PAL Reading Notes

Document directory

• 1. PAL-specific Entry Points
• 2. File System
• 3. Memory Management
• 4. synchronous/asynchronous IO
• Threading
• Networking
• Exception
• CRT (C Runtime)
• Postscript:

PAL = Platform Abstract Layer, which is the dependency of the. Net Platform on the specific operating system level, mainly including

1. Start and end
2. File System
3. Memory Management
4. Synchronous I/O
5. Asynchronous I/O
6. Threading
7. Networking
8. Exception Handling
9. Debugging support
10. CRT (C Runtime Library)

1. PAL-specific Entry Points

The so-called PAL-specific Entry Points refers to the interface defined by the PAL layer, such as start and end. It includes the following methods:

Method Name	Explanation
PAL_Initialize	0 is returned when the call is successful, and other values are returned when the call fails. It is best to prompt the error message. PAL needs to provide the exit and ExitProcess Methods CreateThread method to create a process
PAL_Terminate	If PAL_Initialize is successful, execute PAL_Terminate. After the PAL_Terminate call is complete, if the PAL client is less than 0, it will jump to exit and ExitProcess
PAL_GetUserConfigurationDirectoryW	Returns the Setting data of the corresponding user.
PAL_RegisterLibrary PAL_UnregisterLibrary	Register the lib dll file (lpLibFileName) in DLLMain)
PAL_GetPALDirectoryW	Obtain the directory where the PAL dll runs. For example, c: \ Rotor \ v1.x86chk. rotor \ rotor_pal.dll returns c: \ Rotor \ v1.x86chk. rotor
PAL_Random	Random Number Generation. 1. lpBuffer: used to obtain random bytes. 2. bStrong: used to identify random numbers with additional strength, for example, Key
PAL_get_stdout/PAL_get_stdin/PAL_get_stderr	Corresponding stdout, stdin, and stderr methods of the system
PAL_errno	Returns a pointer to the corresponding thread error code.
PAL_LocalHandleToRemote/PAL_RemoteHandleToLocal	Pointer to mutex, process, and event Returned value: INVALID_HANDLE_VALUE/Handle value or Type

2. File System

Taking the PAL layer of a UNIX system as an example, there are five types of operations on the file system.

1. File Operations
2. Operations on directories
3. Read disk Information

   PALIMPORT BOOL PALAPI GetDiskFreeSpaceW(          LPCWSTR lpDirectoryName,          LPDWORD lpSectorsPerCluster,          LPDWORD lpBytesPerSector,          LPDWORD lpNumberOfFreeClusters,  /* Caller will ignore output value */          LPDWORD lpTotalNumberOfClusters) /* Caller will ignore output value */

4. Search for files

5. Path operations

3. Memory Management

Local: Local Memory Management Heap: Heap-based memory management shared memory: the so-called shared memory means that different processes use the same copy. For example, program B uses. dll, and C is also, so B and C have shared memory. the shared memory also contains the copy-on-write and synchronization parts.

4. synchronous/asynchronous IO

Debug

Threading

Code name	Function
Process. h	Process operations
Thread. h	Thread operations
Localstorage. c	Some basic operations of string, such as contact and copy
Seamphore. c	Semaphores
Mutex. c	Mutex
Event. h/event. c	Event
Critsect. c	CRITICAL_SECTION
Wait. c

Networking

Soket Communication Mechanism

Asynchronous Communication: Async. c

Exception

SEH-Structure ubuntuin Handler

CRT (C Runtime)

Code name	Function
File. c	Operations on files, basic operations on files in C Language
Finite. h	Support for floating point numbers, infinity, and infinity
Lstr	Some basic operations of string, such as contact and copy
Mbstring. c	Multi-bytes string
Misc. c	Interaction with the running environment, such as char * MiscGetenv (const char * name)
Path. c	Path operations
Printf. c	Corresponding OS output
Silent_printf.c	Corresponding Trace Output TODO: Verify this
String. c	Common Operations corresponding to string, comare, _ swab, PAL_strtoul, PAL_atol...
Thread. c	PAL_exit
Wchar. c	Contains operations on char and string.

Postscript:

What involves the PAL level naturally involves a lot of operating system knowledge. Due to the concentration of knowledge and the limitations of personal energy, a detailed explanation is not provided for the time being. If you are interested and competent, thank you for your advice. Thank you.