本文整理汇总了Java中sun.hotspot.WhiteBox.NMTGetHashSize方法的典型用法代码示例。如果您正苦于以下问题:Java WhiteBox.NMTGetHashSize方法的具体用法?Java WhiteBox.NMTGetHashSize怎么用?Java WhiteBox.NMTGetHashSize使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sun.hotspot.WhiteBox
的用法示例。
在下文中一共展示了WhiteBox.NMTGetHashSize方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: main
import sun.hotspot.WhiteBox; //导入方法依赖的package包/类
public static void main(String args[]) throws Exception {
// Size of entries based on malloc tracking header defined in mallocTracker.hpp
// For 32-bit systems, create 257 malloc sites with the same hash bucket to overflow a hash bucket
long entries = 257;
OutputAnalyzer output;
WhiteBox wb = WhiteBox.getWhiteBox();
int MAX_HASH_SIZE = wb.NMTGetHashSize();
// Grab my own PID
String pid = Long.toString(ProcessTools.getProcessId());
ProcessBuilder pb = new ProcessBuilder();
// Verify that current tracking level is "detail"
pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
output = new OutputAnalyzer(pb.start());
output.shouldContain("Native Memory Tracking Statistics");
// Attempt to cause NMT to downgrade tracking level by allocating small amounts
// of memory with random pseudo call stack
int pc = 1;
for (int i = 0; i < entries; i++) {
long addr = wb.NMTMallocWithPseudoStack(1, pc);
if (addr == 0) {
throw new RuntimeException("NMTMallocWithPseudoStack: out of memory");
}
// We free memory here since it doesn't affect pseudo malloc alloc site hash table entries
wb.NMTFree(addr);
pc += MAX_HASH_SIZE;
if (i == entries) {
// Verify that tracking has been downgraded
pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
output = new OutputAnalyzer(pb.start());
output.shouldContain("Tracking level has been downgraded due to lack of resources");
}
}
}
示例2: main
import sun.hotspot.WhiteBox; //导入方法依赖的package包/类
public static void main(String args[]) throws Exception {
// Size of entries based on malloc tracking header defined in mallocTracker.hpp
// For 32-bit systems, create 257 malloc sites with the same hash bucket to overflow a hash bucket
long entries = 257;
OutputAnalyzer output;
WhiteBox wb = WhiteBox.getWhiteBox();
int MAX_HASH_SIZE = wb.NMTGetHashSize();
// Grab my own PID
String pid = Integer.toString(ProcessTools.getProcessId());
ProcessBuilder pb = new ProcessBuilder();
// Verify that current tracking level is "detail"
pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
output = new OutputAnalyzer(pb.start());
output.shouldContain("Native Memory Tracking Statistics");
// Attempt to cause NMT to downgrade tracking level by allocating small amounts
// of memory with random pseudo call stack
int pc = 1;
for (int i = 0; i < entries; i++) {
long addr = wb.NMTMallocWithPseudoStack(1, pc);
if (addr == 0) {
throw new RuntimeException("NMTMallocWithPseudoStack: out of memory");
}
// We free memory here since it doesn't affect pseudo malloc alloc site hash table entries
wb.NMTFree(addr);
pc += MAX_HASH_SIZE;
if (i == entries) {
// Verify that tracking has been downgraded
pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
output = new OutputAnalyzer(pb.start());
output.shouldContain("Tracking level has been downgraded due to lack of resources");
}
}
}