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我正在閱讀AS TANENBAUM的Modern Operation Systems一書，它給出了一個解釋條件變量的例子，如下所示。它看起來有一個僵局，不知道我想念什麼。互斥體中的死鎖，條件變量代碼？
讓我們假設消費者線程首先啓動。 後面緊接着the_mutex被鎖定，消費者線程被阻塞等待條件變量，condc。
如果生產此時運行，the_mutex仍然會被鎖定，因爲消費者永遠不會釋放它。所以製片人也將被封鎖。
這看起來對我來說是一本教科書上的死鎖問題。我在這裏錯過了什麼嗎？ THX
#include <stdio.h>
#include <pthread.h>
#define MAX 10000000000 /* Numbers to produce */
pthread_mutex_t the_mutex;
pthread_cond_t condc, condp;
int buffer = 0;
void* consumer(void *ptr) {
int i;
for (i = 1; i <= MAX; i++) {
pthread_mutex_lock(&the_mutex); /* lock mutex */
/*thread is blocked waiting for condc */
while (buffer == 0) pthread_cond_wait(&condc, &the_mutex);
buffer = 0;
pthread_cond_signal(&condp);
pthread_mutex_unlock(&the_mutex);
}
pthread_exit(0);
}
void* producer(void *ptr) {
int i;
for (i = 1; i <= MAX; i++) {
pthread_mutex_lock(&the_mutex); /* Lock mutex */
while (buffer != 0) pthread_cond_wait(&condp, &the_mutex);
buffer = i;
pthread_cond_signal(&condc);
pthread_mutex_unlock(&the_mutex);
}
pthread_exit(0);
}
int main(int argc, char **argv) {
pthread_t pro, con;
//Simplified main function, ignores init and destroy for simplicity
// Create the threads
pthread_create(&con, NULL, consumer, NULL);
pthread_create(&pro, NULL, producer, NULL);
}