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C $Header: /u/gcmpack/MITgcm/eesupp/src/check_threads.F,v 1.13 2004/03/27 03:51:50 edhill Exp $ |
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C $Name: $ |
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|
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#include "CPP_EEOPTIONS.h" |
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|
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CBOP |
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C !ROUTINE: CHECK_THREADS |
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|
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C !INTERFACE: |
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SUBROUTINE CHECK_THREADS( myThid ) |
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IMPLICIT NONE |
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|
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C !DESCRIPTION: |
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C *========================================================== |
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C | SUBROUTINE CHECK\_THREADS |
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C | o Check that all the threads we need did indeed start. |
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C *========================================================== |
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C | This routine is called during the initialisation phase |
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C | to check whether all the threads have started. |
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C | It is invoked by every thread and if any thread finds an |
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C | error it should set its error flag. |
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C | Notes: |
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C | Different mechanisms may be required on different |
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C | platforms to actually perform the check. For example as |
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C | coded here each thread checks for a semaphore set by the |
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C | other threads to see if they are running. |
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C | It is also possible for a system to schedule threads |
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C | sequentially, unless some system call is made to yield |
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C | the process. This routine would detect this situation too |
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C | and allow a programmer to modify this routine and the |
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C | barrier code to allow threads to be scheduled more |
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C | appropriately. |
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C *========================================================== |
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|
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C !USES: |
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C == Global variables == |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "EESUPPORT.h" |
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|
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C !INPUT PARAMETERS: |
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C == Routine arguments == |
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C myThid :: My thread number |
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INTEGER myThid |
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|
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C !LOCAL VARIABLES: |
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C == Local variables == |
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C I :: Loop counter |
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C numberThreadRunning :: Count of number of threads this thread |
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C thinks are running. |
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C nChecks :: Number of times checked for all threads. After so |
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C many checks give up and report an error. |
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C msgBuffer :: Temp. for preparing text messages. |
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INTEGER I |
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INTEGER numberThreadsRunning |
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INTEGER nChecks |
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CHARACTER*(MAX_LEN_MBUF) msgBuffer |
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CEOP |
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|
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C |
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threadIsRunning(myThid) = .TRUE. |
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nChecks = 0 |
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|
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10 CONTINUE |
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numberThreadsRunning = 0 |
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nChecks = nChecks + 1 |
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DO I = 1, nThreads |
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IF ( threadIsRunning(I) ) |
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& numberThreadsRunning = numberThreadsRunning+1 |
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ENDDO |
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IF ( nChecks .GT. 10 ) THEN |
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thError(myThid) = .TRUE. |
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eeBootError = .TRUE. |
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WRITE(msgBuffer,'(A,I5,A,I5,A)') |
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& 'S/R INI_CHECK_THREADS: Only ',numberThreadsRunning, |
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& ' thread(s), ',nThreads,' are needed for this configuration!' |
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CALL PRINT_ERROR( msgBuffer , myThid) |
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C-- Not enough threads are running so halt the program. |
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C I did not want this here but it is the only place I have found that |
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C KAP deadlocks if it there are fewer threads than iterations in a BLOCKED(1) |
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C loop. The deadlock appears to be in the routine mppjoin which never |
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C returns. I tried putting the STOP in main or breaking out of the loop in main |
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C but this causes KAP to insert a call to mppjoin - which then deadlocks! |
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IF ( myThid .EQ. 1 ) THEN |
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STOP 'ABNORMAL END: S/R CHECK_THREADS' |
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ENDIF |
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GOTO 11 |
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ENDIF |
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IF ( numberThreadsRunning .NE. nThreads ) THEN |
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#ifdef HAVE_SYSTEM |
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CALL SYSTEM('sleep 1') |
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#endif |
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GOTO 10 |
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ENDIF |
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11 CONTINUE |
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|
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C-- check barrier synchronization: 1rst (initial) call. |
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CALL BAR_CHECK( 1, myThid ) |
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|
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RETURN |
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END |
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