在具有32GB DRAM的Linux平台8核CPU上使用c/c ++初始化十亿个整数的优秀posix线程设计是什么？谢谢你的帮助.
使用g ++版本4.7.2,如果我尝试编译以下内容
#include <boost/date_time/local_time/local_time.hpp>
class Bar
{
public:
Bar() { tz_db_.load_from_file("/home/date_time_zonespec.csv"); }
private:
boost::local_time::tz_database tz_db_;
};
int main()
{
return 0;
}
使用-std = c ++ 0x我收到以下错误.
In file included from /usr/local/include/boost/date_time/local_time/local_time_types.hpp:18:0,
from /usr/local/include/boost/date_time/local_time/local_time.hpp:13,
from test.h:4,
from test.cpp:1: /usr/local/include/boost/date_time/local_time/custom_time_zone.hpp: In instantiation of ‘bool boost::local_time::custom_time_zone_base<CharT>::has_dst() const [with CharT = char]’: test.cpp:11:1: required from here /usr/local/include/boost/date_time/local_time/custom_time_zone.hpp:67:30: error: cannot convert ‘const boost::shared_ptr<boost::date_time::dst_day_calc_rule<boost::gregorian::date>
>’ to ‘bool’ in return
如果我不使用c ++ 0x选项,一切都很好.谁能告诉我这里发生了什么？
我试图根据这个安装boost 1.5到android .
当我编译时,我收到一个错误.这是编译错误的一个片段:
gcc.compile.c++ bin.v2/libs/thread/build/gcc-android4.4.3/release/link-static/runtime-link- static/threading-multi/pthread/thread.o
<command-line>: warning: "BOOST_FILESYSTEM_VERSION" redefined
<command-line>: warning: this is the location of the previous definition
In file included from ./boost/thread/thread.hpp:17,
from libs/thread/src/pthread/thread.cpp:11:
./boost/thread/pthread/thread_data.hpp: In member function 'void boost::thread_attributes::set_stack_size(size_t)':
./boost/thread/pthread/thread_data.hpp:42: error: 'PAGE_SIZE' was not declared in this scope
"../../toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/bin/arm-linux-androideabi-g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic --sysroot=../../platforms/android-9/arch-arm -mthumb -Os -fno-strict-aliasing -O2 -DNDEBUG -g -lstdc++ -I../../sources/cxx-stl/gnu-libstdc++/include -I../../sources/cxx-stl/gnu-libstdc++/libs/armeabi/include -D__GLIBC__ -DBOOST_NO_INTRINSIC_WCHAR_T -DBOOST_FILESYSTEM_VERSION=2 -pthread -Wextra -Wno-long-long -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_STATIC_LINK=1 -DBOOST_FILESYSTEM_VERSION=3 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_POSIX -DNDEBUG -I"." -c -o …当我运行此代码时,我得到这个结果:
15
15
我希望输出应该是
15
17
但事实并非如此.问题是:为什么？
def make_adder_and_setter(x):
def setter(n):
x = n
return (lambda y: x + y, setter)
myadder, mysetter = make_adder_and_setter(5)
print myadder(10)
mysetter(7)
print myadder(10)
我一直有错误
UnboundLocalError:赋值前引用的局部变量'new_speedDx'
在尝试运行以下功能时:
def new_speedD(boid1):
bposx = boid1[0]
if bposx < WALL:
new_speedDx = WALL_FORCE
elif bposx > WIDTH - WALL:
new_speedDx = -WALL_FORCE
bposy = boid1[1]
if bposy < WALL:
new_speedDy = WALL_FORCE
elif bposx > WIDTH - WALL:
new_speedDy = -WALL_FORCE
return new_speedDx, new_speedDy
在这个函数中,boid1是一个有4个元素的向量(xpos,ypos,xvelocity,yvelocity),所有大写的变量都是常量(数字).有人知道如何解决这个问题？我在互联网上找到了许多可能的解决方案,但似乎没有任何工作..
在下面的示例中，Visual StudiothreadIdx用红线突出显示“”。
看起来程序执行成功，所以问题只是VisualStudio中的显示问题。
我怎样才能使 Visual Studio 不再突出显示threadIdx为无效？
我的环境： * 操作系统：Windows7，64位 * VisualStudio2010，CUDA5.5
源代码：
#include <cuda_runtime.h>
#include <stdio.h>
#include <math.h>
#include <cuda.h>
#define N 256
__global__ void matrix_vector_multi_gpu_1_256(float *A_d, float *B_d, float *C_d);
int main(){
int i,j;
float A[N], B[N*N], C[N];
float *A_d, *B_d, *C_d;
dim3 blocks(1,1,1);
dim3 threads(256,1,1);
for(j=0;j<N;j++){
for(i=0;i<N;i++){
B[j*N+i]=((float)j)/256.0;
}
}
for(j=0;j<N;j++){
C[j]=1.0F;
}
cudaMalloc((void**)&A_d, N*sizeof(float));
cudaMalloc((void**)&B_d, N*N*sizeof(float));
cudaMalloc((void**)&C_d, N*sizeof(float));
cudaMemcpy(A_d,A,N*sizeof(float),cudaMemcpyHostToDevice);
cudaMemcpy(B_d,B,N*N*sizeof(float),cudaMemcpyHostToDevice);
cudaMemcpy(C_d,C,N*sizeof(float),cudaMemcpyHostToDevice);
matrix_vector_multi_gpu_1_256<<<blocks,threads>>>(A_d,B_d,C_d);
cudaMemcpy(A,A_d,N*sizeof(float),cudaMemcpyDeviceToHost);
for(j=0;j<N;j++){
printf("A[ %d ]=%f \n",j,A[j]);
}
getchar();
cudaFree(A_d);
cudaFree(B_d); …我试图制作一个简短的程序来解决着名的德雷克方程.我让它接受整数输入,十进制输入和小数输入.但是,当程序试图将它们相乘时,我收到此错误(在我输入所有必要值之后,错误发生):
Traceback (most recent call last)
File "C:/Users/Family/Desktop/Programming/Python Files/1/DrakeEquation1.py", line 24, in <module>
calc() #cal calc to execute it
File "C:/Users/Family/Desktop/Programming/Python Files/1/DrakeEquation1.py", line 17, in calc
calc = r*fp*ne*fl*fi*fc*l
TypeError: can't multiply sequence by non-int of type 'str'
我的代码如下:
def intro():
print('This program will evaluate the Drake equation with your values')
def calc():
print('What is the average rate of star formation in the galaxy?')
r = input()
print('What fraction the stars have planets?')
fp = input()
ne = int(input('What is …其实我刚开始学习C语言.我想知道变量名在哪里存储在C的内存中.请考虑以下代码:
int i = 10;
我无法找到名称" i"存储在内存中的位置.
我创建了共享库:
lib.h:
int fun( int a, int b);
lib.cpp:
#include <lib.h>
int fun ( int a, int b)
{
return a+b;
}
编译它:
gcc -fPIC -c lib.cpp
gcc -shared -o -I ./header lib.so lib.o
我的lib.h位于./header中.因此,汇编已经成功.之后我改变了lib.cpp:
#include <lib.h>
int fun ( int a)
{
return a;
}
但什么也没发生.我想看到错误消息或警告.为什么？