Return to sem CVS log

Up to [MW Coherent from dump] / coherent / a / usr / man / COHERENT

Annotation of coherent/a/usr/man/COHERENT/sem, revision 1.1.1.1

1.1       root        1: 
                      2: 
                      3: sem                       Device Driver                       sem
                      4: 
                      5: 
                      6: 
                      7: 
                      8: Semaphore device driver
                      9: 
                     10: 
                     11: /dev/sem is  an interface to the semaphore  device driver.  It is
                     12: assigned major device 23 (minor  device 0) and can be accessed as
                     13: a character-special device.
                     14: 
                     15: All semaphore operations  are performed through the COHERENT sys-
                     16: tem  call ioctl.   The operations semctl,  semget, and  semop are
                     17: performed with an  integer parameter array.  The first element of
                     18: the array is reserved  for the return value (default -1).  Subse-
                     19: quent  elements represent  arguments.  The  call to  ioctl passes
                     20: SEMCTL,  SEMGET,  or  SEMOP  as  the  second  argument,  and  the
                     21: parameter array as the  third argument.  The first argument is an
                     22: open file descriptor to /dev/sem.
                     23: 
                     24: ***** Access *****
                     25: 
                     26: Prior to accessing the devices, a entry must be created in  /dev,
                     27: as follows:
                     28: 
                     29: 
                     30: /etc/mknod /dev/sem c 23 0
                     31: chmod 666 /dev/sem
                     32: 
                     33: 
                     34: ***** Bugs ***** Allocation of too many semaphore ids (NNSSEEMMIIDD) or
                     35: semaphores per  identifier (NNSSEEMM) can exhaust  kernel data space,
                     36: which will stop the system in its tracks.
                     37: 
                     38: Private semaphore sets  are not supported.  Semaphore ids must be
                     39: removed  manually  when   no  longer  required.   To  remove  all
                     40: semaphore identifiers, use the following code:
                     41: 
                     42: 
                     43: #include <sys/sem.h>
                     44: #define NSEMID 16
                     45: 
                     46: semget( 0, 0 );     /* must do first */
                     47: 
                     48: for ( id=0; id < NSEMID; ++id )
                     49:         semctl( id, 0, IPC_RMID, 0 );
                     50: 
                     51: 
                     52: To load the driver sem into memory, use the command drvld.
                     53: 
                     54: ***** Files *****
                     55: 
                     56: /uussrr/iinncclluuddee/ssyyss/iippcc.hh
                     57: /uussrr/iinncclluuddee/ssyyss/sseemm.hh
                     58: /ddeevv/sseemm -- Device
                     59: /ddrrvv/sseemm -- Loadable device driver
                     60: 
                     61: 
                     62: 
                     63: 
                     64: COHERENT Lexicon                                           Page 1
                     65: 
                     66: 
                     67: 
                     68: 
                     69: sem                       Device Driver                       sem
                     70: 
                     71: 
                     72: 
                     73: ***** See Also *****
                     74: 
                     75: device drivers, drvld, semctl(), semget(), semop()
                     76: 
                     77: 
                     78: 
                     79: 
                     80: 
                     81: 
                     82: 
                     83: 
                     84: 
                     85: 
                     86: 
                     87: 
                     88: 
                     89: 
                     90: 
                     91: 
                     92: 
                     93: 
                     94: 
                     95: 
                     96: 
                     97: 
                     98: 
                     99: 
                    100: 
                    101: 
                    102: 
                    103: 
                    104: 
                    105: 
                    106: 
                    107: 
                    108: 
                    109: 
                    110: 
                    111: 
                    112: 
                    113: 
                    114: 
                    115: 
                    116: 
                    117: 
                    118: 
                    119: 
                    120: 
                    121: 
                    122: 
                    123: 
                    124: 
                    125: 
                    126: 
                    127: 
                    128: 
                    129: 
                    130: COHERENT Lexicon                                           Page 2
                    131: 
                    132: 

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.