我整天都在研究这个程序，但我无法解决问题。我已经在互联网上搜索了足够的答案，但我不确定我做错了什么。我已经尝试了我能想到的所有内容，以便从我的代码中获取这些错误。我只需要让程序运行！
我为非常凌乱的代码道歉。 C / C ++真的不是我的强项。
以下是我尝试运行时遇到的错误列表：
hotel.c: In function ‘int main(int, char**)’:
hotel.c:228:53: error: invalid conversion from ‘void* (*)()’ to ‘void* (*)(void*)’ [-fpermissive]
pthread_create(&receptionIn, NULL, Checkin, NULL);
In file included from hotel.c:1:0:
/usr/include/pthread.h:244:12: error: initializing argument 3 of ‘int pthread_create(pthread_t*, const pthread_attr_t*, void* (*)(void*), void*)’ [-fpermissive]
extern int pthread_create (pthread_t *__restrict __newthread,
hotel.c:229:55: error: invalid conversion from ‘void* (*)()’ to ‘void* (*)(void*)’ [-fpermissive]
pthread_create(&receptionOut, NULL, Checkout, NULL);
In file included from hotel.c:1:0:
/usr/include/pthread.h:244:12: error: initializing argument 3 of ‘int pthread_create(pthread_t*, const pthread_attr_t*, void* (*)(void*), void*)’ [-fpermissive]
extern int pthread_create (pthread_t *__restrict __newthread,
hotel.c:233:19: error: request for member ‘guest_id’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
guests[t].guest_id = t;
hotel.c:234:19: error: request for member ‘room’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
guests[t].room = 0;
hotel.c:235:19: error: request for member ‘guestCheckIn’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
guests[t].guestCheckIn = 0;
hotel.c:236:19: error: request for member ‘guestCheckOut’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
guests[t].guestCheckOut = 0;
hotel.c:237:28: error: request for member ‘hasRoom’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
sem_init(guests[t].hasRoom, 0, 0);
hotel.c:238:28: error: request for member ‘checkedOut’ in ‘guests[t]’, which is of non-class type ‘pthread_t {aka long unsigned int}’
sem_init(guests[t].checkedOut, 0, 0);
第233-238行的错误似乎与他们相关的错误有关，但我无法弄清楚造成这些错误的原因。我试图将格式更改为...
来宾[t] - ＆gt; guest_id = t;
...但我得到了不同的错误。
我在这里寻找一个有用的答案，但我找不到足以解释它的答案。
请帮忙！
#include <pthread.h>
#include <semaphore.h>
#include <stdio.h>
#include <stdlib.h>
// Structure for tracking the status of a guest.
struct guest
{
// Variable for tracking which guest/thread this is.
int guest_id;
// Variable for tracking which room a guest is assigned.
int room;
// Variable for determining if a guest is ready to check in.
int guestCheckIn;
// Variable for determining if a guest is ready to check out.
int guestCheckOut;
// Semaphore for keeping track of whether the guest has a room.
sem_t hasRoom;
// Semaphore for keeping track of whether the guest is still at the hotel.
sem_t checkedOut;
};
struct guest guests[10];
// Array for tracking which rooms are available.
int rooms[5];
// Variable for keeping track of how many times the pool was used.
int poolUse = 0;
// Variable for keeping track of how many times the restaurant was used.
int restaurantUse = 0;
// Variable for keeping track of how many times the fitness center was used.
int fitnessCenterUse = 0;
// Variable for keeping track of how many times the business center was used.
int businessCenterUse = 0;
// Semaphore for tracking if the check-in receptionist is busy.
sem_t checkInBusy;
// Variable for determining if a guest wants to check in.
sem_t readyForCheckIn;
// Semaphore for tracking if the check-out receptionist is busy.
sem_t checkOutBusy;
// Variable for determining if a guest wants to check out.
sem_t readyForCheckOut;
// Semaphore for tracking how many available rooms there are.
sem_t numRooms;
/**
* This procedure
**/
void *Checkin()
{
while(true)
{
// Wait if receptionist is already busy.
sem_wait(&checkInBusy);
// Wait for a guest to be ready to check in.
sem_wait(&readyForCheckIn);
// Variable for storing index of available guest.
int readyGuest = 11;
// Find a guest that is ready for check in.
for(int x = 0; x < 10; x++)
{
if(guests[x].guestCheckIn == 1 && readyGuest > x)
{
readyGuest = x;
}
}
printf("The check-in reservationist greets Guest %d\n", readyGuest);
// Variable for storing the available room.
int available = 0;
// Find the guest an available room.
for(int y = 0; y < 5; y++)
{
if(rooms[y] == 0 && available != 0)
{
available = y;
}
}
// Grant the room to the guest.
printf("Assign room %d to Guest %d\n", available, readyGuest);
guests[readyGuest].room = available;
rooms[available] = readyGuest;
sem_post(&guests[readyGuest].hasRoom);
// Guest is now checked in and no longer needs to be ready to do so.
guests[readyGuest].guestCheckIn = 0;
// Increment the corresponding semaphore to indicate that check-in is no longer busy.
sem_post(&checkInBusy);
}
}
/**
*
**/
void *Checkout()
{
while(true)
{
// Wait if receptionist is already busy.
sem_wait(&checkOutBusy);
// Wait for a guest to be ready to check out.
sem_wait(&readyForCheckOut);
// Variable for storing index of available guest.
int readyGuest = 11;
// Find a guest that is ready for check out.
for(int x = 0; x < 10; x++)
{
if(guests[x].guestCheckOut == 1 && readyGuest > x)
{
readyGuest = x;
}
}
// Free up the room the guest occupied.
rooms[guests[readyGuest].room] = 0;
printf("The check-out greets Guest %d and receives the key from room %d\n", readyGuest, guests[readyGuest].room);
printf("Calculate the balance for Guest %d\n", readyGuest);
printf("Receive $1 from Guest %d and complete the check-out\n", readyGuest);
// Guest is now checked out and no longer needs to be ready to do so.
guests[readyGuest].guestCheckOut = 0;
// Increment the corresponding semaphore to indicate that check-out is no longer busy.
sem_post(&checkOutBusy);
}
}
/**
* A guest will attempt to reserve a room but will wait until there is an available room before approaching the receptionist.
* If a room is available, they will approach the check-in, get a room and then proceed to do their hotel thing. Once
* finished, the guest will go to the check out and return the room key.
**/
void *Guest(void *threadarg)
{
struct guest *guest_data;
// Wait if there are no available rooms.
sem_wait(&numRooms);
// Declare guest is ready to be checked in and increment the corresponding semaphore.
printf("Guest %d waits for check-in...", guest_data->guest_id);
guest_data->guestCheckIn = 1;
sem_post(&readyForCheckIn);
// Wait until a room is assigned.
sem_wait(&guest_data->hasRoom);
printf("Guest %d receives Room %d and completes check in\n", guest_data->guest_id, guest_data->room);
// Guest goes to do hotel stuff!
// Generate a random number between 0-3.
int r = rand() % 4;
// Go to pool!
if(r == 0)
{
printf("Go to hotel swimming pool\n");
poolUse++;
}
// Go to restaurant!
if(r == 1)
{
printf("Go to hotel restaurant\n");
restaurantUse++;
}
// Go to fitness center!
if(r == 2)
{
printf("Go to hotel fitness center\n");
fitnessCenterUse++;
}
// Go to business center!
if(r == 4)
{
printf("Go to hotel business center\n");
businessCenterUse++;
}
// Declare a guest is ready to be checked out and increment the corresponding semaphore.
guest_data->guestCheckOut = 1;
sem_post(&readyForCheckOut);
// Wait until a guest is completely checked out.
sem_wait(&guest_data->checkedOut);
printf("Guest %d receives the total balance of $1\n", guest_data->guest_id);
printf("Guest %d makes a payment\n", guest_data->guest_id);
}
/**
* The main procedure creates the threads for the
**/
int main(int argc, char *argv[])
{
pthread_t guests[10];
pthread_t receptionIn;
pthread_t receptionOut;
sem_init(&checkInBusy, 0, 1);
sem_init(&readyForCheckIn, 0, 0);
sem_init(&checkOutBusy, 0, 1);
sem_init(&readyForCheckOut, 0, 0);
sem_init(&numRooms, 0, 5);
pthread_create(&receptionIn, NULL, Checkin, NULL);
pthread_create(&receptionOut, NULL, Checkout, NULL);
for(int t = 0; t < 10; t++)
{
guests[t].guest_id = t;
guests[t].room = 0;
guests[t].guestCheckIn = 0;
guests[t].guestCheckOut = 0;
sem_init(guests[t].hasRoom, 0, 0);
sem_init(guests[t].checkedOut, 0, 0);
pthread_create(&guests[t], NULL, Guest, (void *) &guests[t]);
}
}
答案 0 :(得分：3)
Checkin和Checkout的签名不适合用作pthread的线程函数。使用正确的类型。即函数有一个void*参数。pthread_t guests[10];中的局部变量main()正在影响全局变量struct guest guests[10];。重命名局部变量以避免冲突。答案 1 :(得分：0)
您的receptionIn()和receptionOut()函数不带参数：
void *Checkin()
void *Checkout()
将它们传递给pthread_create()。
pthread_create(&receptionIn, NULL, Checkin, NULL);
pthread_create(&receptionOut, NULL, Checkout, NULL);
您需要做的是查看pthread_create（）函数的文档，以及它所采用的函数指针类型。它没有指向没有任何参数的函数的指针。