.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/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;
+}