shared-memory

问题 The following code parallelizes a for-loop. import networkx as nx; import numpy as np; from joblib import Parallel, delayed; import multiprocessing; def core_func(repeat_index, G, numpy_arrary_2D): for u in G.nodes(): numpy_arrary_2D[repeat_index][u] = 2; return; if __name__ == "__main__": G = nx.erdos_renyi_graph(100000,0.99); nRepeat = 5000; numpy_array = np.zeros([nRepeat,G.number_of_nodes()]); Parallel(n_jobs=4)(delayed(core_func)(repeat_index, G, numpy_array) for repeat_index in range

问题 boost::variant claims that it is a value type. Does this mean that it's safe to simply write out the raw representation of a boost::variant and load it back later, as long as it only contains POD types? Assume that it will be reloaded by code compiled by the same compiler, and same version of boost, on the same architecture. Also, (probably) equivalently, can boost::variant be used in shared memory? 回答1: Regarding serialisation: It should work, yes. But why don't you use boost::variant 's

问题 I'm in Linux 2.6. I have an environment where 2 processes simulate (using shared memory) the exchange of data through a simple implementation of the message passing mode. I have a client process (forked from the parent, which is the server) which writes a struct(message) to a memory mapped region created (after the fork) with: message *m = mmap(NULL, sizeof(message), PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0) This pointer is then written to a queue (in form of a linked list) into

问题 I have a C++.NET app and a C#.NET app. I would like them to communicate via shared memory. How is it possible in .NET version 2.0 ? Mainly want to share a queue object. 回答1: Update: Hey, here's a page I just found with a compleate implmentation. Using C++/CLI, it's quite easy to setup shared memory as per normal C++ API (C++/CLI being able to interact with the managed and native HEAP/memory references). The UnmanagedMemoryStream can then be used to expose a Stream object to C#. I did not

问题 I would like to clear up an execution state with CUDA shared memory and block execution based on the amount of shared memory used per block. State I target on GTX480 nvidia card which has 48KB shared memory per block and 15 streaming multiprocessors. So, if i declare a kernel with 15 blocks, each one uses 48KB of shared memory and no other restriction is reached (registers, maximum threads per block etc.) every block is running into one SM(of 15) until the end. In this case is needed only

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 9 months ago . I'm really new to linux OS. Can someone say how to do this work with linux. I'm not asking the C code. It's hard to understand it. Thank you 1. First program creates a shared memory area using shmget() and maps it to its address space. Then it writes "Hello" in to that shared

问题 The POSIX shm_open() function returns a file descriptor that can be used to access shared memory. This is extremely convenient because one can use all the traditional mechanisms for controlling file descriptors to also control shared memory. The only drawback is that shm_open() always wants a filename. So I need to do this: // Open with a clever temp file name and hope for the best. fd = shm_open(tempfilename, O_RDWR | O_CREAT | O_EXCL, 0600); // Immediately delete the temp file to keep the

问题 Let's use POSIX shared memory like shmget() - a common call to coordinate inter-process communication. How is calling shmget() and coordinating communication on the shared memory segment any different than how Linux implements shared memory and synchronization between threads in a single process. Is one of them more light-weight? 回答1: SHM is for IPC in multiple processes. In modern OS, each process cannot see each others' memory space. Using common key for shmget() to get the share memory and

问题 On Solaris it is possible to get with shmctl the size of a shared memory segment that I did not created and for which I don't have the permission ? For example I want to get the size of a segment created by another user with read-only mode for him only (600). I tried with the code below to get total size of all shared memory segments but I get a permission denied Cannot access shared memory information for segment 0 because Permission denied when I don't have read rights on a segment. int

问题 I need to pass void handler to another application, To replicate the scenario I have created one small program using shared memory and try to pass the void pointer to another application and print the value, I can get the void pointer address in another application, but when I try to dereference the pointer second application crash. Here are the sample application wire.c . #include <sys/ipc.h> #include <sys/shm.h> #include <stdio.h> int main() { key_t key=1235; int shm_id; void *shm; void