[857ee3] | 1 | ////////////////////////////////////////////////////////////////////// |
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| 2 | version="version tasks.lib 4.0.0.0 Dec_2013 "; // $Id$ |
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| 3 | category="General purpose"; |
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| 4 | info=" |
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| 5 | LIBRARY: tasks.lib A parallel framework based on tasks |
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| 6 | |
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| 7 | AUTHOR: Andreas Steenpass, e-mail: steenpass@mathematik.uni-kl.de |
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| 8 | |
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| 9 | OVERVIEW: |
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| 10 | This library provides a parallel framework based on tasks. It introduces a new |
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| 11 | Singular type @code{task}; an object of this type is a command (given by a |
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| 12 | string) applied to a list of arguments. Tasks can be computed in parallel via |
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| 13 | the procedures in this library and they can even be started recursively, i.e. |
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| 14 | from within other tasks. |
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| 15 | |
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| 16 | tasks.lib respects the limits for computational resources defined |
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| 17 | in @ref{resources.lib}, i.e., all tasks within the same Singular session will |
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| 18 | not use more computational resources than provided via resources.lib, even if |
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| 19 | tasks are started recursively. |
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| 20 | |
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| 21 | The Singular library @ref{parallel.lib} provides implementations of several |
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| 22 | parallel 'skeletons' based on tasks.lib. |
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| 23 | |
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| 24 | KEYWORDS: parallelization; distributed computing; task |
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| 25 | |
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| 26 | SEE ALSO: resources_lib, parallel_lib |
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| 27 | |
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| 28 | PROCEDURES: |
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| 29 | createTask(); create a task |
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| 30 | killTask(); kill a task |
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| 31 | copyTask(); copy a task |
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| 32 | compareTasks(); compare two tasks |
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| 33 | printTask(); print a task |
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| 34 | startTasks(); start tasks |
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| 35 | stopTask(); stop a task |
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| 36 | waitTasks(); wait for a certain number of tasks |
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| 37 | waitAllTasks(); wait for all tasks |
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| 38 | pollTask(); poll a task |
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| 39 | getCommand(); get the command of a task |
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| 40 | getArguments(); get the arguments of a task |
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| 41 | getResult(); get the result of a task |
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| 42 | getState(); get the state of a task |
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| 43 | "; |
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| 44 | |
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| 45 | /* |
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| 46 | RATIONALE FOR DEVELOPERS |
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| 47 | |
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| 48 | The Singular type 'task' |
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| 49 | ------------------------ |
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| 50 | tasks.lib introduces a Singular type 'task' which makes use of a pointer-like |
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| 51 | model in order to avoid unnecessary copying of data. 'task' is defined as a |
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| 52 | newstruct whose only member is 'int index'. This index points to an entry in |
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| 53 | the lib-internal list 'tasks'. The elements of this list are of the type |
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| 54 | 'internal_task' which is defined as a newstruct with the following members: |
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| 55 | int id - the internal ID |
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| 56 | string command - the command |
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| 57 | list arguments - the arguments |
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| 58 | def result - the result |
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| 59 | string state - the current state, see 'The life cycle of a task' |
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| 60 | list links - control handles, see 'Links' |
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| 61 | int linkID - the ID of the control handles |
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| 62 | |
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| 63 | |
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| 64 | The life cycle of a task |
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| 65 | ------------------------ |
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| 66 | 'uninitialized' --> 'created' --> 'started' --> 'completed' |
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| 67 | | ^ |
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| 68 | v | |
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| 69 | 'stopped' |
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| 70 | |
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| 71 | The state of a task t is 'uninitialized' iff |
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| 72 | (t.index == 0) or (typeof(tasks[t.index]) != "internal_task"). |
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| 73 | |
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| 74 | A task can be reset to 'uninitialized' by killTask() at any time. |
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| 75 | |
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| 76 | |
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| 77 | Assigned members for 'internal_task' |
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| 78 | ------------------------------------ |
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| 79 | For each state, the following members of an internal_task must be assigned: |
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| 80 | |
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| 81 | created: command arguments state |
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| 82 | started: id command arguments state links linkID |
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| 83 | stopped: command arguments state |
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| 84 | completed: command arguments result state |
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| 85 | |
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| 86 | All other members should be wiped out. |
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| 87 | |
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| 88 | Local supervisors |
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| 89 | ----------------- |
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| 90 | A call of 'startTasks(t(1..n));' for tasks t(1), ..., t(n) creates a child |
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| 91 | process which plays the role of a supervisor for these tasks. The computation |
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| 92 | of the tasks is done in child processes of the supervisor. |
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| 93 | |
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| 94 | The supervisor assigns an internal state to each task which is represented by |
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| 95 | an integer. The meaning of these integers and their relation to the global |
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| 96 | state of each task is as follows: |
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| 97 | |
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| 98 | internal state | meaning | corresponding global state |
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| 99 | ---------------|-------------------|--------------------------- |
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| 100 | 0 | waiting | started |
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| 101 | 1 | started | started |
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| 102 | 2 | (result) computed | started |
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| 103 | 3 | (result) sent | completed |
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| 104 | -1 | stopped | stopped |
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| 105 | |
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| 106 | Links |
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| 107 | ----- |
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| 108 | The ssi link between the main process and the supervisor is named 'l(pid)' |
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| 109 | where pid is the PID of the main process. The links between the supervisor and |
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| 110 | its child processes are named 'll(pid)(1)', 'll(pid)(2)', ... where pid is the |
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| 111 | PID of the supervisor. The link between the child processes of the supervisor |
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| 112 | and the main process is named 'L(pid)' where pid is the PID of the main |
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| 113 | process. This link is only for sending the results to the main process and must |
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| 114 | not be used in the other direction! |
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| 115 | |
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| 116 | For any task t whose state is 'started', tasks[t.index].links is |
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| 117 | list(L(pid), l(pid)) where pid is the PID of the main process. |
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| 118 | |
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| 119 | Communication model |
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| 120 | ------------------- |
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| 121 | stopTask() <--> supervisor |
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| 122 | 0, id --> |
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| 123 | |
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| 124 | waitTasks() <--> supervisor |
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| 125 | (demanded_task is an intvec containing the IDs of the tasks which are being |
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| 126 | waited for; ndemanded is the number of tasks that is being waited for.) |
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| 127 | 1, demanded_tasks, ndemanded --> |
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| 128 | [receiving results] |
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| 129 | 1, 0:2, -1 --> |
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| 130 | results_sent <-- |
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| 131 | [receiving remaining results] |
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| 132 | |
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| 133 | pollTask() <--> supervisor |
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| 134 | 2, id --> |
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| 135 | state <-- |
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| 136 | [receive result if state == 2 (computed)] |
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| 137 | |
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| 138 | startTasks_child() <--> startTasks_grandchild() |
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| 139 | [compute the result] |
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| 140 | 1, id <-- |
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| 141 | [wait until the result is requested] |
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| 142 | 1 --> |
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| 143 | [send the result] |
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| 144 | 2 <-- |
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| 145 | |
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| 146 | sending and receiving results: |
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| 147 | main process <--> supervisor <--> startTasks_grandchild() |
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| 148 | [request the result, see above] |
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| 149 | index, result (main process <-- startTasks_grandchild()) |
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| 150 | 3, id (main process --> supervisor) |
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| 151 | */ |
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| 152 | |
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| 153 | LIB "resources.lib"; |
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| 154 | |
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| 155 | static proc mod_init() |
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| 156 | { |
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| 157 | /* initialize the semaphores */ |
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| 158 | if (!defined(Resources)) { |
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| 159 | LIB "resources.lib"; |
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| 160 | } |
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| 161 | // the number of processor cores |
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| 162 | int sem_cores = Resources::sem_cores; |
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| 163 | exportto(Tasks, sem_cores); |
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| 164 | // the number of leaves in the parallel tree (not strict) |
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| 165 | int sem_leaves = semaphore(system("cpu")+10); |
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| 166 | exportto(Tasks, sem_leaves); |
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| 167 | // the number of processes waiting for sem_cores with low priority |
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| 168 | int sem_queue = semaphore(2); |
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| 169 | exportto(Tasks, sem_queue); |
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| 170 | |
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| 171 | /* define the Singular type 'task' */ |
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| 172 | newstruct("task", "int index"); |
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| 173 | newstruct("internal_task", "int id, string command, list arguments," |
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| 174 | +"def result, string state, list links, int linkID"); |
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| 175 | system("install", "task", "=", createTask, 1); |
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| 176 | system("install", "task", "==", compareTasks, 2); |
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| 177 | system("install", "task", "print", printTask, 1); |
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| 178 | |
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| 179 | /* define (lib-)global variables */ |
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| 180 | list tasks; // the lib-internal list of tasks |
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| 181 | exportto(Tasks, tasks); |
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| 182 | int ntasks; // the current maximal index in 'tasks' |
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| 183 | exportto(Tasks, ntasks); |
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| 184 | int nlinkIDs; // the current maximal linkID |
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| 185 | exportto(Tasks, nlinkIDs); |
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| 186 | } |
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| 187 | |
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| 188 | proc createTask(alias string command, alias list arguments) |
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| 189 | "USAGE: createTask(command, arguments), command string, arguments list |
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| 190 | RETURN: a task with the given command and arguments whose state is 'created'. |
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| 191 | NOTE: 't = command, arguments;' is a shortcut for |
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| 192 | 't = createTask(command, arguments);'. |
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| 193 | SEE ALSO: startTasks, getCommand, getArguments, getState, killTask, copyTask, |
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| 194 | compareTasks, printTask |
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| 195 | EXAMPLE: example createTask; shows an example" |
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| 196 | { |
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| 197 | internal_task T; |
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| 198 | ntasks++; |
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| 199 | tasks[ntasks] = T; |
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| 200 | tasks[ntasks].command = command; |
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| 201 | tasks[ntasks].arguments = arguments; |
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| 202 | tasks[ntasks].state = "created"; |
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| 203 | task t; |
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| 204 | t.index = ntasks; |
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| 205 | return(t); |
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| 206 | } |
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| 207 | example |
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| 208 | { |
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| 209 | "EXAMPLE:"; |
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| 210 | echo = 2; |
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| 211 | ring R = 0, (x,y), dp; |
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| 212 | ideal I = x9y2+x10, x2y7-y8; |
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| 213 | task t = createTask("std", list(I)); |
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| 214 | // This is the same as: |
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| 215 | // task t = "std", list(I); |
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| 216 | t; |
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| 217 | killTask(t); |
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| 218 | } |
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| 219 | |
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| 220 | proc killTask(task t) |
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| 221 | "USAGE: killTask(t), t task |
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| 222 | RETURN: nothing. If the state of t is 'started', then t is stopped first. The |
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| 223 | internal data structures of t are erased and its state is set to |
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| 224 | 'uninitialized'. |
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| 225 | NOTE: 'killTask(t);' is not the same as 'kill t;'. The latter command does |
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| 226 | not erase the internal data structures of t. Hence killTask() should |
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| 227 | be called for any no longer needed task in order to free memory. |
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| 228 | SEE ALSO: stopTask, getState, createTask, printTask |
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| 229 | EXAMPLE: example killTask; shows an example" |
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| 230 | { |
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| 231 | if (t.index == 0) { |
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| 232 | return(); |
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| 233 | } |
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| 234 | if (typeof(tasks[t.index]) != "internal_task") { |
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| 235 | return(); |
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| 236 | } |
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| 237 | if (tasks[t.index].state == "started") { |
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| 238 | stopTask(t); |
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| 239 | } |
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| 240 | tasks[t.index] = def(0); |
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| 241 | } |
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| 242 | example |
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| 243 | { |
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| 244 | "EXAMPLE:"; |
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| 245 | echo = 2; |
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| 246 | ring R = 0, (x,y), dp; |
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| 247 | ideal I = x9y2+x10, x2y7-y8; |
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| 248 | task t = "std", list(I); |
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| 249 | startTasks(t); |
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| 250 | t; |
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| 251 | killTask(t); |
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| 252 | t; |
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| 253 | getState(t); |
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| 254 | } |
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| 255 | |
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| 256 | proc copyTask(task t) |
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| 257 | "USAGE: copyTask(t), t task |
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| 258 | RETURN: a copy of t. |
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| 259 | NOTE: 'task t1 = copyTask(t2);' is not the same as 'task t1 = t2;'. After |
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| 260 | the latter command, t1 points to the same object as t2; any changes |
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| 261 | to t2 will also effect t1. In contrast to this, copyTask() creates a |
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| 262 | new independend task. |
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| 263 | @* A task whose state is 'started' cannot be copied. |
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| 264 | SEE ALSO: getCommand, getArguments, getResult, getState, createTask, killTask, |
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| 265 | compareTasks, printTask |
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| 266 | EXAMPLE: example copyTask; shows an example" |
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| 267 | { |
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| 268 | task t_copy; |
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| 269 | if (t.index == 0) { |
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| 270 | return(t_copy); |
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| 271 | } |
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| 272 | if (typeof(tasks[t.index]) != "internal_task") { |
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| 273 | return(t_copy); |
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| 274 | } |
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| 275 | if (tasks[t.index].state == "started") { |
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| 276 | ERROR("cannot copy a task whose state is 'started'"); |
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| 277 | } |
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| 278 | ntasks++; |
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| 279 | tasks[ntasks] = tasks[t.index]; |
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| 280 | t_copy.index = ntasks; |
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| 281 | return(t_copy); |
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| 282 | } |
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| 283 | example |
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| 284 | { |
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| 285 | "EXAMPLE:"; |
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| 286 | echo = 2; |
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| 287 | ring R = 0, (x,y), dp; |
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| 288 | ideal I = x9y2+x10, x2y7-y8; |
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| 289 | task t1 = "std", list(I); |
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| 290 | startTasks(t1); |
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| 291 | waitAllTasks(t1); |
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| 292 | task t2 = copyTask(t1); |
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| 293 | killTask(t1); |
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| 294 | t2; // t2 survived |
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| 295 | getResult(t2); |
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| 296 | killTask(t2); |
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| 297 | } |
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| 298 | |
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| 299 | proc compareTasks(task t1, task t2) |
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| 300 | "USAGE: compareTasks(t1, t2), t1, t2 tasks |
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| 301 | RETURN: 1, if t1 and t2 coincide; |
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| 302 | 0, otherwise. |
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| 303 | NOTE: The arguments and the results of t1 and t2 are not compared. |
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| 304 | @* 't1 == t2' is a shortcut for 'compareTasks(t1, t2)'. |
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| 305 | SEE ALSO: getCommand, getArguments, getResult, getState, copyTask, printTask |
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| 306 | EXAMPLE: example compareTasks; shows an example" |
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| 307 | { |
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| 308 | if (tasks[t1.index].id != tasks[t2.index].id) { |
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| 309 | return(0); |
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| 310 | } |
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| 311 | if (tasks[t1.index].command != tasks[t2.index].command) { |
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| 312 | return(0); |
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| 313 | } |
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| 314 | if (tasks[t1.index].state != tasks[t2.index].state) { |
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| 315 | return(0); |
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| 316 | } |
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| 317 | if (tasks[t1.index].linkID != tasks[t2.index].linkID) { |
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| 318 | return(0); |
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| 319 | } |
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| 320 | return(1); |
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| 321 | } |
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| 322 | example |
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| 323 | { |
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| 324 | "EXAMPLE:"; |
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| 325 | echo = 2; |
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| 326 | ring R = 0, (x,y), dp; |
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| 327 | ideal I = x9y2+x10, x2y7-y8; |
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| 328 | task t1 = "std", list(I); |
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| 329 | task t2 = "std", list(I); |
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| 330 | compareTasks(t1, t2); |
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| 331 | startTasks(t1); |
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| 332 | waitAllTasks(t1); |
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| 333 | t1 == t2; // the same as compareTasks(t1, t2); |
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| 334 | killTask(t1); |
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| 335 | killTask(t2); |
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| 336 | // The arguments and the result are not compared! |
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| 337 | ideal J = x; |
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| 338 | task t3 = "std", list(I); |
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| 339 | task t4 = "std", list(J); |
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| 340 | t3 == t4; |
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| 341 | killTask(t3); |
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| 342 | killTask(t4); |
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| 343 | } |
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| 344 | |
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| 345 | proc printTask(task t) |
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| 346 | "USAGE: printTask(t), t task |
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| 347 | RETURN: nothing. Prints information about t. |
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| 348 | NOTE: 'print(t);' and 't;' are shortcuts for 'printTask(t)'. |
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| 349 | SEE ALSO: getCommand, getArguments, getResult, getState, createTask, killTask |
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| 350 | EXAMPLE: example printTask; shows an example" |
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| 351 | { |
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| 352 | if (t.index == 0) { |
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| 353 | "An uninitialized task"; |
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| 354 | return(); |
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| 355 | } |
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| 356 | if (typeof(tasks[t.index]) != "internal_task") { |
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| 357 | "An uninitialized task"; |
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| 358 | return(); |
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| 359 | } |
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| 360 | "A task with the following properties:"+newline |
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| 361 | +"command: "+tasks[t.index].command+newline |
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| 362 | +"no. of arguments: "+string(size(tasks[t.index].arguments))+newline |
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| 363 | +"state: "+tasks[t.index].state; |
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| 364 | } |
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| 365 | example |
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| 366 | { |
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| 367 | "EXAMPLE:"; |
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| 368 | echo = 2; |
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| 369 | ring R = 0, (x,y), dp; |
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| 370 | ideal I = x9y2+x10, x2y7-y8; |
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| 371 | task t; |
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| 372 | printTask(t); |
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| 373 | t = "std", list(I); |
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| 374 | t; // the same as printTask(t); |
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| 375 | startTasks(t); |
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| 376 | waitAllTasks(t); |
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| 377 | t; |
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| 378 | killTask(t); |
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| 379 | } |
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| 380 | |
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| 381 | proc startTasks(list #) |
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| 382 | "USAGE: startTasks(t1, t2, ...), t1, t2, ... tasks |
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| 383 | RETURN: nothing. Starts the tasks t1, t2, ... and sets their states to |
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| 384 | 'started'. |
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| 385 | NOTE: A task whose state is neither 'created' nor 'stopped' cannot be |
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| 386 | started. |
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| 387 | @* If startTasks() is applied to a task whose state is 'stopped', then |
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| 388 | the computation of this task will be restarted from the beginning. |
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| 389 | @* Tasks can be started from within other tasks. A started task should |
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| 390 | not be accessed from within any task other than the one within which |
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| 391 | it was started. |
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| 392 | @* For each task, the start of its computation is subject to the |
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| 393 | internal scheduling. |
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| 394 | SEE ALSO: stopTask, waitTasks, pollTask, getState, createTask, printTask |
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| 395 | EXAMPLE: example startTasks; shows an example" |
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| 396 | { |
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| 397 | int nargs = size(#); |
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| 398 | if (nargs == 0) { |
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| 399 | ERROR("missing argument"); |
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| 400 | } |
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| 401 | int i; |
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| 402 | for (i = nargs; i > 0; i--) { |
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| 403 | if (typeof(#[i]) != "task") { |
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| 404 | ERROR("argument not of type 'task' (argument no. "+string(i)+")"); |
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| 405 | } |
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| 406 | if (#[i].index == 0) { |
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| 407 | ERROR("cannot start an uninitialized task (task no. " |
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| 408 | +string(i)+")"); |
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| 409 | } |
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| 410 | if (typeof(tasks[#[i].index]) != "internal_task") { |
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| 411 | ERROR("cannot start an uninitialized task (task no. " |
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| 412 | +string(i)+")"); |
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| 413 | } |
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| 414 | if (tasks[#[i].index].state != "created" |
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| 415 | && tasks[#[i].index].state != "stopped") { |
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| 416 | ERROR("cannot start a task whose state is not"+newline |
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| 417 | +"'created' or 'stopped'"); |
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| 418 | } |
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| 419 | } |
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| 420 | for (i = nargs; i > 0; i--) { |
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| 421 | tasks[#[i].index].id = i; // has to be set before forking |
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| 422 | tasks[#[i].index].state = "started"; |
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| 423 | } |
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| 424 | int pid = system("pid"); |
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| 425 | link l(pid) = "ssi:fork"; |
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| 426 | open(l(pid)); |
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| 427 | write(l(pid), quote(startTasks_child(#, eval(pid)))); |
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| 428 | int port = read(l(pid)); |
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| 429 | link L(pid) = "ssi:connect localhost:"+string(port); |
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| 430 | open(L(pid)); |
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| 431 | nlinkIDs++; |
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| 432 | for (i = nargs; i > 0; i--) { |
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| 433 | tasks[#[i].index].links = list(L(pid), l(pid)); |
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| 434 | tasks[#[i].index].linkID = nlinkIDs; |
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| 435 | } |
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| 436 | } |
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| 437 | example |
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| 438 | { |
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| 439 | "EXAMPLE:"; |
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| 440 | echo = 2; |
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| 441 | ring R = 0, (x,y), dp; |
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| 442 | ideal I = x9y2+x10, x2y7-y8; |
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| 443 | task t1 = "std", list(I); |
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| 444 | task t2 = "slimgb", list(I); |
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| 445 | startTasks(t1, t2); |
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| 446 | waitAllTasks(t1, t2); |
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| 447 | getResult(t1); |
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| 448 | getResult(t2); |
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| 449 | killTask(t1); |
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| 450 | killTask(t2); |
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| 451 | } |
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| 452 | |
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| 453 | /* This procedure is started within the child after forking. */ |
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| 454 | static proc startTasks_child(list localtasks, int pid_parent) |
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| 455 | { |
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| 456 | int port = system("reserve", 1); |
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| 457 | write(l(pid_parent), port); |
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| 458 | link L(pid_parent) = system("reservedLink"); |
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| 459 | export(L(pid_parent)); |
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| 460 | |
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| 461 | int sem_write = semaphore(1); |
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| 462 | int pid = system("pid"); |
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| 463 | |
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| 464 | int nlocaltasks = size(localtasks); |
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| 465 | intvec state = 0:nlocaltasks; |
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| 466 | // the internal state of each localtask (see rationale) |
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| 467 | int nwaiting = nlocaltasks; |
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| 468 | // the number of local tasks with internal state 0 (waiting) |
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| 469 | int nfinished; |
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| 470 | // the number of local tasks with internal state 3 (result sent) or |
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| 471 | // -1 (stopped) |
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| 472 | intvec queue = 0, 1..nlocaltasks, 0; // zeroes for easier handling |
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| 473 | |
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| 474 | list links; |
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| 475 | links[nlocaltasks+1] = l(pid_parent); |
---|
| 476 | intvec assignment = 0:nlocaltasks; |
---|
| 477 | // the task with id = i is running in link no. assignment[i] |
---|
| 478 | int nlinks; |
---|
| 479 | |
---|
| 480 | // data sent by other processes |
---|
| 481 | int code; |
---|
| 482 | int id; |
---|
| 483 | intvec demanded_tasks = 0, 0; // zeroes for easier handling |
---|
| 484 | int ndemanded = -1; |
---|
| 485 | |
---|
| 486 | // internal counts |
---|
| 487 | int granted_leaves; |
---|
| 488 | int results_sent; |
---|
| 489 | |
---|
| 490 | // auxiliary variables |
---|
| 491 | int wait; |
---|
| 492 | int deadlock; |
---|
| 493 | int tmp; |
---|
| 494 | int i; |
---|
| 495 | |
---|
| 496 | while (nwaiting > 0) { |
---|
| 497 | wait = 0; |
---|
| 498 | if (nlinks == 0) { |
---|
| 499 | wait = -1; |
---|
| 500 | granted_leaves++; |
---|
| 501 | while (-wait < nwaiting) { |
---|
| 502 | if (system("semaphore", "try_acquire", sem_leaves) == 1) { |
---|
| 503 | wait--; |
---|
| 504 | } |
---|
| 505 | else { |
---|
| 506 | break; |
---|
| 507 | } |
---|
| 508 | } |
---|
| 509 | } |
---|
| 510 | while (wait == 0) { |
---|
| 511 | wait = waitfirst(links, 500); |
---|
| 512 | if (wait == 0) { |
---|
| 513 | while (-wait < nwaiting) { |
---|
| 514 | if (system("semaphore", "try_acquire", sem_leaves) == 1) { |
---|
| 515 | wait--; |
---|
| 516 | } |
---|
| 517 | else { |
---|
| 518 | break; |
---|
| 519 | } |
---|
| 520 | } |
---|
| 521 | } |
---|
| 522 | } |
---|
| 523 | if (wait < 0) { // open (-wait) new links |
---|
| 524 | while (wait < 0) { |
---|
| 525 | wait++; |
---|
| 526 | nlinks++; |
---|
| 527 | link ll(pid)(nlinks) = "ssi:fork"; |
---|
| 528 | open(ll(pid)(nlinks)); |
---|
| 529 | links[nlinks] = ll(pid)(nlinks); |
---|
| 530 | write(links[nlinks], |
---|
| 531 | quote(startTasks_grandchild( |
---|
| 532 | eval(localtasks[queue[2]].index), eval(pid_parent), |
---|
| 533 | eval(pid), eval(nlinks), eval(sem_write)))); |
---|
| 534 | assignment[queue[2]] = nlinks; |
---|
| 535 | state[queue[2]] = 1; |
---|
| 536 | nwaiting--; |
---|
| 537 | queue = 0, queue[3..size(queue)]; |
---|
| 538 | } |
---|
| 539 | // wait == 0 |
---|
| 540 | } |
---|
| 541 | if (wait > 0 && wait <= nlocaltasks) { |
---|
| 542 | code = read(links[wait]); |
---|
| 543 | if (code == 1) { // result computed |
---|
| 544 | id = read(links[wait]); |
---|
| 545 | state[id] = 2; |
---|
| 546 | if (ndemanded > 0 && isElement(demanded_tasks, id)) { |
---|
| 547 | write(links[wait], 1); |
---|
| 548 | demanded_tasks = removeFromIntvec(demanded_tasks, id); |
---|
| 549 | ndemanded--; |
---|
| 550 | results_sent++; |
---|
| 551 | } |
---|
| 552 | } |
---|
| 553 | // code == 2: startTasks_grandchild() ended, do nothing |
---|
| 554 | } |
---|
| 555 | if (wait == nlocaltasks+1) { |
---|
| 556 | code = read(l(pid_parent)); |
---|
| 557 | if (code == 0) { // stopTask |
---|
| 558 | id = read(l(pid_parent)); |
---|
| 559 | if (state[id] == 0) { // waiting |
---|
| 560 | queue = removeFromIntvec(queue, id); |
---|
| 561 | } |
---|
| 562 | if (state[id] == 1 || state[id] == 2) { // started or computed |
---|
| 563 | close(links[assignment[id]]); |
---|
| 564 | open(links[assignment[id]]); |
---|
| 565 | write(links[assignment[id]], |
---|
| 566 | quote(startTasks_grandchild( |
---|
| 567 | eval(localtasks[queue[2]].index), eval(pid_parent), |
---|
| 568 | eval(pid), eval(assignment[id]), eval(sem_write)))); |
---|
| 569 | assignment[queue[2]] = assignment[id]; |
---|
| 570 | assignment[id] = 0; |
---|
| 571 | state[queue[2]] = 1; |
---|
| 572 | queue = 0, queue[3..size(queue)]; |
---|
| 573 | } |
---|
| 574 | // state[id] == -1 (stopped) or state[id] == 3 (sent) |
---|
| 575 | // should not happen |
---|
| 576 | nwaiting--; |
---|
| 577 | nfinished++; |
---|
| 578 | state[id] = -1; |
---|
| 579 | } |
---|
| 580 | if (code == 1) { // waitTasks |
---|
| 581 | demanded_tasks = read(l(pid_parent)); |
---|
| 582 | ndemanded = read(l(pid_parent)); |
---|
| 583 | if (ndemanded > size(demanded_tasks)-2) { |
---|
| 584 | ndemanded = size(demanded_tasks)-2; |
---|
| 585 | } |
---|
| 586 | if (demanded_tasks == 0:2 && ndemanded == -1) { |
---|
| 587 | write(l(pid_parent), results_sent); |
---|
| 588 | } |
---|
| 589 | else { |
---|
| 590 | results_sent = 0; |
---|
| 591 | } |
---|
| 592 | deadlock = 0; |
---|
| 593 | for (i = size(demanded_tasks)-1; i > 1; i--) { |
---|
| 594 | id = demanded_tasks[i]; |
---|
| 595 | if (state[id] == 0) { // waiting |
---|
| 596 | queue = give_priority(queue, id); |
---|
| 597 | deadlock = 1; |
---|
| 598 | } |
---|
| 599 | if (state[id] == 2) { // computed |
---|
| 600 | write(links[assignment[id]], 1); |
---|
| 601 | demanded_tasks = removeFromIntvec(demanded_tasks, id); |
---|
| 602 | ndemanded--; |
---|
| 603 | results_sent++; |
---|
| 604 | } |
---|
| 605 | } |
---|
| 606 | for (i = size(demanded_tasks)-1; i > 1; i--) { |
---|
| 607 | id = demanded_tasks[i]; |
---|
| 608 | if (state[id] == 1) { // started |
---|
| 609 | deadlock = 0; |
---|
| 610 | } |
---|
| 611 | } |
---|
| 612 | if (deadlock) { |
---|
| 613 | granted_leaves++; |
---|
| 614 | nlinks++; |
---|
| 615 | link ll(pid)(nlinks) = "ssi:fork"; |
---|
| 616 | open(ll(pid)(nlinks)); |
---|
| 617 | links[nlinks] = ll(pid)(nlinks); |
---|
| 618 | write(links[nlinks], |
---|
| 619 | quote(startTasks_grandchild( |
---|
| 620 | eval(localtasks[queue[2]].index), eval(pid_parent), |
---|
| 621 | eval(pid), eval(nlinks), eval(sem_write)))); |
---|
| 622 | assignment[queue[2]] = nlinks; |
---|
| 623 | state[queue[2]] = 1; |
---|
| 624 | nwaiting--; |
---|
| 625 | queue = 0, queue[3..size(queue)]; |
---|
| 626 | } |
---|
| 627 | } |
---|
| 628 | if (code == 2) { // pollTask |
---|
| 629 | id = read(l(pid_parent)); |
---|
| 630 | if (state[id] == 0) { // waiting |
---|
| 631 | queue = give_priority(queue, id); |
---|
| 632 | } |
---|
| 633 | if (state[id] == 2) { // computed |
---|
| 634 | write(links[assignment[id]], 1); |
---|
| 635 | } |
---|
| 636 | write(l(pid_parent), state[id]); |
---|
| 637 | } |
---|
| 638 | if (code == 3) { // got result |
---|
| 639 | id = read(l(pid_parent)); |
---|
| 640 | write(links[assignment[id]], |
---|
| 641 | quote(startTasks_grandchild( |
---|
| 642 | eval(localtasks[queue[2]].index), eval(pid_parent), |
---|
| 643 | eval(pid), eval(assignment[id]), eval(sem_write)))); |
---|
| 644 | assignment[queue[2]] = assignment[id]; |
---|
| 645 | assignment[id] = 0; |
---|
| 646 | state[queue[2]] = 1; |
---|
| 647 | state[id] = 3; |
---|
| 648 | nwaiting--; |
---|
| 649 | nfinished++; |
---|
| 650 | queue = 0, queue[3..size(queue)]; |
---|
| 651 | } |
---|
| 652 | } |
---|
| 653 | } |
---|
| 654 | while (nfinished < nlocaltasks || ndemanded != -1) { |
---|
| 655 | wait = waitfirst(links); |
---|
| 656 | if (wait <= nlocaltasks) { |
---|
| 657 | code = read(links[wait]); |
---|
| 658 | if (code == 1) { // result computed |
---|
| 659 | id = read(links[wait]); |
---|
| 660 | state[id] = 2; |
---|
| 661 | if (ndemanded > 0 && isElement(demanded_tasks, id)) { |
---|
| 662 | write(links[wait], 1); |
---|
| 663 | demanded_tasks = removeFromIntvec(demanded_tasks, id); |
---|
| 664 | ndemanded--; |
---|
| 665 | results_sent++; |
---|
| 666 | } |
---|
| 667 | } |
---|
| 668 | // code == 2: startTasks_grandchild() ended, do nothing |
---|
| 669 | } |
---|
| 670 | if (wait == nlocaltasks+1) { |
---|
| 671 | code = read(l(pid_parent)); |
---|
| 672 | if (code == 0) { // stopTask |
---|
| 673 | id = read(l(pid_parent)); |
---|
| 674 | if (state[id] == 1 || state[id] == 2) { // started or computed |
---|
| 675 | close(links[assignment[id]]); |
---|
| 676 | if (nlinks > granted_leaves) { |
---|
| 677 | tmp = system("semaphore", "release", sem_leaves); |
---|
| 678 | } |
---|
| 679 | links[assignment[id]] = def(0); |
---|
| 680 | nlinks--; |
---|
| 681 | assignment[id] = 0; |
---|
| 682 | nfinished++; |
---|
| 683 | } |
---|
| 684 | // else: nothing to do |
---|
| 685 | state[id] = -1; |
---|
| 686 | } |
---|
| 687 | if (code == 1) { // waitTasks |
---|
| 688 | demanded_tasks = read(l(pid_parent)); |
---|
| 689 | ndemanded = read(l(pid_parent)); |
---|
| 690 | if (ndemanded > size(demanded_tasks)-2) { |
---|
| 691 | ndemanded = size(demanded_tasks)-2; |
---|
| 692 | } |
---|
| 693 | if (demanded_tasks == 0:2 && ndemanded == -1) { |
---|
| 694 | write(l(pid_parent), results_sent); |
---|
| 695 | } |
---|
| 696 | else { |
---|
| 697 | results_sent = 0; |
---|
| 698 | } |
---|
| 699 | for (i = size(demanded_tasks)-1; i > 1; i--) { |
---|
| 700 | id = demanded_tasks[i]; |
---|
| 701 | if (state[id] == 2) { // computed |
---|
| 702 | write(links[assignment[id]], 1); |
---|
| 703 | demanded_tasks = removeFromIntvec(demanded_tasks, id); |
---|
| 704 | ndemanded--; |
---|
| 705 | results_sent++; |
---|
| 706 | } |
---|
| 707 | } |
---|
| 708 | } |
---|
| 709 | if (code == 2) { // pollTask |
---|
| 710 | id = read(l(pid_parent)); |
---|
| 711 | if (state[id] == 2) { // computed |
---|
| 712 | write(links[assignment[id]], 1); |
---|
| 713 | } |
---|
| 714 | write(l(pid_parent), state[id]); |
---|
| 715 | } |
---|
| 716 | if (code == 3) { // got result |
---|
| 717 | id = read(l(pid_parent)); |
---|
| 718 | close(links[assignment[id]]); |
---|
| 719 | if (nlinks > granted_leaves) { |
---|
| 720 | tmp = system("semaphore", "release", sem_leaves); |
---|
| 721 | } |
---|
| 722 | links[assignment[id]] = def(0); |
---|
| 723 | nlinks--; |
---|
| 724 | assignment[id] = 0; |
---|
| 725 | state[id] = 3; |
---|
| 726 | nfinished++; |
---|
| 727 | } |
---|
| 728 | } |
---|
| 729 | } |
---|
| 730 | } |
---|
| 731 | |
---|
| 732 | /* This procedure has to be started within the grandchildren after forking. */ |
---|
| 733 | static proc startTasks_grandchild(int index, int pid_grandparent, |
---|
| 734 | int pid_parent, int link_no, int sem_write) |
---|
| 735 | { |
---|
| 736 | def result; |
---|
| 737 | int tmp = system("semaphore", "acquire", sem_queue); |
---|
| 738 | tmp = system("semaphore", "acquire", sem_cores); |
---|
| 739 | tmp = system("semaphore", "release", sem_queue); |
---|
| 740 | execute("result = "+tasks[index].command+"(" |
---|
| 741 | +argsToString("tasks[index].arguments", size(tasks[index].arguments)) |
---|
| 742 | +");"); |
---|
| 743 | tmp = system("semaphore", "release", sem_cores); |
---|
| 744 | write(ll(pid_parent)(link_no), 1); |
---|
| 745 | write(ll(pid_parent)(link_no), tasks[index].id); |
---|
| 746 | tmp = read(ll(pid_parent)(link_no)); |
---|
| 747 | tmp = system("semaphore", "acquire", sem_write); |
---|
| 748 | write(L(pid_grandparent), index); |
---|
| 749 | write(L(pid_grandparent), result); |
---|
| 750 | tmp = system("semaphore", "release", sem_write); |
---|
| 751 | return(2); |
---|
| 752 | } |
---|
| 753 | |
---|
| 754 | /* Check if n is an element of v[2..(size(v)-1)]. |
---|
| 755 | * Note that v[1] and v[size(v)] are not checked. |
---|
| 756 | */ |
---|
| 757 | static proc isElement(alias intvec v, alias int n) |
---|
| 758 | { |
---|
| 759 | int i; |
---|
| 760 | for (i = size(v)-1; i > 1; i--) { |
---|
| 761 | if (v[i] == n) { |
---|
| 762 | return(1); |
---|
| 763 | } |
---|
| 764 | } |
---|
| 765 | return(0); |
---|
| 766 | } |
---|
| 767 | |
---|
| 768 | /* Remove the first occurence (if any) of n in v[2..(size(v)-1)]. |
---|
| 769 | * Note that v[1] and v[size(v)] are not checked. |
---|
| 770 | */ |
---|
| 771 | static proc removeFromIntvec(intvec v, int n) |
---|
| 772 | { |
---|
| 773 | int size_v = size(v); |
---|
| 774 | int i; |
---|
| 775 | for (i = size_v-1; i > 1; i--) { |
---|
| 776 | if (v[i] == n) { |
---|
| 777 | return(v[1..(i-1)], v[(i+1)..size_v]); |
---|
| 778 | } |
---|
| 779 | } |
---|
| 780 | return(v); |
---|
| 781 | } |
---|
| 782 | |
---|
| 783 | /* Move the first occurence (if any) of id in queue[2..(size(queue)-1)] to |
---|
| 784 | * queue[2]. Note that queue[1] and queue[size(v)] are not checked. |
---|
| 785 | */ |
---|
| 786 | static proc give_priority(intvec queue, int id) |
---|
| 787 | { |
---|
| 788 | int size_queue = size(queue); |
---|
| 789 | int i; |
---|
| 790 | for (i = size_queue-1; i > 2; i--) { |
---|
| 791 | if (queue[i] == id) { |
---|
| 792 | return(0, id, queue[2..(i-1)], queue[(i+1)..size_queue]); |
---|
| 793 | } |
---|
| 794 | } |
---|
| 795 | return(queue); |
---|
| 796 | } |
---|
| 797 | |
---|
| 798 | proc stopTask(task t) |
---|
| 799 | "USAGE: stopTask(t), t task |
---|
| 800 | RETURN: nothing. Stops the t and sets its state to 'stopped'. |
---|
| 801 | NOTE: A task whose state is not 'started' cannot be stopped. |
---|
| 802 | @* Intermediate results are discarded when a task is stopped. |
---|
| 803 | @* killTask() should be called for any no longer needed task. |
---|
| 804 | SEE ALSO: startTasks, waitTasks, pollTask, getState, killTask, printTask |
---|
| 805 | EXAMPLE: example stopTask; shows an example" |
---|
| 806 | { |
---|
| 807 | if (t.index == 0) { |
---|
| 808 | ERROR("cannot stop an uninitialized task"); |
---|
| 809 | } |
---|
| 810 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 811 | ERROR("cannot stop an uninitialized task"); |
---|
| 812 | } |
---|
| 813 | if (tasks[t.index].state != "started") { |
---|
| 814 | ERROR("cannot stop a task whose state is not 'started'"); |
---|
| 815 | } |
---|
| 816 | write(tasks[t.index].links[2], 0); |
---|
| 817 | write(tasks[t.index].links[2], tasks[t.index].id); |
---|
| 818 | tasks[t.index].id = 0; |
---|
| 819 | tasks[t.index].links = list(); |
---|
| 820 | tasks[t.index].linkID = 0; |
---|
| 821 | tasks[t.index].state = "stopped"; |
---|
| 822 | } |
---|
| 823 | example |
---|
| 824 | { |
---|
| 825 | "EXAMPLE:"; |
---|
| 826 | echo = 2; |
---|
| 827 | ring R = 0, (x,y), dp; |
---|
| 828 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 829 | task t = "std", list(I); |
---|
| 830 | startTasks(t); |
---|
| 831 | stopTask(t); |
---|
| 832 | t; |
---|
| 833 | killTask(t); |
---|
| 834 | } |
---|
| 835 | |
---|
| 836 | proc waitTasks(list T, int N, list #) |
---|
| 837 | "USAGE: waitTasks(T, N[, timeout]), T list of tasks, N int, timeout int |
---|
| 838 | RETURN: an ordered list of the indices of those tasks which have been |
---|
| 839 | successfully completed. The state of these tasks is set to |
---|
| 840 | 'completed'. |
---|
| 841 | @* The procedure waits for N tasks to complete. |
---|
| 842 | @* An optional timeout in ms can be provided. Default is 0 which |
---|
| 843 | disables the timeout. |
---|
| 844 | NOTE: A task whose state is neither 'started' nor 'completed' cannot be |
---|
| 845 | waited for. |
---|
| 846 | @* The result of any completed task can be accessed via @ref{getResult}. |
---|
| 847 | @* The returned list may contain more than N entries if the computation |
---|
| 848 | of some tasks has already finished and/or if several tasks finish |
---|
| 849 | \"at the same time\". It may contain less than N entries in |
---|
| 850 | the case of timeout or errors occurring. |
---|
| 851 | @* Polling is guaranteed, i.e. the index of any task t for which |
---|
| 852 | 'pollTask(t);' would return 1 will appear in the returned list. |
---|
| 853 | SEE ALSO: startTasks, pollTask, getResult, getState, printTask |
---|
| 854 | EXAMPLE: example waitTasks; shows an example" |
---|
| 855 | { |
---|
| 856 | /* initialize the timer */ |
---|
| 857 | int oldtimerresolution = system("--ticks-per-sec"); |
---|
| 858 | system("--ticks-per-sec", 1000); |
---|
| 859 | int starting_time = rtimer; |
---|
| 860 | |
---|
| 861 | /* read optional parameters */ |
---|
| 862 | int timeout; |
---|
| 863 | if (size(#) > 0) { |
---|
| 864 | if (size(#) > 1 || typeof(#[1]) != "int") { |
---|
| 865 | ERROR("wrong optional parameter"); |
---|
| 866 | } |
---|
| 867 | timeout = #[1]; |
---|
| 868 | } |
---|
| 869 | |
---|
| 870 | /* check for errors */ |
---|
| 871 | if (timeout < 0) { |
---|
| 872 | ERROR("negative timeout"); |
---|
| 873 | } |
---|
| 874 | int nargs = size(T); |
---|
| 875 | if (nargs == 0) { |
---|
| 876 | ERROR("missing task"); |
---|
| 877 | } |
---|
| 878 | if (N < 1 || N > nargs) { |
---|
| 879 | ERROR("wrong number of tasks to wait for"); |
---|
| 880 | } |
---|
| 881 | int i; |
---|
| 882 | for (i = nargs; i > 0; i--) { |
---|
| 883 | if (typeof(T[i]) != "task") { |
---|
| 884 | ERROR("element not of type 'task' (element no. "+string(i)+")"); |
---|
| 885 | } |
---|
| 886 | if (T[i].index == 0) { |
---|
| 887 | ERROR("cannot wait for an uninitialized task (task no. "+string(i) |
---|
| 888 | +")"); |
---|
| 889 | } |
---|
| 890 | if (typeof(tasks[T[i].index]) != "internal_task") { |
---|
| 891 | ERROR("cannot wait for an uninitialized task (task no. "+string(i) |
---|
| 892 | +")"); |
---|
| 893 | } |
---|
| 894 | if (tasks[T[i].index].state != "started" |
---|
| 895 | && tasks[T[i].index].state != "completed") { |
---|
| 896 | ERROR("cannot wait for a task whose state is not"+newline |
---|
| 897 | +"'started' or 'completed' (task no. "+string(i)+")"); |
---|
| 898 | } |
---|
| 899 | } |
---|
| 900 | |
---|
| 901 | /* sort the tasks */ |
---|
| 902 | int ncompleted; |
---|
| 903 | list requests; |
---|
| 904 | list links; |
---|
| 905 | int sorted_in; |
---|
| 906 | int j; |
---|
| 907 | for (i = 1; i <= nargs; i++) { |
---|
| 908 | if (tasks[T[i].index].state == "completed") { |
---|
| 909 | ncompleted++; |
---|
| 910 | } |
---|
| 911 | else { // tasks[T[i].index].state == "started" |
---|
| 912 | sorted_in = 0; |
---|
| 913 | for (j = size(requests); j > 0; j--) { |
---|
| 914 | if (requests[j][1] == tasks[T[i].index].linkID) { |
---|
| 915 | requests[j][2][size(requests[j][2])+1] = |
---|
| 916 | tasks[T[i].index].id; |
---|
| 917 | sorted_in = 1; |
---|
| 918 | break; |
---|
| 919 | } |
---|
| 920 | } |
---|
| 921 | if (!sorted_in) { |
---|
| 922 | requests[size(requests)+1] = list(tasks[T[i].index].linkID, |
---|
| 923 | intvec(0, tasks[T[i].index].id), |
---|
| 924 | tasks[T[i].index].links[2]); |
---|
| 925 | links[size(links)+1] = tasks[T[i].index].links[1]; |
---|
| 926 | } |
---|
| 927 | } |
---|
| 928 | } |
---|
| 929 | |
---|
| 930 | /* send the reqests */ |
---|
| 931 | for (j = size(requests); j > 0; j--) { |
---|
| 932 | requests[j][2][size(requests[j][2])+1] = 0; |
---|
| 933 | write(requests[j][3], 1); |
---|
| 934 | write(requests[j][3], requests[j][2]); |
---|
| 935 | write(requests[j][3], N-ncompleted); |
---|
| 936 | } |
---|
| 937 | |
---|
| 938 | /* wait for the results */ |
---|
| 939 | int wait; |
---|
| 940 | int index; |
---|
| 941 | int results_got; |
---|
| 942 | int remaining_time; |
---|
| 943 | int tmp; |
---|
| 944 | while (ncompleted < N) { |
---|
| 945 | wait = waitfirst(links, 0); |
---|
| 946 | if (wait == 0) { |
---|
| 947 | if (timeout == 0) { |
---|
| 948 | tmp = system("semaphore", "release", sem_cores); |
---|
| 949 | wait = waitfirst(links); |
---|
| 950 | tmp = system("semaphore", "acquire", sem_cores); |
---|
| 951 | } |
---|
| 952 | else { |
---|
| 953 | remaining_time = timeout-(rtimer-starting_time); |
---|
| 954 | if (remaining_time < 0) { |
---|
| 955 | break; |
---|
| 956 | } |
---|
| 957 | else { |
---|
| 958 | tmp = system("semaphore", "release", sem_cores); |
---|
| 959 | wait = waitfirst(links, remaining_time); |
---|
| 960 | tmp = system("semaphore", "acquire", sem_cores); |
---|
| 961 | } |
---|
| 962 | } |
---|
| 963 | } |
---|
| 964 | if (wait < 1) { |
---|
| 965 | break; |
---|
| 966 | } |
---|
| 967 | index = read(links[wait]); |
---|
| 968 | tasks[index].result = read(links[wait]); |
---|
| 969 | write(tasks[index].links[2], 3); |
---|
| 970 | write(tasks[index].links[2], tasks[index].id); |
---|
| 971 | tasks[index].id = 0; |
---|
| 972 | tasks[index].links = list(); |
---|
| 973 | tasks[index].linkID = 0; |
---|
| 974 | tasks[index].state = "completed"; |
---|
| 975 | ncompleted++; |
---|
| 976 | results_got++; |
---|
| 977 | } |
---|
| 978 | if (wait == -1) { |
---|
| 979 | ERROR("error in waitfirst()"); |
---|
| 980 | } |
---|
| 981 | |
---|
| 982 | /* end communication process */ |
---|
| 983 | for (j = size(requests); j > 0; j--) { |
---|
| 984 | write(requests[j][3], 1); |
---|
| 985 | write(requests[j][3], 0:2); |
---|
| 986 | write(requests[j][3], -1); |
---|
| 987 | } |
---|
| 988 | int results_sent; |
---|
| 989 | for (j = size(requests); j > 0; j--) { |
---|
| 990 | results_sent = results_sent + read(requests[j][3]); |
---|
| 991 | } |
---|
| 992 | while (results_sent > results_got) { |
---|
| 993 | wait = waitfirst(links); |
---|
| 994 | if (wait == -1) { |
---|
| 995 | ERROR("error in waitfirst()"); |
---|
| 996 | } |
---|
| 997 | index = read(links[wait]); |
---|
| 998 | tasks[index].result = read(links[wait]); |
---|
| 999 | write(tasks[index].links[2], 3); |
---|
| 1000 | write(tasks[index].links[2], tasks[index].id); |
---|
| 1001 | tasks[index].id = 0; |
---|
| 1002 | tasks[index].links = list(); |
---|
| 1003 | tasks[index].linkID = 0; |
---|
| 1004 | tasks[index].state = "completed"; |
---|
| 1005 | results_got++; |
---|
| 1006 | } |
---|
| 1007 | |
---|
| 1008 | /* list completed tasks */ |
---|
| 1009 | list completed; |
---|
| 1010 | completed[nargs+1] = 0; |
---|
| 1011 | j = 0; |
---|
| 1012 | for (i = 1; i <= nargs; i++) { |
---|
| 1013 | if (tasks[T[i].index].state == "completed") { |
---|
| 1014 | j++; |
---|
| 1015 | completed[j] = i; |
---|
| 1016 | } |
---|
| 1017 | } |
---|
| 1018 | completed[nargs+1] = def(0); |
---|
| 1019 | |
---|
| 1020 | /* return the result */ |
---|
| 1021 | system("--ticks-per-sec", oldtimerresolution); |
---|
| 1022 | return(completed); |
---|
| 1023 | } |
---|
| 1024 | example |
---|
| 1025 | { |
---|
| 1026 | "EXAMPLE:"; |
---|
| 1027 | echo = 2; |
---|
| 1028 | ring R = 0, (x,y), dp; |
---|
| 1029 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1030 | task t1 = "std", list(I); |
---|
| 1031 | task t2 = "slimgb", list(I); |
---|
| 1032 | startTasks(t1, t2); |
---|
| 1033 | waitTasks(list(t1, t2), 2); // wait for both tasks |
---|
| 1034 | getResult(t1); |
---|
| 1035 | getResult(t2); |
---|
| 1036 | killTask(t1); |
---|
| 1037 | killTask(t2); |
---|
| 1038 | } |
---|
| 1039 | |
---|
| 1040 | proc waitAllTasks(list #) |
---|
| 1041 | "USAGE: waitAllTasks(t1, t2, ...), t1, t2, ... tasks |
---|
| 1042 | RETURN: nothing. Waits for all the tasks t1, t2, ... to complete. The state |
---|
| 1043 | of the tasks is set to 'completed'. |
---|
| 1044 | NOTE: A task whose state is neither 'started' nor 'completed' cannot be |
---|
| 1045 | waited for. |
---|
| 1046 | @* The result of any completed task can be accessed via @ref{getResult}. |
---|
| 1047 | @* 'waitAllTasks(t1, t2, ...);' is a shortcut for |
---|
| 1048 | 'waitTasks(list(t1, t2, ...), size(list(t1, t2, ...)));'. Since |
---|
| 1049 | returning a list of the indices of the completed tasks does not make |
---|
| 1050 | sense in this case, nothing is returned. |
---|
| 1051 | SEE ALSO: waitTasks, startTasks, pollTask, getResult, getState, printTask |
---|
| 1052 | EXAMPLE: example waitAllTasks; shows an example" |
---|
| 1053 | { |
---|
| 1054 | list tmp = waitTasks(#, size(#)); |
---|
| 1055 | } |
---|
| 1056 | example |
---|
| 1057 | { |
---|
| 1058 | "EXAMPLE:"; |
---|
| 1059 | echo = 2; |
---|
| 1060 | ring R = 0, (x,y), dp; |
---|
| 1061 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1062 | task t1 = "std", list(I); |
---|
| 1063 | task t2 = "slimgb", list(I); |
---|
| 1064 | startTasks(t1, t2); |
---|
| 1065 | waitAllTasks(t1, t2); // the same as 'waitTasks(list(t1, t2), 2);', |
---|
| 1066 | // but without return value |
---|
| 1067 | getResult(t1); |
---|
| 1068 | getResult(t2); |
---|
| 1069 | killTask(t1); |
---|
| 1070 | killTask(t2); |
---|
| 1071 | } |
---|
| 1072 | |
---|
| 1073 | proc pollTask(task t) |
---|
| 1074 | "USAGE: pollTask(t), t task |
---|
| 1075 | RETURN: 1, if the computation of the task t has successfully finished; |
---|
| 1076 | 0, otherwise. |
---|
| 1077 | @* The state of any task whose computation has successfully finished is |
---|
| 1078 | set to 'completed'. |
---|
| 1079 | NOTE: A task whose state is neither 'started' nor 'completed' cannot be |
---|
| 1080 | polled. |
---|
| 1081 | @* The result of any completed task can be accessed via @ref{getResult}. |
---|
| 1082 | @* pollTask() should return immediately. However, receiving the result |
---|
| 1083 | of the task may take some time. |
---|
| 1084 | SEE ALSO: startTasks, waitTasks, getResult, getState, printTask |
---|
| 1085 | EXAMPLE: example pollTask; shows an example" |
---|
| 1086 | { |
---|
| 1087 | if (t.index == 0) { |
---|
| 1088 | ERROR("cannot poll an uninitialized task"); |
---|
| 1089 | } |
---|
| 1090 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 1091 | ERROR("cannot poll an uninitialized task"); |
---|
| 1092 | } |
---|
| 1093 | if (tasks[t.index].state != "started" |
---|
| 1094 | && tasks[t.index].state != "completed") { |
---|
| 1095 | ERROR("cannot poll a task whose state is not"+newline |
---|
| 1096 | +"'started' or 'completed'"); |
---|
| 1097 | } |
---|
| 1098 | if (tasks[t.index].state == "completed") { |
---|
| 1099 | return(1); |
---|
| 1100 | } |
---|
| 1101 | // tasks[t.index].state == "started" |
---|
| 1102 | write(tasks[t.index].links[2], 2); |
---|
| 1103 | write(tasks[t.index].links[2], tasks[t.index].id); |
---|
| 1104 | int state = read(tasks[t.index].links[2]); |
---|
| 1105 | if (state == 0 || state == 1) { // waiting or started |
---|
| 1106 | return(0); |
---|
| 1107 | } |
---|
| 1108 | if (state == 2) { // computed |
---|
| 1109 | int index = read(tasks[t.index].links[1]); // index == t.index |
---|
| 1110 | tasks[t.index].result = read(tasks[t.index].links[1]); |
---|
| 1111 | write(tasks[t.index].links[2], 3); |
---|
| 1112 | write(tasks[t.index].links[2], tasks[t.index].id); |
---|
| 1113 | tasks[t.index].id = 0; |
---|
| 1114 | tasks[t.index].links = list(); |
---|
| 1115 | tasks[t.index].linkID = 0; |
---|
| 1116 | tasks[t.index].state = "completed"; |
---|
| 1117 | return(1); |
---|
| 1118 | } |
---|
| 1119 | // state == -1 (stopped) or state == 3 (sent) should not happen |
---|
| 1120 | } |
---|
| 1121 | example |
---|
| 1122 | { |
---|
| 1123 | "EXAMPLE:"; |
---|
| 1124 | echo = 2; |
---|
| 1125 | ring R = 0, (x,y), dp; |
---|
| 1126 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1127 | task t = "std", list(I); |
---|
| 1128 | startTasks(t); |
---|
| 1129 | waitAllTasks(t); |
---|
| 1130 | pollTask(t); // task already completed |
---|
| 1131 | t; |
---|
| 1132 | getResult(t); |
---|
| 1133 | killTask(t); |
---|
| 1134 | } |
---|
| 1135 | |
---|
| 1136 | proc getCommand(task t) |
---|
| 1137 | "USAGE: getCommand(t), t task |
---|
| 1138 | RETURN: a string, the command of t. |
---|
| 1139 | NOTE: This command cannot be applied to tasks whose state is |
---|
| 1140 | 'uninitialized'. |
---|
| 1141 | SEE ALSO: getArguments, getResult, getState, createTask, printTask |
---|
| 1142 | EXAMPLE: example getCommand; shows an example" |
---|
| 1143 | { |
---|
| 1144 | if (t.index == 0) { |
---|
| 1145 | ERROR("cannot get command of an uninitialized task"); |
---|
| 1146 | } |
---|
| 1147 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 1148 | ERROR("cannot get command of an uninitialized task"); |
---|
| 1149 | } |
---|
| 1150 | return(tasks[t.index].command); |
---|
| 1151 | } |
---|
| 1152 | example |
---|
| 1153 | { |
---|
| 1154 | "EXAMPLE:"; |
---|
| 1155 | echo = 2; |
---|
| 1156 | ring R = 0, (x,y), dp; |
---|
| 1157 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1158 | task t = "std", list(I); |
---|
| 1159 | getCommand(t); |
---|
| 1160 | killTask(t); |
---|
| 1161 | } |
---|
| 1162 | |
---|
| 1163 | proc getArguments(task t) |
---|
| 1164 | "USAGE: getArguments(t), t task |
---|
| 1165 | RETURN: a list, the arguments of t. |
---|
| 1166 | NOTE: This command cannot be applied to tasks whose state is |
---|
| 1167 | 'uninitialized'. |
---|
| 1168 | SEE ALSO: getCommand, getResult, getState, createTask, printTask |
---|
| 1169 | EXAMPLE: example getArguments; shows an example" |
---|
| 1170 | { |
---|
| 1171 | if (t.index == 0) { |
---|
| 1172 | ERROR("cannot get arguments of an uninitialized task"); |
---|
| 1173 | } |
---|
| 1174 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 1175 | ERROR("cannot get arguments of an uninitialized task"); |
---|
| 1176 | } |
---|
| 1177 | return(tasks[t.index].arguments); |
---|
| 1178 | } |
---|
| 1179 | example |
---|
| 1180 | { |
---|
| 1181 | "EXAMPLE:"; |
---|
| 1182 | echo = 2; |
---|
| 1183 | ring R = 0, (x,y), dp; |
---|
| 1184 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1185 | task t = "std", list(I); |
---|
| 1186 | getArguments(t); |
---|
| 1187 | killTask(t); |
---|
| 1188 | } |
---|
| 1189 | |
---|
| 1190 | proc getResult(task t) |
---|
| 1191 | "USAGE: getResult(t), t task |
---|
| 1192 | RETURN: the result of t. |
---|
| 1193 | NOTE: This command cannot be applied to tasks whose state is not |
---|
| 1194 | 'completed'. |
---|
| 1195 | SEE ALSO: getCommand, getArguments, getState, waitTasks, pollTask, printTask |
---|
| 1196 | EXAMPLE: example getResult; shows an example" |
---|
| 1197 | { |
---|
| 1198 | if (t.index == 0) { |
---|
| 1199 | ERROR("cannot get result of an uninitialized task"); |
---|
| 1200 | } |
---|
| 1201 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 1202 | ERROR("cannot get result of an uninitialized task"); |
---|
| 1203 | } |
---|
| 1204 | if (tasks[t.index].state != "completed") { |
---|
| 1205 | ERROR("cannot get result of a task which is not completed"); |
---|
| 1206 | } |
---|
| 1207 | return(tasks[t.index].result); |
---|
| 1208 | } |
---|
| 1209 | example |
---|
| 1210 | { |
---|
| 1211 | "EXAMPLE:"; |
---|
| 1212 | echo = 2; |
---|
| 1213 | ring R = 0, (x,y), dp; |
---|
| 1214 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1215 | task t = "std", list(I); |
---|
| 1216 | startTasks(t); |
---|
| 1217 | waitAllTasks(t); |
---|
| 1218 | getResult(t); |
---|
| 1219 | killTask(t); |
---|
| 1220 | } |
---|
| 1221 | |
---|
| 1222 | proc getState(task t) |
---|
| 1223 | "USAGE: getState(t), t task |
---|
| 1224 | RETURN: a string, the state of t. |
---|
| 1225 | SEE ALSO: getCommand, getArguments, getResult, printTask, createTask, |
---|
| 1226 | startTasks, stopTask, waitTasks, pollTask, killTask |
---|
| 1227 | EXAMPLE: example getState; shows an example" |
---|
| 1228 | { |
---|
| 1229 | if (t.index == 0) { |
---|
| 1230 | return("uninitialized"); |
---|
| 1231 | } |
---|
| 1232 | if (typeof(tasks[t.index]) != "internal_task") { |
---|
| 1233 | return("uninitialized"); |
---|
| 1234 | } |
---|
| 1235 | return(tasks[t.index].state); |
---|
| 1236 | } |
---|
| 1237 | example |
---|
| 1238 | { |
---|
| 1239 | "EXAMPLE:"; |
---|
| 1240 | echo = 2; |
---|
| 1241 | ring R = 0, (x,y), dp; |
---|
| 1242 | ideal I = x9y2+x10, x2y7-y8; |
---|
| 1243 | task t = "std", list(I); |
---|
| 1244 | getState(t); |
---|
| 1245 | startTasks(t); |
---|
| 1246 | getState(t); |
---|
| 1247 | waitAllTasks(t); |
---|
| 1248 | getState(t); |
---|
| 1249 | killTask(t); |
---|
| 1250 | getState(t); |
---|
| 1251 | } |
---|
| 1252 | |
---|
| 1253 | / * construct the string "name[1], name[2], name[3], ..., name[length]" */ |
---|
| 1254 | static proc argsToString(string name, int length) |
---|
| 1255 | { |
---|
| 1256 | string output; |
---|
| 1257 | if (length > 0) { |
---|
| 1258 | output = name+"[1]"; |
---|
| 1259 | } |
---|
| 1260 | int i; |
---|
| 1261 | for (i = 2; i <= length; i++) { |
---|
| 1262 | output = output+", "+name+"["+string(i)+"]"; |
---|
| 1263 | } |
---|
| 1264 | return(output); |
---|
| 1265 | } |
---|