DLL Programmer's Guide for TNS/R Systems

Contents

DLL Programmer’s Guide for TNS/R Systems—522203-002

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3. Dynamic Use of DLLs

Dynamic Loading Functions 3-1

Opening a DLL from a Running Loadfile (dlopen) 3-2

dlopen’s Mode Parameter Values 3-3

Returned Value of dlopen 3-4

Accessing Symbols (dlsym) 3-5

Returned Values of dlsym 3-5

Closing a Running Loadfile’s Handle to a DLL (dlclose) 3-6

Returned Values of dlclose 3-6

Error Reporting For Dynamic Library Calls (dlerror and dlresultcode) 3-7

Error Text : dlerror 3-7

Error Encoding: dlresultcode 3-7

Thread Considerations 3-8

Using Dynamically Loaded DLLs to Extend an Application 3-8

4. Finding Symbol Definitions

The loadList 4-1

Global Scope, Import and Export 4-3

Import Controls and SearchLists 4-5

The SearchList for a Localized Loadfile 4-5

The SearchList for a Globalized Loadfile 4-8

The SearchList for a Semi-Globalized Loadfile 4-11

Import Control Summary 4-11

C++ Considerations:

Globalized (Gblzd) Symbols 4-12

System Library and Millicode 4-13

Symbol Resolution at a Glance

4-13

Example: Intercepting an Exported Symbol

4-13

5. Advanced DLL Facility Controls

Linker Input Controls 5-1

Making the Linker Accept Only DLLs or Only Archives 5-1

Augmenting Library Names Automatically in Searches 5-2

Handling Duplicate Symbols among Linkfiles in a Link 5-2

Making the Linker Look for Unresolved Symbols 5-4

Linker Output Controls 5-4

Designating the Main Entry Point of Your Program 5-4

Controlling Which Symbols Your Loadfile Exports 5-5

C++ Mangled Symbol Names 5-5