diff options
Diffstat (limited to 'man7/shm_overview.7')
| -rw-r--r-- | man7/shm_overview.7 | 58 |
1 files changed, 30 insertions, 28 deletions
diff --git a/man7/shm_overview.7 b/man7/shm_overview.7 index 85fbce2a0..a746592ca 100644 --- a/man7/shm_overview.7 +++ b/man7/shm_overview.7 @@ -12,34 +12,34 @@ by sharing a region of memory. .P The interfaces employed in the API are: .TP 15 -.BR shm_open (3) +.MR shm_open 3 Create and open a new object, or open an existing object. This is analogous to -.BR open (2). +.MR open 2 . The call returns a file descriptor for use by the other interfaces listed below. .TP -.BR ftruncate (2) +.MR ftruncate 2 Set the size of the shared memory object. (A newly created shared memory object has a length of zero.) .TP -.BR mmap (2) +.MR mmap 2 Map the shared memory object into the virtual address space of the calling process. .TP -.BR munmap (2) +.MR munmap 2 Unmap the shared memory object from the virtual address space of the calling process. .TP -.BR shm_unlink (3) +.MR shm_unlink 3 Remove a shared memory object name. .TP -.BR close (2) +.MR close 2 Close the file descriptor allocated by -.BR shm_open (3) +.MR shm_open 3 when it is no longer needed. .TP -.BR fstat (2) +.MR fstat 2 Obtain a .I stat structure that describes the shared memory object. @@ -53,10 +53,10 @@ owner and group .RI ( st_gid ). .TP -.BR fchown (2) +.MR fchown 2 To change the ownership of a shared memory object. .TP -.BR fchmod (2) +.MR fchmod 2 To change the permissions of a shared memory object. .SS Versions POSIX shared memory is supported since Linux 2.4 and glibc 2.2. @@ -64,7 +64,7 @@ POSIX shared memory is supported since Linux 2.4 and glibc 2.2. POSIX shared memory objects have kernel persistence: a shared memory object will exist until the system is shut down, or until all processes have unmapped the object and it has been deleted with -.BR shm_unlink (3) +.MR shm_unlink 3 .SS Linking Programs using the POSIX shared memory API must be compiled with .I cc \-lrt @@ -72,7 +72,8 @@ to link against the real-time library, .IR librt . .SS Accessing shared memory objects via the filesystem On Linux, shared memory objects are created in a -.RB ( tmpfs (5)) +\%(\c +.MR tmpfs 5 ) virtual filesystem, normally mounted under .IR /dev/shm . Since Linux 2.6.19, Linux supports the use of access control lists (ACLs) @@ -82,23 +83,24 @@ Typically, processes must synchronize their access to a shared memory object, using, for example, POSIX semaphores. .P System V shared memory -.RB ( shmget (2), -.BR shmop (2), +\%(\c +.MR shmget 2 , +.MR shmop 2 , etc.) is an older shared memory API. POSIX shared memory provides a simpler, and better designed interface; on the other hand POSIX shared memory is somewhat less widely available (especially on older systems) than System V shared memory. .SH SEE ALSO -.BR fchmod (2), -.BR fchown (2), -.BR fstat (2), -.BR ftruncate (2), -.BR memfd_create (2), -.BR mmap (2), -.BR mprotect (2), -.BR munmap (2), -.BR shmget (2), -.BR shmop (2), -.BR shm_open (3), -.BR shm_unlink (3), -.BR sem_overview (7) +.MR fchmod 2 , +.MR fchown 2 , +.MR fstat 2 , +.MR ftruncate 2 , +.MR memfd_create 2 , +.MR mmap 2 , +.MR mprotect 2 , +.MR munmap 2 , +.MR shmget 2 , +.MR shmop 2 , +.MR shm_open 3 , +.MR shm_unlink 3 , +.MR sem_overview 7 |