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;
31 class AliHLTConfiguration;
33 /******************************************************************************/
37 * A task collects all the information which is necessary to process a certain
38 * step in the HLT data processing chain.
39 * - the instance of the component
40 * the task object creates and deletes the component object
41 * - the data buffer which receives the result of the component and provides
42 * the data to other tasks/components
43 * - a list of all dependencies
44 * - a list of consumers
45 * - the task object holds an external pointer to the configuration object;
46 * \b Note: the configuration object must exist through the existence of the
50 * @note This class is only used for the @ref alihlt_system.
52 * @ingroup alihlt_system
54 class AliHLTTask : public TObject, public AliHLTLogging {
56 /** standard constructor */
59 @param pConf pointer to configuration descriptor
61 AliHLTTask(AliHLTConfiguration* pConf);
63 virtual ~AliHLTTask();
66 * Initialize the task.
67 * The task is initialized with a configuration descriptor. It needs a
68 * component handler instance to create the analysis component. The
69 * component is created and initialized.
70 * @param pConf pointer to configuration descriptor, can be NULL if it
71 * was already provided to the constructor
72 * @param pCH the HLT component handler
74 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
77 * De-Initialize the task.
78 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
79 * the component is called. The analysis component is deleted.
84 * Get the name of the object.
85 * This is an overridden TObject function in order to return the configuration
86 * name instead of the class name. Enables use of TList standard functions.
87 * @return name of the configuration
89 const char *GetName() const;
92 * Return pointer to configuration.
93 * The tasks holds internally the configuration object.
94 * @return pointer to configuration
96 AliHLTConfiguration* GetConf() const;
99 * Return pointer to component, which the task internally holds.
100 * <b>Never delete this object!!!</b>
101 * @return instance of the component
103 AliHLTComponent* GetComponent() const;
106 * Find a dependency with a certain <i>name id</i>.
107 * Searches in the list of dependencies for a task.
108 * @param id the id of the <b>CONFIGURATION</b><br>
109 * <b>NOTE:</b> the id does NOT specify a COMPONENT
110 * @return pointer to task
112 AliHLTTask* FindDependency(const char* id);
115 * Add a dependency for the task.
116 * The task maintains a list of other tasks it depends on.
117 * @param pDep pointer to a task descriptor
118 * @return 0 if suceeded, neg error code if failed <br>
119 * -EEXIST : the dependencie exists already
122 int SetDependency(AliHLTTask* pDep);
125 * Clear a dependency.
126 * The ROOT TList touches the object which is in the list, even though
127 * it shouldn't care about. Thats why all lists have to be cleared before
128 * objects are deleted.
130 int UnsetDependency(AliHLTTask* pDep);
133 * Return number of unresolved dependencies.
134 * Iterate through all the configurations the task depends on and check
135 * whether a corresponding task is available in the list.
136 * @return number of unresolved dependencies
138 int CheckDependencies();
141 * Check whether the current task depends on the task pTask.
142 * @param pTask pointer to Task descriptor
143 * @return 1 the current task depends on pTask <br>
144 * 0 no dependency <br>
145 * neg. error code if failed
147 int Depends(AliHLTTask* pTask);
150 * Find a target with a certain id.
151 * Tasks which depend on the current task are referred to be <i>targets</i>.
152 * @param id configuration id to search for
153 * @return pointer to task instance
155 AliHLTTask* FindTarget(const char* id);
158 * Insert task into target list.
159 * The target list specifies all the tasks which depend on the current task.
160 * @param pDep pointer task object
161 * @return >=0 if succeeded, neg. error code if failed
163 int SetTarget(AliHLTTask* pDep);
167 * The ROOT TList touches the object which is in the list, even though
168 * it shouldn't care about. Thats why all lists have to be cleared before
169 * objects are deleted.
171 int UnsetTarget(AliHLTTask* pTarget);
174 * Prepare the task for event processing.
175 * The method initializes the Data Buffer and calls the
176 * @ref AliHLTComponent::Init method of the component.<br>
177 * The @ref ProcessTask method can be called an arbitrary number of times
178 * as soon as the task is in <i>running</i> mode.
183 * Clean-up the task after event processing.
184 * The method cleans up internal structures.
190 * If all dependencies are resolved the tasks subscribes to the data of
191 * all source tasks, builds the block descriptor and calls the
192 * @ref AliHLTComponent::ProcessEvent method of the component, after
193 * processing, the data blocks are released. <br>
194 * The @ref StartRun method must be called before.
196 int ProcessTask(Int_t eventNo);
199 * Determine the number of matching data block between the component and the
200 * data buffer of a consumer component. It checks which data types from the
201 * list of input data types of the consumer component can be provided by data
202 * blocks of the current component.
203 * @param pConsumerTask the task which subscribes to the data
204 * @return number of matching data blocks
206 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
209 * Determine the number of matching data types between the component and a
210 * consumer component. It checks which data types from the list of input data
211 * types of the consumer component can be provided by the current component.
212 * @param pConsumerTask the task which subscribes to the data
213 * @return number of matching data types
215 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
218 * Subscribe to the data of a source task.
219 * The function prepares the block descriptors for subsequent use with the
220 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
221 * descriptors which match the input data type of the consumer the function
222 * returns the number of blocks which would be prepared in case the target
223 * array is big enough.
224 * @param pConsumerTask the task which subscribes to the data
225 * @param arrayBlockDesc pointer to block descriptor to be filled
226 * @param iArraySize size of the block descriptor array
227 * @return number of matching data blocks, negative error code if failed
229 int Subscribe(const AliHLTTask* pConsumerTask,
230 AliHLTComponentBlockData* arrayBlockDesc, int iArraySize);
233 * Release a block descriptor.
234 * Notification from consumer task.
235 * @param pBlockDesc descriptor of the data segment
236 * @param pConsumerTask the task which subscribed to the data
237 * @return: >0 if success, negative error code if failed
239 int Release(AliHLTComponentBlockData* pBlockDesc,
240 const AliHLTTask* pConsumerTask);
243 * Print the status of the task with component, dependencies and targets.
248 * Search task dependency list recursively to find a dependency.
249 * @param id id of the task to search for
250 * @param pTgtList (optional) target list to receive dependency tree
251 * @return 0 if not found, >0 found in the n-th level,
252 dependency list in the target list
254 int FollowDependency(const char* id, TList* pTgtList=NULL);
257 * Print the tree for a certain dependency either from the task or
258 * configuration list.
259 * Each task posseses two "link lists": The configurations are the origin
260 * of the task list. In case of an error during the built of the task list,
261 * the dependencies for the task list might be incomplete. In this case the
262 * configurations can give infomation on the error reason.
263 * @param id id of the dependency to search for
264 * @param bMode 0 (default) from task dependency list, <br>
265 * 1 from configuration list
267 void PrintDependencyTree(const char* id, int bMode=0);
270 * Get number of source tasks.
271 * @return number of source tasks
273 int GetNofSources() const {return fListDependencies.GetSize();}
276 /** prohibited copy constructor */
277 AliHLTTask(const AliHLTTask&);
278 /** prohibited assignment operator */
279 AliHLTTask& operator=(const AliHLTTask&);
281 /** the configuration descriptor (external pointer) */
282 AliHLTConfiguration* fpConfiguration; //! transient
283 /** the component described by this task (created and deleted internally) */
284 AliHLTComponent* fpComponent; //! transient
285 /** the data buffer for the component processing */
286 AliHLTDataBuffer* fpDataBuffer; //! transient
287 /** the list of targets (tasks which depend upon the current one) */
288 TList fListTargets; // see above
289 /** the list of sources (tasks upon which the current one depends) */
290 TList fListDependencies; // see above
293 * block data array to be passed as argument to the
294 * @ref AliHLTComponent::ProcessEvent method.
295 * Filled through subscription to source tasks (@ref Subscribe).
297 vector<AliHLTComponentBlockData> fBlockDataArray; //! transient
299 ClassDef(AliHLTTask, 2);