- Communications
create, delete communication connection
- send, receive messages
- transfer status information
- attach or detach remote devices
types:
- interprocess comm : btw 2 processes
- intraprocess communication: btw a process and a sub-process
Two common models for interprocess comm
- message passing model
- shared-memory model: shared_memory_create(), shared_memory_attach()
Message passing model
entire process is done by the OS
Shared memory
create is used to create attach is used to attach to the shared-memory
after creating and given access the OS has no power, rest is done by process
| Windows | Linux |
|---|---|
| CreatePipe() | pipe() |
| CreateFileMapping() | shm_open() |
| MapViewOfFile() | mmap() |
pipe() -interprocess- pass memory/data
shm_open() [shared memory]- mapping a content of file to mem addr
mmap() - map to shared mem area
- Protection
- File security
- manipulate the permission setting of resources such as files and disks -speicfy whether particular users can be allowed access to certain resources
| Windows | Linux |
|---|---|
| SetFileSecurity() | chmod() |
| InitializeSecurityDescriptor() | umask() |
| SetSecurityDescriptorGroup() | chown() |
chown() - change group permission