- 能够迅速进入专注状态，以及能够长期保持专注状态，是高效学习的两个最重要习惯。
- 因此这里就涉及到最后一个高效的习惯：抗干扰。
Posted from Diigo. The rest of my favorite links are here.
潘长江新闻奖候选作品选登
7 小时前
2009年12月24日 星期四
blogger daily 12/24/2009
Posted from Diigo. The rest of my favorite links are here.
2009年12月23日 星期三
blogger daily 12/23/2009
[concurrency-interest] readValueUnderLock in ConcurrentHashMap
- This is referring to the order as specified in the code (i.e. the
guarantee does not apply if the constructor leaks "this"). Basically, a
write to a final field in a constructor is not allowed to be re-orderd
to occur after a write of the containing object that is after the
constructor.
[concurrency-interest] readValueUnderLock in ConcurrentHashMap
- It means that the HashEntry will not be completely initialized. So the
volatile variable read might see the default initial value, which is null. - Because they are final. Final fields are guaranteed to be visible as
long as the object is not published before the constructor has
completed
Posted from Diigo. The rest of my favorite links are here.
2009年12月22日 星期二
blogger daily 12/22/2009
[concurrency-interest] ConcurrentLinkedQueue implementation
- LinkedList is a Deque, but ConcurrentLinkedQueue intentionally is not.
You could try LinkedBlockingDeque instead.
[concurrency-interest] ConcurrentLinkedList or ConcurrentLinkedDeque?
- - post by lithium
- The use of index-based List operations
- The use of sublists
- Weakly consistent ListIterators would break an implicit assumption
probably held by most code using bidirectional iteration - So, indexed operations, sublists, and ListIterators all CAN be
supported
[concurrency-interest] Handling Null Values in ConcurrentHashMap
- The main one is that if
map.get(key) returns null, you can't detect whether the
key explicitly maps to null vs the key isn't mapped.
In a non-concurrent map, you can check this via map.contains(key),
but in a concurrent one, the map might have changed between calls.
Posted from Diigo. The rest of my favorite links are here.
2009年12月16日 星期三
2009年12月14日 星期一
blogger daily 12/14/2009
IPv4 - Wikipedia, the free encyclopedia
- the maximum size of an IP packet is 65,535 bytes while the typical MTU for Ethernet is 1,500 bytes.
Posted from Diigo. The rest of my favorite links are here.
2009年12月13日 星期日
blogger daily 12/13/2009
- C also provides 'unsigned' types of
each of its integers, which Java
does not. - Java's 'char' also can be
used as an unsigned short, i.e. it represents numbers from 0 up to
2^16. - 'network byte order' aka 'big endian' aka Java's standard
endianness. - "big endian" byte order
was designated as "network order"
Posted from Diigo. The rest of my favorite links are here.
2009年12月11日 星期五
订阅：
帖子 (Atom)
