sizeof

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am attempting to use unix-domain sockets and am developing under the NDK. I am routinely receiving Operation not permitted errors for various actions related to trivial AF_UNIX / SOCK_DGRAM type IPC. I am able to successfully bind both processes to a particular interface but am unable to either connect or send / sendto without getting the error mentioned above. The bound interfaces do appear on the file system if an appropriate ls is done in the specified directory. Also, each interface name is given explicit other-read/write access using

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have a code that plays mono audio event (short beeps at various frequencies). I create an AudioOutputUnit, stop it, and whenever I need to play the audio. I start it. When I've played it for the required time, I stop it. Sounds simple enough. However, AudioOutputUnitStart will take usually 180ms to return on my iPhone 4S (with iOS 5.1), this is way too much. Here is the creation/initialisation of the AudioOutputUnit void createAOU() { m_init = false; // find the default playback output unit AudioComponentDescription

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm developing c++ application . I have allocated memory but im getting the Error Thread 1: EXC_BAD_ACCESS ( code=2,address=0x8) in superfile.cpp. Here is my code : superfile.h struct Node{ Voxel *data; Node *next; }; superfile.cpp int* cnt =(int*)calloc(_width*_height,sizeof(int)); Voxel *temp =(Voxel *)calloc(_width*_height,sizeof(Voxel)); Node *list=(Node *)calloc(_width*_height*2,sizeof(Node)); list[(_width*_height)+l].next = list[_width*yy + xx].next->next; // Thread 1: EXC_BAD_ACCESS ( code=2,address=0x8) Error c++ after debugging the

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have the CSR coordinates of a matrix. /* alloc space for COO matrix */ int *coo_rows = (int*) malloc(K.n_rows * sizeof(int)); int *coo_cols = (int*) malloc(K.n_rows * sizeof(int)); float *coo_vals = (float*) malloc(K.n_rows * sizeof(float)); /*Load coo values*/ int *rowptrs = (int*) malloc((N_unique+1)*sizeof(int)); int *colinds = (int*) malloc(K.n_rows *sizeof(int)); double *vals = (double*) malloc(K.n_rows *sizeof(double)); /* take csr values */ int job[] = { 2, // job(1)=2 (coo->csr with sorting) 0, // job(2)=1 (one-based indexing for

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: What is the difference between objective-c C primitive numbers? I know what they are and how to use them (somewhat), but I'm not sure what the capabilities and uses of each one is. Could anyone clear up which ones are best for some scenarios and not others? int float double long short What can I store with each one? I know that some can store more precise numbers and some can only store whole numbers. Say for example I wanted to store a latitude (possibly retrieved from a CLLocation object), which one should I use to avoid loosing any data?

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: #include main() { if (sizeof(int) > -1) printf("True"); else printf("False"); } It prints False . Why doesn't sizeof() return a value in the if ? 回答1: sizeof is not a function, it's an operator. The parentheses are not part of the operator's name. It's failing because the value generated has the unsigned type size_t , which causes "the usual arithmetic conversions" in which -1 is converted to unsigned, in which case it's a very large number. Basically you're comparing 4 > 0xffffffffu , or something close to that at least. See this question

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I am implementing a median filter in CUDA. For a particular pixel, I extract its neighbors corresponding to a window around the pixel, say a N x N ( 3 x 3 ) window, and now have an array of N x N elements. I do not envision using a window of more than 10 x 10 elements for my application. This array is now locally present in the kernel and already loaded into device memory. From previous SO posts that I have read, the most common sorting algorithms are implemented by Thrust. But, Thrust can only be called from the host. Thread -

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: How can I allocate a bi-dimensional array using malloc ? This is my current code: typedef struct object product, *pprod; struct object{ int type; int quantity; pprod next; }; pprod t[4][3]; Thanks a lot for your help. 回答1: To allocate memory in such a way that the layout is compatible with a normal two-dimensional array - or array of arrays - you need a pointer to an array of appropriate size, pprod (*t)[m] = malloc(n * sizeof *t); Thus t is a pointer to arrays of m elements of type pprod , and you can simply use it t[i][j] as if it were

i have a doubt regarding sizeof operator Code 1: int main() { int p[10]; printf("%d",sizeof(p)); //output -- 40 return 0; } Code 2: int main() { int *p[10]; printf("%d",sizeof(*p)); //output -- 4 return 0; } in the first code p points to an array of ints. in the second code p points to an array of pointers. i am not able to understand why the first code o/p is 40 but 2nd code o/p is 4 thought both points to an array of the same size ? Sangeeth Saravanaraj The output of the following program will give you some hints and understanding about the size of a type and a pointer to a type. #include

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm very new to C, and can't seem to figure out what's wrong with the following code. int main() { char filen[] = "file.txt"; FILE *file = fopen ( filen, "r" ); if ( file != NULL ) { char line [ 128 ]; while ( fgets ( line, sizeof line, file ) != NULL ) /* read a line */ { int i; char *result; for(i=0; i< NUM;i++) { char *rep; rep = (char *) malloc (sizeof(mychars[i][0])); strcpy(rep, mychars[i][0]); char *with; with = (char *) malloc (sizeof(mychars[i][1])); strcpy(with, cgichars[i][1]); result = (char *) malloc (sizeof(char) * 128); result