大约有 40,000 项符合查询结果（耗时：0.0311秒） [XML]
How efficient is locking an unlocked mutex? What is the cost of a mutex?
...ate is:
This shows the result of benchmark runs on the following code:
uint64_t do_Ndec(int thread, int loop_count)
{
uint64_t start;
uint64_t end;
int __d0;
asm volatile ("rdtsc\n\tshl $32, %%rdx\n\tor %%rdx, %0" : "=a" (start) : : "%rdx");
mutex.lock();
mutex.unlock();
asm volat...
C/C++ with GCC: Statically add resource files to executable/library
...erface looks something like
/** created from binary via objcopy */
extern uint8_t foo_data[] asm("_binary_foo_data_bin_start");
extern uint8_t foo_data_size[] asm("_binary_foo_data_bin_size");
extern uint8_t foo_data_end[] asm("_binary_foo_data_bin_end");
so you can do stuff like
for (uint...
What is the most effective way for float and double comparison?
...to a primitive type with that
// size. e.g.
//
// TypeWithSize<4>::UInt
//
// is typedef-ed to be unsigned int (unsigned integer made up of 4
// bytes).
//
// Such functionality should belong to STL, but I cannot find it
// there.
//
// Google Test uses this class in the implementation of fl...
How to quickly check if folder is empty (.NET)?
...tial, CharSet = CharSet.Auto)]
private struct WIN32_FIND_DATA
{
public uint dwFileAttributes;
public System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
public System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
public System.Runtime.InteropServices.ComTyp...
What is a rune?
..._compare.go
Output:
hello你好, type: string, len: 11
s[0]: 104, type: uint8
s[10]: 189, type: uint8
[104 101 108 108 111 20320 22909], type: []int32, len: 7
Explanation:
The string hello你好 has length 11, because first 5 chars each take 1 byte only, while the last 2 Chinese chars each t...
How do I use valgrind to find memory leaks?
...>
int main() {
char* alphabet = calloc(26, sizeof(char));
for(uint8_t i = 0; i < 26; i++) {
*(alphabet + i) = 'A' + i;
}
*(alphabet + 26) = '\0'; //null-terminate the string?
free(alphabet);
return 0;
}
Notice that Valgrind points us to the commented line o...
How to save an HTML5 Canvas as an image on a server?
...h binary.charCodeAt(i)
i++
# Return our Blob object
new Blob([ new Uint8Array(array) ], type: 'image/png')
And canvas code here:
canvas = document.getElementById('canvas')
file = dataURLtoBlob(canvas.toDataURL())
After that you can use ajax with Form:
fd = new FormData
# Append our...
How do I iterate over an NSArray?
...s and other collections:
[array enumerateObjectsUsingBlock:^(id object, NSUInteger idx, BOOL *stop) {
// do something with object
}];
You can also use -enumerateObjectsWithOptions:usingBlock: and pass NSEnumerationConcurrent and/or NSEnumerationReverse as the options argument.
10.4 or earl...
MFC Static透明背景色的实现、Static控件自绘、Static字体修改 - C/C++ - ...
...一种：pDC->SetBkMode(TRANSPARENT);afx_msg HBRUSH CtlColor(CDC* *pDC* , UINT *nCtlColor* );COLORREF m_crText;COLORREF m_...第一种：pDC->SetBkMode(TRANSPARENT);
afx_msg HBRUSH CtlColor(CDC* /*pDC*/, UINT /*nCtlColor*/);
COLORREF m_crText;
COLORREF m_crBk;
HBRUSH m_hbkbr;
...
BEGIN_MES...
Why can templates only be implemented in the header file?
...ecific set of types, for instance numeric types: int8_t, int16_t, int32_t, uint8_t, uint16_t, etc. In this case, it still makes sense to use a template, but explicitly instantiating them for the whole set of types is also possible and, in my opinion, recommended.
– UncleZeiv
...