5 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
6 * See cxx source for full Copyright notice */
9 @author Matthias Richter
11 @brief base class for HLT tasks
17 #include "AliHLTDataTypes.h"
18 #include "AliHLTLogging.h"
19 #include "AliHLTDataBuffer.h"
21 struct AliHLTComponentBlockData;
22 class AliHLTComponent;
23 class AliHLTComponentHandler;
25 /******************************************************************************/
29 * A task collects all the information which is necessary to process a certain
30 * step in the HLT data processing chain.
31 * - the instance of the component
32 * the task object creates and deletes the component object
33 * - the data buffer which receives the result of the component and provides
34 * the data to other tasks/components
35 * - a list of all dependencies
36 * - a list of consumers
37 * - the task object holds an external pointer to the configuration object;
38 * \b Note: the configuration object must exist through the existence of the
42 * @note This class is only used for the @ref alihlt_system.
44 * @ingroup alihlt_system
46 class AliHLTTask : public TObject, public AliHLTLogging {
48 /** standard constructor */
51 @param pConf pointer to configuration descriptor
53 AliHLTTask(AliHLTConfiguration* pConf);
54 /** not a valid copy constructor, defined according to effective C++ style */
55 AliHLTTask(const AliHLTTask&);
56 /** not a valid assignment op, but defined according to effective C++ style */
57 AliHLTTask& operator=(const AliHLTTask&);
59 virtual ~AliHLTTask();
62 * Initialize the task.
63 * The task is initialized with a configuration descriptor. It needs a
64 * component handler instance to create the analysis component. The
65 * component is created and initialized.
66 * @param pConf pointer to configuration descriptor, can be NULL if it
67 * was already provided to the constructor
68 * @param pCH the HLT component handler
70 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
73 * De-Initialize the task.
74 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
75 * the component is called. The analysis component is deleted.
80 * Get the name of the object.
81 * This is an overridden TObject function in order to return the configuration
82 * name instead of the class name. Enables use of TList standard functions.
83 * @return name of the configuration
85 const char *GetName() const;
88 * Return pointer to configuration.
89 * The tasks holds internally the configuration object.
90 * @return pointer to configuration
92 AliHLTConfiguration* GetConf() const;
95 * Return pointer to component, which the task internally holds.
96 * <b>Never delete this object!!!</b>
97 * @return instance of the component
99 AliHLTComponent* GetComponent() const;
102 * Find a dependency with a certain <i>name id</i>.
103 * Searches in the list of dependencies for a task.
104 * @param id the id of the <b>CONFIGURATION</b><br>
105 * <b>NOTE:</b> the id does NOT specify a COMPONENT
106 * @return pointer to task
108 AliHLTTask* FindDependency(const char* id);
111 * Add a dependency for the task.
112 * The task maintains a list of other tasks it depends on.
113 * @param pDep pointer to a task descriptor
114 * @return 0 if suceeded, neg error code if failed <br>
115 * -EEXIST : the dependencie exists already
118 int SetDependency(AliHLTTask* pDep);
121 * Return number of unresolved dependencies.
122 * Iterate through all the configurations the task depends on and check
123 * whether a corresponding task is available in the list.
124 * @return number of unresolved dependencies
126 int CheckDependencies();
129 * Check whether the current task depends on the task pTask.
130 * @param pTask pointer to Task descriptor
131 * @return 1 the current task depends on pTask <br>
132 * 0 no dependency <br>
133 * neg. error code if failed
135 int Depends(AliHLTTask* pTask);
138 * Find a target with a certain id.
139 * Tasks which depend on the current task are referred to be <i>targets</i>.
140 * @param id configuration id to search for
141 * @return pointer to task instance
143 AliHLTTask* FindTarget(const char* id);
146 * Insert task into target list.
147 * The target list specifies all the tasks which depend on the current task.
148 * @param pDep pointer task object
149 * @return >=0 if succeeded, neg. error code if failed
151 int SetTarget(AliHLTTask* pDep);
154 * Prepare the task for event processing.
155 * The method initializes the Data Buffer and calls the
156 * @ref AliHLTComponent::Init method of the component.<br>
157 * The @ref ProcessTask method can be called an arbitrary number of times
158 * as soon as the task is in <i>running</i> mode.
163 * Clean-up the task after event processing.
164 * The method cleans up internal structures.
170 * If all dependencies are resolved the tasks subscribes to the data of
171 * all source tasks, builds the block descriptor and calls the
172 * @ref AliHLTComponent::ProcessEvent method of the component, after
173 * processing, the data blocks are released. <br>
174 * The @ref StartRun method must be called before.
178 // clear the list of source data blocks
179 // the list of source data blocks has to be cleared at the beginning of
181 /* this function is most likely depricated
182 int ClearSourceBlocks();
186 * Determine the number of matching data block between the component and the
187 * data buffer of a consumer component. It checks which data types from the
188 * list of input data types of the consumer component can be provided by data
189 * blocks of the current component.
190 * @param pConsumerTask the task which subscribes to the data
191 * @return number of matching data blocks
193 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
196 * Determine the number of matching data types between the component and a
197 * consumer component. It checks which data types from the list of input data
198 * types of the consumer component can be provided by the current component.
199 * @param pConsumerTask the task which subscribes to the data
200 * @return number of matching data types
202 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
205 * Subscribe to the data of a source task.
206 * The function prepares the block descriptors for subsequent use with the
207 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
208 * descriptors which match the input data type of the consumer the function
209 * returns the number of blocks which would be prepared in case the target
210 * array is big enough.
211 * @param pConsumerTask the task which subscribes to the data
212 * @param arrayBlockDesc pointer to block descriptor to be filled
213 * @param iArraySize size of the block descriptor array
214 * @return number of matching data blocks, negative error code if failed
216 int Subscribe(const AliHLTTask* pConsumerTask,
217 AliHLTComponentBlockData* arrayBlockDesc, int iArraySize);
220 * Release a block descriptor.
221 * Notification from consumer task.
222 * @param pBlockDesc descriptor of the data segment
223 * @param pConsumerTask the task which subscribed to the data
224 * @return: >0 if success, negative error code if failed
226 int Release(AliHLTComponentBlockData* pBlockDesc,
227 const AliHLTTask* pConsumerTask);
230 * Print the status of the task with component, dependencies and targets.
235 * Search task dependency list recursively to find a dependency.
236 * @param id id of the task to search for
237 * @param pTgtList (optional) target list to receive dependency tree
238 * @return 0 if not found, >0 found in the n-th level,
239 dependency list in the target list
241 int FollowDependency(const char* id, TList* pTgtList=NULL);
244 * Print the tree for a certain dependency either from the task or
245 * configuration list.
246 * Each task posseses two "link lists": The configurations are the origin
247 * of the task list. In case of an error during the built of the task list,
248 * the dependencies for the task list might be incomplete. In this case the
249 * configurations can give infomation on the error reason.
250 * @param id id of the dependency to search for
251 * @param bMode 0 (default) from task dependency list, <br>
252 * 1 from configuration list
254 void PrintDependencyTree(const char* id, int bMode=0);
257 * Get number of source tasks.
258 * @return number of source tasks
260 int GetNofSources() const {return fListDependencies.GetSize();}
263 /** the configuration descriptor (external pointer) */
264 AliHLTConfiguration* fpConfiguration;
265 /** the component described by this task (created and deleted by the task object) */
266 AliHLTComponent* fpComponent;
267 /** the data buffer for the component processing */
268 AliHLTDataBuffer* fpDataBuffer;
269 /** the list of targets (tasks which depend upon the current one) */
271 /** the list of sources (tasks upon which the current one depends) */
272 TList fListDependencies;
275 * block data array to be passed as argument to the
276 * @ref AliHLTComponent::ProcessEvent method.
277 * Filled through subscription to source tasks (@ref Subscribe).
279 AliHLTComponentBlockData* fpBlockDataArray;
280 /** size of the block data array */
281 int fBlockDataArraySize;
283 ClassDef(AliHLTTask, 1);