From 43331d634498154f6a1835c8c417dd07eaefd45d Mon Sep 17 00:00:00 2001 From: Guillaume Maudoux Date: Wed, 27 Feb 2019 23:32:12 +0100 Subject: detail memory roots --- src/libstore/gc.cc | 61 +++++++++++++++++++++++++++--------------------------- 1 file changed, 31 insertions(+), 30 deletions(-) (limited to 'src/libstore/gc.cc') diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc index b415d5421..ecfa5e1ed 100644 --- a/src/libstore/gc.cc +++ b/src/libstore/gc.cc @@ -333,9 +333,7 @@ Roots LocalStore::findRootsNoTemp() NIX_ROOT_FINDER environment variable. This is typically used to add running programs to the set of roots (to prevent them from being garbage collected). */ - size_t n = 0; - for (auto & root : findRuntimeRoots()) - roots[fmt("{memory:%d}", n++)] = root; + findRuntimeRoots(roots); return roots; } @@ -357,8 +355,7 @@ Roots LocalStore::findRoots() return roots; } - -static void readProcLink(const string & file, StringSet & paths) +static void readProcLink(const string & file, Roots & roots) { /* 64 is the starting buffer size gnu readlink uses... */ auto bufsiz = ssize_t{64}; @@ -377,7 +374,7 @@ try_again: goto try_again; } if (res > 0 && buf[0] == '/') - paths.emplace(static_cast(buf), res); + roots.emplace(file, std::string(static_cast(buf), res)); return; } @@ -387,20 +384,20 @@ static string quoteRegexChars(const string & raw) return std::regex_replace(raw, specialRegex, R"(\$&)"); } -static void readFileRoots(const char * path, StringSet & paths) +static void readFileRoots(const char * path, Roots & roots) { try { - paths.emplace(readFile(path)); + roots.emplace(path, readFile(path)); } catch (SysError & e) { if (e.errNo != ENOENT && e.errNo != EACCES) throw; } } -PathSet LocalStore::findRuntimeRoots() +void LocalStore::findRuntimeRoots(Roots & roots) { - PathSet roots; - StringSet paths; + Roots unchecked; + auto procDir = AutoCloseDir{opendir("/proc")}; if (procDir) { struct dirent * ent; @@ -410,8 +407,8 @@ PathSet LocalStore::findRuntimeRoots() while (errno = 0, ent = readdir(procDir.get())) { checkInterrupt(); if (std::regex_match(ent->d_name, digitsRegex)) { - readProcLink((format("/proc/%1%/exe") % ent->d_name).str(), paths); - readProcLink((format("/proc/%1%/cwd") % ent->d_name).str(), paths); + readProcLink((format("/proc/%1%/exe") % ent->d_name).str(), unchecked); + readProcLink((format("/proc/%1%/cwd") % ent->d_name).str(), unchecked); auto fdStr = (format("/proc/%1%/fd") % ent->d_name).str(); auto fdDir = AutoCloseDir(opendir(fdStr.c_str())); @@ -423,7 +420,7 @@ PathSet LocalStore::findRuntimeRoots() struct dirent * fd_ent; while (errno = 0, fd_ent = readdir(fdDir.get())) { if (fd_ent->d_name[0] != '.') { - readProcLink((format("%1%/%2%") % fdStr % fd_ent->d_name).str(), paths); + readProcLink((format("%1%/%2%") % fdStr % fd_ent->d_name).str(), unchecked); } } if (errno) { @@ -434,18 +431,22 @@ PathSet LocalStore::findRuntimeRoots() fdDir.reset(); try { - auto mapLines = - tokenizeString>(readFile((format("/proc/%1%/maps") % ent->d_name).str(), true), "\n"); + auto mapFile = (format("/proc/%1%/maps") % ent->d_name).str(); + auto mapLines = tokenizeString>(readFile(mapFile, true), "\n"); + int n = 0; for (const auto& line : mapLines) { + n++; auto match = std::smatch{}; if (std::regex_match(line, match, mapRegex)) - paths.emplace(match[1]); + unchecked.emplace((format("{%1%:%2%}") % mapFile % n).str(), match[1]); } - auto envString = readFile((format("/proc/%1%/environ") % ent->d_name).str(), true); + auto envFile = (format("/proc/%1%/environ") % ent->d_name).str(); + auto envString = readFile(envFile, true); auto env_end = std::sregex_iterator{}; + n = 0; for (auto i = std::sregex_iterator{envString.begin(), envString.end(), storePathRegex}; i != env_end; ++i) - paths.emplace(i->str()); + unchecked.emplace((format("{%1%:%2%}") % envFile % envString).str(), i->str()); } catch (SysError & e) { if (errno == ENOENT || errno == EACCES || errno == ESRCH) continue; @@ -462,10 +463,11 @@ PathSet LocalStore::findRuntimeRoots() std::regex lsofRegex(R"(^n(/.*)$)"); auto lsofLines = tokenizeString>(runProgram(LSOF, true, { "-n", "-w", "-F", "n" }), "\n"); + int n = 0; for (const auto & line : lsofLines) { std::smatch match; if (std::regex_match(line, match, lsofRegex)) - paths.emplace(match[1]); + unchecked.emplace((format("{%1%:%2%}" % LSOF % n++).str(), match[1]); } } catch (ExecError & e) { /* lsof not installed, lsof failed */ @@ -473,21 +475,20 @@ PathSet LocalStore::findRuntimeRoots() #endif #if defined(__linux__) - readFileRoots("/proc/sys/kernel/modprobe", paths); - readFileRoots("/proc/sys/kernel/fbsplash", paths); - readFileRoots("/proc/sys/kernel/poweroff_cmd", paths); + readFileRoots("/proc/sys/kernel/modprobe", unchecked); + readFileRoots("/proc/sys/kernel/fbsplash", unchecked); + readFileRoots("/proc/sys/kernel/poweroff_cmd", unchecked); #endif - for (auto & i : paths) - if (isInStore(i)) { - Path path = toStorePath(i); - if (roots.find(path) == roots.end() && isStorePath(path) && isValidPath(path)) { + for (auto & root : unchecked) { + if (isInStore(root.second)) { + Path path = toStorePath(root.second); + if (isStorePath(path) && isValidPath(path)) { debug(format("got additional root '%1%'") % path); - roots.insert(path); + roots.emplace(root.first, path); } } - - return roots; + } } -- cgit v1.2.3