如何解决不知道为什么会发生这个问题，也无法解决这个问题谁能解决这个问题？
这是生产消费者问题的示例代码。 在第 58,86,116,166,194 行中，在函数‘void* Producer1(void*)’中出错：从‘void*’到‘int’的转换失去了精度 [-fpermissive]。 仍然不知道为什么会发生此错误，也无法找出解决方案。
我使用 Ubuntu 作为操作系统和 g++ -pthread 库函数来解决这个问题。 代码在这里：
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include<semaphore.h>
//#include </usr/include/semaphore.h>
// for sleep
#include <unistd.h>
#define BUFF_SIZE 5 /* total number of slots */
typedef struct //Producing queue
{
char buf1[BUFF_SIZE]; /* shared var */
int in1; /* buf[in%BUFF_SIZE] is the first empty slot */
int out1; /* buf[out%BUFF_SIZE] is the first full slot */
sem_t full; /* keep track of the number of full spots */
sem_t empty; /* keep track of the number of empty spots */
// use correct type here
pthread_mutex_t mutex; /* enforce mutual exclusion to shared data */
} sbuf_t1;
typedef struct //Chokolate Cake queue
{
char buf2[BUFF_SIZE]; /* shared var */
int in2; /* buf[in%BUFF_SIZE] is the first empty slot */
int out2; /* buf[out%BUFF_SIZE] is the first full slot */
sem_t full; /* keep track of the number of full spots */
sem_t empty; /* keep track of the number of empty spots */
// use correct type here
pthread_mutex_t mutex; /* enforce mutual exclusion to shared data */
} sbuf_t2;
typedef struct //Vanilla Cake queue
{
char buf3[BUFF_SIZE]; /* shared var */
int in3; /* buf[in%BUFF_SIZE] is the first empty slot */
int out3; /* buf[out%BUFF_SIZE] is the first full slot */
sem_t full; /* keep track of the number of full spots */
sem_t empty; /* keep track of the number of empty spots */
// use correct type here
pthread_mutex_t mutex; /* enforce mutual exclusion to shared data */
} sbuf_t3;
sbuf_t1 shared1;
sbuf_t2 shared2;
sbuf_t3 shared3;
void *Producer1(void *arg)
{
int i,index;
char item;
index = (int)arg;
for(i=0; i<10; ++i)
{
sem_wait(&shared1.empty); //down called in this line
pthread_mutex_lock(&shared1.mutex); //acquired mutex lock Now it can produced no contex will be switched
sleep(1);
shared1.buf1[shared1.in1] = 'C'; //item pusch in buffer like item[in] = item;
shared1.in1 = (shared1.in1+1)%BUFF_SIZE; //queue operation q = (in + 1) % buff_size
printf("[P%d] Producing Chokolate Cake...\n",index);
fflush(stdout);
/* Release the buffer */
pthread_mutex_unlock(&shared1.mutex); // unclock the mutex
/* Increment the number of full slots */
sem_post(&shared1.full); //buffer is full
//if (i % 2 == 1) sleep(1);
}
return NULL;
}
void *Producer2(void *arg)
{
int i,index;
char item;
index = (int)arg;
for(i=0; i<10; ++i)
{
item = i;
sem_wait(&shared1.empty);
pthread_mutex_lock(&shared1.mutex);
sleep(1);
shared1.buf1[shared1.in1] = 'V';
shared1.in1 = (shared1.in1+1)%BUFF_SIZE;
printf("[P%d] Producing Vanilla Cake...\n",index);
fflush(stdout);
/* Release the buffer */
pthread_mutex_unlock(&shared1.mutex);
/* Increment the number of full slots */
sem_post(&shared1.full);
//if (i % 2 == 1) sleep(1);
}
return NULL;
}
void *Chef_Z(void *arg)
{
int i,index;
char item;
index = (int)arg;
for (i=10; i > 0; i--) {
sem_wait(&shared1.full);
pthread_mutex_lock(&shared1.mutex);
sleep(1);
item=shared1.buf1[shared1.out1];
if(item == 'C') // Chokolate Cake queue
{
sem_wait(&shared2.full);
pthread_mutex_lock(&shared2.mutex);
shared2.buf2[shared2.in2]=item;
shared2.in2 = (shared2.in2+1)%BUFF_SIZE;
printf("[C_Z] Consuming Chokolate Cake and stored it in Chokolate queue ...\n");
pthread_mutex_unlock(&shared2.mutex);
/* Increment the number of full slots */
sem_post(&shared2.empty);
}
else if(item == 'V') // Vanilla Cake queue
{
sem_wait(&shared3.full);
pthread_mutex_lock(&shared3.mutex);
shared3.buf3[shared3.in3]=item;
shared3.in3 = (shared3.in3+1)%BUFF_SIZE;
printf("[C_Z] Consuming Vanilla Cake and stored it in Vanilla queue ...\n");
pthread_mutex_unlock(&shared3.mutex);
/* Increment the number of full slots */
sem_post(&shared3.empty);
}
shared1.out1 = (shared1.out1+1)%BUFF_SIZE;
fflush(stdout);
/* Release the buffer */
pthread_mutex_unlock(&shared1.mutex);
/* Increment the number of full slots */
sem_post(&shared1.empty);
/* Interleave producer and consumer execution */
//if (i % 2 == 1) sleep(1);
}
return NULL;
}
void *Waiter1(void *arg) //Chokolate cake waiter
{
int i,index;
char item;
index = (int)arg;
for (i=10; i > 0; i--) {
sem_wait(&shared2.full);
pthread_mutex_lock(&shared2.mutex);
sleep(1);
item=shared2.buf2[shared2.out2];
shared2.out2 = (shared2.out2+1)%BUFF_SIZE;
printf("[W%d] Consuming Chokolate Cake ...\n",index);
fflush(stdout);
/* Release the buffer */
pthread_mutex_unlock(&shared2.mutex);
/* Increment the number of full slots */
sem_post(&shared2.empty);
/* Interleave producer and consumer execution */
//if (i % 2 == 1) sleep(1);
}
return NULL;
}
void *Waiter2(void *arg) // Vanilla cake waiter
{
int i,index;
char item;
index = (int)arg;
for (i=10; i > 0; i--) {
sem_wait(&shared3.full);
pthread_mutex_lock(&shared3.mutex);
sleep(1);
item=shared3.buf3[shared3.out3];
shared3.out3 = (shared3.out3+1)%BUFF_SIZE;
printf("[W%d] Consuming Vanilla Cake ...\n",index);
fflush(stdout);
/* Release the buffer */
pthread_mutex_unlock(&shared3.mutex);
/* Increment the number of full slots */
sem_post(&shared3.empty);
/* Interleave producer and consumer execution */
//if (i % 2 == 1) sleep(1);
}
return NULL;
}
int main()
{
//pthread_t idP,idC;
pthread_t thread1,thread2,thread3,thread4,thread5;
int index;
void *producer1End;
void *producer2End;
void *chef_zEnd;
void *waiter1End;
void *waiter2End;
sem_init(&shared1.full,0);
sem_init(&shared1.empty,BUFF_SIZE);
pthread_mutex_init(&shared1.mutex,NULL);
sem_init(&shared2.full,0);
sem_init(&shared2.empty,BUFF_SIZE);
pthread_mutex_init(&shared2.mutex,NULL);
sem_init(&shared3.full,0);
sem_init(&shared3.empty,BUFF_SIZE);
pthread_mutex_init(&shared3.mutex,NULL);
pthread_create(&thread1,NULL,Producer1,(void*)1 );
pthread_create(&thread2,Producer2,(void*)2 );
pthread_create(&thread3,Chef_Z,(void*)1 );
pthread_create(&thread4,Waiter1,(void*)1);
pthread_create(&thread5,Waiter2,(void*)2);
pthread_join(thread1,&producer1End);
pthread_join(thread2,&producer2End);
pthread_join(thread3,&chef_zEnd);
pthread_join(thread4,&waiter1End);
pthread_join(thread5,&waiter2End);
pthread_exit(NULL);
}
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