NATLIB.C

/* 
 
Copyright (c) 1996-1997  Microsoft Corporation 
 
*/ 
 
#include <windows.h> 
#include <native.h> 
#include "JMain.h" 
#include "JFoo.h" 
#include "JThread1.h" 
#include "JThread2.h" 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//RNIGetCompatibleVersion 
// 
//Called by the virtual machine to determine what level of RNI compatibility 
//this DLL offers. 
// 
//// 
DWORD __cdecl RNIGetCompatibleVersion() 
{ 
return RNIVER; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//JMain_Square() 
// 
//returns the square of its parameter;  simple callout from java to 
//native code to perform this operation. 
// 
//// 
__declspec(dllexport) long __cdecl JMain_Square(struct HJMain *pThis, long lVal) 
{ 
return lVal * lVal ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//JMain_DoubleInstanceVar() 
// 
//executes a java-implemented method to retrieve the value of an 
//instance variable;  returns twice the retrieved value. 
// 
//// 
__declspec(dllexport) void __cdecl JMain_DoubleInstanceVar(struct HJMain *pThis) 
{ 
long lVal ; 
 
lVal = execute_java_dynamic_method(0, (HObject*) pThis, "GetiVar1", "()I") ; 
 
pThis->iVar1 = lVal << 1 ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//Jmain_showMemberArray() 
// 
//executes a class method which returns a private member array of 
//ints (java); loops through and displays the array members. 
// 
//// 
__declspec(dllexport) void __cdecl JMain_showMemberArray(struct HJMain *pThis) 
{ 
ClassArrayOfInt *paiVar1 ; 
long*plVar2 ; 
intcIndex ; 
 
// get a pointer to an instance array of int, and display it. 
paiVar1 = (ClassArrayOfInt *) execute_java_dynamic_method(0, (HObject *) pThis, "GetiCVar2", "()[I") ; 
plVar2 = paiVar1->body ; 
 
for (cIndex = 0; cIndex < paiVar1->length; cIndex++) 
{ 
printf("%5d", *plVar2++) ; 
} 
printf("\n") ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//JMain_Various() 
// 
//finds JFoo class; executes a static method in that class 
// 
//// 
__declspec(dllexport) void __cdecl JMain_Various(struct HJMain *pThis) 
{ 
_int64 i64Val = 10 ; 
ClassClass *pcls = FindClass(NULL, "JFoo", TRUE) ; 
 
if (pcls) 
{ 
// and exec the static method 
execute_java_static_method(NULL, pcls, "StaticMethod", "(J)V", i64Val) ; 
} 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//w32CreateEvent() 
// 
//wrapper for win32 API CreateEvent() 
// 
//// 
__declspec(dllexport) long __cdecl JMain_w32CreateEvent(struct HJMain *pThis, long bInit) 
{ 
BOOLbInitialState ; 
HANDLEhEvent ; 
 
// determine if initial state is signaled or non-signaled. 
if (bInit) 
{ 
bInitialState = TRUE ; 
} 
else 
{ 
bInitialState = FALSE ; 
} 
 
// create Event object and return handle 
return (long) CreateEvent(NULL, FALSE, bInitialState, NULL) ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//w32PulseEvent() 
// 
//wrapper for win32 API PulseEvent() 
// 
//// 
__declspec(dllexport) void __cdecl JThread1_w32PulseEvent(struct HJThread1 *pThis,long hEvent) 
{ 
PulseEvent((HANDLE) hEvent) ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//w32CloseHandle() 
// 
//wrapper for win32 API CloseHandle() 
// 
//// 
__declspec(dllexport) long __cdecl JThread2_w32CloseHandle(struct HJThread2 *pThis, long hObject) 
{ 
return (long) CloseHandle((HANDLE) hObject) ; 
} 
 
//////////////////////////////////////////////////////////////////////////////// 
// 
//GCSafeNative() 
// 
//method demonstrates GC safe way of performing GC-sensitive operations 
//in native code. 
// 
//// 
__declspec(dllexport) void __cdecl JThread2_GCSafeNative(struct HJThread2 *pThis, long hEvent) 
{ 
struct 
{ 
HJFoo *pJFoo1, *pJFoo2 ; 
} gcSafe ;// struct holds out pointers to JObjects 
GCFrame gcf ; 
 
// GCFramePush() creates storage for GC-sensitive data (JObjects in this case) 
GCFramePush(&gcf, &gcSafe, sizeof(gcSafe)) ; 
 
// set our member variables to point to two JObjects 
gcSafe.pJFoo1 = (HJFoo *) execute_java_constructor(0, "JFoo", 0, "(I)", 10) ; 
gcSafe.pJFoo2 = (HJFoo *) execute_java_constructor(0, "JFoo", 0, "()") ; 
 
// call GCEnable() - we don't know how long we might be blocked 
GCEnable() ; 
 
// block 
WaitForSingleObject((HANDLE) hEvent, INFINITE) ; 
 
// display instance variable values for above-created JObjects. 
printf("gcSafe.pJFoo1->m_iVal = %d\tgcSafe.pJFoo2->m_iVal = %d\n", gcSafe.pJFoo1->m_iVal, gcSafe.pJFoo2->m_iVal) ; 
 
// disable GC and pop our storage 
GCDisable() ; 
GCFramePop(&gcf) ; 
}