大约有 23,300 项符合查询结果（耗时：0.0144秒） [XML]
Why does sun.misc.Unsafe exist, and how can it be used in the real world?
...traction levels and numerous of checks. Failing the CAS is a bad in a loop esp. when the hardware decides to mispredict the branch (due to high contention) but having few more compare/branches just hurts. Park/Unpark are exposed through LockSupport not AQS (that latter is more of a lock impl. than ...
What is the fastest integer division supporting division by zero no matter what the result is?
...ype f, @function
f:
pushl %ebp
xorl %eax, %eax
movl %esp, %ebp
movl 12(%ebp), %edx
testl %edx, %edx
sete %al
addl %edx, %eax
movl 8(%ebp), %edx
movl %eax, %ecx
popl %ebp
movl %edx, %eax
sarl $31, %edx
idivl %ec...
Is there a practical use for weak references? [duplicate]
...e quick&dirty caches via soft references but they are just unreliable, esp. w/o control over the GC and caches shall not be a driving force how to configure the GC.
– bestsss
Jan 16 '12 at 2:48
...
Parsing JSON with Unix tools
...
On the basis that some of the recommendations here (esp in the comments) suggested the use of Python, I was disappointed not to find an example.
So, here's a one liner to get a single value from some JSON data. It assumes that you are piping the data in (from somewhere) and s...
What is the difference between a weak reference and an unowned reference?
...ned above. Check "Resolving Strong Reference Cycles for Closures" section, esp. Quote: " Swift requires you to write self.someProperty or self.someMethod() (rather than just someProperty or someMethod()) whenever you refer to a member of self within a closure. This helps you remember that it’s pos...
Can I use assert on Android devices?
... at a package level, or at a class level which enables assertions at that respective level. The flag is off by default, as a result of which the assertion checks are skipped.
I wrote the following code in my sample Activity:
public class AssertActivity extends Activity {
@Override
protected v...
How do I protect Python code? [closed]
... your secrets and trying to protect against NSA-class reverse engineering. Esp if you have a big python code base and reasons to be paranoid. ;)
– Macke
Jan 8 '16 at 8:18
...
What is the fastest way to compute sin and cos together?
...
.align 4,0x90
.globl _fsincos
_fsincos:
pushl %ebp
movl %esp, %ebp
fldl 12(%ebp)
fsincos
movl 8(%ebp), %eax
fstpl 8(%eax)
fstpl (%eax)
leave
ret $4
.subsections_via_symbols
Tada, it uses the fsincos instruction!
...
Performance of foreach, array_map with lambda and array_map with static function
...eed. It would be interesting to see the opcodes generated by this version, especially comparing with/without opcache since it does a lot of optimizations besides code caching.
– FGM
Jan 14 '17 at 16:04
...
C++ performance challenge: integer to std::string conversion
...
MB/s is a strange metric, especially seeing how you don't remove trailing whitespaces from the string in your implementations. My updated code runs faster than your implementation with x64 VC++ 2005 on Core i7 920 (16.2M ops/s vs. 14.8M ops/s), _ltoa ...