現在我正在處理我的項目,並且有關於信號量初始化的問題。其實我在Mac OS X上編程,但我試圖在Linux上編譯我的項目,但它不能編譯。在OS X上編譯,但每次在初始化時崩潰。使用信號量的一些問題
sem_t *mutex_1, *mutex_2, *mutex_3, *reader, *writer;
int initialization_semaphores (void)
{
int ERROR = EOK;
if ((mutex_1 = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, 0, 0)) == MAP_FAILED)
ERROR = ESEM;
if ((mutex_2 = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, 0, 0)) == MAP_FAILED)
ERROR = ESEM;
if ((mutex_3 = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, 0, 0)) == MAP_FAILED)
ERROR = ESEM;
if ((reader = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, 0, 0)) == MAP_FAILED)
ERROR = ESEM;
if ((writer = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, 0, 0)) == MAP_FAILED)
ERROR = ESEM;
if (ERROR == EOK) {
if (sem_init(mutex_1, 1, 1) == -1)
ERROR = ESEM;
if (sem_init(mutex_2, 1, 1) == -1)
ERROR = ESEM;
if (sem_init(mutex_3, 1, 1) == -1)
ERROR = ESEM;
if (sem_init(reader, 1, 1) == -1)
ERROR = ESEM;
if (sem_init(writer, 1, 1) == -1)
ERROR = ESEM;
}
}
當我試圖編譯它在Linux上我看到這一點:
/tmp/ccmkN9G7.o: In function `initialization_semaphores':
readerWriter.c:(.text+0x1a2): undefined reference to `sem_init'
readerWriter.c:(.text+0x1cb): undefined reference to `sem_init'
readerWriter.c:(.text+0x1f4): undefined reference to `sem_init'
readerWriter.c:(.text+0x21d): undefined reference to `sem_init'
readerWriter.c:(.text+0x246): undefined reference to `sem_init'
readerWriter.c:(.text+0x275): undefined reference to `shm_open'
是不是? :
int ERROR = EOK;
mutex_1 = sem_open("mutex1", O_CREAT, S_IRUSR | S_IWUSR, 1);
mutex_2 = sem_open("mutex2", O_CREAT, S_IRUSR | S_IWUSR, 1);
mutex_3 = sem_open("mutex3", O_CREAT, S_IRUSR | S_IWUSR, 1);
reader = sem_open("reader", O_CREAT, S_IRUSR | S_IWUSR, 1);
writer = sem_open("writer", O_CREAT, S_IRUSR | S_IWUSR, 1);
我注意到你不會從你的函數返回一個值,即使它被聲明爲返回一個'int'。這應該提出警告 - 是否提出了可能有用的其他警告? (儘管R ..總是正確的,但在錯誤或警告中仍可能有些啓發。) – sarnold
順便說一句,錯誤和警告幾乎不可能在評論中讀取;編輯帖子可能會更好。 :) – sarnold
我返回了一個函數的值形式,實際上我並沒有在這裏粘貼我所有的函數。 – nikigx2