6 /* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
7 * See cxx source for full Copyright notice */
10 @author Matthias Richter
12 @brief base class for HLT tasks
15 // see below for class documentation
17 // refer to README to build package
19 // 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);
61 /** not a valid copy constructor, defined according to effective C++ style */
62 AliHLTTask(const AliHLTTask&);
63 /** not a valid assignment op, but defined according to effective C++ style */
64 AliHLTTask& operator=(const AliHLTTask&);
66 virtual ~AliHLTTask();
69 * Initialize the task.
70 * The task is initialized with a configuration descriptor. It needs a
71 * component handler instance to create the analysis component. The
72 * component is created and initialized.
73 * @param pConf pointer to configuration descriptor, can be NULL if it
74 * was already provided to the constructor
75 * @param pCH the HLT component handler
77 int Init(AliHLTConfiguration* pConf, AliHLTComponentHandler* pCH);
80 * De-Initialize the task.
81 * Final cleanup after the run. The @ref AliHLTComponent::Deinit method of
82 * the component is called. The analysis component is deleted.
87 * Get the name of the object.
88 * This is an overridden TObject function in order to return the configuration
89 * name instead of the class name. Enables use of TList standard functions.
90 * @return name of the configuration
92 const char *GetName() const;
95 * Return pointer to configuration.
96 * The tasks holds internally the configuration object.
97 * @return pointer to configuration
99 AliHLTConfiguration* GetConf() const;
102 * Return pointer to component, which the task internally holds.
103 * <b>Never delete this object!!!</b>
104 * @return instance of the component
106 AliHLTComponent* GetComponent() const;
109 * Find a dependency with a certain <i>name id</i>.
110 * Searches in the list of dependencies for a task.
111 * @param id the id of the <b>CONFIGURATION</b><br>
112 * <b>NOTE:</b> the id does NOT specify a COMPONENT
113 * @return pointer to task
115 AliHLTTask* FindDependency(const char* id);
118 * Add a dependency for the task.
119 * The task maintains a list of other tasks it depends on.
120 * @param pDep pointer to a task descriptor
121 * @return 0 if suceeded, neg error code if failed <br>
122 * -EEXIST : the dependencie exists already
125 int SetDependency(AliHLTTask* pDep);
128 * Clear a dependency.
129 * The ROOT TList touches the object which is in the list, even though
130 * it shouldn't care about. Thats why all lists have to be cleared before
131 * objects are deleted.
133 int UnsetDependency(AliHLTTask* pDep);
136 * Return number of unresolved dependencies.
137 * Iterate through all the configurations the task depends on and check
138 * whether a corresponding task is available in the list.
139 * @return number of unresolved dependencies
141 int CheckDependencies();
144 * Check whether the current task depends on the task pTask.
145 * @param pTask pointer to Task descriptor
146 * @return 1 the current task depends on pTask <br>
147 * 0 no dependency <br>
148 * neg. error code if failed
150 int Depends(AliHLTTask* pTask);
153 * Find a target with a certain id.
154 * Tasks which depend on the current task are referred to be <i>targets</i>.
155 * @param id configuration id to search for
156 * @return pointer to task instance
158 AliHLTTask* FindTarget(const char* id);
161 * Insert task into target list.
162 * The target list specifies all the tasks which depend on the current task.
163 * @param pDep pointer task object
164 * @return >=0 if succeeded, neg. error code if failed
166 int SetTarget(AliHLTTask* pDep);
170 * The ROOT TList touches the object which is in the list, even though
171 * it shouldn't care about. Thats why all lists have to be cleared before
172 * objects are deleted.
174 int UnsetTarget(AliHLTTask* pTarget);
177 * Prepare the task for event processing.
178 * The method initializes the Data Buffer and calls the
179 * @ref AliHLTComponent::Init method of the component.<br>
180 * The @ref ProcessTask method can be called an arbitrary number of times
181 * as soon as the task is in <i>running</i> mode.
186 * Clean-up the task after event processing.
187 * The method cleans up internal structures.
193 * If all dependencies are resolved the tasks subscribes to the data of
194 * all source tasks, builds the block descriptor and calls the
195 * @ref AliHLTComponent::ProcessEvent method of the component, after
196 * processing, the data blocks are released. <br>
197 * The @ref StartRun method must be called before.
199 int ProcessTask(Int_t eventNo);
202 * Determine the number of matching data block between the component and the
203 * data buffer of a consumer component. It checks which data types from the
204 * list of input data types of the consumer component can be provided by data
205 * blocks of the current component.
206 * @param pConsumerTask the task which subscribes to the data
207 * @return number of matching data blocks
209 int GetNofMatchingDataBlocks(const AliHLTTask* pConsumerTask) const;
212 * Determine the number of matching data types between the component and a
213 * consumer component. It checks which data types from the list of input data
214 * types of the consumer component can be provided by the current component.
215 * @param pConsumerTask the task which subscribes to the data
216 * @return number of matching data types
218 int GetNofMatchingDataTypes(const AliHLTTask* pConsumerTask) const;
221 * Subscribe to the data of a source task.
222 * The function prepares the block descriptors for subsequent use with the
223 * @ref AliHLTComponent::ProcessEvent method, the method prepares all block
224 * descriptors which match the input data type of the consumer the function
225 * returns the number of blocks which would be prepared in case the target
226 * array is big enough.
227 * @param pConsumerTask the task which subscribes to the data
228 * @param arrayBlockDesc pointer to block descriptor to be filled
229 * @param iArraySize size of the block descriptor array
230 * @return number of matching data blocks, negative error code if failed
232 int Subscribe(const AliHLTTask* pConsumerTask,
233 AliHLTComponentBlockData* arrayBlockDesc, int iArraySize);
236 * Release a block descriptor.
237 * Notification from consumer task.
238 * @param pBlockDesc descriptor of the data segment
239 * @param pConsumerTask the task which subscribed to the data
240 * @return: >0 if success, negative error code if failed
242 int Release(AliHLTComponentBlockData* pBlockDesc,
243 const AliHLTTask* pConsumerTask);
246 * Print the status of the task with component, dependencies and targets.
251 * Search task dependency list recursively to find a dependency.
252 * @param id id of the task to search for
253 * @param pTgtList (optional) target list to receive dependency tree
254 * @return 0 if not found, >0 found in the n-th level,
255 dependency list in the target list
257 int FollowDependency(const char* id, TList* pTgtList=NULL);
260 * Print the tree for a certain dependency either from the task or
261 * configuration list.
262 * Each task posseses two "link lists": The configurations are the origin
263 * of the task list. In case of an error during the built of the task list,
264 * the dependencies for the task list might be incomplete. In this case the
265 * configurations can give infomation on the error reason.
266 * @param id id of the dependency to search for
267 * @param bMode 0 (default) from task dependency list, <br>
268 * 1 from configuration list
270 void PrintDependencyTree(const char* id, int bMode=0);
273 * Get number of source tasks.
274 * @return number of source tasks
276 int GetNofSources() const {return fListDependencies.GetSize();}
279 /** the configuration descriptor (external pointer) */
280 AliHLTConfiguration* fpConfiguration; //! transient
281 /** the component described by this task (created and deleted internally) */
282 AliHLTComponent* fpComponent; //! transient
283 /** the data buffer for the component processing */
284 AliHLTDataBuffer* fpDataBuffer; //! transient
285 /** the list of targets (tasks which depend upon the current one) */
286 TList fListTargets; // see above
287 /** the list of sources (tasks upon which the current one depends) */
288 TList fListDependencies; // see above
291 * block data array to be passed as argument to the
292 * @ref AliHLTComponent::ProcessEvent method.
293 * Filled through subscription to source tasks (@ref Subscribe).
295 AliHLTComponentBlockData* fpBlockDataArray; //! transient
296 /** size of the block data array */
297 int fBlockDataArraySize; // see above
299 ClassDef(AliHLTTask, 1);