somemethod() { AccessController.doPrivileged(new PrivilegedAction() { public Object run() { // Code goes here. Any permission checks from // this point forward require both the current // context and the snapshot's context to have // the desired permission. } }); ...normal code here....
void* mmap ( void * addr , size_t len , int prot , int flags , int fd , off_t offset ) 参数fd为即将映射到进程空间的文件描述字,一般由open()返回,同时,fd可以指定为-1,此时须指定flags参数中的MAP_ANON,表明进行 的是匿名映射(不涉及具体的文件名,避免了文件的创建及打开,很显然只能用于具有...
this);//JavaThread对象中传入的entry_point为Thread对象的Thread::run方法}DTRACE_THREAD_PROBE(sto...
C++ was the language of choice. But over time the difficulties encountered with C++ grew to the point where the problems could best be addressed by creating an entirely new language platform. Design and architecture decisions drew from a variety of languages such as Eiffel, SmallTalk, Objective ...
For example, 3.0 is a double-precision floating point literal, and "a" is a character literal. local variable A data item known within a block, but inaccessible to code outside the block. For example, any variable defined within a method is a local variable and can't be used outside...
Sun JavaTMSystem Directory Proxy Server 提供註冊與管理目錄代理伺服器實例的瀏覽器介面與指令行工具。此瀏覽器介面稱為目錄服務控制中心 (DSCC)。本章說明透過使用 DSCC 或指令行管理目錄代理伺服器所需的基本作業。 若要決定是使用 DSCC 或是指令行來執行特定作業,請參閱決定 DSCC 與指令行的使用時機。
Attach a debugger and set a breakpoint in the Runtime.gc method. Then inspect the call stack. Common Callers of System.gc DirectByteBuffer usage maydrive calls to System.gc. If using RMI, a background thread calls System.gc every hour by default. This interval may be controlled with JVM...
{ r } 12: repeat until fixpoint (i.e. I is not changed) // find all of the synchronized blocks using the object reachable from r transitively 13: T = {} 14: foreach r ∈ Worklist 15: S = S ∪ getSynchronizedBlock(r) // get a synchronized block having the lock object r 16:...
Java is a horrible language, even from an application point of view. The OO approach in Java is so cumbersome. The entire paradigm of Java style OO is fundamentally flawed and long since abandoned by other communities. Even C++ has adopted a more usable framework than the archaic OO in ...
Object object = new Point(1, 2); if (object instanceof Point(int i, int j)) { System.out.println("Object is a Point(" + i + "," + j+")"); }Notice how you can directly access the x and y values if the object is of type Point. The same can be done in a switch statem...