Java VM类代码示例

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Attempt to allocate backing memory for the structure.
 * 
 * @param size in bytes ito allocate
 * @throws IllegalArgumentException if the requested size is smaller than the default size
 * @throws OutOfMemoryError if backing native memory cannot be allocated.
 * @throws IllegalStateException if this structure already has memory allocated
 */
public void allocateMemory(int size) throws OutOfMemoryError {
    int defaultsize = size();
    if (size < defaultsize) {
        throw new IllegalArgumentException();
    }
    if (backingNativeMemory != null &&
        backingNativeMemory.isValid()) {
        throw new IllegalStateException();
    }
    backingNativeMemory = new Pointer(size);
    if (DEBUG) {
        VM.print("Allocated memory of special size for ");
        VMprintStruct();
    }
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Dynamically look up a native function address by name.
 * Look up the symbol in the specified library
 *
 * @param funcName
 * @return address of the function
 * @throws RuntimeException if there is no function by that name.
 */
private Address getFunction0(String funcName) {
    Address result = getSymbolAddress(funcName);
    if (DEBUG) {
        VM.print("Function Lookup for ");
        VM.print(funcName);
        VM.print(" = ");
        VM.printAddress(result);
        VM.println();
    }
    if (result.isZero()) {
        if (Platform.getPlatform().isWindows()) {
            if (funcName.charAt(funcName.length() - 1) != 'A') {
                return getFunction0(funcName + 'A');
            }
        } else if (funcName.charAt(0) != '_') {
            return getFunction0("_" + funcName);
        }
        throw new RuntimeException("Can't find native symbol " + funcName + ". OS Error: " + errorStr());
    }
    return result;
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Close the library, as in dlclose.
 * @throws RuntimeException if dlcose fails
 */
public void dispose() {
    if (closed || ptr.isZero()) {
        throw new RuntimeException("closed or RTLD_DEFAULT");
    }
    if (DEBUG) {
        VM.print("Calling DLCLOSE on ");
        VM.println(name);
    }
    Pointer name0 = Pointer.createStringBuffer(name);
    int result = VM.execSyncIO(ChannelConstants.DLCLOSE, ptr.toUWord().toInt(), 0, 0, 0, 0, 0, 0, null, null);
    name0.free();
    if (result != 0) {
        throw new RuntimeException("Error on dlclose: " + errorStr());
    }
    closed = true;
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
private static Platform makePlatform() {
    if (DEBUG) {
        VM.println("Making Platform...");
    }
    Platform result = (Platform) getInstance(getNativePlatformName());
    if (result == null) {
        result = (Platform) getInstance("Posix");
    }
    if (result != null) {
        if (DEBUG) {
            VM.println("    created platform: " + result);
        }
        return result;
    }
    VM.println("Error in makePlatform for " + getNativePlatformName() + ". Exiting...");
    VM.haltVM(1);
    return null;
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
private static int getSuiteVerifiedFlagAddress(int suiteAddress) throws IllegalArgumentException {
	int slotSize = VM.execSyncIO(ChannelConstants.GET_ALLOCATED_FILE_SIZE, suiteAddress);
	if (slotSize <=0 ) {
		String errorMessage = "suiteAddress 0x" + Integer.toHexString(suiteAddress) + " is not pointing to a mapped file";
		if (SignatureVerifier.DEBUG) {
			System.out.println(errorMessage);
		}
		throw new IllegalArgumentException(errorMessage);
	}
	int verifiedFlagAddress = suiteAddress + slotSize - 1;
	if (SignatureVerifier.DEBUG) {
		System.out.println("verifiedFlagAddres for suite address " + Integer.toHexString(suiteAddress) + " is "
				+ Integer.toHexString(verifiedFlagAddress));
       }
	return verifiedFlagAddress;
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Dynamically look up a native variable by name.
 * 
 * Look up the symbol in the default list of loaded libraries.
 * 
 * @param varName 
 * @param size the size of the variable in bytes
 * @return a Pointer that can be used to get/set the variable
 * @throws RuntimeException if there is no function by that name.
 */
public VarPointer getGlobalVariableAddress(String varName, int size) {
    Address result = getSymbolAddress(varName);
    if (DEBUG) {
        VM.print("Var Lookup for ");
        VM.print(varName);
        VM.print(", size: ");
        VM.print(size);
        VM.print(" returned ");
        VM.printAddress(result);
        VM.println();
    }
    if (result.isZero()) {
        if (varName.charAt(0) != '_') {
            return getGlobalVariableAddress("_" + varName, size);
        }
        throw new RuntimeException("Can't find native symbol " + varName + ". OS Error: " + errorStr());
    }
    return new VarPointer(varName, result, size);
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
public static void printTable(SquawkHashtable table) {
    HashtableEntry[] array = table.entryTable;
    for (int i = 0; i < array.length; i++) {
        HashtableEntry entry = array[i];
        if (entry != null) {
            VM.print("    key: ");
            if (entry.key != null) {
                GC.printObject(entry.key);
            } else {
                VM.print("null");
            }
            VM.print("    value: ");
            if (entry.value != null) {
                GC.printObject(entry.value);
            } else {
                VM.print("null");
            }
        }
    }
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
     * 
     * @param purpose  One of INorFlashMemorySector.USER_PURPOSED, RMS_PURPOSED, or SYSTEM_PURPOSED.
     * @return Vector<INorFlashMemorySector>
     */
    public static Vector getNorFlashSectors(int purpose) {
        // Get all user purposed flash memory sectors
    	
    	INorFlashSectorAllocator allocator = (INorFlashSectorAllocator) VM.getPeripheralRegistry().getSingleton(INorFlashSectorAllocator.class);
    	if (allocator == null) {
    		throw new IllegalStateException(
/*if[VERBOSE_EXCEPTIONS]*/
                    "No INorFlashSectorAllocator available"
/*end[VERBOSE_EXCEPTIONS]*/
                    );
    	}
    	INorFlashSector[] allFlashMemorySectors;
		try {
			allFlashMemorySectors = allocator.getInitialSectors(purpose);
		} catch (IOException e) {
		    throw new UnexpectedException(e);
		}
        Vector userSectors = new Vector(allFlashMemorySectors.length);
        for (int i=0, max=allFlashMemorySectors.length; i < max; i++) {
            userSectors.addElement(allFlashMemorySectors[i]);
        }
        return userSectors;
    }
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Copy string value to the location at <code>offset</code>. Convert the data in <code>value</code> to a
 * NULL-terminated C string, converted to native encoding.
 * 
 * @param offset the byte offset of the c string from the base of this pointer
 * @param value the string to copy
 */
public final void setString(int offset, String value) {
    // optimize for 8-bit strings.
    if (GC.getKlass(value).getSystemID() == CID.STRING_OF_BYTES) {
        int len = value.length();
        checkMultiWrite(offset, len + 1, 1);
        VM.setData(getAddress(), offset, value, 0, len, 1);
        setByte((long) len, (byte) 0); // null terminate   
    } else {
        setString(offset, value.getBytes());
    }
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Creates a Mailbox with the given name and registers it with the system. 
 * 
 * <code>create</code> may immediately begin receiving messages.
 * The <code>handler</code> will be used to initiate and close the logical connection to a client.
 *
 * @param name        the name that this Mailbox can be looked up under.
 * @param handler     the class used to manage clients opening and closing new logical connections to the new Mailbox.
 * @return the new Mailbox.
 * @throws MailboxInUseException if there is already a mailbox registered under the name <code>name</code>.
 */
public static Mailbox create(String name, MailboxHandler handler) throws MailboxInUseException {
    if (name == null) throw new IllegalArgumentException();
    
    Mailbox box = new Mailbox(name, handler);
    
    if (VM.registerMailbox(name, box)) {
        box.registered = true;
        return box;
    } else {
        box.close();
        throw new MailboxInUseException(name);
    }
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
static void setSystemClockMock(long newTime) {
    System.out.println("-----------------------------");
    printLog("setting time to : " + newTime);
    VM.setSystemClockMock(newTime);
    printLog("time now set");
    System.out.println("-----------------------------");
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Zero the first "size" bytes of memory
 * @param size number of bytes
 */
public void clear(int size) {
    Address addr = getAddress();
    if (size().lo(UWord.fromPrimitive(size))) {
        throw new IllegalArgumentException();
    }
    if (addr.isZero()) {
         throw new IllegalStateException();
    }
    VM.setBytes(addr, (byte)0, size);
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
public void write(byte b[], int off, int len) throws IOException {
    Arrays.boundsCheck(b.length, off, len);
    if (len == 0) {
        return;
    }
    int old;
    if (err) {
        old = VM.setStream(VM.STREAM_STDERR);
    } else {
        old = VM.setStream(VM.STREAM_STDOUT);
    }
    VM.printBytes(b, off, len);
    VM.setStream(old);
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
 * Zero memory
 */
public void clear() {
    Address addr = getAddress();
    if (addr.isZero()) {
        throw new IllegalStateException();
    }
    VM.setBytes(addr, (byte) 0, getSize());
}
 

import com.sun.squawk.VM; //导入依赖的package包/类
/**
     * Given the classes's access and the suite type,
     * determine the final accessibility of the class outside of this suite.
     *
     * @param klass the klass
     * @return true if an external suite could possibly access this klass.
     */
    public boolean isExternallyVisible(Klass klass) {
        int modifiers = klass.getModifiers();
        int suiteType = translator.getSuiteType();

        if (VM.isDynamic(klass)) {
            // if "dynamic", then class may be loaded by Class.findClass(), so we have to assume that it is used.
            Assert.always(!VM.isInternal(klass));
            return true;
        } else if (VM.isInternal(klass)) {
            // if the symbol wasn't marked as "export" or "dynamic" in the library.proprties file,
            // then there is no way that this is externally visible.
            return false;
        } else {
            // It's declared externally visible, but is it really?
            Assert.that(Modifier.isPackagePrivate(modifiers) || Modifier.isProtected(modifiers) || Modifier.isPublic(modifiers));

            switch (suiteType) {
                case Suite.APPLICATION:
                    return false;
                case Suite.LIBRARY:
                    // what can we do here
                    if (Modifier.isPackagePrivate(modifiers)) {
                        // treat as internal:
/*if[ENABLE_VERBOSE]*/
                        if (VM.isVerbose()) {
                            System.out.println("### FYI - Found package-private class: " + klass);
                        }
/*end[ENABLE_VERBOSE]*/			
                        return false;
                    }
                    return true;
                default:
                    // extendable and debuggable suites leave all symbols externally visible.
                    return true;
            }
        }
    }