1. Differences between processes and threads
The process is independent, which is manifested in memory space, context; thread runs in the process space.
Generally speaking (not using a special technology) process is unable to break through the memory space within the process boundary; threads, the threads generated by the same process shared the same memory space due to the process space. (Figure 1)
The two codes in the same process cannot be executed at the same time, unless the thread is introduced.
Threads are processed, and the threads generated by the process when the process exits is forced and cleared.
Thread occupied resources less than the resources occupied by the process.
Process and threads can have priority.
The process in the thread system is also a thread. The process can be understood as the first thread of a program.
2. Implement the creation of the process Bool CreateProcess
Lpctstr lpapplicationname, // Execute program file name
LPTSTR LPCOMMANDLINE, // Parameter Line
LPSecurity_attributes lpprocessattributes, // Process security parameters
LPSecurity_attributes lpthreadattributes, // thread security parameters
Bool binherithandles, // inheritance mark
DWORD DWCREATIONFLAGS, // Create tag
LPVOID LPENVIRONMENT, / / environment variable
LPCTSTR LPCURRENTDIRECTORY, / / Run the initial directory of the child process
LPStartupinfo lpstartupinfo, // Create related parameters for this child process
LPPROCESS_INFORMATION LPPROCESSINFORMATION // created information used to create sub-process
);
3. Implement the end of the process
Bool TerminateProcess
Handle hprocess, // process handle
Uint uExitcode // exit code
);
Focus:
CreateProcess's LPStartupinfo, parameter structure
Typedef struct _startupinfo {// si
DWORD CB; // Structural length
Lptstr lpreserved; // retain
LPTSTR LPDESKTOP; / /
LPTSTR LPTITLE; / / If the program is displayed for the console process
DWORD DWX; // Window location
DWORD DWY; // Window location
DWORD DWXSIZE; // Window Size
DWORD dwysize; // window size
DWORD dwxcountchars; // Console window word symbol width
DWORD DWYCOUNTCHARS; // Console window word symbol height
DWORD DWFILLATTRIBUTE; // Console Window Fill Mode
DWORD dwflags; // Create tag
Word wshowwindow; // window display tag is like a tag in showwindow
Word CBRESERVED2; //
LPBYTE LPRESERVED2; //
Handle HSTDINPUT; / / Standard Enter Handle
Handle hstdoutput; // Standard output handle
Handle hstderror; // Standard error handle
} Startupinfo, * lpstartupinfo;
If you want to work in the structure, you must set the dwflags correctly. For example, dwflags contains StartF_USSize to indicate dwxsize and dwysize, including startf_useposition, which is valid, DWX and DWY.
LPPROCESSINFORMATION parameters in CreateProcess
LPPROCESSINFORMATION: Used to receive related information after the process is created, the structure is filled out by the system. Typedef struct _process_information {// pihandle hprocess; // process handle
Handle Hthread; // Main thread handle
DWORD DWPROCESSID; // Process ID
DWORD DWTHREADID; // Main thread ID of the process
} Process_information;
prompt:
1.
Startupinfo Si;
StartupInfo must initialize 0
Should be Startupinfo Si = {0};
Otherwise, the system will prompt the error.
2.
C: //winnt/notepad.exe must double slash
in conclusion
Use CreateProcess to perform a program under Windows, but it does not use the dos shell to explain it, so it cannot identify the ">" operation symbol, just use it as a command line parameter that runs it as a run.
explain:
1. CREATEPROCESS parameter description
LPApplicationName: For the executor's file name, if you want to use a parameter when you create a process, the parameter can be NULL.
LPCommandline: For parameter rows, if the parameters can be null, set the following settings when there is parameter to the process: lpapplicationName = null; lpcommandline = para, such as lpcommandline = "c: //windows/notepad.exe c: // autoexec .bat.
LPPRocessAttributes, LPTHREADATIADATTRIBUTES: The created process and thread security properties are described, and if null is used to represent the default security description.
BinheritHandles: Indicates whether the handle in the current process can be inherited by the sub-process that can be created.
DWCREATIONFLAGS: Represents the creation tag, which can set the creation status and priority of the process via this tag. Commonly used tags:
CREATE_NEW_CONSOLE: Create a new console for the child process.
· CREATE_SUSPENDED: The child process is hang when it is created.
High_Priority_Class / Normal_Priority_Class: High / ordinary priority.
LpenVironment: Indicates the environment variable used by the child process. If null, the same environment variable is used to use the current process.
LpCurrentDirectory: Indicates the initial directory of the sub-process run.
LPSTARTUPINFO: Used to set various properties when creating a child process. :
LPPROCESSINFORMATION: Used to receive information after the process is created
2. Error handling problem
Find the error code in WineError.h, you can know the general meaning of the error
Ready-made error message processing function: formatMessage (). The following is an example of error information corresponding to error encoding returned by getLastError (): lpvoid lpmsgbuf;
