wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-06-27 00:11:17 +02:00
Code Activity

runProgram(): Distinguish between empty input and no input

Browse source 
For example, if we call brotli with an empty input, it shouldn't read
from the caller's stdin.
This commit is contained in:
Eelco Dolstra 2017-03-15 14:40:47 +01:00
parent 042975ea8e
commit 25dff2b7db
No known key found for this signature in database
GPG key ID: 8170B4726D7198DE
5 changed files with 30 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

33
src/libutil/util.cc
View file

@ -1,6 +1,7 @@
#include "util.hh"
#include "affinity.hh"
#include "sync.hh"
#include "finally.hh"
#include <cctype>
#include <cerrno>
@ -10,6 +11,7 @@
#include <iostream>
#include <sstream>
#include <thread>
#include <future>
#include <sys/wait.h>
#include <unistd.h>
@ -837,23 +839,21 @@ std::vector<char *> stringsToCharPtrs(const Strings & ss)
string runProgram(Path program, bool searchPath, const Strings & args,
const string & input)
const std::experimental::optional<std::string> & input)
{
checkInterrupt();
/* Create a pipe. */
Pipe out, in;
out.create();
if (!input.empty()) in.create();
if (input) in.create();
/* Fork. */
Pid pid = startProcess([&]() {
if (dup2(out.writeSide.get(), STDOUT_FILENO) == -1)
throw SysError("dupping stdout");
if (!input.empty()) {
if (dup2(in.readSide.get(), STDIN_FILENO) == -1)
throw SysError("dupping stdin");
}
if (input && dup2(in.readSide.get(), STDIN_FILENO) == -1)
throw SysError("dupping stdin");
Strings args_(args);
args_.push_front(program);
@ -872,10 +872,23 @@ string runProgram(Path program, bool searchPath, const Strings & args,
std::thread writerThread;
if (!input.empty()) {
std::promise<void> promise;
Finally doJoin([&]() {
if (writerThread.joinable())
writerThread.join();
});
if (input) {
in.readSide = -1;
writerThread = std::thread([&]() {
writeFull(in.writeSide.get(), input);
try {
writeFull(in.writeSide.get(), *input);
promise.set_value();
} catch (...) {
promise.set_exception(std::current_exception());
}
in.writeSide = -1;
});
}
@ -888,8 +901,8 @@ string runProgram(Path program, bool searchPath, const Strings & args,
throw ExecError(status, format("program ‘%1%’ %2%")
% program % statusToString(status));
if (!input.empty())
writerThread.join();
/* Wait for the writer thread to finish. */
if (input) promise.get_future().get();
return result;
}