/*
?*?Some?functions?callable?from?fortran?to?use?shared?memory
?*?wv?2011
?*?shmem?stuff?from?Willem?Vermin?SARA
?*/
#include?
#include?
#include?
#include?
#include?
#include?
/*
?*?get?a?shared?memory?segment
?*?input:?size?（fortran?integer*8）
?*?output:?shmem?id
?*/
void?getshmem_（size_t?*size?int*id）
{
??key_t?key;
??int?shmflg;
??int?shmid;
??key?=?IPC_PRIVATE;
??shmflg?=?IPC_CREAT?|?IPC_EXCL?|?0600?|?SHM_NORESERVE?;
??shmid?=?shmget（key?*size?shmflg）;
??if?（shmid?==?-1）
??{
????fprintf（stderr“%s?in?%s:?cannot?create?shared?segment?%ld?\n“__FUNCTION____FILE__*size）;
????perror（0）;
????exit（1）;
??}
??*id?=?shmid;
}

void?getshmem_error_（size_t?*size?int*id）
{
??key_t?key;
??int?shmflg;
??int?shmid;
??key?=?IPC_PRIVATE;
??shmflg?=?IPC_CREAT?|?IPC_EXCL?|?0600?|?SHM_NORESERVE?;
??shmid?=?shmget（key?*size?shmflg）;
??*id?=?shmid;
}
/*
?*?attach?shared?memory?to?a?pointer
?*?input:?shhmid:?shared?memory?id
?*?output:?address?（fortran?integer*8）
?*/
void?attachshmem_（int?*shmid?void?**address）
{
??void?*shmaddr*r;
??int?shmflg;
??shmflg?=?0;
??shmaddr?=?0;

??r?=?shmat（*shmid?shmaddr?shmflg）;
??if?（r?==?（void*）?-1）
??{
????fprintf（stderr“%s?in?%s:?cannot?get?address?of?shared?segment\n“__FUNCTION____FILE__）;
????perror（0）;
????exit（1）;
??}
??*address?=?r;
}
/*
?*?detach?shared?memory?from?pointer
?*?input:?address?（fortran?integer*8）
?*/
void?detachshmem_（void?**address）
{
??int?r;
??r?=?shmdt（*address）;
??if?（r?==?-1）
??{
????fprintf（stderr“%s?in?%s:%d:?cannot?detach?shared?segment\n“__FUNCTION____FILE____LINE__）;
????perror（0）;
????exit（1）;
??}
}
/*
?*?destroy?shared?memory
?*?input:?shmid:?shared?memory?id
?*/
void?destroyshmem_（int?*shmid）
{
??struct?shmid_ds?buf;
??int?r?=?shmctl（*shmidIPC_RMID&buf）;
??if?（r?==?-1）
??{
????fprintf（stderr“%s?in?%s:%d:?cannot?destroy?shared?segment\n“__FUNCTION____FILE____LINE__）;
????perror（0）;
????exit（1）;
??}
}


/*
?*?get?a?set?of?semaphores
?*?input:?size?
?*?output:?semaphores?id
?*/
void?getsem_（int?*size?int*id）
{
??key_t?key;
??int?semflg;
??int?semid;
??int?mysize;
??int?i?rc;
??short??sarray[（*size）+1];

??key?=?IPC_PRIVATE;
??semflg?=?IPC_CREAT?|?IPC_EXCL?|?0600;
??semflg?=?IPC_CREAT?|?0600;
??mysize=（*size）+1?;
??/*?here?I?have?an?odd?problem:?using?*size+1?instead?of?mysize?
?????sometimes?failed
?????very?odd?some?cross?C-Fortran?problem?no?idea??????????*/
??semid?=?semget（key?mysize?semflg）;
??if?（semid?==?-1）
??{
????perror（0）;
????fprintf（stderr“%s?in?%s:?cannot?create?semaphores?\n“__FUNCTION____FILE__）;
????fprintf（stderr“requested?size?was?%d\n“?mysize）;
????exit（1）;
??}
??/*????????‘1‘?--??The?shared?memory?segment?is?being?used.???????*/
??/*????????‘0‘?--??The?shared?memory?segment?is?freed.????????????*/
??/*?the?very?first?sempaphore?can?be??used?to?loc?all?others?
?????currently?this?is?not?entirely?thread?save?and?might?fail?if?no?barrier
?????is?used?before?this?lock?since?we?do?not