将参数传递给pthread_create-从void（*）（）到void（*）（void *）的无效转换

Question

我正在编写一个小的简单程序，该程序使用pthreads实现循环执行计划。 我首先编写了没有pthreads的程序，现在尝试将参数正确地传递到pthread_create中。 我知道args是：

int pthread_create（pthread_t * thread，const pthread_attr_t * attr，void *（* start_routine）（void *），void * arg）;

但是将线程发送到ttable（日程表）给我带来了困难。 现在，我正在使用线程，即使我没有使用它，我也添加了void * x参数（是否需要此参数？）我尝试不使用任何参数的调度，并将NULL作为pthread_create的最后一个参数传入。 我目前的错误是：错误：从'void（*）（）'到'void（*）（void *）'的无效转换[-fpermissive]}; ^

这是代码：

#include <ctype.h>
#include <unistd.h>
#include <sys/times.h>
#include <pthread.h>

#define SLOTX   6
#define CYCLEX  4
#define SLOT_T  1000    //1 second slot time
#define NUM_THREADS 3

int tps;
int i;
int j;
int rc;
int cycle = 0;
int slot = 0;
struct tms n;

void one(void* x){
        printf("Task 1 running\n");
        sleep(1);
}

void two(void* x){
        printf("Task 2 running\n");
        sleep(1);
}

void three(void* x){
        printf("Task 3 running\n");
        sleep(1);
}

void burn(void* x){
        printf("Burn cycle\n");
        sleep(1);
}

void (*ttable[SLOTX][CYCLEX])(void* x) = {
        {one,   one,    two,    two},
        {three, three,  three,  three},
        {two,   two,    one,    one},
        {burn,  two,    two,    burn},
        {three, three,  three,  three},
        {one,   one,    two,    two}
};

main(){
        tps = sysconf(_SC_CLK_TCK);
        pthread_t thread[NUM_THREADS];
        printf("clock ticks/sec = %d\n\n", tps);
        while(1){
                printf("Starting new hyperperiod\n");
                for(slot = 0; slot<SLOTX; slot++){
                        printf("Starting new frame\n");
                        for(cycle = 0; cycle<CYCLEX; cycle++){
                                for(i = 0; i<NUM_THREADS; i++){
                                        rc = pthread_create(&thread[i], NULL, (*ttable[slot][cycle]), *(void*)j);
                                }
                        }
                }
        }

}

Answer 1

pthread_create启动函数必须恰好带有一个类型为void *参数。 您的参数为零。 修复它们，使其采用类型为void *的虚拟参数，一切都应该正常。

Answer 2

使用以下内容：

typedef void* (*ThreadFunc_t) (void *);
ThreadFunc_t ttable[SLOTX][CYCLEX] = {
    {one,   one,    two,    two},
    {three, three,  three,  three},
    {two,   two,    one,    one},
    {burn,  two,    two,    burn},
    {three, three,  three,  three},
    {one,   one,    two,    two}
};

...

rc = pthread_create(&thread[i], NULL, (ttable[slot][cycle]), (void*)i);

如果使用pthread_ctreate，则必须遵循其接口：int pthread_create（pthread_t * restrict tidp，const pthread_attr_t * restrict_attr，void *（* start_rtn）（void *），void * restrict arg）;

希望对您有所帮助！