1TM(3) Library Functions Manual TM(3)
2
6 tm_init, tm_nodeinfo, tm_poll, tm_notify, tm_spawn, tm_kill, tm_obit,
7 tm_taskinfo, tm_atnode, tm_rescinfo, tm_publish, tm_subscribe,
8 tm_finalize - task management API
9
11 #include <tm.h>
12 int tm_init(info, roots)
14 void ∗info;
15 struct tm_roots ∗roots;
16 int tm_nodeinfo(list, nnodes)
18 tm_node_id *list;
19 int ∗nnodes;
20 int tm_poll(poll_event, result_event, wait, tm_errno)
22 tm_event_t poll_event;
23 tm_event_t ∗result_event;
24 int wait;
25 int ∗tm_errno;
26 int tm_notify(tm_signal)
28 int tm_signal;
29 int tm_spawn(argc, argv, envp, where, tid, event)
31 int argc;
32 char ∗∗argv;
33 char ∗∗envp;
34 tm_node_id where;
35 tm_task_id ∗tid;
36 tm_event_t ∗event;
37 int tm_kill(tid, sig, event)
39 tm_task_id tid;
40 int sig;
41 tm_event_t event;
42 int tm_obit(tid, obitval, event)
44 tm_task_id tid;
45 int ∗obitval;
46 tm_event_t event;
47 int tm_taskinfo(node, tid_list, list_size, ntasks, event)
49 tm_node_id node;
50 tm_task_id ∗tid_list;
51 int list_size;
52 int ∗ntasks;
53 tm_event_t event;
54 int tm_atnode(tid, node)
56 tm_task_id tid;
57 tm_node_id ∗node;
58 int tm_rescinfo(node, resource, len, event)
60 tm_node_id node;
61 char ∗resource;
62 int len;
63 tm_event_t event;
64 int tm_publish(name, info, len, event)
66 char ∗name;
67 void ∗info;
68 int len;
69 tm_event_t event;
70 int tm_subscribe(tid, name, info, len, info_len, event)
72 tm_task_id tid;
73 char ∗name;
74 void ∗info;
75 int len;
76 int ∗info_len;
77 tm_event_t event;
78 int tm_finalize()
80
82 These functions provide a partial implementation of the task management
83 interface part of the PSCHED API. In PBS, MOM provides the task man‐
84 ager functions. This library opens a tcp socket to the MOM running on
85 the local host and sends and receives messages.
86 The PSCHED Task Management API description used to create this library
88 was commited to paper on Novermber 15, 1996 and was given the version
89 number 0.1. Changes may have taken place since that time which are not
90 reflected in this library.
91 The API description uses several data types that it purposefully does
93 not define. This was done so an implementaion would not be confined in
94 the way it was written. For this specific work, the definitions fol‐
95 low:
96 typedef int tm_node_id; /* job-relative node id */
98 #define TM_ERROR_NODE ((tm_node_id)-1)
99 typedef int tm_event_t; /* event handle, > 0 for real events */
101 #define TM_NULL_EVENT ((tm_event_t)0)
102 #define TM_ERROR_EVENT ((tm_event_t)-1)
103 typedef unsigned long tm_task_id;
105 #define TM_NULL_TASK (tm_task_id)0
106 There are a number of error values defined as well: TM_SUCCESS,
108 TM_ESYSTEM, TM_ENOEVENT, TM_ENOTCONNECTED, TM_EUNKNOWNCMD, TM_ENOTIM‐
109 PLEMENTED, TM_EBADENVIRONMENT, TM_ENOTFOUND.
110 tm_init() initializes the library by opening a socket to the MOM on the
112 local host and sending a TM_INIT message, then waiting for the reply.
113 The info paramenter has no use and is included to conform with the
114 PSCHED document. The roots pointer will contain valid data after the
115 function returns and has the following structure:
116 struct tm_roots {
118 tm_task_id tm_me;
119 tm_task_id tm_parent;
120 int tm_nnodes;
121 int tm_ntasks;
122 int tm_taskpoolid;
123 tm_task_id *tm_tasklist;
124 };
125 tm_me The task id of this calling task.
128 tm_parent The task id of the task which spawned this task or
130 TM_NULL_TASK if the calling task is the initial
131 task started by PBS.
132 tm_nnodes The number of nodes allocated to the job.
134 tm_ntasks This will always be 0 for PBS.
136 tm_taskpoolid PBS does not support task pools so this will always
138 be -1.
139 tm_tasklist This will be NULL for PBS.
141 The tm_ntasks, tm_taskpoolid and tm_tasklist fields are not filled with
143 data specified by the PSCHED document. PBS does not support task pools
144 and, at this time, does not return information about current running
145 tasks from tm_init. There is a separate call to get information for
146 current running tasks called tm_taskinfo which is described below. The
147 return value from tm_init be TM_SUCCESS if the library initialization
148 was successful, or an error return otherwise.
149 tm_nodeinfo() places a pointer to a malloc'ed array of tm_node_id's in
151 the pointer pointed at by list. The order of the tm_node_id's in list
152 is the same as that specified to MOM in the "exec_host" attribute. The
153 int pointed to by nnodes contains the number of nodes allocated to the
154 job. This is information that is returned during initialization and
155 does not require communication with MOM. If tm_init has not been
156 called, TM_ESYSTEM is returned, otherwise TM_SUCCESS is returned.
157 tm_poll() is the function which will retrieve information about the
159 task management system to locations specified when other routines
160 request an action take place. The bookkeeping for this is done by gen‐
161 erating an event for each action. When the task manager (MOM) sends a
162 message that an action is complete, the event is reported by tm_poll
163 and information is placed where the caller requested it. The argument
164 poll_event is meant to be used to request a specific event. This
165 implementation does not use it and it must be set to TM_NULL_EVENT or
166 an error is returned. Upon return, the argument result_event will con‐
167 tain a valid event number or TM_ERROR_EVENT on error. If wait is zero
168 and there are no events to report, result_event is set to
169 TM_NULL_EVENT. If wait is non-zero an there are no events to report,
170 the function will block waiting for an event. If no local error takes
171 place, TM_SUCCESS is returned. If an error is reported by MOM for an
172 event, then the argument tm_errno will be set to an error code.
173 tm_notify() is described in the PSCHED documentation, but is not imple‐
175 mented for PBS yet. It will return TM_ENOTIMPLEMENTED.
176 tm_spawn() sends a message to MOM to start a new task. The node id of
178 the host to run the task is given by where. The parameters argc, argv
179 and envp specify the program to run and its arguments and environment
180 very much like exec(). The full path of the program executable must be
181 given by argv[0] and the number of elements in the argv array is given
182 by argc. The array envp is NULL terminated. The argument event points
183 to a tm_event_t variable which is filled in with an event number. When
184 this event is returned by tm_poll , the tm_task_id pointed to by tid
185 will contain the task id of the newly created task. In addition, the
186 tid is available to the process in the PBS_TASKNUM environment vari‐
187 able. Similarly, the node number is in the PBS_NODENUM variable and
188 the cpu number is in the PBS_VNODENUM variable.
189 tm_kill() sends a signal specified by sig to the task tid and puts an
191 event number in the tm_event_t pointed to by event.
192 tm_obit() creates an event which will be reported when the task tid
194 exits. The int pointed to by obitval will contain the exit value of
195 the task when the event is reported.
196 tm_taskinfo() returns the list of tasks running on the node specified
198 by node. The PSCHED documentation mentions a special ability to
199 retrieve all tasks running in the job. This is not supported by PBS.
200 The argument tid_list points to an array of tm_task_id's which contains
201 list_size elements. Upon return, event will contain an event number.
202 When this event is polled, the int pointed to by ntasks will contain
203 the number of tasks running on the node and the array will be filled in
204 with tm_task_id's. If ntasks is greater than list_size, only list_size
205 tasks will be returned.
206 tm_atnode() will place the node id where the task tid exists in the
208 tm_node_id pointed to by node.
209 tm_rescinfo() makes a request for a string specifying the resources
211 available on a node given by the argument node. The string is returned
212 in the buffer pointed to by resource and is terminated by a NUL charac‐
213 ter unless the number of characters of information is greater than
214 specified by len. The resource string PBS returns is formated as fol‐
215 lows:
216 A space separated set of strings from the uname system call followed by
218 a colon (:). The order of the strings is sysname, nodename, release,
219 version, machine.
220 A comma spearated set of strings giving the components of the
222 "Resource_List" attribute of the job. Each component has the resource
223 name, an equal sign, and the limit value.
224 For example, a return for a task running on an SGI workstation might
226 look like:
227 IRIX golum 6.2 03131015 IP22:cput=20:00,mem=400kb
229 tm_publish() causes len bytes of information pointed at by info to be
231 sent to the local MOM to be saved under the name given by name.
232 tm_subscribe() returns a copy of the information named by name for the
234 task given by tid. The argument info points to a buffer of size len
235 where the information will be returned. The argument info_len will be
236 set with the size of the published data. If this is larger than the
237 supplied buffer, the data will have been truncated.
238 tm_finalize() may be called to free any memory in use by the library
240 and close the connection to MOM.
241
243 pbs_mom, PSCHED: An API for Parallel Job/Resource Managment,
244 http://parallel.nas.nasa.gov/Psched/psched-api-report.ps
245 21 May 1997 TM(3)