6 /* This file is property of and copyright by the ALICE HLT Project *
7 * ALICE Experiment at CERN, All rights reserved. *
8 * See cxx source for full Copyright notice */
10 /** @file AliHLTTask.h
11 @author Matthias Richter
13 @brief base class for HLT tasks
16 // see below for class documentation
18 // refer to README to build package
20 // visit http://web.ift.uib.no/~kjeks/doc/alice-hlt
24 #include "AliHLTDataTypes.h"
25 #include "AliHLTLogging.h"
26 #include "AliHLTDataBuffer.h"
28 struct AliHLTComponentBlockData;
29 class AliHLTComponent;
30 class AliHLTComponentHandler;
32 /******************************************************************************/
36 * A task collects all the information which is necessary to process a certain
37 * step in the HLT data processing chain.
38 * - the instance of the component
39 * the task object creates and deletes the component object
40 * - the data buffer which receives the result of the component and provides
41 * the data to other tasks/components
42 * - a list of all dependencies
43 * - a list of consumers
44 * - the task object holds an external pointer to the configuration object;
45 * \b Note: the configuration object must exist through the existence of the
49 * @note This class is only used for the @ref alihlt_system.
51 * @ingroup alihlt_system
53 class AliHLTTask : public TObject, public AliHLTLogging {
55 /** standard constructor */
58 @param pConf pointer to configuration descriptor
60 AliHLTTask(AliHLTConfiguration* pConf);
62 virtual ~AliHLTTask();
65 * Initialize the task.
66 * The task is initialized with a configuration descriptor. It needs a
67 * component handler instance to create the analysis component. The
68 * component is created and initialized.
69 * @param pConf pointer to configuration descriptor, can be NULL if it
70 * was already provided to the constructor
71 * @param pCH the HLT component handler
73 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
76 * De-Initialize the task.
77 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
78 * the component is called. The analysis component is deleted.
83 * Get the name of the object.
84 * This is an overridden TObject function in order to return the configuration
85 * name instead of the class name. Enables use of TList standard functions.
86 * @return name of the configuration
88 const char *GetName() const;
91 * Return pointer to configuration.
92 * The tasks holds internally the configuration object.
93 * @return pointer to configuration
95 AliHLTConfiguration* GetConf() const;
98 * Return pointer to component, which the task internally holds.
99 * <b>Never delete this object!!!</b>
100 * @return instance of the component
102 AliHLTComponent* GetComponent() const;
105 * Find a dependency with a certain <i>name id</i>.
106 * Searches in the list of dependencies for a task.
107 * @param id the id of the <b>CONFIGURATION</b><br>
108 * <b>NOTE:</b> the id does NOT specify a COMPONENT
109 * @return pointer to task
111 AliHLTTask* FindDependency(const char* id);
114 * Add a dependency for the task.
115 * The task maintains a list of other tasks it depends on.
116 * @param pDep pointer to a task descriptor
117 * @return 0 if suceeded, neg error code if failed <br>
118 * -EEXIST : the dependencie exists already
121 int SetDependency(AliHLTTask* pDep);
124 * Clear a dependency.
125 * The ROOT TList touches the object which is in the list, even though
126 * it shouldn't care about. Thats why all lists have to be cleared before
127 * objects are deleted.
129 int UnsetDependency(AliHLTTask* pDep);
132 * Return number of unresolved dependencies.
133 * Iterate through all the configurations the task depends on and check
134 * whether a corresponding task is available in the list.
135 * @return number of unresolved dependencies
137 int CheckDependencies();
140 * Check whether the current task depends on the task pTask.
141 * @param pTask pointer to Task descriptor
142 * @return 1 the current task depends on pTask <br>
143 * 0 no dependency <br>
144 * neg. error code if failed
146 int Depends(AliHLTTask* pTask);
149 * Find a target with a certain id.
150 * Tasks which depend on the current task are referred to be <i>targets</i>.
151 * @param id configuration id to search for
152 * @return pointer to task instance
154 AliHLTTask* FindTarget(const char* id);
157 * Insert task into target list.
158 * The target list specifies all the tasks which depend on the current task.
159 * @param pDep pointer task object
160 * @return >=0 if succeeded, neg. error code if failed
162 int SetTarget(AliHLTTask* pDep);
166 * The ROOT TList touches the object which is in the list, even though
167 * it shouldn't care about. Thats why all lists have to be cleared before
168 * objects are deleted.
170 int UnsetTarget(AliHLTTask* pTarget);
173 * Prepare the task for event processing.
174 * The method initializes the Data Buffer and calls the
175 * @ref AliHLTComponent::Init method of the component.<br>
176 * The @ref ProcessTask method can be called an arbitrary number of times
177 * as soon as the task is in <i>running</i> mode.
182 * Clean-up the task after event processing.
183 * The method cleans up internal structures.
189 * If all dependencies are resolved the tasks subscribes to the data of
190 * all source tasks, builds the block descriptor and calls the
191 * @ref AliHLTComponent::ProcessEvent method of the component, after
192 * processing, the data blocks are released. <br>
193 * The @ref StartRun method must be called before.
195 int ProcessTask(Int_t eventNo);
198 * Determine the number of matching data block between the component and the
199 * data buffer of a consumer component. It checks which data types from the
200 * list of input data types of the consumer component can be provided by data
201 * blocks of the current component.
202 * @param pConsumerTask the task which subscribes to the data
203 * @return number of matching data blocks
205 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
208 * Determine the number of matching data types between the component and a
209 * consumer component. It checks which data types from the list of input data
210 * types of the consumer component can be provided by the current component.
211 * @param pConsumerTask the task which subscribes to the data
212 * @return number of matching data types
214 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
217 * Subscribe to the data of a source task.
218 * The function prepares the block descriptors for subsequent use with the
219 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
220 * descriptors which match the input data type of the consumer the function
221 * returns the number of blocks which would be prepared in case the target
222 * array is big enough.
223 * @param pConsumerTask the task which subscribes to the data
224 * @param arrayBlockDesc pointer to block descriptor to be filled
225 * @param iArraySize size of the block descriptor array
226 * @return number of matching data blocks, negative error code if failed
228 int Subscribe(const AliHLTTask* pConsumerTask,
229 AliHLTComponentBlockData* arrayBlockDesc, int iArraySize);
232 * Release a block descriptor.
233 * Notification from consumer task.
234 * @param pBlockDesc descriptor of the data segment
235 * @param pConsumerTask the task which subscribed to the data
236 * @return: >0 if success, negative error code if failed
238 int Release(AliHLTComponentBlockData* pBlockDesc,
239 const AliHLTTask* pConsumerTask);
242 * Print the status of the task with component, dependencies and targets.
247 * Search task dependency list recursively to find a dependency.
248 * @param id id of the task to search for
249 * @param pTgtList (optional) target list to receive dependency tree
250 * @return 0 if not found, >0 found in the n-th level,
251 dependency list in the target list
253 int FollowDependency(const char* id, TList* pTgtList=NULL);
256 * Print the tree for a certain dependency either from the task or
257 * configuration list.
258 * Each task posseses two "link lists": The configurations are the origin
259 * of the task list. In case of an error during the built of the task list,
260 * the dependencies for the task list might be incomplete. In this case the
261 * configurations can give infomation on the error reason.
262 * @param id id of the dependency to search for
263 * @param bMode 0 (default) from task dependency list, <br>
264 * 1 from configuration list
266 void PrintDependencyTree(const char* id, int bMode=0);
269 * Get number of source tasks.
270 * @return number of source tasks
272 int GetNofSources() const {return fListDependencies.GetSize();}
275 /** prohibited copy constructor */
276 AliHLTTask(const AliHLTTask&);
277 /** prohibited assignment operator */
278 AliHLTTask& operator=(const AliHLTTask&);
280 /** the configuration descriptor (external pointer) */
281 AliHLTConfiguration* fpConfiguration; //! transient
282 /** the component described by this task (created and deleted internally) */
283 AliHLTComponent* fpComponent; //! transient
284 /** the data buffer for the component processing */
285 AliHLTDataBuffer* fpDataBuffer; //! transient
286 /** the list of targets (tasks which depend upon the current one) */
287 TList fListTargets; // see above
288 /** the list of sources (tasks upon which the current one depends) */
289 TList fListDependencies; // see above
292 * block data array to be passed as argument to the
293 * @ref AliHLTComponent::ProcessEvent method.
294 * Filled through subscription to source tasks (@ref Subscribe).
296 vector<AliHLTComponentBlockData> fBlockDataArray; //! transient
298 ClassDef(AliHLTTask, 2);