From 398909328cd0d3390f6e0943b54a26bfb382a68d Mon Sep 17 00:00:00 2001
From: blankie <blankie@nixnetmail.com>
Date: Tue, 17 Jan 2023 21:44:17 +0700
Subject: [PATCH] Create stdout and stderr pipes

---
 logcat_thread.cpp | 69 +++++++++++++++++++++++++++++++++++++++++++++++
 logcat_thread.h   |  4 +++
 2 files changed, 73 insertions(+)

diff --git a/logcat_thread.cpp b/logcat_thread.cpp
index c11a33c..531c94c 100644
--- a/logcat_thread.cpp
+++ b/logcat_thread.cpp
@@ -1,5 +1,7 @@
+#include <fcntl.h>
 #include <unistd.h>
 #include <sys/epoll.h>
+#include <system_error>
 
 #include "log.h"
 #include "misc.h"
@@ -7,11 +9,66 @@
 
 #define EPOLL_MAX_EVENTS 10
 
+static void mark_nonblock(int fd) {
+    int flags = fcntl(fd, F_GETFL);
+    if (flags < 0) {
+        throw make_system_error("fcntl(fd, F_GETFL)");
+    }
+    if (!(flags & O_NONBLOCK) && fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
+        throw make_system_error("fcntl(fd, F_SETFL)");
+    }
+}
+
+
 LogcatThread::LogcatThread(bool* run_event_loop) {
+    int fds[2];
+    struct epoll_event event = {.events = EPOLLIN | EPOLLET};
+
+    if (pipe(fds)) {
+        std::system_error e = make_system_error("pipe() for stdout");
+        this->~LogcatThread();
+        throw e;
+    }
+    this->_stdout_read_fd = fds[0];
+    this->_stdout_write_fd = fds[1];
+    try {
+        mark_nonblock(this->_stdout_read_fd);
+    } catch (const std::exception& e) {
+        this->~LogcatThread();
+        throw;
+    }
+
+    if (pipe(fds)) {
+        std::system_error e = make_system_error("pipe() for stderr");
+        this->~LogcatThread();
+        throw e;
+    }
+    this->_stderr_read_fd = fds[0];
+    this->_stderr_write_fd = fds[1];
+    try {
+        mark_nonblock(this->_stderr_read_fd);
+    } catch (const std::exception& e) {
+        this->~LogcatThread();
+        throw;
+    }
+
     this->_epoll_fd = epoll_create1(EPOLL_CLOEXEC);
     if (this->_epoll_fd == -1) {
         throw make_system_error("epoll_create1()");
     }
+    event.data.fd = this->_stdout_read_fd;
+    if (epoll_ctl(this->_epoll_fd, EPOLL_CTL_ADD, this->_stdout_read_fd, &event)) {
+        std::system_error e = make_system_error("epoll_ctl() for stdout");
+        this->~LogcatThread();
+        throw e;
+    }
+    event.data.fd = this->_stderr_read_fd;
+    if (epoll_ctl(this->_epoll_fd, EPOLL_CTL_ADD, this->_stderr_read_fd, &event)) {
+        std::system_error e = make_system_error("epoll_ctl() for stderr");
+        this->~LogcatThread();
+        throw e;
+    }
+
     this->_thread = std::thread(&LogcatThread::_run, this, run_event_loop);
 }
 
@@ -19,6 +76,18 @@ LogcatThread::~LogcatThread() {
     if (this->_epoll_fd != -1 && close(this->_epoll_fd)) {
         log(std::string("Failed to close epoll file descriptor: ") + make_system_error("close()").what());
     }
+    if (this->_stdout_read_fd != -1 && close(this->_stdout_read_fd)) {
+        log(std::string("Failed to close stdout read pipe: ") + make_system_error("close()").what());
+    }
+    if (this->_stdout_write_fd != -1 && close(this->_stdout_write_fd)) {
+        log(std::string("Failed to close stdout write pipe: ") + make_system_error("close()").what());
+    }
+    if (this->_stderr_read_fd != -1 && close(this->_stderr_read_fd)) {
+        log(std::string("Failed to close stderr read pipe: ") + make_system_error("close()").what());
+    }
+    if (this->_stderr_write_fd != -1 && close(this->_stderr_write_fd)) {
+        log(std::string("Failed to close stderr write pipe: ") + make_system_error("close()").what());
+    }
 }
 
 void LogcatThread::join() {
diff --git a/logcat_thread.h b/logcat_thread.h
index cdd6ae8..7765281 100644
--- a/logcat_thread.h
+++ b/logcat_thread.h
@@ -16,5 +16,9 @@ private:
     void _run(bool* run_event_loop);
 
     int _epoll_fd = -1;
+    int _stdout_read_fd = -1;
+    int _stdout_write_fd = -1;
+    int _stderr_read_fd = -1;
+    int _stderr_write_fd = -1;
     std::thread _thread;
 };