mirror of https://github.com/t1meshift/os_labs.git
Add 9th and 10th labs
parent
9e82285e43
commit
4ad7a6d3ab
GPG Key ID:
B133F3167ABF94D8
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@ -19,3 +19,5 @@ define_lab(lab4)
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define_lab(lab5)
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define_lab(lab5)
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define_lab(lab6)
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define_lab(lab6)
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define_lab(lab7)
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define_lab(lab7)
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define_lab(lab9)
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define_lab(lab10)
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@ -0,0 +1,7 @@
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#!/usr/bin/env bash
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set -euo pipefail
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IFS=$'\n\t'
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echo "TODO!"
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exit 1
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@ -0,0 +1,35 @@
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cmake_minimum_required(VERSION 3.16)
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set(CMAKE_C_STANDARD 11)
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# Lab name
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set(LAB_NAME "lab10")
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# Lab tasks
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list(APPEND SOURCE_FILES
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killer.c
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reader.c
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)
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list(APPEND NON_COMPILABLE_SRC
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.execme
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)
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### Here goes the template
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project("${LAB_NAME}" C)
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add_custom_target("${LAB_NAME}")
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foreach (file IN LISTS SOURCE_FILES)
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add_executable("${LAB_NAME}_${file}_run" "${file}")
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add_dependencies("${LAB_NAME}" "${LAB_NAME}_${file}_run")
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endforeach ()
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foreach (file IN LISTS NON_COMPILABLE_SRC)
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add_custom_command(
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TARGET "${LAB_NAME}" POST_BUILD
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DEPENDS "${file}"
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COMMAND ${CMAKE_COMMAND} -E copy
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"${CMAKE_CURRENT_SOURCE_DIR}/${file}"
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"${CMAKE_CURRENT_BINARY_DIR}/${file}"
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)
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endforeach ()
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@ -0,0 +1,76 @@
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# Лабораторная работа №10
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## Задание 1
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С операцией чтения ничего не произошло (она завершилась успешно), так как согласно документации:
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> if any process has the file open when this happens, deletion is postponed until all processes have closed the file.
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> (https://www.gnu.org/software/libc/manual/html_node/Deleting-Files.html#Deleting-Files)
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## Задание 2
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Герц = 1 с^(-1)
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2 000 000 * 4 = 8 000 000 - количество операций, необходимых для вычисления программы процессором.
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Тогда 8 000 000 / 8 000 000 Гц = 1 с.
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Т.е. для проведения данных вычислений нам нужна 1 секунда.
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## Задание 3
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Так как виртуальный адрес состоит из номера страницы и смещения в ней, то:
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размер виртуального адреса в битах (обозначим за n) = количеству бит под номер страницы (p)
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+ количество бит под смещение в странице (d)
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n = p + d
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p = n - d
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n = 20 (по условию)
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d = log2 (размера страницы) = log2 (1KB) = 10
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p = 20 - 10 = 10 - количество бит отделяемых в виртуальном адресе под номер страницы.
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Тогда возможное число страниц:
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2^p = 2^10 = 1024
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Ответ: 1024 элемента в таблице страниц.
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## Задание 4
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[https://www.intuit.ru/studies/courses/641/497/lecture/11286?page=1](https://www.intuit.ru/studies/courses/641/497/lecture/11286?page=1)
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Рассмотрим алгоритмы диспетчеризации по следующим критериям:
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1. время ожидания
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2. starvation
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3. Время обработки процесса (turnaround time)
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4. Разница во времени выполнения процесса
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### Алгоритмы:
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1. First-Come-First-Served (FCFS)
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1. Зависит от сложившейся ситуации. В большинстве случаев является не минимальным, так как не оптимизируется.
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2. Отсутствует
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3. Зависит от сложившейся ситуации.
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4. Зависит от порядка входа.
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2. Shortest Job First (SJF)
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1. практически минимальное среднее время ожидания.
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2. возможно, для тяжёлых процессов.
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3. для длительных процессов время выполнение гораздо больше, чем в FCFS.
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4. отсутствует.
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3. Shortest-Remaining-Time-First (SRTF) - SJF с прерыванием, если пришедший процесс выполнять быстрее чем текущий, то мы останавливаем его и берём новый.
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1. минимальное среднее время ожидания.
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2. возможно, для тяжёлых процессов, но не так сильно, как в SJF.
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3. для длительных процессов время выполнение гораздо больше, чем в SJF, так требует затраты на переключение, во время выполнения процесса.
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4. отсутствует.
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4. Round Robin (RR) - даём всем процессам одинаковое время по очереди.
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1. для всех одинаковое.
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2. отсутствует.
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3. зависит от выбранного кванта, если он достаточно большой, то ситуация напоминает FCFS, если же сильно мал, то становятся значительными затраты на переключение процессов.
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4. зависит от выбранного кванта.
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@ -0,0 +1,10 @@
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#include <stdio.h>
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#include <unistd.h>
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int main() {
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if (unlink("test.txt") != 0) {
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printf("Unlink error.");
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return -1;
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}
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return 0;
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}
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#include <stdio.h>
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int main() {
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char c;
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FILE *f = fopen("test.txt", "r"); // открыли файл
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if (!f) { // проверили успешность открытия
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printf("File not found.");
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return -1;
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}
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while (1) {
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fseek(f, 0, SEEK_SET);
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while ((c = fgetc(f)) !=
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EOF) { // считали символ, и проверили что он не конечный
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printf("%c", c); // добавили XOR к ответу символа
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}
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}
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fclose(f);
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return 0;
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}
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@ -0,0 +1,7 @@
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#!/usr/bin/env bash
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set -euo pipefail
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IFS=$'\n\t'
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echo "TODO!"
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exit 1
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@ -0,0 +1,57 @@
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cmake_minimum_required(VERSION 3.16)
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set(CMAKE_C_STANDARD 11)
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# Lab name
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set(LAB_NAME "lab9")
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# Lab tasks
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#list(APPEND SOURCE_FILES
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# task1.c
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# task2.c
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# mytail.c
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# mystat.c
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# myls.c
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# task6.c
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# )
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list(APPEND NON_COMPILABLE_SRC
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.execme
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)
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### Here goes the template
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project("${LAB_NAME}" C)
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add_custom_target("${LAB_NAME}")
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#foreach (file IN LISTS SOURCE_FILES)
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# add_executable("${LAB_NAME}_${file}_run" "${file}")
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# add_dependencies("${LAB_NAME}" "${LAB_NAME}_${file}_run")
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#endforeach ()
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find_package (Threads)
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add_executable(${LAB_NAME}_main-race_run main-race.c mythread.h)
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add_executable(${LAB_NAME}_main-deadlock_run main-deadlock.c mythread.h)
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add_executable(${LAB_NAME}_main-deadlock-global_run main-deadlock-global.c mythread.h)
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add_executable(${LAB_NAME}_main-signal_run main-signal.c mythread.h)
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add_executable(${LAB_NAME}_main-signal-cv_run main-signal-cv.c mythread.h)
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target_link_libraries (${LAB_NAME}_main-race_run ${CMAKE_THREAD_LIBS_INIT})
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target_link_libraries (${LAB_NAME}_main-deadlock_run ${CMAKE_THREAD_LIBS_INIT})
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target_link_libraries (${LAB_NAME}_main-deadlock-global_run ${CMAKE_THREAD_LIBS_INIT})
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target_link_libraries (${LAB_NAME}_main-signal_run ${CMAKE_THREAD_LIBS_INIT})
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target_link_libraries (${LAB_NAME}_main-signal-cv_run ${CMAKE_THREAD_LIBS_INIT})
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add_dependencies("${LAB_NAME}" ${LAB_NAME}_main-race_run)
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add_dependencies("${LAB_NAME}" ${LAB_NAME}_main-deadlock_run)
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add_dependencies("${LAB_NAME}" ${LAB_NAME}_main-deadlock-global_run)
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add_dependencies("${LAB_NAME}" ${LAB_NAME}_main-signal_run)
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add_dependencies("${LAB_NAME}" ${LAB_NAME}_main-signal-cv_run)
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foreach (file IN LISTS NON_COMPILABLE_SRC)
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add_custom_command(
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TARGET "${LAB_NAME}" POST_BUILD
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DEPENDS "${file}"
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COMMAND ${CMAKE_COMMAND} -E copy
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"${CMAKE_CURRENT_SOURCE_DIR}/${file}"
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"${CMAKE_CURRENT_BINARY_DIR}/${file}"
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)
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endforeach ()
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@ -0,0 +1,231 @@
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# Лабораторная работа №9
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## Задание 2
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Команда запуска:
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`valgrind --tool=helgrind ./lab9_main-race_run`
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Результат:
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```text
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...
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==4862== Possible data race during read of size 4 at 0x30A014 by thread #1
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==4862== Locks held: none
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==4862== at 0x108D27: main (main-race.c:15)
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==4862==
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==4862== This conflicts with a previous write of size 4 by thread #2
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==4862== Locks held: none
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==4862== at 0x108CDF: worker (main-race.c:8)
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==4862== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==4862== by 0x4E496DA: start_thread (pthread_create.c:463)
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==4862== by 0x518288E: clone (clone.S:95)
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==4862== Address 0x30a014 is 0 bytes inside data symbol "balance"
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...
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```
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helgrind сообщает, что возможно использование переменной balance в двух потоках параллельно.
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### Решение проблемы:
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Блокировать незащищенный процесс.
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Заменить:
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```c
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balance++;
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```
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на:
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```c
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Pthread_mutex_lock(&m); // блокировка мьютекса
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balance++;
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Pthread_mutex_unlock(&m); // разблокировка
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```
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## Задание 3
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Команда запуска:
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`valgrind --tool=helgrind ./lab9_main-deadlock_run`
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Результат:
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```text
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...
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==6272== Thread #3: lock order "0x30A040 before 0x30A080" violated
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==6272==
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==6272== Observed (incorrect) order is: acquisition of lock at 0x30A080
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==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
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==6272== by 0x108D06: worker (main-deadlock.c:13)
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==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
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==6272== by 0x518288E: clone (clone.S:95)
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==6272==
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==6272== followed by a later acquisition of lock at 0x30A040
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==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
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==6272== by 0x108D12: worker (main-deadlock.c:14)
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==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
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==6272== by 0x518288E: clone (clone.S:95)
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==6272==
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==6272== Required order was established by acquisition of lock at 0x30A040
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==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
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==6272== by 0x108CEC: worker (main-deadlock.c:10)
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==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
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==6272== by 0x518288E: clone (clone.S:95)
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==6272==
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==6272== followed by a later acquisition of lock at 0x30A080
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==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
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==6272== by 0x108CF8: worker (main-deadlock.c:11)
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==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
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==6272== by 0x518288E: clone (clone.S:95)
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==6272==
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==6272== Lock at 0x30A040 was first observed
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==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
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==6272== by 0x108CEC: worker (main-deadlock.c:10)
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==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
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==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
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==6272== by 0x518288E: clone (clone.S:95)
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==6272== Address 0x30a040 is 0 bytes inside data symbol "m1"
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==6272==
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==6272== Lock at 0x30A080 was first observed
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||||||
|
==6272== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==6272== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==6272== by 0x108CF8: worker (main-deadlock.c:11)
|
||||||
|
==6272== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==6272== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==6272== by 0x518288E: clone (clone.S:95)
|
||||||
|
==6272== Address 0x30a080 is 0 bytes inside data symbol "m2"
|
||||||
|
...
|
||||||
|
```
|
||||||
|
|
||||||
|
helgrind сообщает, что блокировка мьютексов происходит в неправильном порядке.
|
||||||
|
|
||||||
|
## Задание 4
|
||||||
|
|
||||||
|
Команда запуска:
|
||||||
|
|
||||||
|
`valgrind --tool=helgrind ./lab9_main-deadlock-global_run`
|
||||||
|
|
||||||
|
Результат:
|
||||||
|
```text
|
||||||
|
...
|
||||||
|
==7133== Thread #3: lock order "0x30A080 before 0x30A0C0" violated
|
||||||
|
==7133==
|
||||||
|
==7133== Observed (incorrect) order is: acquisition of lock at 0x30A0C0
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108D12: worker (main-deadlock-global.c:15)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133==
|
||||||
|
==7133== followed by a later acquisition of lock at 0x30A080
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108D1E: worker (main-deadlock-global.c:16)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133==
|
||||||
|
==7133== Required order was established by acquisition of lock at 0x30A080
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108CF8: worker (main-deadlock-global.c:12)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133==
|
||||||
|
==7133== followed by a later acquisition of lock at 0x30A0C0
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108D04: worker (main-deadlock-global.c:13)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133==
|
||||||
|
==7133== Lock at 0x30A080 was first observed
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108CF8: worker (main-deadlock-global.c:12)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133== Address 0x30a080 is 0 bytes inside data symbol "m1"
|
||||||
|
==7133==
|
||||||
|
==7133== Lock at 0x30A0C0 was first observed
|
||||||
|
==7133== at 0x4C3403C: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x108AD7: Pthread_mutex_lock (mythreads.h:23)
|
||||||
|
==7133== by 0x108D04: worker (main-deadlock-global.c:13)
|
||||||
|
==7133== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7133== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7133== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7133== Address 0x30a0c0 is 0 bytes inside data symbol "m2"
|
||||||
|
...
|
||||||
|
```
|
||||||
|
|
||||||
|
helgrind сообщает об аналогичной ошибке 3 заданию, тогда как она отсутствует, так как дополнительный мьютекс не допускает такую ситуацию.
|
||||||
|
|
||||||
|
## Задание 5
|
||||||
|
|
||||||
|
Команда запуска:
|
||||||
|
|
||||||
|
`valgrind --tool=helgrind ./lab9_main-signal_run`
|
||||||
|
|
||||||
|
Результат:
|
||||||
|
|
||||||
|
```text
|
||||||
|
...
|
||||||
|
==7499== Possible data race during write of size 4 at 0x30A014 by thread #2
|
||||||
|
==7499== Locks held: none
|
||||||
|
==7499== at 0x108D36: worker (main-signal.c:9)
|
||||||
|
==7499== by 0x4C36C26: ??? (in /usr/lib/valgrind/vgpreload_helgrind-amd64-linux.so)
|
||||||
|
==7499== by 0x4E496DA: start_thread (pthread_create.c:463)
|
||||||
|
==7499== by 0x518288E: clone (clone.S:95)
|
||||||
|
==7499==
|
||||||
|
==7499== This conflicts with a previous read of size 4 by thread #1
|
||||||
|
==7499== Locks held: none
|
||||||
|
==7499== at 0x108D83: main (main-signal.c:16)
|
||||||
|
==7499== Address 0x30a014 is 0 bytes inside data symbol "done"
|
||||||
|
...
|
||||||
|
```
|
||||||
|
|
||||||
|
helgrind сообщает о возможном одновременном использовании переменной done.
|
||||||
|
|
||||||
|
Такой метод ожидания потока не является эффективным, так как:
|
||||||
|
|
||||||
|
- может наступить чтение в момент записи
|
||||||
|
- требует дополнительных затрат ожидающего потока.
|
||||||
|
|
||||||
|
Наиболее эффективно было бы использовать мьютексы.
|
||||||
|
|
||||||
|
## Задание 6
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
Команда запуска:
|
||||||
|
|
||||||
|
`valgrind --tool=helgrind ./lab9_main-signal-cv_run`
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
|
Результат:
|
||||||
|
|
||||||
|
```text
|
||||||
|
...
|
||||||
|
==9132== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 7 from 7)
|
||||||
|
...
|
||||||
|
```
|
||||||
|
|
||||||
|
helgrind не удалось обнаружить ошибок.
|
||||||
|
|
||||||
|
По сравнению с прошлой программой данная более эффективна, так как она не производит постоянный опрос,
|
||||||
|
а ожидает возвращение cond, и более безопасна для данных.
|
||||||
|
|
@ -0,0 +1,31 @@
|
||||||
|
#include <stdio.h>
|
||||||
|
|
||||||
|
#include "mythread.h"
|
||||||
|
|
||||||
|
pthread_mutex_t g = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
pthread_mutex_t m2 = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
|
||||||
|
void* worker(void* arg) {
|
||||||
|
Pthread_mutex_lock(&g);
|
||||||
|
if ((long long) arg == 0) {
|
||||||
|
Pthread_mutex_lock(&m1);
|
||||||
|
Pthread_mutex_lock(&m2);
|
||||||
|
} else {
|
||||||
|
Pthread_mutex_lock(&m2);
|
||||||
|
Pthread_mutex_lock(&m1);
|
||||||
|
}
|
||||||
|
Pthread_mutex_unlock(&m1);
|
||||||
|
Pthread_mutex_unlock(&m2);
|
||||||
|
Pthread_mutex_unlock(&g);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[]) {
|
||||||
|
pthread_t p1, p2;
|
||||||
|
Pthread_create(&p1, NULL, worker, (void *) (long long) 0);
|
||||||
|
Pthread_create(&p2, NULL, worker, (void *) (long long) 1);
|
||||||
|
Pthread_join(p1, NULL);
|
||||||
|
Pthread_join(p2, NULL);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
@ -0,0 +1,28 @@
|
||||||
|
#include <stdio.h>
|
||||||
|
|
||||||
|
#include "mythread.h"
|
||||||
|
|
||||||
|
pthread_mutex_t m1 = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
pthread_mutex_t m2 = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
|
||||||
|
void* worker(void* arg) {
|
||||||
|
if ((long long) arg == 0) {
|
||||||
|
Pthread_mutex_lock(&m1);
|
||||||
|
Pthread_mutex_lock(&m2);
|
||||||
|
} else {
|
||||||
|
Pthread_mutex_lock(&m2);
|
||||||
|
Pthread_mutex_lock(&m1);
|
||||||
|
}
|
||||||
|
Pthread_mutex_unlock(&m1);
|
||||||
|
Pthread_mutex_unlock(&m2);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[]) {
|
||||||
|
pthread_t p1, p2;
|
||||||
|
Pthread_create(&p1, NULL, worker, (void *) (long long) 0);
|
||||||
|
Pthread_create(&p2, NULL, worker, (void *) (long long) 1);
|
||||||
|
Pthread_join(p1, NULL);
|
||||||
|
Pthread_join(p2, NULL);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
@ -0,0 +1,23 @@
|
||||||
|
#include <stdio.h>
|
||||||
|
|
||||||
|
#include "mythread.h"
|
||||||
|
|
||||||
|
pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
|
||||||
|
int balance = 0;
|
||||||
|
|
||||||
|
void *worker(void *arg) {
|
||||||
|
Pthread_mutex_lock(&m);
|
||||||
|
balance++;
|
||||||
|
Pthread_mutex_unlock(&m);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[]) {
|
||||||
|
pthread_t p;
|
||||||
|
Pthread_create(&p, NULL, worker, NULL);
|
||||||
|
Pthread_mutex_lock(&m); // блокировка мютекса
|
||||||
|
balance++;
|
||||||
|
Pthread_mutex_unlock(&m); // разблокировка
|
||||||
|
Pthread_join(p, NULL);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
@ -0,0 +1,56 @@
|
||||||
|
|
||||||
|
#include <stdio.h>
|
||||||
|
|
||||||
|
#include "mythread.h"
|
||||||
|
|
||||||
|
//
|
||||||
|
// simple synchronizer: allows one thread to wait for another
|
||||||
|
// structure "synchronizer_t" has all the needed data
|
||||||
|
// methods are:
|
||||||
|
// init (called by one thread)
|
||||||
|
// wait (to wait for a thread)
|
||||||
|
// done (to indicate thread is done)
|
||||||
|
//
|
||||||
|
typedef struct __synchronizer_t {
|
||||||
|
pthread_mutex_t lock;
|
||||||
|
pthread_cond_t cond;
|
||||||
|
int done;
|
||||||
|
} synchronizer_t;
|
||||||
|
|
||||||
|
synchronizer_t s;
|
||||||
|
|
||||||
|
void signal_init(synchronizer_t *s) {
|
||||||
|
Pthread_mutex_init(&s->lock, NULL);
|
||||||
|
Pthread_cond_init(&s->cond, NULL);
|
||||||
|
s->done = 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
void signal_done(synchronizer_t *s) {
|
||||||
|
Pthread_mutex_lock(&s->lock);
|
||||||
|
s->done = 1;
|
||||||
|
Pthread_cond_signal(&s->cond);
|
||||||
|
Pthread_mutex_unlock(&s->lock);
|
||||||
|
}
|
||||||
|
|
||||||
|
void signal_wait(synchronizer_t *s) {
|
||||||
|
Pthread_mutex_lock(&s->lock);
|
||||||
|
while (s->done == 0)
|
||||||
|
Pthread_cond_wait(&s->cond, &s->lock);
|
||||||
|
Pthread_mutex_unlock(&s->lock);
|
||||||
|
}
|
||||||
|
|
||||||
|
void* worker(void* arg) {
|
||||||
|
printf("this should print first\n");
|
||||||
|
signal_done(&s);
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[]) {
|
||||||
|
pthread_t p;
|
||||||
|
signal_init(&s);
|
||||||
|
Pthread_create(&p, NULL, worker, NULL);
|
||||||
|
signal_wait(&s);
|
||||||
|
printf("this should print last\n");
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
@ -0,0 +1,20 @@
|
||||||
|
#include <stdio.h>
|
||||||
|
|
||||||
|
#include "mythread.h"
|
||||||
|
|
||||||
|
int done = 0;
|
||||||
|
|
||||||
|
void* worker(void* arg) {
|
||||||
|
printf("this should print first\n");
|
||||||
|
done = 1;
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[]) {
|
||||||
|
pthread_t p;
|
||||||
|
Pthread_create(&p, NULL, worker, NULL);
|
||||||
|
while (done == 0)
|
||||||
|
;
|
||||||
|
printf("this should print last\n");
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
@ -0,0 +1,55 @@
|
||||||
|
#include <pthread.h>
|
||||||
|
#include <assert.h>
|
||||||
|
#include <stdlib.h>
|
||||||
|
#include <sys/time.h>
|
||||||
|
|
||||||
|
double Time_GetSeconds() {
|
||||||
|
struct timeval t;
|
||||||
|
int rc = gettimeofday(&t, NULL);
|
||||||
|
assert(rc == 0);
|
||||||
|
return (double) ((double)t.tv_sec + (double)t.tv_usec / 1e6);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_mutex_init(pthread_mutex_t *mutex,
|
||||||
|
const pthread_mutexattr_t *attr) {
|
||||||
|
int rc = pthread_mutex_init(mutex, attr);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_mutex_lock(pthread_mutex_t *m) {
|
||||||
|
int rc = pthread_mutex_lock(m);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_mutex_unlock(pthread_mutex_t *m) {
|
||||||
|
int rc = pthread_mutex_unlock(m);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_cond_init(pthread_cond_t *cond,
|
||||||
|
const pthread_condattr_t *attr) {
|
||||||
|
int rc = pthread_cond_init(cond, attr);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_cond_wait(pthread_cond_t *cond,
|
||||||
|
pthread_mutex_t *mutex) {
|
||||||
|
int rc = pthread_cond_wait(cond, mutex);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_cond_signal(pthread_cond_t *cond) {
|
||||||
|
int rc = pthread_cond_signal(cond);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_create(pthread_t *thread, const pthread_attr_t *attr,
|
||||||
|
void *(*start_routine)(void*), void *arg) {
|
||||||
|
int rc = pthread_create(thread, attr, start_routine, arg);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
|
|
||||||
|
void Pthread_join(pthread_t thread, void **value_ptr) {
|
||||||
|
int rc = pthread_join(thread, value_ptr);
|
||||||
|
assert(rc == 0);
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue