feat: Initial commit

Lab09/es2.c

@@ -0,0 +1,79 @@
+#include <pthread.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#define M_LEN (sizeof(int)+2*sizeof(float))
+
+sem_t *sR;
+sem_t *sC[3];
+sem_t *sM[3];
+float res[3];
+
+int line = 0;
+
+int fin;
+
+void* compute(void* arg) {
+	int id = *((int *) arg);
+	free(arg);
+	int n;
+	float c, x;
+	while(1) {
+		sem_wait(sM[id]);
+		sem_wait(sR);
+		int r = lseek(fin, (line*3+id)*M_LEN, SEEK_SET);
+		if (r == -1) {
+			pthread_exit(NULL);
+		}
+		read(fin, &c, sizeof(float));
+		read(fin, &x, sizeof(float));
+		read(fin, &n, sizeof(int));
+		printf("%d-%d-%d: %f %f %d\n",id,line,r,c,x,n);
+		sem_post(sR);
+
+		res[id] = c;
+		for (int i = 0; i<n;i++)
+			res[id]*=x;
+
+		sem_post(sC[id]);
+	}
+}
+
+void* merge(void* arg) {
+	while (1) {
+		float sum = 0;
+		for (int i = 0; i < 3; i++) {
+			sem_wait(sC[i]);
+			sum += res[i];
+		}
+		printf("%f\n", sum);
+		sleep(3);
+		line++;
+		sem_post(sM[0]);
+		sem_post(sM[1]);
+		sem_post(sM[2]);
+	}
+}
+
+int main(int argc, char ** argv) {
+	pthread_t t;
+	fin = open(argv[1], O_RDONLY);
+	if (fin == NULL) exit(1);
+	sR = malloc(sizeof(sem_t));
+	sem_init(sR,0,1);
+	for (int i = 0; i<3;i++) {
+		int * arg=malloc(sizeof(int));
+		*arg=i;
+		sC[i] = malloc(sizeof(sem_t));
+		sM[i] = malloc(sizeof(sem_t));
+		sem_init(sC[i],0,0);
+		sem_init(sM[i],0,1);
+		pthread_create(&t,NULL,compute,(void *)arg);
+	}
+
+	pthread_create(&t,NULL,merge,NULL);
+	pthread_join(t,NULL);
+	close(fin);
+}