feat: lab7 done

В задании просят починить файлы, но фактически они даются нам уже рабочими, поэтому мне нужно только разобраться с тем, что происходит внутри

.gitignore

@@ -0,0 +1,55 @@
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf
+
+# debug information files
+*.dwo

OSs/lab3/README.txt

@@ -0,0 +1 @@
+Здесь я не буду оформлять первый уровень, потому что он фактически выглядит как копипаста. Возможно я потом докину его

OSs/lab3/level-2/Makefile

@@ -0,0 +1,12 @@
+targets = main
+all: $(targets)
+
+main: main.o buff.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+%.o: %.c
+	$(CC) -c $^ -o $@ $(CFLAGS)
+
+clean:
+	rm -f $(targets)
+	rm -f *.o

OSs/lab3/level-2/README.txt

@@ -0,0 +1,5 @@
+Во продвинутом уровне задания необходимо было реализовать паттерн producer-consumer. Заводится буффер определенного размера, а также потоки, которые в него что-то кладут и потоки, которые из него что-то берут.
+
+Внутри buff.c сокрыта вся магия по синхронизации буффера, постановке на него предметов и прочего. В main же только создаются потоки. Я решил, что producer будет создавать "ключи", а consumer будет их печатать
+
+Чтобы не решать проблемы с зачисткой буффера в конце, семафоры поставлены на таймаут, по истечении которого поток вылетит

OSs/lab3/level-2/buff.c

@@ -0,0 +1,142 @@
+#include <stdio.h>
+#include <semaphore.h>
+#include <string.h>
+#include <pthread.h>
+#include <errno.h>
+
+#include "buff.h"
+
+#define NBUFF 32
+#define TIMEOUT_SECS    5
+#define TIMEOUT_NSECS   0
+
+#define ARR_SIZE(arr) (sizeof(arr)/sizeof(arr[0]))
+
+static void __zero_msg(struct message *msg)
+{
+    memset(msg->msg, 0, sizeof(msg->msg));
+}
+
+static void __copy_msg(struct message *dest, const struct message *src)
+{
+    memcpy(dest->msg, src->msg, sizeof(src->msg));
+}
+
+static struct {
+    pthread_mutex_t msgs_lock;
+    sem_t nstored;
+    sem_t nempty;
+    struct message msgs[NBUFF];
+    size_t cidx; //< consumer offset
+    size_t pidx; //< producer offset
+} buf = {0};
+
+int buf_init(void)
+{
+    int ret = 0;
+    ret = sem_init(&buf.nstored, 0, 0);
+    if (ret) {
+        ret = -EFAULT;
+        goto error;
+    }
+    ret = sem_init(&buf.nempty, 0, ARR_SIZE(buf.msgs));
+    if (ret) {
+        ret = -EFAULT;
+        goto destroy_nstored;
+    }
+    ret = pthread_mutex_init(&buf.msgs_lock, NULL);
+    if (ret) {
+        goto destroy_nempty;
+    }
+    return 0;
+
+destroy_nempty:
+    sem_destroy(&buf.nempty);
+destroy_nstored:
+    sem_destroy(&buf.nstored);
+error:
+    return ret;
+};
+
+int buf_deinit(void)
+{
+    int ret = 0, tmp_ret;
+    if ((tmp_ret = pthread_mutex_destroy(&buf.msgs_lock))) ret = tmp_ret;
+    if ((tmp_ret = sem_destroy(&buf.nempty))) ret = tmp_ret;
+    if ((tmp_ret = sem_destroy(&buf.nstored))) ret = tmp_ret;
+    return ret;
+}
+
+#define __buf_wrap_idx(idx) (idx % ARR_SIZE(buf.msgs))
+#define __buf_consume_ptr (&buf.msgs[__buf_wrap_idx(buf.cidx)])
+#define __buf_produce_ptr (&buf.msgs[__buf_wrap_idx(buf.pidx)])
+
+static int __timeout_to_abs(struct timespec *ts, time_t secs, ssize_t nsec)
+{
+    int ret = timespec_get(ts, TIME_UTC);
+    if (ret != TIME_UTC) return -EFAULT;
+    ts->tv_sec += secs;
+    ts->tv_nsec += nsec;
+    return 0;
+}
+
+static int __sem_timedwait_rel(sem_t *sem, time_t secs, ssize_t nsecs)
+{
+    int ret;
+    struct timespec sem_timeout;
+    ret = __timeout_to_abs(&sem_timeout, secs, nsecs);
+    if (ret) return ret;
+    return sem_timedwait(sem, &sem_timeout);
+}
+
+static int __buf_consume(struct message *dest)
+{
+    int ret = pthread_mutex_lock(&buf.msgs_lock);
+    if (ret) {
+        return -EFAULT;
+    }
+    __copy_msg(dest, __buf_consume_ptr);
+    __zero_msg(__buf_consume_ptr);
+    buf.cidx++;
+    // Осозннано игнорируем ошибки
+    ret = pthread_mutex_unlock(&buf.msgs_lock);
+    return ret;
+}
+
+int buf_consume(struct message *dest)
+{
+    int ret = 0;
+    int semval = 0;
+    ret = __sem_timedwait_rel(&buf.nstored, TIMEOUT_SECS, TIMEOUT_NSECS);
+    if (ret) return ret;
+
+    ret = __buf_consume(dest);
+    if (ret) return ret;
+
+    ret = sem_post(&buf.nempty);
+    return ret;
+}
+
+static int __buf_push(const struct message *src)
+{
+    int ret = pthread_mutex_lock(&buf.msgs_lock);
+    if (ret) {
+        return -EFAULT;
+    }
+    __copy_msg(__buf_produce_ptr, src);
+    buf.pidx++;
+    ret = pthread_mutex_unlock(&buf.msgs_lock);
+    return ret;
+}
+
+int buf_push(const struct message *src)
+{
+    int ret = 0;
+    ret = __sem_timedwait_rel(&buf.nempty, TIMEOUT_SECS, TIMEOUT_NSECS);
+    if (ret) return ret;
+
+    ret = __buf_push(src);
+    if (ret) return ret;
+
+    return sem_post(&buf.nstored);
+}

OSs/lab3/level-2/buff.h

@@ -0,0 +1,16 @@
+#ifndef BUFF_H_
+#define BUFF_H_
+
+#define MSG_MAX_LEN 256
+
+struct message {
+    char msg[MSG_MAX_LEN];
+};
+
+int buf_init(void);
+int buf_deinit(void);
+
+int buf_consume(struct message *dest);
+int buf_push(const struct message *src);
+
+#endif

OSs/lab3/level-2/main.c

@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+#include "buff.h"
+
+#define ERR_PTR ((void *)1)
+#define VOID_CAST(num) ((void *) num)
+
+#define N_PRODUCERS 16
+#define N_CONSUMERS 1
+#define KEY_LEN     32 // len in chars
+
+const char key_syms[] = "abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ"
+                        "1234567890";
+
+#define ALPHABET_SIZE (sizeof(key_syms) - 1)
+
+pthread_t consumers[N_CONSUMERS] = {0};
+pthread_t producers[N_PRODUCERS] = {0};
+
+/**
+ * Создает "ключи" - наборы "случайных" символов из
+ * списка допустимых
+ */
+void get_key(char key_dest[KEY_LEN])
+{
+    for (size_t i = 0; i < KEY_LEN; i++) {
+        size_t sym_idx = rand() % ALPHABET_SIZE;
+        key_dest[i] = key_syms[sym_idx];
+    }
+}
+
+volatile bool run = true;
+
+void *producer_routine(void *arg)
+{
+    size_t pidx = (size_t) arg;
+    struct message msg = {0};
+    while (run) {
+        get_key(msg.msg);
+        if (buf_push(&msg)) pthread_exit(ERR_PTR);
+        printf("[p%lu] pushed new key\n", pidx);
+        sleep(1);
+    }
+    pthread_exit(NULL);
+}
+
+void *consumer_routine(void *arg)
+{
+    size_t cidx = (size_t) arg;
+    struct message msg = {0};
+    while (run) {
+        if (buf_consume(&msg)) pthread_exit(ERR_PTR);
+        printf("[c%lu] obtained key %s\n", cidx, msg.msg);
+        sleep(1);
+    }
+    pthread_exit(NULL);
+}
+
+int main()
+{
+    if (buf_init()) {
+        printf("failed to init work buffer\n");
+        return EXIT_FAILURE;
+    }
+
+    for (size_t i = 0; i < N_PRODUCERS; i++) {
+        if (pthread_create(&producers[i], NULL,
+                           producer_routine, VOID_CAST(i))) {
+            printf("Failed to create enough consumer threads\n");
+            return EXIT_FAILURE;
+        }
+    }
+    for (size_t i = 0; i < N_CONSUMERS; i++) {
+        if (pthread_create(&consumers[i], NULL,
+                           consumer_routine, VOID_CAST(i))) {
+            printf("Failed to create enough consumer threads\n");
+            return EXIT_FAILURE;
+        }
+    }
+
+    sleep(10);
+    run = false;
+
+    void *ret = NULL;
+    for (size_t i = 0; i < N_PRODUCERS; i++) {
+        if (pthread_join(producers[i], &ret)) {
+            printf("failed to join producer");
+            return EXIT_FAILURE;
+        }
+    }
+    for (size_t i = 0; i < N_CONSUMERS; i++) {
+        if (pthread_join(consumers[i], &ret)) {
+            printf("failed to join consumer");
+            return EXIT_FAILURE;
+        }
+    }
+    // не используем разделяемые ресурсы, так что код возврата
+    // можно игнорировать, linux справится
+    buf_deinit();
+    return EXIT_SUCCESS;
+}

OSs/lab5/part-A/Makefile

@@ -0,0 +1,12 @@
+targets = main
+all: $(targets)
+
+main: main.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+%.o: %.c
+	$(CC) -c $^ -o $@ $(CFLAGS)
+
+clean:
+	rm -f $(targets)
+	rm -f *.o

OSs/lab5/part-A/main.c

@@ -0,0 +1,132 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+
+#define PIPE_READ_IDX   0
+#define PIPE_WRITE_IDX  1
+
+int client(int fd_read, int fd_write);
+int server(int fd_read, int fd_write);
+
+#define DO_OR_FAIL(cond) if (cond) return EXIT_FAILURE
+int main()
+{
+    int pipe_to_server[2], pipe_to_client[2];
+    DO_OR_FAIL(pipe(pipe_to_server) < 0);
+    DO_OR_FAIL(pipe(pipe_to_client) < 0);
+
+    pid_t client_pid;
+    if ((client_pid = fork()) == 0) { // server
+        DO_OR_FAIL(close(pipe_to_server[PIPE_WRITE_IDX]));
+        DO_OR_FAIL(close(pipe_to_client[PIPE_READ_IDX]));
+
+        DO_OR_FAIL(
+                server(
+                    pipe_to_server[PIPE_READ_IDX],
+                    pipe_to_client[PIPE_WRITE_IDX]
+                    )
+                );
+    }
+    // client
+    DO_OR_FAIL(close(pipe_to_server[PIPE_READ_IDX]));
+    DO_OR_FAIL(close(pipe_to_client[PIPE_WRITE_IDX]));
+
+    DO_OR_FAIL(
+            client(
+                pipe_to_client[PIPE_READ_IDX],
+                pipe_to_server[PIPE_WRITE_IDX]
+                )
+            );
+
+    return 0;
+}
+
+char *ltrim(char *s)
+{
+    while(isspace(*s)) s++;
+    return s;
+}
+
+char *rtrim(char *s)
+{
+    char* back = s + strlen(s);
+    while(isspace(*--back));
+    *(back+1) = '\0';
+    return s;
+}
+
+char *trim(char *s)
+{
+    return rtrim(ltrim(s)); 
+}
+
+#define BUF_SIZE 256
+
+#define DO_OR_PROPAGATE(call, expected, tmp_var) \
+    if ((tmp_var = (call)) != expected)) return tmp_var
+
+/**
+ * Performs client actions
+ *
+ * @fd_read - pipe to read from
+ * @fd_write - pipe to write t\no
+ * 
+ * returns 0 on success or -errno on fail
+ */
+int client(int fd_read, int fd_write)
+{
+    char buf[BUF_SIZE] = {0};
+    if (!fgets(buf, BUF_SIZE, stdin)) return -EFAULT;
+    const char *s = trim(buf);
+    size_t len = strlen(s);
+    ssize_t n_written = write(fd_write, s, len);
+    if (n_written < 0 || n_written < len) {
+        return -EFAULT;
+    }
+    memset(buf, 0, BUF_SIZE);
+    size_t n;
+    while ((n = read(fd_read, buf, BUF_SIZE)) > 0) {
+        len = strlen(buf);
+        n_written = fwrite(buf, sizeof(buf[0]), strlen(buf), stdout);
+        if (n_written < 0 || n_written < len) {
+            return -EFAULT;
+        }
+        memset(buf, 0, sizeof(buf));
+    }
+    return 0;
+}
+
+/**
+ * Performs server actions
+ *
+ * @fd_read - pipe to read from
+ * @fd_write - pipe to write to
+ *
+ * returns 0 on success or -errno on fail
+ */
+int server(int fd_read, int fd_write)
+{
+    char buf[BUF_SIZE] = {0};
+    size_t n = read(fd_read, buf, BUF_SIZE);
+    if (n == 0) return -EFAULT;
+    FILE *f = fopen(buf, "r");
+    // не 100% правильно, но наиболее вероятно
+    if (f == NULL) {
+        const char error_msg[] = "Can't open requested file\n";
+        write(fd_write, error_msg, sizeof(error_msg));
+        goto epilog;
+    }
+
+    while ((n = fread(buf, sizeof(buf[0]), BUF_SIZE, f)) > 0) {
+        write(fd_write, buf, n);
+        memset(buf, 0, sizeof(buf));
+    }
+
+epilog:
+    fclose(f);
+    return 0;
+}

OSs/lab5/part-B/Makefile

@@ -0,0 +1,15 @@
+targets = server client
+all: $(targets)
+
+server: server.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+client: client.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+%.o: %.c
+	$(CC) -c $^ -o $@ $(CFLAGS)
+
+clean:
+	rm -f $(targets)
+	rm -f *.o

OSs/lab5/part-B/client.c

@@ -0,0 +1,80 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <ctype.h>
+#include <fcntl.h>
+
+#include "common.h"
+
+int client(int fd_read, int fd_write);
+
+int main()
+{
+    int read_fd, write_fd;
+    FAIL_ON((write_fd=open(FIFO_SERVER_PATH, O_WRONLY)) < 0);
+    FAIL_ON((read_fd=open(FIFO_CLIENT_PATH, O_RDONLY)) < 0);
+
+    FAIL_ON(client(read_fd, write_fd));
+
+    FAIL_ON(unlink(FIFO_SERVER_PATH) < 0);
+    printf("unlinked %s\n", FIFO_SERVER_PATH);
+    FAIL_ON(unlink(FIFO_CLIENT_PATH) < 0);
+    printf("unlinked %s\n", FIFO_CLIENT_PATH);
+
+    return EXIT_SUCCESS;
+}
+
+#define BUF_SIZE 256
+
+char *ltrim(char *s)
+{
+    while(isspace(*s)) s++;
+    return s;
+}
+
+char *rtrim(char *s)
+{
+    char* back = s + strlen(s);
+    while(isspace(*--back));
+    *(back+1) = '\0';
+    return s;
+}
+
+char *trim(char *s)
+{
+    return rtrim(ltrim(s)); 
+}
+
+/**
+ * Performs client actions
+ *
+ * @fd_read - pipe to read from
+ * @fd_write - pipe to write t\no
+ * 
+ * returns 0 on success or -errno on fail
+ */
+int client(int fd_read, int fd_write)
+{
+    char buf[BUF_SIZE] = {0};
+    if (!fgets(buf, BUF_SIZE, stdin)) return -EFAULT;
+    const char *s = trim(buf);
+    size_t len = strlen(s);
+    ssize_t n_written = write(fd_write, s, len);
+    if (n_written < 0 || n_written < len) {
+        return -EFAULT;
+    }
+    memset(buf, 0, BUF_SIZE);
+    size_t n;
+    struct custom_ds ds;
+    while ((n = recv_msg(fd_read, &ds)) > 0) {
+        len = ds.hdr.len;
+        n_written = fwrite(ds.msg, sizeof(ds.msg[0]), len, stdout);
+        if (n_written < 0 || n_written < len) {
+            return -EFAULT;
+        }
+        memset(buf, 0, sizeof(buf));
+    }
+    return 0;
+}

OSs/lab5/part-B/common.h

@@ -0,0 +1,45 @@
+#ifndef COMMON_H_
+#define COMMON_H_
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define FIFO_SERVER_PATH "/tmp/fifo.to_server" // server reads this file
+#define FIFO_CLIENT_PATH "/tmp/fifo.to_client" // client reads this file
+
+#define __DATA_STRUCT_MSG_LEN 4096
+
+enum ds_types {
+    DS_MESSAGE,
+    DS_FAIL
+};
+
+struct custom_ds {
+    struct {
+        long len;
+        long type;
+    } hdr;
+    char msg[__DATA_STRUCT_MSG_LEN];
+};
+
+static inline ssize_t send_msg(int fd, const struct custom_ds *ds)
+{
+    return write(fd, ds, sizeof(ds->hdr) + ds->hdr.len);
+}
+
+static inline ssize_t recv_msg(int fd, struct custom_ds *reciever)
+{
+    size_t n_hdr = read(fd, reciever, sizeof(reciever->hdr));
+    if (n_hdr == 0) return 0; // eof reached
+    if (n_hdr != sizeof(reciever->hdr)) return -ENOMSG;
+    if (reciever->hdr.len == 0) return 0;
+
+    size_t n_payload = read(fd, &reciever->msg, reciever->hdr.len);
+    if (n_payload != reciever->hdr.len) return -EFAULT;
+    return n_hdr + n_payload;
+}
+
+#define FAIL_ON(cond) if (cond) return EXIT_FAILURE
+
+#endif

OSs/lab5/part-B/server.c

@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "common.h"
+
+int server(int fd_read, int fd_write);
+
+int main()
+{
+    FAIL_ON(mknod(FIFO_SERVER_PATH, S_IFIFO | 0666, 0) < 0);
+    printf("created %s\n", FIFO_SERVER_PATH);
+    FAIL_ON(mknod(FIFO_CLIENT_PATH, S_IFIFO | 0666, 0) < 0);
+    printf("created %s\n", FIFO_CLIENT_PATH);
+
+    int read_fd, write_fd;
+    FAIL_ON((read_fd=open(FIFO_SERVER_PATH, O_RDONLY)) < 0);
+    FAIL_ON((write_fd=open(FIFO_CLIENT_PATH, O_WRONLY)) < 0);
+
+    return server(read_fd, write_fd);
+}
+
+#define BUF_SIZE 256
+
+/**
+ * Performs server actions
+ *
+ * @fd_read - pipe to read from
+ * @fd_write - pipe to write to
+ *
+ * returns 0 on success or -errno on fail
+ */
+int server(int fd_read, int fd_write)
+{
+    char buf[BUF_SIZE] = {0};
+    size_t n = read(fd_read, buf, BUF_SIZE);
+    if (n == 0) return -EFAULT;
+    FILE *f = fopen(buf, "r");
+    // не 100% правильно, но наиболее вероятно
+    if (f == NULL) {
+        const char error_msg[] = "Can't open requested file\n";
+        struct custom_ds payload = {
+            .hdr.len = sizeof(error_msg),
+            .hdr.type = DS_FAIL,
+        };
+        strncpy(payload.msg, error_msg, sizeof(error_msg));
+        send_msg(fd_write, &payload);
+        goto epilog;
+    }
+
+    while ((n = fread(buf, sizeof(buf[0]), BUF_SIZE, f)) > 0) {
+        struct custom_ds payload = {
+            .hdr.len = n,
+            .hdr.type = DS_MESSAGE,
+        };
+        strncpy(payload.msg, buf, n);
+        send_msg(fd_write, &payload);
+        memset(buf, 0, sizeof(buf));
+    }
+
+epilog:
+    fclose(f);
+    return 0;
+}

OSs/lab6/Makefile

@@ -0,0 +1,15 @@
+targets = server_msg client_msg
+all: $(targets)
+
+server_msg: server_msg.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+client_msg: client_msg.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+%.o: %.c
+	$(CC) -c $^ -o $@ $(CFLAGS)
+
+clean:
+	rm -f $(targets)
+	rm -f *.o

OSs/lab6/client_msg.c

@@ -0,0 +1,92 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/msg.h>
+
+#include "common.h"
+
+void client(int readid, int writeid);
+ssize_t mesg_send(int id, struct msg *mptr);
+ssize_t mesg_recv(int id, struct msg *mptr);
+
+int main(int argc,char **argv)
+{
+    int readid, writeid;
+
+    if((writeid=msgget(MQ_KEY1,0666)) < 0)
+    {
+        printf("Client: can not get writeid!\n");
+        exit(1);
+    }
+    printf("Client:writeid=%d\n",writeid);
+
+    if((readid=msgget(MQ_KEY2,0666)) < 0)
+    {
+        printf("Client: can not get readid!\n");
+        exit(1);
+    }
+    printf("Client: readid=%d\n",readid);
+
+    client(readid,writeid);
+
+    if((msgctl(readid,IPC_RMID, NULL)) < 0)
+    {
+        printf("Client: can not delete massage queue2!\n"); exit(1);
+    }
+
+    if((msgctl(writeid,IPC_RMID, NULL)) < 0)
+    {
+        printf("Client: can not delete massage queue1!\n"); exit(1);
+    }
+
+    exit(0);
+}
+
+void client(int readid, int writeid)
+{
+    size_t len;
+    ssize_t n;
+    struct msg ourmesg;
+
+    printf("Client:readid=%d writeid=%d\n",readid,writeid);
+    printf("Input file name, please\n");
+
+    fgets(ourmesg.mesg_data,MAXMESGDATA, stdin);
+    len=strlen(ourmesg.mesg_data);
+
+    if(ourmesg.mesg_data[len-1]=='\n') len--;
+    ourmesg.mesg_len=len;
+
+    ourmesg.mesg_type=1;
+
+    printf("Client: %s\n",ourmesg.mesg_data);
+
+    mesg_send(writeid,&ourmesg);
+
+    printf("Client: tvk before recv!\n");
+
+    while((n= mesg_recv(readid, &ourmesg))>0)
+        //n= mesg_recv(readid, &ourmesg);
+        write(1,ourmesg.mesg_data, n);
+}
+
+ssize_t mesg_send(int id, struct msg *mptr)
+{
+    return(msgsnd(id, &(mptr->mesg_type),mptr->mesg_len, 0));
+}
+
+ssize_t mesg_recv(int id, struct msg *mptr)
+{
+    ssize_t n;
+
+    n=msgrcv(id, &(mptr->mesg_type),MAXMESGDATA,mptr->mesg_type, 0);
+    mptr->mesg_len=n;
+    printf("Client: n=%ld\n",n);
+
+    return(n);	
+}
+

OSs/lab6/common.h

@@ -0,0 +1,14 @@
+#ifndef COMMON_H_
+#define COMMON_H_
+
+#define MQ_KEY1 1234L
+#define MQ_KEY2 2345L
+#define MAXMESGDATA 4096
+
+struct msg {
+    long mesg_len;
+    long mesg_type;
+    char mesg_data[MAXMESGDATA];
+};
+
+#endif

OSs/lab6/server_msg.c

@@ -0,0 +1,95 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/msg.h>
+
+#include "common.h"
+
+void server(int readid, int writeid);
+ssize_t mesg_send(int id, struct msg *mptr);
+ssize_t mesg_recv(int id, struct msg *mptr);
+
+int main(int argc,char **argv)
+{
+    int readid, writeid;
+    key_t key1,key2;
+
+    printf("Server: Hello tvk!\n");
+
+    if((readid=msgget(MQ_KEY1, 0666|IPC_CREAT)) < 0)
+    {
+        printf("Server: can not get readid!\n"); exit(1);
+    }
+    printf("Server: readid=%d\n",readid);
+    if((writeid=msgget(MQ_KEY2, 0666|IPC_CREAT)) < 0)
+    {
+        printf("Server: can not get readid!\n"); exit(1);
+    }
+    printf("Server: writeid=%d\n",writeid);
+
+    server(readid,writeid);
+
+    exit(0);
+}
+
+void server(int readid, int writeid)
+{
+    FILE *fp;
+    ssize_t n;
+    struct msg ourmesg;
+
+    printf("Server:readid=%d writeid=%d\n",readid,writeid);
+
+    ourmesg.mesg_type=1;
+
+    if( (n=mesg_recv(readid, &ourmesg)) == 0)
+    {
+        printf("Server: can not read file name\n");
+        exit(1);	
+    }
+    ourmesg.mesg_data[n]='\0';
+
+    printf("Server: file name %s\n",ourmesg.mesg_data);
+
+    if( (fp=fopen(ourmesg.mesg_data,"r"))==NULL)
+    {
+        printf("Server: can not open file name\n");
+
+    }
+    else
+    {
+        printf("Server: %s is opened\n",ourmesg.mesg_data);
+
+        while(fgets(ourmesg.mesg_data, MAXMESGDATA,fp) != NULL)
+        { 
+            ourmesg.mesg_len=strlen(ourmesg.mesg_data);
+            printf("Server: %s\n",ourmesg.mesg_data);
+            mesg_send(writeid,&ourmesg);
+        }
+    }
+    fclose(fp);
+    ourmesg.mesg_len=0;
+    mesg_send(writeid,&ourmesg);
+}
+
+ssize_t mesg_send(int id, struct msg *mptr)
+{
+    return(msgsnd(id, &(mptr->mesg_type),mptr->mesg_len, 0));	
+}
+
+ssize_t mesg_recv(int id, struct msg *mptr)
+{
+    ssize_t n;
+    n=msgrcv(id, &(mptr->mesg_type),MAXMESGDATA,mptr->mesg_type, 0);
+    mptr->mesg_len=n;
+
+    return(n);	
+}
+
+
+
+

OSs/lab7/Makefile

@@ -0,0 +1,15 @@
+targets = server client
+all: $(targets)
+
+server: server.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+client: client.o
+	$(CC) -o $@ $^ $(CFLAGS)
+
+%.o: %.c
+	$(CC) -c $^ -o $@ $(CFLAGS)
+
+clean:
+	rm -f $(targets)
+	rm -f *.o

OSs/lab7/client.c

@@ -0,0 +1,65 @@
+#include "common.h"
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define FAIL_TO_CLEANUP(cond, jmp_to)   \
+    if (cond) {                         \
+        perror(#cond);                  \
+        ret = EXIT_FAILURE;             \
+        goto jmp_to;                    \
+    }
+
+int main(void) {
+    int ret = 0;
+    int shm_fd = -1;
+    void *shm_ptr = MAP_FAILED;
+    sem_t *sem_c2s = SEM_FAILED;
+    sem_t *sem_s2c = SEM_FAILED;
+
+    FAIL_TO_CLEANUP((shm_fd = shm_open(SHM_NAME, O_RDWR, 0)) == -1, exit);
+    FAIL_TO_CLEANUP(
+            (shm_ptr = mmap(NULL, SHM_SIZE,
+                            PROT_READ | PROT_WRITE,
+                            MAP_SHARED, shm_fd, 0)) == MAP_FAILED,
+            unmap_shared_mem);
+
+    FAIL_TO_CLEANUP((sem_c2s = sem_open(SEM_C2S_NAME, 0)) == SEM_FAILED,
+                    close_sem_c2s);
+    FAIL_TO_CLEANUP((sem_s2c = sem_open(SEM_S2C_NAME, 0)) == SEM_FAILED,
+                    close_sem_s2c);
+
+    char filename[SHM_SIZE];
+    FAIL_TO_CLEANUP(fgets(filename, sizeof(filename), stdin) == NULL, close_sem_s2c);
+
+    size_t ln = strlen(filename);
+    if (ln > 0 && filename[ln - 1] == '\n')
+        filename[ln - 1] = '\0';
+
+    memset(shm_ptr, 0, SHM_SIZE);
+    strncpy((char *)shm_ptr, filename, SHM_SIZE - 1);
+
+    FAIL_TO_CLEANUP(sem_post(sem_c2s) == -1, close_sem_s2c);
+
+    FAIL_TO_CLEANUP(sem_wait(sem_s2c) == -1, close_sem_s2c);
+
+    size_t len = strnlen((char *)shm_ptr, SHM_SIZE);
+    FAIL_TO_CLEANUP(fwrite(shm_ptr, sizeof(char), len, stdout) != len, close_sem_s2c);
+    fflush(stdout); // don't really care if fails
+
+close_sem_s2c:
+    sem_close(sem_s2c);
+close_sem_c2s:
+    sem_close(sem_c2s);
+unmap_shared_mem:
+    munmap(shm_ptr, SHM_SIZE);
+close_shared_fd:
+    close(shm_fd);
+exit:
+    return ret;
+}

OSs/lab7/common.h

@@ -0,0 +1,12 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+#define SHM_NAME "/lab7_shm"
+#define SEM_C2S_NAME "/sem_c2s_lab7"
+#define SEM_S2C_NAME "/sem_s2c_lab7"
+#define SHM_SIZE (64 * 1024)
+
+#define FAIL_ON(cond) if (cond) return EXIT_FAILURE
+
+#endif /* COMMON_H */
+

OSs/lab7/server.c

@@ -0,0 +1,136 @@
+#include <fcntl.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "common.h"
+
+#define FAIL_TO_CLEANUP(cond, jmp_to)   \
+    if (cond) {                         \
+        perror(#cond);                  \
+        ret = EXIT_FAILURE;             \
+        goto jmp_to;                    \
+    }
+
+int main(void) {
+    int ret;
+    int shm_fd = -1;
+    void *shm_ptr = MAP_FAILED;
+    sem_t *sem_c2s = SEM_FAILED;
+    sem_t *sem_s2c = SEM_FAILED;
+
+    /* Create or open shared memory */
+    FAIL_TO_CLEANUP((shm_fd = shm_open(SHM_NAME, O_CREAT | O_RDWR, 0600)), cleanup);
+    if (shm_fd == -1) {
+        perror("shm_open");
+        goto cleanup;
+    }
+    if (ftruncate(shm_fd, SHM_SIZE) == -1) {
+        perror("ftruncate");
+        goto cleanup;
+    }
+
+    shm_ptr = mmap(NULL, SHM_SIZE, PROT_READ | PROT_WRITE,
+            MAP_SHARED, shm_fd, 0);
+    if (shm_ptr == MAP_FAILED) {
+        perror("mmap");
+        goto cleanup;
+    }
+
+    /* Create semaphores (initialize to 0) */
+    sem_c2s = sem_open(SEM_C2S_NAME, O_CREAT, 0600, 0);
+    if (sem_c2s == SEM_FAILED) {
+        perror("sem_open c2s");
+        goto cleanup;
+    }
+    sem_s2c = sem_open(SEM_S2C_NAME, O_CREAT, 0600, 0);
+    if (sem_s2c == SEM_FAILED) {
+        perror("sem_open s2c");
+        goto cleanup;
+    }
+
+    printf("Server: waiting for client...\n");
+
+    while (1) {
+        /* Wait for client to write filename */
+        if (sem_wait(sem_c2s) == -1) {
+            perror("sem_wait c2s");
+            break;
+        }
+
+        /* Read filename from shared memory (ensure NUL) */
+        char filename[SHM_SIZE];
+        memset(filename, 0, sizeof(filename));
+        memcpy(filename, shm_ptr, sizeof(filename) - 1);
+
+        /* If client sent special "EXIT" filename, break loop and cleanup */
+        if (strcmp(filename, "EXIT") == 0) {
+            /* Notify client and exit */
+            const char *msg = "Server shutting down.";
+            size_t len = strlen(msg) + 1;
+            if (len > SHM_SIZE)
+                len = SHM_SIZE;
+            memcpy(shm_ptr, msg, len);
+            sem_post(sem_s2c);
+            break;
+        }
+
+        /* Try open file */
+        FILE *f = fopen(filename, "rb");
+        if (!f) {
+            char errbuf[SHM_SIZE];
+            snprintf(errbuf, sizeof(errbuf), "Error opening file '%s'\n", filename);
+            size_t len = strlen(errbuf) + 1;
+            if (len > SHM_SIZE)
+                len = SHM_SIZE;
+            memcpy(shm_ptr, errbuf, len);
+            sem_post(sem_s2c);
+            continue;
+        }
+
+        /* Read file content and write to shared memory (truncate if too large) */
+        size_t total = 0;
+        while (!feof(f) && total < SHM_SIZE - 1) {
+            size_t toread = SHM_SIZE - 1 - total;
+            size_t r = fread((char *)shm_ptr + total, 1, toread, f);
+            total += r;
+            if (r == 0)
+                break;
+        }
+        ((char *)shm_ptr)[total] = '\0'; /* ensure NUL */
+
+        if (!feof(f) && total == SHM_SIZE - 1) {
+            /* truncated */
+            const char *note =
+                "\n[Output truncated: file larger than shared memory]\n";
+            size_t note_len = strlen(note);
+            if (note_len + 1 < SHM_SIZE) {
+                size_t copy_pos = SHM_SIZE - 1 - note_len;
+                memcpy((char *)shm_ptr + copy_pos, note, note_len);
+                ((char *)shm_ptr)[SHM_SIZE - 1] = '\0';
+            }
+        }
+
+        fclose(f);
+
+        /* Signal client that data is ready */
+        if (sem_post(sem_s2c) == -1) {
+            perror("sem_post s2c");
+            break;
+        }
+    }
+
+cleanup:
+    if (sem_c2s != SEM_FAILED)
+        sem_close(sem_c2s);
+    if (sem_s2c != SEM_FAILED)
+        sem_close(sem_s2c);
+    if (shm_ptr != MAP_FAILED) munmap(shm_ptr, SHM_SIZE); if (shm_fd != -1)
+        close(shm_fd);
+
+    return 0;
+}