Linux-OS

Home
Architecture-of-computing-system
Architecture-of-computing-system
- Introduction
Operating-system
Operating-system
- Introduction
Course-upenn-CSE-380-Computer-Operating-Systems
Course-upenn-CSE-380-Computer-Operating-Systems
- Introduction
- Lecture-Note-2-Processes-and-Threads
  Lecture-Note-2-Processes-and-Threads
  - Introduction
Unix-standardization-and-implementation
Unix-standardization-and-implementation
Linux-Foundation
Linux-Foundation
- Introduction
- LSB-Core
  LSB-Core
  - Introduction
  - librt
- Core-Infrastructure-Initiative
  Core-Infrastructure-Initiative
  - Introduction
  - CII-Best-Practices
    CII-Best-Practices
    
    Introduction
Kernel
Kernel
- Introduction
- Operating-system-kernel
  Operating-system-kernel
  - Introduction
- Guide
  Guide
  - Kernel-architecture
    Kernel-architecture
    
    Introduction
  - Control-path-and-context-switch
    Control-path-and-context-switch
    
    Introduction
  - Kernel-thread
    Kernel-thread
    
    Introduction
  - System-resource
    System-resource
    
    Introduction
- Book-Understanding-the-Linux-Kernel
  Book-Understanding-the-Linux-Kernel
  - Introduction
  - Chapter-1-Introduction
    Chapter-1-Introduction
    
    Introduction
    
    1.1-Linux-Versus-Other-Unix-Like-Kernels
    1.1-Linux-Versus-Other-Unix-Like-Kernels
    
    Introduction
    
    Giant-lock
    
    1.2-Hardware-Dependency
    1.2-Hardware-Dependency
    
    Introduction
    
    1.4-Basic-Operating-System-Concepts
    1.4-Basic-Operating-System-Concepts
    
    Introduction
    
    1.6-An-Overview-of-Unix-Kernels
    1.6-An-Overview-of-Unix-Kernels
    
    Introduction
    
    1.6.1-The-Process-Kernel-Model
    1.6.1-The-Process-Kernel-Model
    
    Introduction
    
    1.6.2-Process-Implementation
    1.6.2-Process-Implementation
    
    Introduction
    
    1.6.3-Reentrant-Kernels
    1.6.3-Reentrant-Kernels
    
    Introduction
    
    1.6.4-Process-Address-Space
    1.6.4-Process-Address-Space
    
    Introduction
    
    1.6.5-Synchronization-and-Critical-Regions
    1.6.5-Synchronization-and-Critical-Regions
    
    Introduction
    
    1.6.6-Signals-and-Interprocess-Communication
    1.6.6-Signals-and-Interprocess-Communication
    
    Introduction
    
    1.6.7-Process-Management
    1.6.7-Process-Management
    
    Introduction
    
    1.6.8-Memory-Management
    1.6.8-Memory-Management
    
    Introduction
    
    1.6.9-Device-Drivers
    1.6.9-Device-Drivers
    
    Introduction
  - Chapter-2-Memory-Addressing
    Chapter-2-Memory-Addressing
    
    Introduction
    
    2.1-Memory-Addresses
    2.1-Memory-Addresses
    
    Introduction
    
    2.2-Segmentation-in-Hardware
    2.2-Segmentation-in-Hardware
    
    Introduction
    
    2.3-Segmentation-in-Linux
    2.3-Segmentation-in-Linux
    
    Introduction
    
    2.4-Paging-in-Hardware
    2.4-Paging-in-Hardware
    
    Introduction
    
    2.5-Paging-in-Linux
    2.5-Paging-in-Linux
    
    Introduction
    
    TODO
    TODO
    
    Multilevel-Paging-in-Operating-System
    Multilevel-Paging-in-Operating-System
    
    Introduction
    
    How-are-the-segment-registers-used-in-Linux
  - Chapter-3-Processes
    Chapter-3-Processes
    
    Introduction
    
    3.1-Processes-and-Lightweight-Processes-and-Threads
    3.1-Processes-and-Lightweight-Processes-and-Threads
    
    Introduction
    
    3.2-Process-Descriptor
    3.2-Process-Descriptor
    
    Introduction
    
    3.2.1-Process-State
    3.2.1-Process-State
    
    Introduction
    
    3.2.2-Identifying-a-Process
    3.2.2-Identifying-a-Process
    
    Introduction
    
    3.2.2.1-Process-descriptors-handling
    3.2.2.1-Process-descriptors-handling
    
    Introduction
    
    3.2.2.2-Identifying-the-current-process
    3.2.2.2-Identifying-the-current-process
    
    Introduction
    
    3.2.2.3-Doubly-linked-lists
    3.2.2.3-Doubly-linked-lists
    
    Introduction
    
    3.2.2.4-The-process-list
    3.2.2.4-The-process-list
    
    Introduction
    
    3.2.2.5-The-lists-of-TASK_RUNNING-processes
    3.2.2.5-The-lists-of-TASK_RUNNING-processes
    
    Introduction
    
    3.2.3-Relationships-Among-Processes
    3.2.3-Relationships-Among-Processes
    
    Introduction
    
    3.2.4-How-Processes-Are-Organized
    3.2.4-How-Processes-Are-Organized
    
    Introduction
    
    3.2.5-Process-Resource-Limits
    3.2.5-Process-Resource-Limits
    
    Introduction
    
    3.3-Process-Switch
    3.3-Process-Switch
    
    Introduction
    
    3.4-Creating-Processes
    3.4-Creating-Processes
    
    Introduction
    
    3.4.2-Kernel-Threads
    3.4.2-Kernel-Threads
    
    Introduction
  - Chapter-4-Interrupts-and-Exceptions
    Chapter-4-Interrupts-and-Exceptions
    
    Introduction
    
    4.1-The-Role-of-Interrupt-Signals
    4.1-The-Role-of-Interrupt-Signals
    
    Introduction
    
    4.2-Interrupts-and-Exceptions
    4.2-Interrupts-and-Exceptions
    
    Introduction
    
    4.3-Nested-Execution-of-Exception-and-Interrupt-Handlers
    4.3-Nested-Execution-of-Exception-and-Interrupt-Handlers
    
    Introduction
    
    4.5-Exception-Handling
    4.5-Exception-Handling
    
    Introduction
  - Chapter-6-Timing-Measurements
    Chapter-6-Timing-Measurements
    
    Introduction
    
    6.1-Clock-and-Timer-Circuits
    6.1-Clock-and-Timer-Circuits
    
    Introduction
    
    6.2-The-Linux-Timekeeping-Architecture
    6.2-The-Linux-Timekeeping-Architecture
    
    Introduction
    
    6.4-Updating-System-Statistics
    6.4-Updating-System-Statistics
    
    Introduction
  - Chapter-7-Process-Scheduling
    Chapter-7-Process-Scheduling
    
    Introduction
  - Chapter-8-Memory-Management
    Chapter-8-Memory-Management
    
    Introduction
    
    8.1-Page-Frame-Management
    8.1-Page-Frame-Management
    
    Introduction
  - Chapter-9-Process-Address-Space
    Chapter-9-Process-Address-Space
    
    Introduction
    
    9.1-The-Process's-Address-Space
    9.1-The-Process's-Address-Space
    
    Introduction
    
    9.2-The-Memory-Descriptor
    9.2-The-Memory-Descriptor
    
    Introduction
- 主要功能
  主要功能
  - Introduction
  - Interaction-with-hardware
    Interaction-with-hardware
    
    Linux-OS-kernel-is-event-driven
    
    Kernel-control-path-and-reentrant-kernel
    
    Linux-OS-interrupt-and-interrupte-handler
  - Multitasking
  - User-system
    User-system
    
    Introduction
  - Memory-management
    Memory-management
    
    Introduction
    
    Memory-protection
    Memory-protection
    
    Introduction
    
    Virtual-memory
    Virtual-memory
    
    Introduction
    
    Paging
    Paging
    
    Introduction
    
    Unix-system-page-size
    
    Difference-Between-Paging-and-Segmentation-in-OS
    
    Fragmentation
    Fragmentation
    
    Introduction
    
    Heap-fragmentation
    Heap-fragmentation
    
    Introduction
    
    TODO-design-reuse-Dynamic-Memory-Allocation-and-Fragmentation
    TODO-design-reuse-Dynamic-Memory-Allocation-and-Fragmentation
    
    Introduction
    
    Defragmentation
    Defragmentation
    
    Introduction
- Read-code
  Read-code
  - Introduction
  - Kernel-data-structure
    Kernel-data-structure
    
    Introduction
- Debug-kernel
  Debug-kernel
  - Introduction
  - System.map
    System.map
    
    Introduction
  - oops
- The-Linux-Kernel-documentation
  The-Linux-Kernel-documentation
  - Introduction
Linux-startup-process
Linux-startup-process
- Introduction
- Entry-point-of-kernel
  Entry-point-of-kernel
  - Introduction
System-call
System-call
- Introduction
- Why-system-call-slow
  Why-system-call-slow
  - Introduction
- Classification
  Classification
  - Introduction
  - System-call-with-timeout
    System-call-with-timeout
    
    Introduction
- Interrupted-system-call
  Interrupted-system-call
  - Introduction
- Zero-copy
  Zero-copy
  - Introduction
  - linuxjournal-Zero-Copy-I-User-Mode-Perspective
    linuxjournal-Zero-Copy-I-User-Mode-Perspective
    
    Introduction
  - developpaper-Analysis-of-zero-copy-technology-in-Linux
    developpaper-Analysis-of-zero-copy-technology-in-Linux
    
    Introduction
  - joshbialkowski-Linux-Zero-Copy
    joshbialkowski-Linux-Zero-Copy
    
    Introduction
  - splice系列-zero-copy-system-call
    splice系列-zero-copy-system-call
    
    Introduction
  - Zero-copy-VS-COW-copy-on-write
    Zero-copy-VS-COW-copy-on-write
    
    Introduction
- p-system-call
  p-system-call
  - Introduction
- Linux-system-call-table
  Linux-system-call-table
  - Introduction
Multitasking
Multitasking
- Introduction
- Process-thread-model
  Process-thread-model
  - Introduction
  - Process-thread
    Process-thread
    
    Introduction
    
    wikipedia-Process(computing)
    wikipedia-Process(computing)
    
    Introduction
  - Process-run-model
    Process-run-model
    
    Introduction
  - Process-control-block
    Process-control-block
    
    Introduction
  - Process-table
    Process-table
    
    Introduction
  - Process-resource
    Process-resource
    
    Introduction
  - Process-lifetime
    Process-lifetime
    
    Introduction
  - Linux-implementation
    Linux-implementation
    
    Introduction
    
    man-2-clone
    man-2-clone
    
    Introduction
    
    opensourceforu-The-Life-of-a-Process
    opensourceforu-The-Life-of-a-Process
    
    Introduction
- Process-memory
  Process-memory
  - Introduction
  - Process-address-space
    Process-address-space
    
    Introduction
    
    Thinking
    
    Segment
    Segment
    
    BSS
    BSS
    
    Introduction
    
    Data-segment
    Data-segment
    
    Introduction
    
    Code-segment
    Code-segment
    
    Introduction
    
    Heap
    Heap
    
    Introduction
    
    Stack-VS-heap
    Stack-VS-heap
    
    Introduction
    
    Operation-on-stack-VS-on-heap
    Operation-on-stack-VS-on-heap
    
    Introduction
    
    Memory-mapped-file
    Memory-mapped-file
    
    Introduction
  - Linux-implementation
    Linux-implementation
    
    Introduction
    
    dynamic-allocation-system-call
    dynamic-allocation-system-call
    
    man-2-brk
    man-2-brk
    
    Introduction
    
    man-2-sbrk
    man-2-sbrk
    
    Introduction
    
    Program-break
    Program-break
    
    Introduction
    
    输出内存布局
    输出内存布局
    
    Introduction
    
    Holberton-Hack-the-virtual-memory
    Holberton-Hack-the-virtual-memory
    
    Introduction
    
    The-stack-registers-and-assembly-code
    The-stack-registers-and-assembly-code
    
    Introduction
    
    Chapter-0-C-strings&proc-filesystem
    Chapter-0-C-strings&proc-filesystem
    
    Introduction
    
    Chapter-2-Drawing-the-VM-diagram
    Chapter-2-Drawing-the-VM-diagram
    
    Introduction
    
    Chapter-3-malloc-the-heap&the-program-break
    Chapter-3-malloc-the-heap&the-program-break
    
    Introduction
    
    CSDN-Linux下C程序进程地址空间布局
    CSDN-Linux下C程序进程地址空间布局
    
    Introduction
    
    Size
    Size
    
    Unix-virtual-address-space
    
    Virtual-address-space-size-reading-list
- Process-file
  Process-file
  - Introduction
- Scheduler
  Scheduler
  - Introduction
  - Preemptive-multitasking
    Preemptive-multitasking
    
    Introduction
    
    Kernel-preemption
  - Cooperative-multitasking
    Cooperative-multitasking
    
    Introduction
  - Context-switch
    Context-switch
    
    Introduction
  - Linux-implementation
    Linux-implementation
    
    Introduction
    
    man-7-sched
    man-7-sched
    
    Introduction
    
    Processor-affinity
    Processor-affinity
    
    Introduction
    
    man-1-taskset
    man-1-taskset
    
    Introduction
  - Multicore-scheduler-process
    Multicore-scheduler-process
    
    Introduction
- System-call-summary
  System-call-summary
  - Introduction
- Linux-process
  Linux-process
  - Organization-of-process
    Organization-of-process
    
    Introduction
    
    Process-group
    Process-group
    
    Introduction
    
    man-7-cgroups
    man-7-cgroups
    
    Introduction
    
    TODO-How-kernel-organize-process
    TODO-How-kernel-organize-process
    
    Introduction
  - Process-state
    Process-state
    
    Introduction
    
    wikipedia-Process-state
    wikipedia-Process-state
    
    Introduction
  - Create-process
    Create-process
    
    man-2-fork
    man-2-fork
    
    Introduction
  - Wait-child-process
    Wait-child-process
    
    Child-process-exit-status
    Child-process-exit-status
    
    Introduction
  - Process-termination
    Process-termination
    
    Introduction
    
    man-3-abort
    man-3-abort
    
    Introduction
  - Block-process
    Block-process
    
    Introduction
  - Daemon
    Daemon
    
    man-7-daemon
    
    man-3-daemon
  - IPC
    IPC
    
    Introduction
    
    Beej's-Guide-to-Unix-IPC
    Beej's-Guide-to-Unix-IPC
    
    Introduction
    
    pipe
    pipe
    
    man-7-pipe
    man-7-pipe
    
    Introduction
    
    Unix-PIPE_BUF
    
    System-V-IPC
    System-V-IPC
    
    man-7-SVIPC
    man-7-SVIPC
    
    Introduction
    
    POSIX-IPC
    POSIX-IPC
    
    Introduction
    
    message-queues
    message-queues
    
    man-7-mq_overview
    man-7-mq_overview
    
    Introduction
    
    semaphores
    semaphores
    
    man-7-sem_overview
    man-7-sem_overview
    
    Introduction
    
    shared-memory
    shared-memory
    
    Introduction
    
    man-7-shm_overview
    man-7-shm_overview
    
    Introduction
    
    man-2-mmap
    man-2-mmap
    
    Introduction
    
    man-2-mmap
    man-2-mmap
    
    Introduction
    
    linuxhint-How-to-use-mmap-function-in-C-language
    linuxhint-How-to-use-mmap-function-in-C-language
    
    Introduction
    
    Unix-domain-socket
    Unix-domain-socket
    
    man-7-unix
    man-7-unix
    
    Introduction
    
    Tools
    Tools
    
    man-1-ipcmk
    man-1-ipcmk
    
    Introduction
    
    man-1-ipcrm
    man-1-ipcrm
    
    Introduction
    
    man-1-ipcs
    man-1-ipcs
    
    Introduction
    
    man-1-lsipc
    man-1-lsipc
    
    Introduction
    
    man-7-ipc_namespaces
    man-7-ipc_namespaces
    
    Introduction
    
    Inter-process-lock
    Inter-process-lock
    
    Introduction
- Linux-thread
  Linux-thread
  - Introduction
  - Thread-control-block
    Thread-control-block
    
    Introduction
  - man-7-pthreads
    man-7-pthreads
    
    Introduction
  - man-7-attributes
    man-7-attributes
    
    Introduction
  - Create-thread
    Create-thread
    
    man-3-pthread_create
    man-3-pthread_create
    
    Introduction
    
    Thread-ID
    Thread-ID
    
    man-3-pthread_self
    man-3-pthread_self
    
    Introduction
    
    man-3-pthread_equal
    man-3-pthread_equal
    
    Introduction
    
    Thread-attri
    Thread-attri
    
    Introduction
  - Cancel-thread
    Cancel-thread
    
    man-3-pthread_cancel
    man-3-pthread_cancel
    
    Introduction
    
    man-3-pthread_setcancel
    man-3-pthread_setcancel
    
    Introduction
  - Join-thread
    Join-thread
    
    man-3-pthread_join
    man-3-pthread_join
    
    Introduction
  - Detach-thread
    Detach-thread
    
    man-3-pthread_detach
    man-3-pthread_detach
    
    Introduction
  - Synchronization
    Synchronization
    
    Barrier
    Barrier
    
    Introduction
    
    Condition-variables
    Condition-variables
    
    Introduction
    
    man-3-pthread_cond_timedwait
    man-3-pthread_cond_timedwait
    
    Introduction
    
    man-2-futex
    man-2-futex
    
    Introduction
- Limit
  Limit
  - Introduction
  - Limit-via-configuration
  - Limit-via-system-call
  - man-ulimit
    man-ulimit
    
    Introduction
  - Process-resource-limits-under-the-hood
  - man-5-limits.conf
    man-5-limits.conf
    
    Introduction
  - man-5-sysctl.conf
    man-5-sysctl.conf
    
    Introduction
- Credential
  Credential
  - man-7-credentials
    man-7-credentials
    
    Introduction
- proc-filesystem
  proc-filesystem
  - man-5-proc
    man-5-proc
    
    Introduction
- Tools
  Tools
  - Introduction
  - procps
    procps
    
    Introduction
    
    ps
    ps
    
    Introduction
    
    man-1-ps
    man-1-ps
    
    Introduction
    
    Wait-channel
    
    top
    top
    
    Introduction
    
    htop
    htop
    
    Introduction
    
    pgrep
    
    pstree
Programming
Programming
- Introduction
- Book-APUE
  Book-APUE
  - Introduction
  - 1-UNIX-System-Overview
    1-UNIX-System-Overview
    
    Introduction
    
    1.7-Error-Handling
    1.7-Error-Handling
    
    Introduction
  - 2-UNIX-Standardization-and-Implementations
    2-UNIX-Standardization-and-Implementations
    
    Introduction
  - 3-File-IO
    3-File-IO
    
    Introduction
    
    3.2-File-Descriptors
    3.2-File-Descriptors
    
    Introduction
    
    3.3-open-and-openat-Functions
    3.3-open-and-openat-Functions
    
    Introduction
    
    3.4-creat-Function
    3.4-creat-Function
    
    Introduction
    
    3.5-close-Function
    3.5-close-Function
    
    Introduction
    
    3.10-File-Sharing
    3.10-File-Sharing
    
    Introduction
    
    3.11-Atomic-Operations
    3.11-Atomic-Operations
    
    Introduction
    
    3.12-dup-and-dup2-Functions
    3.12-dup-and-dup2-Functions
    
    Introduction
    
    3.13-sync-fsync-and-fdatasync-Functions
    3.13-sync-fsync-and-fdatasync-Functions
    
    Introduction
  - 4-Files-and-Directories
    4-Files-and-Directories
    
    Introduction
  - 5-Standard-IO-Library
    5-Standard-IO-Library
    
    Introduction
  - 6-System-Data-Files-and-Information
    6-System-Data-Files-and-Information
    
    Introduction
  - 7-Process-Environment
    7-Process-Environment
    
    Introduction
  - 8-Process-Control
    8-Process-Control
    
    Introduction
    
    8.3-fork-Function
    8.3-fork-Function
    
    Introduction
    
    8.9-Race-Conditions
    8.9-Race-Conditions
    
    Introduction
  - 9-Process-Relationships
    9-Process-Relationships
    
    Introduction
  - 10-Signals
    10-Signals
    
    Introduction
    
    10.2-Signal-Concepts
    10.2-Signal-Concepts
    
    Introduction
    
    10.6-Reentrant-Functions
    10.6-Reentrant-Functions
    
    Introduction
    
    10.5-Interrupted-System-Calls
    10.5-Interrupted-System-Calls
    
    Introduction
  - 11-Threads
    11-Threads
    
    Introduction
  - 12-Thread-Control
    12-Thread-Control
    
    Introduction
  - 13-Daemon-Processes
    13-Daemon-Processes
    
    Introduction
  - 14-Advanced-IO
    14-Advanced-IO
    
    Introduction
    
    14.2-Nonblocking-IO
    14.2-Nonblocking-IO
    
    Introduction
  - 15-Interprocess-Communication
    15-Interprocess-Communication
    
    Introduction
  - 16-Network-IPC-Sockets
    16-Network-IPC-Sockets
    
    Introduction
  - 17-Advanced-IPC
    17-Advanced-IPC
    
    Introduction
    
    17.4-Passing-File-Descriptors
    17.4-Passing-File-Descriptors
    
    Introduction
  - 18-Terminal-IO
    18-Terminal-IO
    
    Introduction
  - 19-Pseudo-Terminals
    19-Pseudo-Terminals
    
    Introduction
  - 20-A-Database-Library
    20-A-Database-Library
    
    Introduction
  - 21-Communicating-with-a-Network-Printer
    21-Communicating-with-a-Network-Printer
    
    Introduction
  - Race-condition
    Race-condition
    
    Introduction
- Book-TLPL
  Book-TLPL
  - Introduction
- Book-UNP
  Book-UNP
  - Introduction
  - Chapter-6-IO-Multiplexing-The-select-and-poll-Functions
    Chapter-6-IO-Multiplexing-The-select-and-poll-Functions
    
    6.1-Introduction
- Common
  Common
  - Linux-name-convention
    Linux-name-convention
    
    Introduction
  - Function-attribute
    Function-attribute
    
    Introduction
    
    Idempotence
    Idempotence
    
    Introduction
    
    POSIX-safety
    POSIX-safety
    
    Introduction
    
    Reentrancy
    Reentrancy
    
    Introduction
    
    wikipedia-Reentrancy
    wikipedia-Reentrancy
    
    Introduction
    
    man-7-signal-safety
    man-7-signal-safety
    
    Introduction
    
    Async-cancel-safety
    Async-cancel-safety
    
    Introduction
  - Path-resolution
  - errno
    errno
    
    man-3-errno
    man-3-errno
    
    Introduction
    
    Is-errno-thread-local
    Is-errno-thread-local
    
    Introduction
    
    errno-EAGAIN-EWOULDBLOCK
    errno-EAGAIN-EWOULDBLOCK
    
    Introduction
    
    errno-EEXIST
    errno-EEXIST
    
    Introduction
- Philosophy
  Philosophy
  - Introduction
  - Unix-philosophy
    Unix-philosophy
    
    Introduction
  - Everything-is-a-file
    Everything-is-a-file
    
    Introduction
- library
  library
  - Introduction
  - library-glibc
    library-glibc
    
    Introduction
    
    doc
    doc
    
    Introduction
    
    1.2-Standards-and-Portability
    1.2-Standards-and-Portability
    
    Introduction
    
    11-Input-Output-Overview
    11-Input-Output-Overview
    
    Introduction
    
    12-Input-Output-on-Streams
    12-Input-Output-on-Streams
    
    Introduction
    
    13-Low-Level-Input-Output
    13-Low-Level-Input-Output
    
    Introduction
    
    13.8-Memory-mapped-IO
    13.8-Memory-mapped-IO
    
    Introduction
    
    13.14-File-Descriptor-Flags
    13.14-File-Descriptor-Flags
    
    Introduction
    
    13.15-File-Status-Flags
    13.15-File-Status-Flags
    
    Introduction
    
    13.15.1-File-Access-Modes
    13.15.1-File-Access-Modes
    
    Introduction
    
    13.15.2-Open-time-Flags
    13.15.2-Open-time-Flags
    
    Introduction
    
    13.15.3-IO-Operating-Modes
    13.15.3-IO-Operating-Modes
    
    Introduction
- IO
  IO
  - Introduction
  - What-is-IO
    What-is-IO
    
    Introduction
  - File-system
    File-system
    
    Unix-filesystem
    Unix-filesystem
    
    Introduction
    
    Linux-virtual-file-system
    Linux-virtual-file-system
    
    Introduction
    
    Vnode
    Vnode
    
    Introduction
    
    man-7-file-hierarchy
    man-7-file-hierarchy
    
    Introduction
    
    Inode
    Inode
    
    Introduction
    
    man-2-stat
    man-2-stat
    
    Introduction
    
    File-type
    File-type
    
    Introduction
    
    Tools
    Tools
    
    Introduction
  - IO-model
    IO-model
    
    Introduction
    
    UNP-6.1-IO-Multiplexing
    UNP-6.1-IO-Multiplexing
    
    Introduction
  - IO-data-structure
    IO-data-structure
    
    Introduction
    
    File-descriptor
    File-descriptor
    
    Introduction
    
    wikipedia-File-descriptor
    wikipedia-File-descriptor
    
    Introduction
    
    Pass-file-descriptor
    Pass-file-descriptor
    
    Introduction
    
    fd-is-reference
    fd-is-reference
    
    Introduction
    
    IO-buffer
    IO-buffer
    
    Introduction
  - IO-流派
    IO-流派
    
    Introduction
    
    Stream-based-IO
    Stream-based-IO
    
    Stream
    
    Standard-streams
    
    Stream-VS-fd
    Stream-VS-fd
    
    Introduction
  - Asynchronous-IO
    Asynchronous-IO
    
    Introduction
    
    ibm-Boost-application-performance-using-asynchronous-IO
    ibm-Boost-application-performance-using-asynchronous-IO
    
    Introduction
    
    library-libeio
    library-libeio
    
    Introduction
  - IO-multiplexing
    IO-multiplexing
    
    Introduction
    
    What-is-multiplexing
    What-is-multiplexing
    
    Introduction
    
    What-is-IO-multiplexing
    What-is-IO-multiplexing
    
    Introduction
    
    zhihu-What-is-IO-multiplexing
    zhihu-What-is-IO-multiplexing
    
    Introduction
    
    Multiplex-on-file-descriptor
    Multiplex-on-file-descriptor
    
    Introduction
    
    Notify-via-fd
    Notify-via-fd
    
    Introduction
    
    eventfd
    eventfd
    
    Introduction
    
    yangyang-Worker-Pool-With-Eventfd
    yangyang-Worker-Pool-With-Eventfd
    
    Introduction
    
    man-2-eventfd
    man-2-eventfd
    
    Introduction
    
    timefd
    timefd
    
    Introduction
    
    signalfd
    signalfd
    
    Introduction
    
    man-2-signalfd
    man-2-signalfd
    
    Introduction
    
    self-pipe-trick
    self-pipe-trick
    
    Introduction
    
    select
    select
    
    Introduction
    
    man-2-select
    man-2-select
    
    Introduction
    
    man-2-select_tut
    man-2-select_tut
    
    Introduction
    
    pselect-VS-select
    pselect-VS-select
    
    Introduction
    
    poll
    poll
    
    Introduction
    
    epoll
    epoll
    
    wikipedia-epoll
    wikipedia-epoll
    
    Introduction
    
    man-7-epoll
    man-7-epoll
    
    Introduction
    
    man-2-epoll_create
    man-2-epoll_create
    
    Introduction
    
    man-2-epoll_wait
    man-2-epoll_wait
    
    Introduction
    
    man-2-epoll_ctl
    man-2-epoll_ctl
    
    Introduction
    
    EPOLLHUP
    EPOLLHUP
    
    Introduction
    
    EPOLLRDHUP
    EPOLLRDHUP
    
    Introduction
    
    EPOLLRDHUP-VS-EPOLLHUP
    EPOLLRDHUP-VS-EPOLLHUP
    
    Introduction
    
    epoll-impl
    epoll-impl
    
    Introduction
    
    idndx-The-Implementation-of-epoll
    idndx-The-Implementation-of-epoll
    
    Introduction
    
    Edge-trigger-VS-level-trigger
    Edge-trigger-VS-level-trigger
    
    Introduction
    
    epoll-nonblocking-IO
    epoll-nonblocking-IO
    
    Introduction
    
    kovyrin-Using-epoll-For-Asynchronous-Network-Programming
    kovyrin-Using-epoll-For-Asynchronous-Network-Programming
    
    Introduction
    
    Summary
    Summary
    
    Introduction
    
    IO-multiplexing-and-signal
    IO-multiplexing-and-signal
    
    Introduction
    
    select-VS-poll-VS-epoll
    select-VS-poll-VS-epoll
    
    Introduction
  - File-IO
    File-IO
    
    Introduction
    
    File-format
    File-format
    
    Introduction
    
    System-call
    System-call
    
    Introduction
    
    man-2-open
    man-2-open
    
    Introduction
    
    man-2-openat
    man-2-openat
    
    Introduction
    
    man-2-close
    man-2-close
    
    Introduction
    
    man-2-read
    man-2-read
    
    Introduction
    
    man-2-fcntl
    man-2-fcntl
    
    Introduction
    
    File-lock
    File-lock
    
    wikipedia-File-locking
    wikipedia-File-locking
    
    Introduction
    
    man-2-flock
    man-2-flock
    
    Introduction
    
    Notify
    Notify
    
    inotify
    inotify
    
    man-7-inotify
    man-7-inotify
    
    Introduction
    
    fanotify
    fanotify
    
    man-7-fanotify
    man-7-fanotify
    
    Introduction
  - Network-IO
    Network-IO
    
    Introduction
  - IO-redirection
    IO-redirection
    
    Introduction
    
    opengroup-dup-and-dup2
    opengroup-dup-and-dup2
    
    Introduction
  - Vectored-IO
    Vectored-IO
    
    Introduction
    
    man-2-readv-writev
    man-2-readv-writev
    
    Introduction
  - Tools
    Tools
    
    man-1-fuser
    man-1-fuser
    
    Introduction
    
    man-1-lsof
    man-1-lsof
    
    Introduction
- Date-time
  Date-time
  - Introduction
  - man-2-clock_gettime
    man-2-clock_gettime
    
    Introduction
  - localtime
    localtime
    
    Introduction
  - codeofmatt-List-of-2020-Leap-Day-Bugs
    codeofmatt-List-of-2020-Leap-Day-Bugs
    
    Introduction
- Signal
  Signal
  - Introduction
  - wikipedia-Signal(IPC)
    wikipedia-Signal(IPC)
    
    Introduction
  - man-7-signal
    man-7-signal
    
    Introduction
  - Unix-Termination-Signals
    Unix-Termination-Signals
    
    Introduction
  - Signal-handler
    Signal-handler
    
    Introduction
  - Scheduler-signal
    Scheduler-signal
    
    Introduction
  - Ctrl-z-and-Ctrl-c
    Ctrl-z-and-Ctrl-c
    
    Introduction
  - Block-signal
    Block-signal
    
    Introduction
- Virtualization
  Virtualization
  - Introduction
  - Virtualization
    Virtualization
    
    Introduction
    
    Memory-virtualization
    Memory-virtualization
    
    Introduction
  - Linux-containers
    Linux-containers
    
    Introduction
  - Linux-namespaces
    Linux-namespaces
    
    Introduction
    
    toptal-Separation-Anxiety-Tutorial-for-Isolating-Your-System-with-Linux-Namespaces
    toptal-Separation-Anxiety-Tutorial-for-Isolating-Your-System-with-Linux-Namespaces
    
    Introduction
    
    man-7-namespaces
    man-7-namespaces
    
    Introduction
  - Linux-control-groups
    Linux-control-groups
    
    Introduction
- Util
  Util
  - Introduction
  - Log
    Log
    
    Linux-log-files
    
    Syslog
    Syslog
    
    Syslog
- Computer-errors
  Computer-errors
  - Introduction
  - CWE
    CWE
    
    Introduction
  - Memory-access-error
    Memory-access-error
    
    Introduction
- Kernel-module
  Kernel-module
  - Loadable-kernel-module
  - Tool
    Tool
    
    Introduction
- Object-file
  Object-file
  - Introduction
  - ELF
    ELF
    
    Introduction
    
    Classification-of-object-file
    Classification-of-object-file
    
    Introduction
    
    man-5-elf
    man-5-elf
    
    Introduction
    
    Tools
    Tools
    
    man-1-strip
    
    man-1-readelf
    
    man-1-objdump
    
    man-1-addr2line
  - Shared-library
    Shared-library
    
    Introduction
    
    Symbol-of-shared-library
    Symbol-of-shared-library
    
    Introduction
    
    Tools
    Tools
    
    man-1-ldd
    man-1-ldd
    
    Introduction
    
    version
    version
    
    Introduction
  - Symbol
    Symbol
    
    Introduction
    
    nm
    nm
    
    Introduction
- Core-dump
  Core-dump
  - Introduction
- Terminal
  Terminal
  - Introduction
  - linusakesson-The-TTY-demystified
    linusakesson-The-TTY-demystified
    
    Introduction
  - tty-pty
    tty-pty
    
    Introduction
- Expert-Marek
  Expert-Marek
  - Introduction
  - When-Bloom-filters-don't-bloom
    When-Bloom-filters-don't-bloom
    
    Introduction
  - Bind-before-connect
    Bind-before-connect
    
    Introduction
Network
Network
- Introduction
- Network-model
  Network-model
  - Introduction
  - Layered-network-protocol-model
    Layered-network-protocol-model
    
    Introduction
    
    PDU-MTU-SDU-MSS
    PDU-MTU-SDU-MSS
    
    Introduction
  - RCF
    RCF
    
    Introduction
  - Link-layer
    Link-layer
    
    Address-Resolution-Protocol
    Address-Resolution-Protocol
    
    Introduction
  - Network-layer
    Network-layer
    
    man-7-ip
    man-7-ip
    
    Introduction
    
    man-7-ipv6
    man-7-ipv6
    
    Introduction
    
    ICMP
    ICMP
    
    Introduction
    
    IGMP
    IGMP
    
    Introduction
  - Transport-layer
    Transport-layer
    
    TCP
    TCP
    
    Introduction
    
    Course-miami-TCP-in-a-nutshell
    Course-miami-TCP-in-a-nutshell
    
    Introduction
    
    coolshell-TCP的那些事儿
    coolshell-TCP的那些事儿
    
    上
    上
    
    Introduction
    
    下
    下
    
    Introduction
    
    wikipedia-Transmission-Control-Protocol
    wikipedia-Transmission-Control-Protocol
    
    Introduction
    
    TCP-connection
    TCP-connection
    
    Introduction
    
    TCP-connection-tuple
    TCP-connection-tuple
    
    Introduction Introduction
    Table of contents
    
    stackoverflow How many tuples are there in a connection?
    
    A
    
    networkengineering Why is a TCP Socket identified by a 4 tuple?
    
    TCP-长连接-短连接
    TCP-长连接-短连接
    
    Introduction
    
    Half-open-close
    Half-open-close
    
    Introduction
    
    TCP-glossary
    TCP-glossary
    
    Introduction
    
    TCP-FSM
    TCP-FSM
    
    Introduction
    
    Connection-synchronization
    Connection-synchronization
    
    Introduction
    
    Data-transfer
    Data-transfer
    
    Introduction
    
    Sequence-number&&acknowledge-number
    Sequence-number&&acknowledge-number
    
    Introduction
    
    Nagle's-algorithm
    Nagle's-algorithm
    
    Introduction
    
    TCP-segment-of-a-reassembled-PDU
    
    Connection-termination
    Connection-termination
    
    Introduction
    
    Connection-finish
    Connection-finish
    
    Introduction
    
    freesoft-4.2.2.13-Closing-a-Connection-RFC-793-Section-3.5
    freesoft-4.2.2.13-Closing-a-Connection-RFC-793-Section-3.5
    
    Introduction
    
    Connection-reset
    Connection-reset
    
    Introduction
    
    Flow-control
    Flow-control
    
    Introduction
    
    Sliding-window
    Sliding-window
    
    Introduction
    
    Congestion-control
    Congestion-control
    
    Introduction
    
    TCP-tuning
    TCP-tuning
    
    Introduction
    
    UDP
    UDP
    
    Introduction
    
    UDP-broadcast
    UDP-broadcast
    
    Introduction
    
    Reliable-UDP-RUDP
    Reliable-UDP-RUDP
    
    Introduction
    
    tencent-告知你不为人知的UDP疑难杂症和使用
    tencent-告知你不为人知的UDP疑难杂症和使用
    
    Introduction
    
    TCP-VS-UDP
    TCP-VS-UDP
    
    Introduction
  - Application-layer
    Application-layer
    
    Introduction
    
    Design-protocol
    Design-protocol
    
    Introduction
    
    Protocol-data-format
    Protocol-data-format
    
    Introduction
    
    Binary-VS-textual-protocol
    Binary-VS-textual-protocol
    
    Introduction
    
    IDL
    IDL
    
    Introduction
    
    Schema-evaluation
    
    TCP-message-boundary
    TCP-message-boundary
    
    Introduction
    
    CSDN-经典-tcp粘包分析
    CSDN-经典-tcp粘包分析
    
    Introduction
    
    Domain-Name-System
    Domain-Name-System
    
    Introduction
    
    TODO-根域名服务器是否只有13台
    TODO-根域名服务器是否只有13台
    
    Introduction
    
    WebSocket
    WebSocket
    
    Introduction
    
    HTTP
    HTTP
    
    Introduction
    
    HTTP-persistent-connection
    HTTP-persistent-connection
    
    Introduction
  - Message-boundary
    Message-boundary
    
    Introduction
  - Ethernet
    Ethernet
    
    Introduction
- Network-security
  Network-security
  - Introduction
  - DoS-attack
    DoS-attack
    
    Introduction
    
    Syn-flood
    Syn-flood
    
    Introduction
- Network-topology
  Network-topology
  - Introduction
  - mesh
    mesh
    
    Introduction
- RDMA
  RDMA
  - Introduction
  - zhihu-RDMA技术详解
    zhihu-RDMA技术详解
    
    Introduction
  - paper-RDMC-A-Reliable-RDMA-Multicast-for-Large-Objects
    paper-RDMC-A-Reliable-RDMA-Multicast-for-Large-Objects
    
    Introduction
- Programming
  Programming
  - Introduction
  - course-dartmouth-CS60-Computer-Networks
    course-dartmouth-CS60-Computer-Networks
    
    Introduction
    
    Lecture 3-and-4-Socket-Programming
    Lecture 3-and-4-Socket-Programming
    
    Introduction
  - Book-Beej's-Guide-to-Network-Programming
    Book-Beej's-Guide-to-Network-Programming
    
    Introduction
    
    1-Intro
    1-Intro
    
    Introduction
    
    2-What-is-a-socket
    2-What-is-a-socket
    
    Introduction
    
    3-IP-Addresses-structs-and-Data-Munging
    3-IP-Addresses-structs-and-Data-Munging
    
    Introduction
    
    5-System-Calls-or-Bust
    5-System-Calls-or-Bust
    
    Introduction
    
    6-Client-Server-Background
    6-Client-Server-Background
    
    Introduction
  - Linux-TCP-impl
    Linux-TCP-impl
    
    Introduction
    
    Data-structure
    Data-structure
    
    Introduction
    
    SND-RCV-Buffer
    SND-RCV-Buffer
    
    Introduction
    
    Network-IO-events
    Network-IO-events
    
    Introduction
    
    backlog
    backlog
    
    Introduction
    
    Bufferbloat
    Bufferbloat
    
    Introduction
    
    man-7-TCP
    man-7-TCP
    
    Introduction
    
    TCP-parameter
    TCP-parameter
    
    Introduction
    
    tcp_max_syn_backlog-VS-somaxcon
    tcp_max_syn_backlog-VS-somaxcon
    
    Introduction
  - Socket
    Socket
    
    Introduction
    
    man-7-socket
    man-7-socket
    
    Introduction
    
    man-2-socket
    man-2-socket
    
    Introduction
    
    man-7-address_families
    man-7-address_families
    
    Introduction
    
    Socket-option
    Socket-option
    
    Introduction
    
    man-2-setsockopt
    man-2-setsockopt
    
    Introduction
    
    Mark-socket
    Mark-socket
    
    Introduction
    
    CSDN-Linux socket设置mark的必要性
    CSDN-Linux socket设置mark的必要性
    
    Introduction
    
    SO_REUSEADDR-SO_REUSEPORT
    SO_REUSEADDR-SO_REUSEPORT
    
    Introduction
    
    stackoverflow-How-SO_REUSEADDR-SO_REUSEPORT-differ
    stackoverflow-How-SO_REUSEADDR-SO_REUSEPORT-differ
    
    Introduction
    
    SO_REUSEADDR
    SO_REUSEADDR
    
    Introduction
    
    microsoft-Using-SO_REUSEADDR-and-SO_EXCLUSIVEADDRUSE
    microsoft-Using-SO_REUSEADDR-and-SO_EXCLUSIVEADDRUSE
    
    Introduction
    
    SO_REUSEPORT
    SO_REUSEPORT
    
    lwn-The-SO_REUSEPORT-socket-option
    lwn-The-SO_REUSEPORT-socket-option
    
    Introduction
    
    SO_LINGER
    SO_LINGER
    
    Introduction
    
    Control-message
    Control-message
    
    Introduction
    
    man-3-cmsg
    man-3-cmsg
    
    Introduction
    
    Out-of-band
    Out-of-band
    
    Introduction
  - Port
    Port
    
    Introduction
    
    Ephemeral-port
    Ephemeral-port
    
    Introduction
    
    Process&port
    Process&port
    
    Introduction
  - man-2-bind
    man-2-bind
    
    Introduction
  - INADDR_ANY-local_host
    INADDR_ANY-local_host
    
    Introduction
  - man-2-listen
    man-2-listen
    
    Introduction
  - man-3-getaddrinfo
    man-3-getaddrinfo
    
    Introduction
  - Close-socket
    Close-socket
    
    Introduction
    
    man-2-shutdown
    man-2-shutdown
    
    Introduction
    
    close-VS-shutdown
  - Reconnect
  - man-2-sendfile
    man-2-sendfile
    
    Introduction
  - Broadcast-multicast
    Broadcast-multicast
    
    Introduction
  - TCP-Wrappers
    TCP-Wrappers
    
    Introduction
  - TCP-Keepalive
    TCP-Keepalive
    
    Introduction
    
    jianshu-KeepAlive详解
    jianshu-KeepAlive详解
    
    Introduction
  - TIME_WAIT=2MSL
    TIME_WAIT=2MSL
    
    Introduction
    
    解决TIME_WAIT过多问题
    解决TIME_WAIT过多问题
    
    Introduction
    
    serverframework-TIME_WAIT
    serverframework-TIME_WAIT
    
    Introduction
    
    cnblogs-解决TIME_WAIT过多造成的问题
    cnblogs-解决TIME_WAIT过多造成的问题
    
    Introduction
    
    MSL-Maximum-segment-lifetime
    MSL-Maximum-segment-lifetime
    
    Introduction
  - Thundering-Herd-problem
    Thundering-Herd-problem
    
    Introduction
    
    uwsgi-Serializing-accept-AKA-Thundering-Herd-AKA-the-Zeeg-Problem
    uwsgi-Serializing-accept-AKA-Thundering-Herd-AKA-the-Zeeg-Problem
    
    Introduction
    
    SO_REUSEPORT-EPOLLEXCLUSIVE-mitigate-Thundering-herd
    SO_REUSEPORT-EPOLLEXCLUSIVE-mitigate-Thundering-herd
    
    Introduction
- Performance-optimization
  Performance-optimization
  - Introduction
  - Delayed-ACK
    Delayed-ACK
    
    Introduction
- Expert-packetlife
  Expert-packetlife
  - Introduction
  - packetlife-Understanding-TCP-Sequence-and-Acknowledgment-Numbers
    packetlife-Understanding-TCP-Sequence-and-Acknowledgment-Numbers
    
    Introduction
- Tools
  Tools
  - Introduction
  - Packet-analyzer
    Packet-analyzer
    
    Introduction
    
    tcpdump
    tcpdump
    
    Introduction
    
    Wireshark
    Wireshark
    
    Introduction
    
    TODO-ngrep
  - netstat(obsolete)
    netstat(obsolete)
    
    Introduction
  - iproute2
    iproute2
    
    Introduction
  - software-Nmap
    software-Nmap
    
    Introduction
  - software-netfilter
    software-netfilter
    
    Introduction
  - Troubleshoot
    Troubleshoot
    
    Introduction
    
    Troubleshoot-local-network
    Troubleshoot-local-network
    
    Introduction
    
    Troubleshoot-remote-network
    Troubleshoot-remote-network
    
    Introduction
    
    Troubleshoot-packet-loss
    Troubleshoot-packet-loss
    
    Introduction
- Glossary
  Glossary
  - Wire-protocol
    Wire-protocol
    
    Introduction
  - Host(network)
    Host(network)
    
    Introduction
  - Hostname
    Hostname
    
    Introduction
  - MAC-address
    MAC-address
    
    Introduction
Event-driven-concurrent-server
Event-driven-concurrent-server
- Introduction
- linuxgazette-Concurrent-Server-Design
  linuxgazette-Concurrent-Server-Design
  - Introduction
- linuxjournal-Thinking-Concurrently
  linuxjournal-Thinking-Concurrently
  - Introduction
Security
Security
- Introduction
- Capability-based-security
  Capability-based-security
  - Introduction
  - TODO-Object-capability-model
    TODO-Object-capability-model
    
    Introduction
- Capabilities
  Capabilities
  - Introduction
  - man-7-Capabilities
    man-7-Capabilities
    
    Introduction
运维管理
运维管理
- Introduction
- init-process
  init-process
  - Introduction
  - SysVinit
    SysVinit
    
    Introduction
  - TODO-Upstart
- Service-management
  Service-management
  - Introduction
  - TODO-Service-run-level
  - init.d-service-management
    init.d-service-management
    
    Introduction
  - systemd
    systemd
    
    Introduction
    
    systemd-service
    systemd-service
    
    Introduction
- Super-server-daemon
  Super-server-daemon
  - Introduction
  - inetd
    inetd
    
    Introduction
  - xinetd
    xinetd
    
    Introduction
- Centos-network
  Centos-network
  - Introduction
  - Set-NetworkManager-start-onboot
    Set-NetworkManager-start-onboot
    
    Introduction
  - CentOS-8-ifconfig-ens33-not-exist
    CentOS-8-ifconfig-ens33-not-exist
    
    Introduction
  - Restart-network-service
    Restart-network-service
    
    Introduction
Shell&&tool
Shell&&tool
- Introduction
- Shell
  Shell
  - Introduction
  - bash
    bash
    
    Introduction
    
    Manual
    Manual
    
    Introduction
    
    7-Job-Control
    7-Job-Control
    
    Introduction
  - Run-command
    Run-command
    
    Introduction
- Tools
  Tools
  - Introduction
  - GNU-toolchain
    GNU-toolchain
    
    Introduction
  - Dmesg
    Dmesg
    
    Dmesg
    
    Dmesg-format
    
    Dmesg-segfaulting
  - Rsync
    Rsync
    
    Rsync
  - Debug
    Debug
    
    Introduction
    
    Trace
    Trace
    
    Introduction
    
    System-call-trace
    System-call-trace
    
    man-1-ptrace
    man-1-ptrace
    
    Introduction
    
    man-1-strace
    man-1-strace
    
    Introduction
    
    Library-call-trace
    Library-call-trace
    
    man-1-ltrace
    man-1-ltrace
    
    Introduction
    
    Stack-trace
    Stack-trace
    
    Introduction
    
    man-1-pstack
    man-1-pstack
    
    Introduction
    
    GDB
    GDB
    
    Introduction
    
    Guide
    Guide
    
    Introduction
    
    gdb-primer
    gdb-primer
    
    gdb-primer
    
    Design-of-gdb
    Design-of-gdb
    
    Introduction
    
    Abstraction-in-GDB
    
    Structure-in-GDB
    
    Guide-to-examining-data
    
    Point-in-GDB
    
    Function
    Function
    
    Introduction
    
    Automate
    Automate
    
    Gdb-automate-debug
    
    Args
    Args
    
    Introduction
    
    Debug-process
    Debug-process
    
    Introduction
    
    Debug-stuck-process
    Debug-stuck-process
    
    Introduction
    
    Debug-shared-library
    Debug-shared-library
    
    Introduction
    
    Debug-HS-middleware
    Debug-HS-middleware
    
    Introduction
    
    Debug-multi-thread
    Debug-multi-thread
    
    Introduction
    
    Show-thread-start-rtn
    Show-thread-start-rtn
    
    Introduction
    
    Debug-race-condition
    Debug-race-condition
    
    Introduction
    
    Debug-dead-lock
    Debug-dead-lock
    
    Introduction
    
    Debug-assembly
    Debug-assembly
    
    Introduction
    
    Debugging-with-gdb
    Debugging-with-gdb
    
    2-Getting-In-and-Out-of-gdb
    2-Getting-In-and-Out-of-gdb
    
    2-Getting-In-and-Out-of-gdb
    
    4-Running-Programs-Under-gdb
    4-Running-Programs-Under-gdb
    
    Introduction
    
    5-Stopping-and-Continuing
    5-Stopping-and-Continuing
    
    5-Stopping-and-Continuing
    
    5.5-Stopping-and-Starting-Multi-thread-Programs
    
    Breakpoint-conditional-expressions
    
    6-Running-programs-backward
    6-Running-programs-backward
    
    6-Running-programs-backward
    
    7-Recording-Inferior's-Execution-and-Replaying-It
    7-Recording-Inferior's-Execution-and-Replaying-It
    
    Introduction
    
    8-Examining-the-Stack
    8-Examining-the-Stack
    
    8-Examining-the-Stack
    
    9-Examining-Source-Files
    9-Examining-Source-Files
    
    9-Examining-Source-Files
    
    10-Examining-Data
    10-Examining-Data
    
    10.11-Convenience-Variables
    
    10.13-Registers
    
    10.19-Produce-a-Core-File-from-Your-Program
    
    11-Debugging-Optimized-Code
    11-Debugging-Optimized-Code
    
    11-Debugging-Optimized-Code
    
    13-Tracepoints
    13-Tracepoints
    
    Tracepoints
    
    15-Using-GDB-with-Different-Languages
    15-Using-GDB-with-Different-Languages
    
    Introduction
    
    15.4-Supported-Languages
    15.4-Supported-Languages
    
    C-family-language
    
    16-Examining-the-Symbol-Table
    16-Examining-the-Symbol-Table
    
    Symbol-table
    
    18-gdb-Files
    18-gdb-Files
    
    18-gdb-Files
    
    19-Specifying-a-Debugging-Target
    19-Specifying-a-Debugging-Target
    
    Specifying-a-Debugging-Target
    
    23-Extending-GDB
    23-Extending-GDB
    
    Introduction
    
    25-gdb-Text-User-Interface
    25-gdb-Text-User-Interface
    
    25-gdb-Text-User-Interface
  - Performance
    Performance
    
    Introduction
    
    System-load
    System-load
    
    System-Load
    
    uptime
    
    Troubleshoot-disk-IO-bottleneck
    
    Troubleshoot-CPU-bound-bottleneck
    
    man-1-perf
    man-1-perf
    
    Introduction
    
    Expert-Brendan-D-Gregg
    Expert-Brendan-D-Gregg
    
    Introduction
    
    sysstat
    sysstat
    
    Introduction
    
    iostat
    iostat
    
    Introduction
  - Build
    Build
    
    Autoconf
    Autoconf
    
    Introduction
    
    Configure-script
    Configure-script
    
    Introduction
    
    Automake
    Automake
    
    Automake
    
    Autotools-Mythbuster
    Autotools-Mythbuster
    
    Introduction
    
    pkg-config
    pkg-config
    
    Introduction
    
    Make
    Make
    
    Make-and-makefile
    
    Makefile
    Makefile
    
    Makefile
    
    Code
    Code
    
    Introduction
    
    Code1
    Code1
    
    Introduction
    
    Code2
    Code2
    
    Introduction
  - Hardware
    Hardware
    
    lshw
    
    CPU
    CPU
    
    lscpu
  - Cron
    Cron
    
    Introduction
Book
Book
- gitbooks-Linux-insides
  gitbooks-Linux-insides
  - Introduction

TCP connection tuple

一个TCP connection由哪些要素组成，一般说法是4个:

client IP address, client port number, server IP address, server port number

stackoverflow How many tuples are there in a connection?

Some people said that there are 4 tuples in a connection

client IP address, client port number, server IP address, server port number

Some said that there are 5

client IP address, client port number, server IP address, server port number, protocol

Which one is correct ?

A

You've misunderstood the terminology. A TCP connection is identified by a 5-tuple. That means *one*tuple, with 5 elements. The five elements are:

Protocol. This is often omitted as it is understood that we are talking about TCP, which leaves 4.
Source IP address.
Source port.
Target IP address.
Target port.

networkengineering Why is a TCP Socket identified by a 4 tuple?

Newbie to networking here. I'm reading the Computer Networking (3^rd edition) book, and in section 3.2 they are discussing multiplexing / demultiplexing for both UDP and TCP.

In the UDP protocol, a socket is uniquely identified by the source IP and the source port.

In the TCP protocol, the socket is uniquely identified by the source IP, source port, destination IP, and destination port. Why does the TCP protocol require two extra pieces of information for the receiving host to correctly demultiplex the segment and send it to the correct process?

The only reason I can think of why this is necessary is if clients always send the TCP segment to the same port as the connection-request segment. For example, my browser always sends data to port 80 of the server even though the server has established a TCP socket specifically for that session on a different port. In that case, TCP has to use the source IP and source port information to demultiplex to the correct socket. It can't rely solely on the source IP information, because a single host can establish multiple sessions, but each session has to be on a different port.

The reason why UDP does not have this problem is because the destination IP / port combo identifies the socket to which the process that will handle the request is attached, since in UDP there is no "spawning" of multiple new sockets for requests.

Is this correct or have I reached the wrong conclusion?