1 files changed, 136 insertions, 0 deletions
diff --git a/competition/process.cpp b/competition/process.cpp
new file mode 100644
index 0000000..a728401
--- /dev/null
+++ b/competition/process.cpp
@@ -0,0 +1,136 @@
+#include <iostream>
+#include <cstdlib>
+#include <fcntl.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() {
+	while (true) {
+		int status;
+		if (waitpid(pid, &status, 0) < 0) {
+			if (errno == EINTR) continue;
+			perror("waitpid");
+			break;
+		}
+		if (WIFEXITED(status)) 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) {
+	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() {
+	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;
+		}
+		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() {
+	if (pid != -1) kill(pid, SIGTERM);
+}