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#include <iostream>
#include <cstdlib>
#include <fcntl.h>
#include <signal.h>
#include <sys/wait.h>
#include "process.h"
#include "error.h"
Process::Process(const string_view execname)
: execname(execname) {}
void Process::redirectStderr(const string_view fname) {
stderrRedirect = fname;
}
void Process::run() {
int stderrfd = -1;
if (stderrRedirect) {
stderrfd = open(stderrRedirect->data(), O_WRONLY|O_CREAT|O_TRUNC, 0644);
if (stderrfd < 0) {
perror("open");
cout << endl << "ERROR: Cannot open player log file '" << *stderrRedirect << "'" << endl;
throw StopCompetitionError();
}
}
int pipefds[2];
if (pipe(pipefds) < 0) {
perror("pipe");
exit(1);
}
infd = pipefds[1];
int child_in = pipefds[0];
if (pipe(pipefds) < 0) {
perror("pipe");
exit(1);
}
outfd = pipefds[0];
int child_out = pipefds[1];
pid = fork();
if (pid < 0) {
perror("fork");
exit(1);
}
if (pid == 0) {
if (stderrRedirect) dup2(stderrfd, STDERR_FILENO);
dup2(child_in, STDIN_FILENO);
dup2(child_out, STDOUT_FILENO);
close(infd);
close(outfd);
execlp(execname.data(), execname.data(), NULL);
cerr << endl << "ERROR: Error executing player file '" << execname << "'" << endl;
exit(255);
}
if (stderrfd >= 0) close(stderrfd);
close(child_in);
close(child_out);
}
void Process::wait() {
if (pid == -1) return;
while (true) {
int status;
if (waitpid(pid, &status, 0) < 0) {
if (errno == EINTR) continue;
if (errno == ECHILD) break;
perror("waitpid");
break;
}
if (WIFEXITED(status)) {
pid = -1;
break;
}
}
}
void Process::stop() {
if (pid != -1) kill(pid, SIGSTOP);
}
void Process::unStop() {
if (pid != -1) kill(pid, SIGCONT);
}
bool Process::writeLine(const string_view line) {
if (pid == -1) return false;
string str;
str.reserve(line.size() + 1);
str += line;
str += '\n';
size_t cursor = 0;
while (cursor < str.size()) {
ssize_t nw = write(infd, str.data() + cursor, str.size() - cursor);
if (nw < 0) {
if (errno == EINTR) continue;
perror("write");
return false;
}
cursor += nw;
}
return true;
}
optional<string> Process::readLine() {
if (pid == -1) return nullopt;
size_t idx = readBuf.find('\n');
if (idx != string::npos) {
string res = readBuf.substr(0, idx);
readBuf = readBuf.substr(idx + 1);
return res;
}
while (true) {
string s(1024, '\0');
ssize_t nr = read(outfd, &s[0], s.size());
if (nr < 0) {
if (errno == EINTR) continue;
perror("read");
return nullopt;
}
if (nr == 0) { // EOF
return nullopt;
}
s.resize(nr);
idx = s.find('\n');
if (idx != string::npos) {
string res = readBuf + s.substr(0, idx);
readBuf = s.substr(idx + 1);
return res;
}
readBuf += s;
}
}
void Process::terminate() {
// TODO: send only SIGTERM, then wait a little while, then send
// SIGKILL if necessary
if (pid != -1) {
kill(pid, SIGKILL); // force kill
wait();
pid = -1;
}
}
pid_t Process::getPid() const {
return pid;
}
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