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
25 #include "AliHLTDataTypes.h"
26 #include "AliHLTLogging.h"
27 #include "AliHLTDataBuffer.h"
29 struct AliHLTComponentBlockData;
30 class AliHLTComponent;
31 class AliHLTComponentHandler;
32 class AliHLTConfiguration;
35 typedef vector<AliHLTTask*> AliHLTTaskPList;
37 /******************************************************************************/
41 * A task collects all the information which is necessary to process a certain
42 * step in the HLT data processing chain.
43 * - the instance of the component
44 * the task object creates and deletes the component object
45 * - the data buffer which receives the result of the component and provides
46 * the data to other tasks/components
47 * - a list of all dependencies
48 * - a list of consumers
49 * - the task object holds an external pointer to the configuration object;
50 * \b Note: the configuration object must exist through the existence of the
54 * @note This class is only used for the @ref alihlt_system.
56 * @ingroup alihlt_system
58 class AliHLTTask : public TObject, public AliHLTLogging {
60 /** standard constructor */
63 @param pConf pointer to configuration descriptor
65 AliHLTTask(AliHLTConfiguration* pConf);
67 virtual ~AliHLTTask();
70 * Initialize the task.
71 * The task is initialized with a configuration descriptor. It needs a
72 * component handler instance to create the analysis component. The
73 * component is created and initialized.
74 * @param pConf pointer to configuration descriptor, can be NULL if it
75 * was already provided to the constructor
76 * @param pCH the HLT component handler
78 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
81 * De-Initialize the task.
82 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
83 * the component is called. The analysis component is deleted.
88 * Get the name of the object.
89 * This is an overridden TObject function in order to return the configuration
90 * name instead of the class name. Enables use of TList standard functions.
91 * @return name of the configuration
93 const char *GetName() const;
96 * Return pointer to configuration.
97 * The tasks holds internally the configuration object.
98 * @return pointer to configuration
100 AliHLTConfiguration* GetConf() const;
103 * Return pointer to component, which the task internally holds.
104 * <b>Never delete this object!!!</b>
105 * @return instance of the component
107 AliHLTComponent* GetComponent() const;
110 * Find a dependency with a certain <i>name id</i>.
111 * Searches in the list of dependencies for a task.
112 * @param id the id of the <b>CONFIGURATION</b><br>
113 * <b>NOTE:</b> the id does NOT specify a COMPONENT
114 * @return pointer to task
116 AliHLTTask* FindDependency(const char* id);
119 * Add a dependency for the task.
120 * The task maintains a list of other tasks it depends on.
121 * @param pDep pointer to a task descriptor
122 * @return 0 if suceeded, neg error code if failed <br>
123 * -EEXIST : the dependencie exists already
126 int SetDependency(AliHLTTask* pDep);
129 * Clear a dependency.
130 * The ROOT TList touches the object which is in the list, even though
131 * it shouldn't care about. Thats why all lists have to be cleared before
132 * objects are deleted.
134 int UnsetDependency(AliHLTTask* pDep);
137 * Return number of unresolved dependencies.
138 * Iterate through all the configurations the task depends on and check
139 * whether a corresponding task is available in the list.
140 * @return number of unresolved dependencies
142 int CheckDependencies();
145 * Check whether the current task depends on the task pTask.
146 * @param pTask pointer to Task descriptor
147 * @return 1 the current task depends on pTask <br>
148 * 0 no dependency <br>
149 * neg. error code if failed
151 int Depends(AliHLTTask* pTask);
154 * Find a target with a certain id.
155 * Tasks which depend on the current task are referred to be <i>targets</i>.
156 * @param id configuration id to search for
157 * @return pointer to task instance
159 AliHLTTask* FindTarget(const char* id);
162 * Insert task into target list.
163 * The target list specifies all the tasks which depend on the current task.
164 * @param pDep pointer task object
165 * @return >=0 if succeeded, neg. error code if failed
167 int SetTarget(AliHLTTask* pDep);
171 * The ROOT TList touches the object which is in the list, even though
172 * it shouldn't care about. Thats why all lists have to be cleared before
173 * objects are deleted.
175 int UnsetTarget(AliHLTTask* pTarget);
178 * Prepare the task for event processing.
179 * The method initializes the Data Buffer and calls the
180 * @ref AliHLTComponent::Init method of the component.<br>
181 * The @ref ProcessTask method can be called an arbitrary number of times
182 * as soon as the task is in <i>running</i> mode.
187 * Clean-up the task after event processing.
188 * The method cleans up internal structures.
194 * If all dependencies are resolved the tasks subscribes to the data of
195 * all source tasks, builds the block descriptor and calls the
196 * @ref AliHLTComponent::ProcessEvent method of the component, after
197 * processing, the data blocks are released. <br>
198 * The @ref StartRun method must be called before.
200 int ProcessTask(Int_t eventNo);
203 * Determine the number of matching data block between the component and the
204 * data buffer of a consumer component. It checks which data types from the
205 * list of input data types of the consumer component can be provided by data
206 * blocks of the current component.
207 * @param pConsumerTask the task which subscribes to the data
208 * @return number of matching data blocks
210 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
213 * Determine the number of matching data types between the component and a
214 * consumer component. It checks which data types from the list of input data
215 * types of the consumer component can be provided by the current component.
216 * @param pConsumerTask the task which subscribes to the data
217 * @return number of matching data types
219 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
222 * Subscribe to the data of a source task.
223 * The function prepares the block descriptors for subsequent use with the
224 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
225 * descriptors which match the input data type of the consumer the function
226 * returns the number of blocks which would be prepared in case the target
227 * array is big enough.
228 * @param pConsumerTask the task which subscribes to the data
229 * @param blockDescList block descriptor list to be filled
230 * @return number of matching data blocks, negative error code if failed
232 int Subscribe(const AliHLTTask* pConsumerTask, AliHLTComponentBlockDataList& blockDescList);
235 * Release a block descriptor.
236 * Notification from consumer task.
237 * @param pBlockDesc descriptor of the data segment
238 * @param pConsumerTask the task which subscribed to the data
239 * @return: >0 if success, negative error code if failed
241 int Release(AliHLTComponentBlockData* pBlockDesc,
242 const AliHLTTask* pConsumerTask);
245 * Print the status of the task with component, dependencies and targets.
250 * Search task dependency list recursively to find a dependency.
251 * @param id id of the task to search for
252 * @param pTgtList (optional) target list to receive dependency tree
253 * @return 0 if not found, >0 found in the n-th level,
254 dependency list in the target list
256 int FollowDependency(const char* id, TList* pTgtList=NULL);
259 * Print the tree for a certain dependency either from the task or
260 * configuration list.
261 * Each task posseses two "link lists": The configurations are the origin
262 * of the task list. In case of an error during the built of the task list,
263 * the dependencies for the task list might be incomplete. In this case the
264 * configurations can give infomation on the error reason.
265 * @param id id of the dependency to search for
266 * @param bMode 0 (default) from task dependency list, <br>
267 * 1 from configuration list
269 void PrintDependencyTree(const char* id, int bMode=0);
272 * Get number of source tasks.
273 * @return number of source tasks
275 int GetNofSources() const {return fListDependencies.GetSize();}
278 /** prohibited copy constructor */
279 AliHLTTask(const AliHLTTask&);
280 /** prohibited assignment operator */
281 AliHLTTask& operator=(const AliHLTTask&);
284 * Custom initialization for child tasks.
286 virtual int CustomInit(AliHLTComponentHandler* pCH);
289 * Custom clean up for child tasks.
291 virtual int CustomCleanup();
294 /** the configuration descriptor (external pointer) */
295 AliHLTConfiguration* fpConfiguration; //! transient
296 /** the component described by this task (created and deleted internally) */
297 AliHLTComponent* fpComponent; //! transient
298 /** the data buffer for the component processing */
299 AliHLTDataBuffer* fpDataBuffer; //! transient
302 /** the list of targets (tasks which depend upon the current one) */
303 TList fListTargets; // see above
304 /** the list of sources (tasks upon which the current one depends) */
305 TList fListDependencies; // see above
308 * block data array to be passed as argument to the
309 * @ref AliHLTComponent::ProcessEvent method.
310 * Filled through subscription to source tasks (@ref Subscribe).
312 vector<AliHLTComponentBlockData> fBlockDataArray; //! transient
314 ClassDef(AliHLTTask, 2);