iso88591qcolin20nevin colin_nevinyahoocom hi question bit tricky wondering anyone come across problem could point right direction involved porting sco unix application linux encountered problem way semaphores handled application uses mulitple processes run application code main process known bsh controls io screen file io syncronisation handled via semaphores certain circumstances main process application child process seem lock waiting syncronisation semaphores change state attached ddd processes seems semaphore code correct things syncronisation processes stay stuck semop system call also noticed introduce slight delay changing semaphore states problem goes away causes entire application run really sloooww lol anything weird different standard implemenation semaphores modern linux could cause semop fail pick change state semaphore immediately setting sem_flg ipc_nowait checking errno eagain recalling semop semop call fails 1 also fixes problem system performance goes toilet parent controlling process run uid parent creates semaphores permissions 0666 pointers would appreciated rgds colin nevin __________________________________________________ yahoo everything youll ever need one web page news sport email music charts httpukmyyahoocom irish linux users group iluglinuxie httpwwwlinuxiemailmanlistinfoilug unsubscription information list maintainer listmasterlinuxie fri 6 sep 2002 112417 0100 bst ilug semaphores linux rh73