Shulou(Shulou.com)06/03 Report--

In LoadRunner suppression, sometimes the requested parameters are encrypted, and the encryption rules are generated by calling a segment of DLL. In this way, the suppression request through parameterized simulation cannot achieve the desired effect. In this case, you need to call DLL, get the return value of DLL, and use the return value to construct the suppression request. So how do I call DLL?

First of all, let's talk about the conditions required to call DLL:

1. VuGen can only recognize standard C-compiled DLL, so functions created with VC6 must add extern "C" at the beginning of the function, which tells the compiler to compile the function in the same way as standard C.

2. The derived function of standard C is required. You can view it through Dependency Walker:

Once these two points are met, you can call this DLL in the LoadRunner script.

There are two ways to call an external DLL:

● (in a single script) uses the lr_load_dll function in the script.

● (global settings, all scripts) is achieved by modifying the mdrv.dat file.

The first method can be implemented directly through the lr_load_dll function.

In this way, the user's subsequent suppression parameters of the return value can be saved directly. But this method can only be used by a single script, and cannot be used by other scripts.

The second method is the global setting, which is equivalent to loading dll into LoadRunner's DLL library. You can call all the scripts.

1. Copy the required DLL to the Bin directory of the LoadRunner installation path.

2. Modify the mdrv.dat file, find the [lrun_api] node, and add a sentence at the end:

WINNT_DLLS=XXX.dll

In this way, instead of using the lr_load_dll function, you can directly call the function in XXX.dll.

In addition, when you specifically suppress through agent, you will find the following error:

Error: CCI security error:You are running under secure mode and the function ci_load_dll is not allowed in this mode.

This is due to the fact that the remote agent press cannot load DLL. The workaround is to add the referenced DLL when you add the script.

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