IsBadCodePtr

This function determines whether the calling process has read access to the memory at the specified address.

At a Glance

Header file:	Winbase.h
Windows CE versions:	1.0 and later

Syntax

BOOL IsBadCodePtr( FARPROC lpfn );

Parameters

lpfn

Pointer to an address in memory.

Return Values

Zero indicates that the calling process has read access to the specified memory. Nonzero indicates that the calling process does not have read access to the specified memory. To get extended error information, call GetLastError.

If the application is compiled as a debugging version, and the process does not have read access to all bytes in the specified memory range, the function causes an assertion and breaks into the debugger. Leaving the debugger, the function continues as usual, and returns a nonzero value This behavior is by design, as a debugging aid.

Remarks

IsBadCodePtr checks the read access only at the specified address and does not guarantee read access to a range of memory.

In a preemptive multitasking environment, it is possible for some other thread to change the process’s access to the memory being tested. Even when the function indicates that the process has read access to the specified memory, you should use structured exception handling when attempting to access the memory. Use of structured exception handling enables the system to notify the process if an access violation exception occurs, giving the process an opportunity to handle the exception.