rt-thread/components/libc/posix/ipc/Kconfig

menu "Interprocess Communication (IPC)"

config RT_USING_POSIX_PIPE
    bool "Enable pipe and FIFO"
    select RT_USING_POSIX_FS
    select RT_USING_POSIX_DEVIO
    select RT_USING_POSIX_POLL
    select RT_USING_RESOURCE_ID
    default n
    help
        Enable POSIX pipes and FIFOs for inter-process communication.
        
        Provides:
        - Anonymous pipes: pipe(pipefd)
        - Named pipes (FIFOs): mkfifo(path, mode)
        - Unidirectional byte streams
        - Blocking and non-blocking I/O
        
        Features:
        - Simple producer-consumer pattern
        - Works with select/poll for multiplexing
        - File descriptor based (can use read/write)
        
        Use cases:
        - Parent-child process communication
        - Shell command pipelines
        - Simple message passing
        - Event notification
        
        Buffer size: RT_USING_POSIX_PIPE_SIZE
        
        Enable for POSIX pipe/FIFO support.
        Essential for shell pipeline and process IPC.

config RT_USING_POSIX_PIPE_SIZE
    int "Set pipe buffer size"
    depends on RT_USING_POSIX_PIPE
    default 512
    help
        Size of pipe buffer in bytes.
        
        Default: 512 bytes
        
        Trade-offs:
        Larger buffer:
        + More data can be buffered
        + Better performance for burst writes
        - More memory per pipe
        
        Smaller buffer:
        + Less memory usage
        - More frequent blocking on writes
        
        Typical values: 512-4096 bytes
        Adjust based on typical message sizes and memory constraints.

# We have't implement of 'systemv ipc', so hide it firstly.
#
# config RT_USING_POSIX_IPC_SYSTEM_V
#     bool "Enable System V IPC"
#     default n
#     help
#         System V supplies an alternative form of interprocess communication consisting of thress
#         features: shared memory, message, and semaphores.

config RT_USING_POSIX_MESSAGE_QUEUE
    bool "Enable posix message queue <mqueue.h>"
    select RT_USING_POSIX_CLOCK
    select RT_USING_MESSAGEQUEUE_PRIORITY
    select RT_USING_DFS_MQUEUE
    default n
    help
        Enable POSIX message queues for IPC.
        
        Provides POSIX message queue APIs:
        - mq_open(): Open/create message queue
        - mq_send()/mq_receive(): Send/receive messages
        - mq_timedsend()/mq_timedreceive(): With timeout
        - mq_notify(): Async notification
        - mq_getattr()/mq_setattr(): Queue attributes
        
        Features:
        - Priority-based message delivery
        - Named queues (visible in /dev/mqueue)
        - Blocking and non-blocking modes
        - Timeout support
        - Asynchronous notification
        
        vs. Pipes:
        + Message boundaries preserved
        + Priority-based delivery
        + Can be used with select/poll
        - More overhead per message
        
        Use cases:
        - Process communication with priorities
        - Event notification systems
        - Service request queues
        - RT-Smart IPC
        
        Requires DFS with MQUEUE support.
        Enable for POSIX message queue IPC.

config RT_USING_POSIX_MESSAGE_SEMAPHORE
    bool "Enable posix semaphore <semaphore.h>"
    select RT_USING_POSIX_CLOCK
    default n
    help
        Enable POSIX named and unnamed semaphores.
        
        Provides semaphore APIs:
        - sem_init()/sem_destroy(): Unnamed semaphores
        - sem_open()/sem_close()/sem_unlink(): Named semaphores
        - sem_wait()/sem_trywait()/sem_timedwait(): Acquire
        - sem_post(): Release
        - sem_getvalue(): Get current value
        
        Types:
        - Unnamed (memory-based): For thread synchronization
        - Named (file-based): For process synchronization
        
        Features:
        - Counting semaphore (value > 1)
        - Binary semaphore (value = 0 or 1)
        - Timeout support
        - Non-blocking try operation
        
        Use cases:
        - Thread/process synchronization
        - Resource counting
        - Producer-consumer patterns
        - Mutual exclusion
        
        vs. Mutex:
        + Can be used for signaling (sem_post from any thread)
        + Counting capability
        - No ownership tracking
        
        Enable for POSIX semaphore support.
        Essential for POSIX synchronization.

comment "Socket is in the 'Network' category"

endmenu