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#include "current-process.hh"
#include "file-system.hh"
#include "logging.hh"
#include "signals.hh"
#include "util.hh"
#ifdef __APPLE__
# include <mach-o/dyld.h>
#endif
#if __linux__
# include <sys/resource.h>
#endif
#include <sys/mount.h>
#include <cgroup.hh>
namespace nix {
unsigned int getMaxCPU()
{
#if __linux__
try {
auto cgroupFS = getCgroupFS();
if (!cgroupFS) return 0;
auto cgroups = getCgroups("/proc/self/cgroup");
auto cgroup = cgroups[""];
if (cgroup == "") return 0;
auto cpuFile = *cgroupFS + "/" + cgroup + "/cpu.max";
auto cpuMax = readFile(cpuFile);
auto cpuMaxParts = tokenizeString<std::vector<std::string>>(cpuMax, " \n");
if (cpuMaxParts.size() != 2) {
return 0;
}
auto quota = cpuMaxParts[0];
auto period = cpuMaxParts[1];
if (quota != "max")
return std::ceil(std::stoi(quota) / std::stof(period));
} catch (Error &) { ignoreException(lvlDebug); }
#endif
return 0;
}
rlim_t savedStackSize = 0;
void setStackSize(rlim_t stackSize)
{
struct rlimit limit;
if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) {
savedStackSize = limit.rlim_cur;
limit.rlim_cur = std::min(stackSize, limit.rlim_max);
if (setrlimit(RLIMIT_STACK, &limit) != 0) {
logger->log(
lvlError,
HintFmt(
"Failed to increase stack size from %1% to %2% (maximum allowed stack size: %3%): %4%",
savedStackSize,
stackSize,
limit.rlim_max,
std::strerror(errno)
).str()
);
}
}
}
void restoreProcessContext(bool restoreMounts)
{
restoreSignals();
if (restoreMounts) {
restoreMountNamespace();
}
if (savedStackSize) {
struct rlimit limit;
if (getrlimit(RLIMIT_STACK, &limit) == 0) {
limit.rlim_cur = savedStackSize;
setrlimit(RLIMIT_STACK, &limit);
}
}
}
std::optional<Path> getSelfExe()
{
static auto cached = []() -> std::optional<Path>
{
#if __linux__
return readLink("/proc/self/exe");
#elif __APPLE__
char buf[1024];
uint32_t size = sizeof(buf);
if (_NSGetExecutablePath(buf, &size) == 0)
return buf;
else
return std::nullopt;
#else
return std::nullopt;
#endif
}();
return cached;
}
}
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