找到了一些@NamedQuery注释的示例,例如:
@NamedQuery(name="employeeBySsn" query="select e from Employee e where e.ssn = :ssn")
参数e是什么意思?
它的第二种用法似乎是表的别名,"select e“部件是什么意思?
最近,我一直在研究Go的源代码。当我查看sync.Pool的细节时,我发现了一条我无法理解的评论。
// Local per-P Pool appendix.
type poolLocalInternal struct {
private interface{} // Can be used only by the respective P.
shared []interface{} // Can be used by any P.
Mutex // Protects shared.
}
局部P池阑尾。
每-P是什么意思?
我有一份来自瓦兰的产出:
==4836== 10,232 bytes in 1 blocks are still reachable in loss record 1 of 1
==4836== at 0x4C2779D: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4836== by 0x401865: thrt() (main.cpp:221)
==4836== by 0x4048B1: main (tester.cpp:35)
==4836==是什么意思?
0x4C2779D