as shown in FIG.

  The first acquisition / holding unit 14 has a function of acquiring and holding each Bundle Symbolic Name of a plurality of priority bundles and their priorities from the Java system property file 12.

  The notification unit 18 has a function of performing event notification on a priority basis for each event listener of a plurality of matching bundle symbolic names based on the collation result in the collation unit 17 based on the set priority order.

  Next, the operation of the event notification device 100 will be described. FIG. 5 is a diagram illustrating a processing flow of the event notification device 100. However, it is assumed that each Bundle Symbol Name of a plurality of priority bundles and the priority order thereof are already set in the Java system property file 12.

  First, when the OSGi framework is activated (step S201), the Java system property file 12 is read (step S202), and the bundle symbolic name of the priority bundle is set in the read Java system property file 12 by the first determination unit 13. Whether or not (Yes) or not (No) is determined (step S203).

  If the determination result in step S203 is Yes, then the first acquisition / holding unit 14 reads and holds the Bundle Symbolic Names of all the set priority bundles from the Java system property file 12, respectively. (Step S204). If the determination result in step S203 is No, the process proceeds to step S205 without performing step S204.

  Next, when the event listener is registered in the OSGi framework (step S205), when the BundleContext # addBundleListener (BundleListener) is called by the second determination unit 15 when the event listener is registered, the BundleContext # addBundleLister (Bundle) It is determined using the instanceof operator whether or not the type of the BundleListener registered in (the type of event listener) is the Synchronous BundleLister type (Yes) (No).

  If the determination result in step S206 is Yes, then the second acquisition / holding unit 16 acquires the Bundle SymbolicName from all the bundles that called the BundleContext # addBundleListener (BundleListener), and holds them in the event notification target bundle list. (Step S207). In addition, when the determination result of step S206 is No, it progresses to step S211 mentioned later.

  If a bundle status change occurs (step S208), the collation unit 17 collates the Bundle Symbolic Name in the event notification target bundle list held in step S207 with each Bundle Symbolic Name held in step S204. (Step S209).

  Thereafter, the notification unit 18 sets each event listener of a plurality of Bundle Symbolic Names that match the collation result in step S209 in the event notification target bundle list (that is, a Synchronous Bundle Listener and receives event notifications with priority). Event notification) is preferentially performed according to the designated priority order (step S210).

  On the other hand, for event listeners of BundleLabelName that do not match (that is, event listeners of bundles that are SynchronousBundleListeners but are not set to receive event notifications preferentially), existing event notifications defined in the OSGi specification Processing is performed (step S211).

  As a result, event notification is preferentially performed according to the specified priority order for each event listener of the Synchronous Bundle Listener registered by the bundle having the Bundle Symbolic Name set in the Java system property file 12 read when the framework is started. .

  Finally, since there may be a plurality of various event lists registered in addition to such preferentially processed event listeners, there is an event listener that has not yet been notified of events after step S210 or step S211. It is determined whether or not (Yes) or not (No) (step S212). If the determination result is Yes, the process returns to step S209 to notify the remaining event listeners of the event. On the other hand, if the determination result is No, the process ends.

  According to the present embodiment, there are a plurality of bundles that are preferentially receiving event notifications, and the notification unit 18 determines the matching bundle identifiers as a result of the above collation based on the priority order of the plurality of bundle identifiers. Since event notification is performed for each event listener, it is possible to guarantee the order of event notification between bundles that receive event notification preferentially.

  In other words, in the conventional technology, when a bundle status change occurs, any bundle listener of SynchronousBundleListener that can receive event notifications can be registered with any privilege, and the calling order can be guaranteed. There wasn't. However, by using the event notification device 100 described so far, it becomes possible to guarantee the priority event notification for the bundle that should preferentially detect the event.

  Finally, as the priority bundle described in the first embodiment and the priority bundle having the highest priority described in the second embodiment, for example, a memory management bundle that performs resource management of other bundles (problem) Memory management MA) described in the above. As a result, when performing bundle resource management, such as managing heap memory consumption, using specific events, priority is given to the bundle to be managed, thereby eliminating resource omissions due to uncertain priority. be able to.

DESCRIPTION OF SYMBOLS 100 ... Event notification apparatus 11 ... Setting part 12 ... Java system property file 13 ... 1st determination part 14 ... 1st acquisition / holding | maintenance part (1st holding means)
15 ... 2nd determination part 16 ... 2nd acquisition and holding | maintenance part (2nd holding means)
17 ... Verification unit 18 ... Notification unit (notification means)
S101-S112, S201-S212 ... step

Claims (7)

In the event notification method for notifying the event listener of the Synchronous BundleListener,
By computer
A first step of reading from the property file and holding the identifier of the bundle that receives the event notification preferentially;
A second step of storing, in the event notification target list, identifiers of all bundles that have called the addBundleLister method of the BundleContext interface when registering the event listener with the OSGi framework;
When the bundle status is changed, the event notification is performed preferentially to the event listener of the bundle identifier that matches the bundle identifier read from the property file among the bundle identifiers held in the event notification target list. 3 and the step of, the possess,
The bundle that receives the event notification with priority is:
An event notification method characterized by being a bundle for performing resource management of another bundle . There are a plurality of bundles that receive the event notification preferentially,
In the first step , the priority order of the plurality of bundle identifiers is further maintained,
In the third step,
The event notification method according to claim 1, wherein event notification is performed to each event listener of the plurality of matching bundle identifiers based on the priority. Among the bundles that are preferentially notified of events, the bundle with the highest priority is
3. The event notification method according to claim 2, wherein the event notification method is a bundle for performing resource management of another bundle. In an event notification device for notifying an event listener of a Synchronous BundleListener,
First holding means for reading and holding an identifier of a bundle that receives event notification preferentially from a property file;
A second holding unit that holds, in the event notification target list, identifiers of all bundles that have called the addBundleLister method of the BundleContext interface when registering the event listener in the OSGi framework;
Notification that preferentially notifies the event listener of the bundle identifier that matches the bundle identifier read from the property file among the bundle identifiers held in the event notification target list when the status of the bundle changes Means,
The bundle that receives the event notification with priority is:
An event notification device characterized by being a bundle for performing resource management of another bundle. There are a plurality of bundles that receive the event notification preferentially,
The first holding means further holds the priority order of a plurality of bundle identifiers,
The notification means includes
The event notification device according to claim 4, wherein event notification is performed to each event listener of the plurality of matching bundle identifiers based on the priority. Among the bundles that are preferentially notified of events, the bundle with the highest priority is
6. The event notification device according to claim 5, wherein the event notification device is a bundle that performs resource management of another bundle. An event notification program causing a computer to execute the event notification method according to claim 1.

Images