Pthreads n 体问题
▶ 《并行程序设计导论》第六章中讨论了 n 体问题，分别使用了 MPI，Pthreads，OpenMP 来进行实现，这里是 Pthreads 的代码，分为基本算法和简化算法（引力计算量为基本算法的一半，但是消息传递较为复杂）
● 基本算法
// pth_nbody_basic.c，Pthreads 基本算法
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <pthread.h>
#include "D:\Code\Ptheads\timer.h"
#pragma comment(lib, "pthreadVC2.lib") #define OUTPUT
#define DEBUG
#define DIM 2
#define X 0
#define Y 1
const double G = 6.673e-11;
const int BLOCK = , CYCLIC = ;// 任务分配方式，BLCOK 块调度，CYCLIC 循环调度
typedef double vect_t[DIM];
struct particle_s
{
double m;
vect_t s;
vect_t v;
};
int nThread, n, n_steps, output_freq;
double delta_t;
struct particle_s* curr;
vect_t* forces;
int b_thread_count; // 栅栏计数器
pthread_mutex_t b_mutex; // 栅栏互斥量
pthread_cond_t b_cond_var; // 栅栏条件变量 void Usage(char* prog_name)
{
fprintf(stderr, "usage: %s <nThreads> <nParticles> <nTimestep> <sizeTimestep> <outputFrequency> <g|i>\n", prog_name);
fprintf(stderr, " 'g': inite condition by random\n 'i': inite condition from stdin\n");
exit();
} void Get_args(int argc, char* argv[], char* g_i_p)
{
if (argc != )
Usage(argv[]);
nThread = strtol(argv[], NULL, );
n = strtol(argv[], NULL, );
n_steps = strtol(argv[], NULL, );
delta_t = strtod(argv[], NULL);
output_freq = strtol(argv[], NULL, );
*g_i_p = argv[][];
if (nThread < || n <= || n % nThread || n_steps < || delta_t <= || *g_i_p != 'g' && *g_i_p != 'i')
{
Usage(argv[]);
exit();
}
# ifdef DEBUG
printf("Get_args, nThread%2d n %d n_steps %d delta_t %e output_freq %d g_i %c\n",
nThread, n, n_steps, delta_t, output_freq, *g_i_p);
fflush(stdout);
# endif
} void Gen_init_cond(void)
{
const double mass = 5.0e24, gap = 1.0e5, speed = 3.0e4;
//srand(2);
for (int i = ; i < n; i++)
{
curr[i].m = mass;
curr[i].s[X] = i * gap;
curr[i].s[Y] = 0.0;
curr[i].v[X] = 0.0;
// vel[i][Y] = speed * (2 * rand() / (double)RAND_MAX) - 1);
curr[i].v[Y] = (i % ) ? -speed : speed;
}
} void Get_init_cond(void)
{
printf("For each particle, enter (in order): mass x-coord y-coord x-velocity y-velocity\n");
for (int i = ; i < n; i++)
{
scanf_s("%lf", &curr[i].m);
scanf_s("%lf", &curr[i].s[X]);
scanf_s("%lf", &curr[i].s[Y]);
scanf_s("%lf", &curr[i].v[X]);
scanf_s("%lf", &curr[i].v[Y]);
}
} void Loop_schedule(int my_rank, int nThread, int n, int sched, int* first_p, int* last_p, int* incr_p)
{
if (sched == CYCLIC)// 循环调度，从自己线程编号开始，每隔 nThread 个元素取一个，直到取到 n 为止
{
*first_p = my_rank;
*last_p = n;
*incr_p = nThread;
}
else // 块调度，每线程平均取 n / nThread 个，若不能整除，则前 remainder 个线程每线程多拿一个
{
int quotient = n / nThread;
int remainder = n % nThread;
int myCount;
*incr_p = ;
if (my_rank < remainder)
{
*first_p = my_rank * (quotient + );
*last_p = *first_p + quotient + ;
}
else
{
*first_p = my_rank * quotient + remainder;
*last_p = *first_p + quotient;
}
}
} void Barrier_init(void)// 条件变量等待法同步所有线程
{
b_thread_count = ;
pthread_mutex_init(&b_mutex, NULL);
pthread_cond_init(&b_cond_var, NULL);
} void Barrier(void)
{
pthread_mutex_lock(&b_mutex);
b_thread_count++;
if (b_thread_count == nThread)
{
b_thread_count = ;
pthread_cond_broadcast(&b_cond_var);
}
else
while (pthread_cond_wait(&b_cond_var, &b_mutex) != );
pthread_mutex_unlock(&b_mutex);
} void Barrier_destroy(void)
{
pthread_mutex_destroy(&b_mutex);
pthread_cond_destroy(&b_cond_var);
} void Output_state(double time)
{
printf("Output_state, time = %.2f\n", time);
for (int i = ; i < n; i++)
printf("%2d %10.3e %10.3e %10.3e %10.3e %10.3e\n", i, curr[i].m, curr[i].s[X], curr[i].s[Y], curr[i].v[X], curr[i].v[Y]);
printf("\n");
fflush(stdout);
} void Compute_force(int part)
{
int k;
vect_t f_part_k;
double len, fact;
for (forces[part][X] = forces[part][Y] = 0.0, k = ; k < n; k++)
{
if (k != part)
{
f_part_k[X] = curr[part].s[X] - curr[k].s[X];
f_part_k[Y] = curr[part].s[Y] - curr[k].s[Y];
len = sqrt(f_part_k[X] * f_part_k[X] + f_part_k[Y] * f_part_k[Y]);
fact = -G * curr[part].m * curr[k].m / (len * len * len);
f_part_k[X] *= fact;
f_part_k[Y] *= fact;
forces[part][X] += f_part_k[X];
forces[part][Y] += f_part_k[Y];
# ifdef DEBUG
printf("Compute_force, k%2d> %10.3e %10.3e %10.3e %10.3e\n", k, len, fact, f_part_k[X], f_part_k[Y]);
# endif
}
}
} void Update_part(int part)
{
const double fact = delta_t / curr[part].m;
# ifdef DEBUG
printf("Update_part before, part%2d %10.3e %10.3e %10.3e %10.3e %10.3e %10.3e\n",
part, curr[part].s[X], curr[part].s[Y], curr[part].v[X], curr[part].v[Y], forces[part][X], forces[part][Y]);
fflush(stdout);
# endif
curr[part].s[X] += delta_t * curr[part].v[X];
curr[part].s[Y] += delta_t * curr[part].v[Y];
curr[part].v[X] += fact * forces[part][X];
curr[part].v[Y] += fact * forces[part][Y];
# ifdef DEBUG
printf("Update_part after, part%2d %10.3e %10.3e %10.3e %10.3e)\n",
part, curr[part].s[X], curr[part].s[Y], curr[part].v[X], curr[part].v[Y]);
# endif
} void* Thread_work(void* rank)
{
const long long my_rank = (long long)rank;
int step, part; // 循环变量
int first, last, incr; // 每个线程分配颗粒的起始标号，最后编号，间隔数
Loop_schedule(my_rank, nThread, n, BLOCK, &first, &last, &incr);
for (step = ; step <= n_steps; step++)
{
for (part = first; part < last; Compute_force(part), part += incr);
Barrier();
for (part = first; part < last; Update_part(part), part += incr);
Barrier();
# ifdef OUTPUT
if (step % output_freq == && my_rank == )
Output_state(step * delta_t);
# endif
}
return NULL;
} int main(int argc, char* argv[])
{
char g_i;
long thread;
//double start, finish; // 无法计时
pthread_t* thread_handles; Get_args(argc, argv, &g_i);
curr = (particle_s*)malloc(n * sizeof(struct particle_s));
forces = (vect_t*)malloc(n * sizeof(vect_t));
thread_handles = (pthread_t*)malloc(nThread * sizeof(pthread_t));
if (g_i == 'g')
Gen_init_cond();
else
Get_init_cond();
Barrier_init(); //GET_TIME(start);
# ifdef OUTPUT
Output_state(0.0);
# endif
for (thread = ; thread < nThread; thread++)
pthread_create(&thread_handles[thread], NULL, Thread_work, (void*)thread);
for (thread = ; thread < nThread; thread++)
pthread_join(thread_handles[thread], NULL); //GET_TIME(finish);
//printf("Elapsed time = %e ms\n", (finish - start) * 1000);
Barrier_destroy();
free(thread_handles);
free(curr);
free(forces);
return ;
}
● 输出结果，由于 time.h 有点问题，没能进行及时，但是结果还是正确的。
D:\Code\Ptheads\PthreadsProjectTemp\x64\Debug>PthreadsProjectTemp.exe g
Output_state, time = 0.00
5.000e+24 0.000e+00 0.000e+00 0.000e+00 3.000e+04
5.000e+24 1.000e+05 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 2.000e+05 0.000e+00 0.000e+00 3.000e+04
5.000e+24 3.000e+05 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 4.000e+05 0.000e+00 0.000e+00 3.000e+04
5.000e+24 5.000e+05 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 6.000e+05 0.000e+00 0.000e+00 3.000e+04
5.000e+24 7.000e+05 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 8.000e+05 0.000e+00 0.000e+00 3.000e+04
5.000e+24 9.000e+05 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 1.000e+06 0.000e+00 0.000e+00 3.000e+04
5.000e+24 1.100e+06 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 1.200e+06 0.000e+00 0.000e+00 3.000e+04
5.000e+24 1.300e+06 0.000e+00 0.000e+00 -3.000e+04
5.000e+24 1.400e+06 0.000e+00 0.000e+00 3.000e+04
5.000e+24 1.500e+06 0.000e+00 0.000e+00 -3.000e+04 Output_state, time = 1.00
5.000e+24 0.000e+00 3.000e+04 5.273e+04 3.000e+04
5.000e+24 1.000e+05 -3.000e+04 1.922e+04 -3.000e+04
5.000e+24 2.000e+05 3.000e+04 1.071e+04 3.000e+04
5.000e+24 3.000e+05 -3.000e+04 6.802e+03 -3.000e+04
5.000e+24 4.000e+05 3.000e+04 4.485e+03 3.000e+04
5.000e+24 5.000e+05 -3.000e+04 2.875e+03 -3.000e+04
5.000e+24 6.000e+05 3.000e+04 1.614e+03 3.000e+04
5.000e+24 7.000e+05 -3.000e+04 5.213e+02 -3.000e+04
5.000e+24 8.000e+05 3.000e+04 -5.213e+02 3.000e+04
5.000e+24 9.000e+05 -3.000e+04 -1.614e+03 -3.000e+04
5.000e+24 1.000e+06 3.000e+04 -2.875e+03 3.000e+04
5.000e+24 1.100e+06 -3.000e+04 -4.485e+03 -3.000e+04
5.000e+24 1.200e+06 3.000e+04 -6.802e+03 3.000e+04
5.000e+24 1.300e+06 -3.000e+04 -1.071e+04 -3.000e+04
5.000e+24 1.400e+06 3.000e+04 -1.922e+04 3.000e+04
5.000e+24 1.500e+06 -3.000e+04 -5.273e+04 -3.000e+04 Output_state, time = 2.00
5.000e+24 5.273e+04 6.000e+04 9.288e+04 1.641e+04
5.000e+24 1.192e+05 -6.000e+04 3.818e+04 -3.791e+03
5.000e+24 2.107e+05 6.000e+04 2.116e+04 3.791e+03
5.000e+24 3.068e+05 -6.000e+04 1.356e+04 -3.101e+03
5.000e+24 4.045e+05 6.000e+04 8.930e+03 3.101e+03
5.000e+24 5.029e+05 -6.000e+04 5.739e+03 -2.959e+03
5.000e+24 6.016e+05 6.000e+04 3.218e+03 2.959e+03
5.000e+24 7.005e+05 -6.000e+04 1.043e+03 -2.929e+03
5.000e+24 7.995e+05 6.000e+04 -1.043e+03 2.929e+03
5.000e+24 8.984e+05 -6.000e+04 -3.218e+03 -2.959e+03
5.000e+24 9.971e+05 6.000e+04 -5.739e+03 2.959e+03
5.000e+24 1.096e+06 -6.000e+04 -8.930e+03 -3.101e+03
5.000e+24 1.193e+06 6.000e+04 -1.356e+04 3.101e+03
5.000e+24 1.289e+06 -6.000e+04 -2.116e+04 -3.791e+03
5.000e+24 1.381e+06 6.000e+04 -3.818e+04 3.791e+03
5.000e+24 1.447e+06 -6.000e+04 -9.288e+04 -1.641e+04 Output_state, time = 3.00
5.000e+24 1.456e+05 7.641e+04 1.273e+05 -1.575e+03
5.000e+24 1.574e+05 -6.379e+04 5.867e+04 2.528e+04
5.000e+24 2.319e+05 6.379e+04 2.685e+04 -2.069e+04
5.000e+24 3.204e+05 -6.310e+04 1.884e+04 2.228e+04
5.000e+24 4.134e+05 6.310e+04 1.235e+04 -2.151e+04
5.000e+24 5.086e+05 -6.296e+04 8.111e+03 2.179e+04
5.000e+24 6.048e+05 6.296e+04 4.537e+03 -2.163e+04
5.000e+24 7.016e+05 -6.293e+04 1.493e+03 2.169e+04
5.000e+24 7.984e+05 6.293e+04 -1.493e+03 -2.169e+04
5.000e+24 8.952e+05 -6.296e+04 -4.537e+03 2.163e+04
5.000e+24 9.914e+05 6.296e+04 -8.111e+03 -2.179e+04
5.000e+24 1.087e+06 -6.310e+04 -1.235e+04 2.151e+04
5.000e+24 1.180e+06 6.310e+04 -1.884e+04 -2.228e+04
5.000e+24 1.268e+06 -6.379e+04 -2.685e+04 2.069e+04
5.000e+24 1.343e+06 6.379e+04 -5.867e+04 -2.528e+04
5.000e+24 1.354e+06 -7.641e+04 -1.273e+05 1.575e+03
● 简化算法
//pth_nbody_red.c，Pthreads 简化算法
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <pthread.h>
#include "D:\Code\Ptheads\timer.h"
#pragma comment(lib, "pthreadVC2.lib") //#define OUTPUT
//#define DEBUG
#define DIM 2
#define X 0
#define Y 1
const double G = 6.673e-11;
const int BLOCK = , CYCLIC = ;// 任务分配方式，BLCOK 块调度，CYCLIC 循环调度
typedef double vect_t[DIM];
struct particle_s
{
double m;
vect_t s;
vect_t v;
};
int nThread, n, n_steps, output_freq;
double delta_t;
struct particle_s* curr;
vect_t *forces, *loc_forces; // 多一个 loc_forces
int b_thread_count;
pthread_mutex_t b_mutex;
pthread_cond_t b_cond_var; void Usage(char* prog_name)
{
fprintf(stderr, "usage: %s <nThreads> <nParticles> <nTimestep> <sizeTimestep> <outputFrequency> <g|i>\n", prog_name);
fprintf(stderr, " 'g': inite condition by random\n 'i': inite condition from stdin\n");
exit();
} void Get_args(int argc, char* argv[], char* g_i_p)
{
if (argc != )
Usage(argv[]);
nThread = strtol(argv[], NULL, );
n = strtol(argv[], NULL, );
n_steps = strtol(argv[], NULL, );
delta_t = strtod(argv[], NULL);
output_freq = strtol(argv[], NULL, );
*g_i_p = argv[][];
if (nThread < || n <= || n % nThread || n_steps < || delta_t <= || *g_i_p != 'g' && *g_i_p != 'i')
{
Usage(argv[]);
exit();
}
# ifdef DEBUG
printf("Get_args, nThread%2d n %d n_steps %d delta_t %e output_freq %d g_i %c\n",
nThread, n, n_steps, delta_t, output_freq, *g_i_p);
fflush(stdout);
# endif
} void Gen_init_cond(void)
{
const double mass = 5.0e24, gap = 1.0e5, speed = 3.0e4;
//srand(2);
for (int i = ; i < n; i++)
{
curr[i].m = mass;
curr[i].s[X] = i * gap;
curr[i].s[Y] = 0.0;
curr[i].v[X] = 0.0;
// vel[i][Y] = speed * (2 * rand() / (double)RAND_MAX) - 1);
curr[i].v[Y] = (i % ) ? -speed : speed;
}
} void Get_init_cond(void)
{
printf("For each particle, enter (in order): mass x-coord y-coord x-velocity y-velocity\n");
for (int i = ; i < n; i++)
{
scanf_s("%lf", &curr[i].m);
scanf_s("%lf", &curr[i].s[X]);
scanf_s("%lf", &curr[i].s[Y]);
scanf_s("%lf", &curr[i].v[X]);
scanf_s("%lf", &curr[i].v[Y]);
}
} void Loop_schedule(int my_rank, int nThread, int n, int sched, int* first_p, int* last_p, int* incr_p)
{
if (sched == CYCLIC)
{
*first_p = my_rank;
*last_p = n;
*incr_p = nThread;
}
else
{
int quotient = n / nThread;
int remainder = n % nThread;
int myCount;
*incr_p = ;
if (my_rank < remainder)
{
*first_p = my_rank * (quotient + );
*last_p = *first_p + quotient + ;
}
else
{
*first_p = my_rank * quotient + remainder;
*last_p = *first_p + quotient;
}
}
} void Barrier_init(void)
{
b_thread_count = ;
pthread_mutex_init(&b_mutex, NULL);
pthread_cond_init(&b_cond_var, NULL);
} void Barrier(void)
{
pthread_mutex_lock(&b_mutex);
b_thread_count++;
if (b_thread_count == nThread)
{
b_thread_count = ;
pthread_cond_broadcast(&b_cond_var);
}
else
while (pthread_cond_wait(&b_cond_var, &b_mutex) != );
pthread_mutex_unlock(&b_mutex);
} void Barrier_destroy(void)
{
pthread_mutex_destroy(&b_mutex);
pthread_cond_destroy(&b_cond_var);
} void Output_state(double time)
{
printf("Output_state, time = %.2f\n", time);
for (int i = ; i < n; i++)
printf("%2d %10.3e %10.3e %10.3e %10.3e %10.3e\n", i, curr[i].m, curr[i].s[X], curr[i].s[Y], curr[i].v[X], curr[i].v[Y]);
printf("\n");
fflush(stdout);
} void Compute_force(int part, vect_t loc_forces[])// 多一个参数 loc_forces[]
{
int k;
vect_t f_part_k;
double len, fact;
for (k = part + ; k < n; k++)
{
f_part_k[X] = curr[part].s[X] - curr[k].s[X];
f_part_k[Y] = curr[part].s[Y] - curr[k].s[Y];
len = sqrt(f_part_k[X] * f_part_k[X] + f_part_k[Y] * f_part_k[Y]);
fact = -G * curr[part].m * curr[k].m / (len * len * len);
f_part_k[X] *= fact;
f_part_k[Y] *= fact;
loc_forces[part][X] += f_part_k[X];
loc_forces[part][Y] += f_part_k[Y];
loc_forces[k][X] -= f_part_k[X];
loc_forces[k][Y] -= f_part_k[Y];
# ifdef DEBUG
printf("Compute_force, k%2d> %10.3e %10.3e %10.3e %10.3e\n", k, len, fact, f_part_k[X], f_part_k[Y]);
# endif
}
} void Update_part(int part)
{
const double fact = delta_t / curr[part].m;
# ifdef DEBUG
printf("Update_part before, part%2d %10.3e %10.3e %10.3e %10.3e %10.3e %10.3e\n",
part, curr[part].s[X], curr[part].s[Y], curr[part].v[X], curr[part].v[Y], forces[part][X], forces[part][Y]);
fflush(stdout);
# endif
curr[part].s[X] += delta_t * curr[part].v[X];
curr[part].s[Y] += delta_t * curr[part].v[Y];
curr[part].v[X] += fact * forces[part][X];
curr[part].v[Y] += fact * forces[part][Y];
# ifdef DEBUG
printf("Update_part after, part%2d %10.3e %10.3e %10.3e %10.3e)\n",
part, curr[part].s[X], curr[part].s[Y], curr[part].v[X], curr[part].v[Y]);
# endif
} void* Thread_work(void* rank)
{
const long long my_rank = (long long)rank;
int thread;
int step, part;
int bfirst, blast, bincr;// 计算采用循环调度，更新数据采用块调度
int cfirst, clast, cincr; Loop_schedule(my_rank, nThread, n, BLOCK, &bfirst, &blast, &bincr);
Loop_schedule(my_rank, nThread, n, CYCLIC, &cfirst, &clast, &cincr);
for (step = ; step <= n_steps; step++)
{
memset(loc_forces + my_rank*n, , n * sizeof(vect_t));
Barrier();
for (part = cfirst; part < clast; Compute_force(part, loc_forces + my_rank*n), part += cincr);
Barrier();
for (part = bfirst; part < blast; part += bincr)
{
forces[part][X] = forces[part][Y] = 0.0;
for (thread = ; thread < nThread; thread++)
{
forces[part][X] += loc_forces[thread*n + part][X];
forces[part][Y] += loc_forces[thread*n + part][Y];
}
}
Barrier();
for (part = bfirst; part < blast; Update_part(part), part += bincr);
Barrier();
# ifdef OUTPUT
if (step % output_freq == && my_rank == )
Output_state(step * delta_t);
# endif
}
return NULL;
} int main(int argc, char* argv[])
{
char g_i;
long thread;
//double start, finish;
pthread_t* thread_handles; Get_args(argc, argv, &g_i);
curr = (particle_s*)malloc(n * sizeof(struct particle_s));
forces = (vect_t*)malloc(n * sizeof(vect_t));
loc_forces = (vect_t*)malloc(nThread * n * sizeof(vect_t));// 多一个 loc_force 的初始化
thread_handles = (pthread_t*)malloc(nThread * sizeof(pthread_t));
if (g_i == 'g')
Gen_init_cond();
else
Get_init_cond();
Barrier_init(); //GET_TIME(start);
# ifdef OUTPUT
Output_state(0.0);
# endif
for (thread = ; thread < nThread; thread++)
pthread_create(&thread_handles[thread], NULL, Thread_work, (void*)thread);
for (thread = ; thread < nThread; thread++)
pthread_join(thread_handles[thread], NULL); //GET_TIME(finish);
//printf("Elapsed time = %e ms\n", (finish - start) * 1000);
Barrier_destroy();
free(thread_handles);
free(curr);
free(forces);
free(loc_forces);
return ;
}
● 输出结果，与基本算法类似。直观上，pthreads 简化算法花费的时间是 MPI，OpenMP，Pthreads 中最少的，好像 6 秒以内就算完了 1024 体 3600 秒的模拟
Pthreads n 体问题的更多相关文章
- OpenMP n 体问题
▶ <并行程序设计导论>第六章中讨论了 n 体问题,分别使用了 MPI,Pthreads,OpenMP 来进行实现,这里是 OpenMP 的代码,分为基本算法和简化算法(引力计算量为基本算 ...
- MPI n 体问题
▶ <并行程序设计导论>第六章中讨论了 n 体问题,分别使用了 MPI,Pthreads,OpenMP 来进行实现,这里是 MPI 的代码,分为基本算法和简化算法(引力计算量为基本算法的一 ...
- pthreads 2.0.10 test
CentOS 6.3 cd /root mkdir pthreads //get php-5.6 and install zts version wget cn2.php.net/get/php-5. ...
- 如何让您的php也支持pthreads多线程
我们常常会碰到这样一种情况,开发环境在windows下开发,而生产环境确是linux.windows下能正常运行,上传到linux后却无法好好地玩耍了.然后开始了一轮尼玛式的疯狂的查找原因,最后发现是 ...
- php多线程pthreads的安装与使用
安装Pthreads 基本上需要重新编译PHP,加上 --enable-maintainer-zts 参数,但是用这个文档很少:bug会很多很有很多意想不到的问题,生成环境上只能呵呵了,所以这个东西玩 ...
- [资料]pthreads PHP
1. 参考手册http://php.net/manual/zh/book.pthreads.php 2. windows下安装php真正的多线程扩展pthreads教程http://www.think ...
- PHP安装pthreads多线程扩展教程[windows篇]
from:http://blog.csdn.net/aoyoo111/article/details/19020161 一.判断PHP是ts还是nts版 通过phpinfo(); 查看其中的 Thre ...
- 一个高在线（可以超过1024）多线程的socket echo server（pthreads 和 libevent扩展）
研究了3周吧,本来打算用pthreads+event扩展的,结果event扩展太原始了,太多函数了,实在不知道怎么在外部随时发送数据给客户端,所以改用libevent, 改用libevent之后花了2 ...
- PHP 多线程扩展（正儿八经的线程）pthreads安装
环境CentOS 6.3 64bit,php 5.4.5 pthreads需要线程安全环境, 下载php的安装包,解压: tar zxvf php-5.4.5.tar.gz//名字是不是这个我不确定, ...
随机推荐
- ES5和ES6中的继承
看到一篇写的非常好的关于js继承的文章,其中对构造函数.原型.实例之间的关系的描述十分透彻,故转载作者文章以随时学习,并供大家共同进步! ES5 ES5中的继承,看图: function Super( ...
- uva10689矩阵快速幂
#include<map> #include<set> #include<cmath> #include<queue> #include<stac ...
- JavaScript学习总结(二十一)——使用JavaScript的数组实现数据结构中的队列与堆栈
今天在项目中要使用JavaScript实现数据结构中的队列和堆栈,这里做一下总结. 一.队列和堆栈的简单介绍 1.1.队列的基本概念 队列:是一种支持先进先出(FIFO)的集合,即先被插入的数据,先被 ...
- Reverse engineer powerdesigner link odbc
Reverse engineer powerdesigner link odbc Option Explicit ValidationMode = True Interactive ...
- android 笔记一
1.Fragment创建extents FragmentView rootView = inflater.inflate(R.layout.fragment_main, container, fals ...
- Linux运维学习笔记-常用快捷键及vi、vim总结
vim是vi的增强版,vim完全兼容vi
- c++ istringstream的用法
一.测试代码 istringstream 是将字符串变成字符串迭代器一样,将字符串流在依次拿出,比较好的是,它不会将空格作为流.这样就实现了字符串的空格切割. #include<iostream ...
- Dijkstra算法（C语言）
Dijkstra算法 1.定义概览 Dijkstra(迪杰斯特拉)算法是典型的单源最短路径算法,用于计算一个节点到其他所有节点的最短路径.主要特点是以起始点为中心向外层层扩展,直到扩展到终点为止.Di ...
- 【Xamarin】Visual Studio 2013 Xamarin for Android开发环境搭建与配置&Genymotion
Xamarin Xamarin是基于Mono的平台. Xamarin旨在让开发者可以用C#编写iOS, Android, Mac应用程序,也就是跨平台移动开发. 下载资源 1,进入Xamarin官方网 ...
- C#对Jason序列化匿名对象
引用: using System.Web.Script.Serialization; 代码: var resp = new { flag = false, url = ConfigReader.Log ...