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-rw-r--r--src/download-via-ssh/download-via-ssh.cc32
-rw-r--r--src/libstore/build.cc73
-rw-r--r--src/libstore/local-store.cc35
-rw-r--r--src/libutil/util.cc107
-rw-r--r--src/libutil/util.hh7
-rw-r--r--src/nix-daemon/nix-daemon.cc51
-rw-r--r--src/nix-store/nix-store.cc29
7 files changed, 128 insertions, 206 deletions
diff --git a/src/download-via-ssh/download-via-ssh.cc b/src/download-via-ssh/download-via-ssh.cc
index 6cbcd9891..6834634f3 100644
--- a/src/download-via-ssh/download-via-ssh.cc
+++ b/src/download-via-ssh/download-via-ssh.cc
@@ -24,30 +24,14 @@ static std::pair<FdSink, FdSource> connect(const string & conn)
Pipe to, from;
to.create();
from.create();
- pid_t child = fork();
- switch (child) {
- case -1:
- throw SysError("unable to fork");
- case 0:
- try {
- restoreAffinity();
- if (dup2(to.readSide, STDIN_FILENO) == -1)
- throw SysError("dupping stdin");
- if (dup2(from.writeSide, STDOUT_FILENO) == -1)
- throw SysError("dupping stdout");
- execlp("ssh"
- , "ssh"
- , "-x"
- , "-T"
- , conn.c_str()
- , "nix-store --serve"
- , NULL);
- throw SysError("executing ssh");
- } catch (std::exception & e) {
- std::cerr << "error: " << e.what() << std::endl;
- }
- _exit(1);
- }
+ startProcess([&]() {
+ if (dup2(to.readSide, STDIN_FILENO) == -1)
+ throw SysError("dupping stdin");
+ if (dup2(from.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("dupping stdout");
+ execlp("ssh", "ssh", "-x", "-T", conn.c_str(), "nix-store --serve", NULL);
+ throw SysError("executing ssh");
+ });
// If child exits unexpectedly, we'll EPIPE or EOF early.
// If we exit unexpectedly, child will EPIPE or EOF early.
// So no need to keep track of it.
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 70a3effb2..d3184507c 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -602,42 +602,29 @@ HookInstance::HookInstance()
builderOut.create();
/* Fork the hook. */
- pid = fork();
- switch (pid) {
+ pid = startProcess([&]() {
- case -1:
- throw SysError("unable to fork");
+ commonChildInit(fromHook);
- case 0:
- try { /* child */
+ if (chdir("/") == -1) throw SysError("changing into `/");
- commonChildInit(fromHook);
+ /* Dup the communication pipes. */
+ if (dup2(toHook.readSide, STDIN_FILENO) == -1)
+ throw SysError("dupping to-hook read side");
- if (chdir("/") == -1) throw SysError("changing into `/");
+ /* Use fd 4 for the builder's stdout/stderr. */
+ if (dup2(builderOut.writeSide, 4) == -1)
+ throw SysError("dupping builder's stdout/stderr");
- /* Dup the communication pipes. */
- if (dup2(toHook.readSide, STDIN_FILENO) == -1)
- throw SysError("dupping to-hook read side");
+ execl(buildHook.c_str(), buildHook.c_str(), settings.thisSystem.c_str(),
+ (format("%1%") % settings.maxSilentTime).str().c_str(),
+ (format("%1%") % settings.printBuildTrace).str().c_str(),
+ (format("%1%") % settings.buildTimeout).str().c_str(),
+ NULL);
- /* Use fd 4 for the builder's stdout/stderr. */
- if (dup2(builderOut.writeSide, 4) == -1)
- throw SysError("dupping builder's stdout/stderr");
+ throw SysError(format("executing `%1%'") % buildHook);
+ });
- execl(buildHook.c_str(), buildHook.c_str(), settings.thisSystem.c_str(),
- (format("%1%") % settings.maxSilentTime).str().c_str(),
- (format("%1%") % settings.printBuildTrace).str().c_str(),
- (format("%1%") % settings.buildTimeout).str().c_str(),
- NULL);
-
- throw SysError(format("executing `%1%'") % buildHook);
-
- } catch (std::exception & e) {
- writeToStderr("build hook error: " + string(e.what()) + "\n");
- }
- _exit(1);
- }
-
- /* parent */
pid.setSeparatePG(true);
pid.setKillSignal(SIGTERM);
fromHook.writeSide.close();
@@ -2781,32 +2768,18 @@ void SubstitutionGoal::tryToRun()
const char * * argArr = strings2CharPtrs(args);
/* Fork the substitute program. */
- pid = fork();
-
- switch (pid) {
+ pid = startProcess([&]() {
- case -1:
- throw SysError("unable to fork");
+ commonChildInit(logPipe);
- case 0:
- try { /* child */
+ if (dup2(outPipe.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("cannot dup output pipe into stdout");
- commonChildInit(logPipe);
+ execv(sub.c_str(), (char * *) argArr);
- if (dup2(outPipe.writeSide, STDOUT_FILENO) == -1)
- throw SysError("cannot dup output pipe into stdout");
+ throw SysError(format("executing `%1%'") % sub);
+ });
- execv(sub.c_str(), (char * *) argArr);
-
- throw SysError(format("executing `%1%'") % sub);
-
- } catch (std::exception & e) {
- writeToStderr("substitute error: " + string(e.what()) + "\n");
- }
- _exit(1);
- }
-
- /* parent */
pid.setSeparatePG(true);
pid.setKillSignal(SIGTERM);
outPipe.writeSide.close();
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 08ab269b3..e66042c57 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1083,31 +1083,16 @@ void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter &
setSubstituterEnv();
- run.pid = fork();
-
- switch (run.pid) {
-
- case -1:
- throw SysError("unable to fork");
-
- case 0: /* child */
- try {
- restoreAffinity();
- if (dup2(toPipe.readSide, STDIN_FILENO) == -1)
- throw SysError("dupping stdin");
- if (dup2(fromPipe.writeSide, STDOUT_FILENO) == -1)
- throw SysError("dupping stdout");
- if (dup2(errorPipe.writeSide, STDERR_FILENO) == -1)
- throw SysError("dupping stderr");
- execl(substituter.c_str(), substituter.c_str(), "--query", NULL);
- throw SysError(format("executing `%1%'") % substituter);
- } catch (std::exception & e) {
- std::cerr << "error: " << e.what() << std::endl;
- }
- _exit(1);
- }
-
- /* Parent. */
+ run.pid = startProcess([&]() {
+ if (dup2(toPipe.readSide, STDIN_FILENO) == -1)
+ throw SysError("dupping stdin");
+ if (dup2(fromPipe.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("dupping stdout");
+ if (dup2(errorPipe.writeSide, STDERR_FILENO) == -1)
+ throw SysError("dupping stderr");
+ execl(substituter.c_str(), substituter.c_str(), "--query", NULL);
+ throw SysError(format("executing `%1%'") % substituter);
+ });
run.program = baseNameOf(substituter);
run.to = toPipe.writeSide.borrow();
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 5f6203bc2..faa2b83c3 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1,5 +1,8 @@
#include "config.h"
+#include "util.hh"
+#include "affinity.hh"
+
#include <iostream>
#include <cerrno>
#include <cstdio>
@@ -16,8 +19,6 @@
#include <sys/syscall.h>
#endif
-#include "util.hh"
-
extern char * * environ;
@@ -714,6 +715,13 @@ Pid::Pid()
}
+Pid::Pid(pid_t pid)
+{
+ Pid();
+ *this = pid;
+}
+
+
Pid::~Pid()
{
kill();
@@ -801,43 +809,30 @@ void killUser(uid_t uid)
users to which the current process can send signals. So we
fork a process, switch to uid, and send a mass kill. */
- Pid pid;
- pid = fork();
- switch (pid) {
-
- case -1:
- throw SysError("unable to fork");
-
- case 0:
- try { /* child */
+ Pid pid = startProcess([&]() {
- if (setuid(uid) == -1)
- throw SysError("setting uid");
+ if (setuid(uid) == -1)
+ throw SysError("setting uid");
- while (true) {
+ while (true) {
#ifdef __APPLE__
- /* OSX's kill syscall takes a third parameter that, among other
- things, determines if kill(-1, signo) affects the calling
- process. In the OSX libc, it's set to true, which means
- "follow POSIX", which we don't want here
+ /* OSX's kill syscall takes a third parameter that, among
+ other things, determines if kill(-1, signo) affects the
+ calling process. In the OSX libc, it's set to true,
+ which means "follow POSIX", which we don't want here
*/
- if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break;
+ if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break;
#else
- if (kill(-1, SIGKILL) == 0) break;
+ if (kill(-1, SIGKILL) == 0) break;
#endif
- if (errno == ESRCH) break; /* no more processes */
- if (errno != EINTR)
- throw SysError(format("cannot kill processes for uid `%1%'") % uid);
- }
-
- } catch (std::exception & e) {
- writeToStderr((format("killing processes belonging to uid `%1%': %2%\n") % uid % e.what()).str());
- _exit(1);
+ if (errno == ESRCH) break; /* no more processes */
+ if (errno != EINTR)
+ throw SysError(format("cannot kill processes for uid `%1%'") % uid);
}
+
_exit(0);
- }
+ });
- /* parent */
int status = pid.wait(true);
if (status != 0)
throw Error(format("cannot kill processes for uid `%1%': %2%") % uid % statusToString(status));
@@ -852,6 +847,25 @@ void killUser(uid_t uid)
//////////////////////////////////////////////////////////////////////
+pid_t startProcess(std::function<void()> fun, const string & errorPrefix)
+{
+ pid_t pid = fork();
+ if (pid == -1) throw SysError("unable to fork");
+
+ if (pid == 0) {
+ try {
+ restoreAffinity();
+ fun();
+ } catch (std::exception & e) {
+ writeToStderr(errorPrefix + string(e.what()) + "\n");
+ }
+ _exit(1);
+ }
+
+ return pid;
+}
+
+
string runProgram(Path program, bool searchPath, const Strings & args)
{
checkInterrupt();
@@ -867,32 +881,17 @@ string runProgram(Path program, bool searchPath, const Strings & args)
pipe.create();
/* Fork. */
- Pid pid;
- pid = fork();
-
- switch (pid) {
+ Pid pid = startProcess([&]() {
+ if (dup2(pipe.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("dupping stdout");
- case -1:
- throw SysError("unable to fork");
-
- case 0: /* child */
- try {
- if (dup2(pipe.writeSide, STDOUT_FILENO) == -1)
- throw SysError("dupping stdout");
-
- if (searchPath)
- execvp(program.c_str(), (char * *) &cargs[0]);
- else
- execv(program.c_str(), (char * *) &cargs[0]);
- throw SysError(format("executing `%1%'") % program);
-
- } catch (std::exception & e) {
- writeToStderr("error: " + string(e.what()) + "\n");
- }
- _exit(1);
- }
+ if (searchPath)
+ execvp(program.c_str(), (char * *) &cargs[0]);
+ else
+ execv(program.c_str(), (char * *) &cargs[0]);
- /* Parent. */
+ throw SysError(format("executing `%1%'") % program);
+ });
pipe.writeSide.close();
diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 07c027a1f..ad0d377a4 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -7,6 +7,7 @@
#include <dirent.h>
#include <unistd.h>
#include <signal.h>
+#include <functional>
#include <cstdio>
@@ -237,6 +238,7 @@ class Pid
int killSignal;
public:
Pid();
+ Pid(pid_t pid);
~Pid();
void operator =(pid_t pid);
operator pid_t();
@@ -252,6 +254,11 @@ public:
void killUser(uid_t uid);
+/* Fork a process that runs the given function, and return the child
+ pid to the caller. */
+pid_t startProcess(std::function<void()> fun, const string & errorPrefix = "error: ");
+
+
/* Run a program and return its stdout in a string (i.e., like the
shell backtick operator). */
string runProgram(Path program, bool searchPath = false,
diff --git a/src/nix-daemon/nix-daemon.cc b/src/nix-daemon/nix-daemon.cc
index 0464ac965..265131c61 100644
--- a/src/nix-daemon/nix-daemon.cc
+++ b/src/nix-daemon/nix-daemon.cc
@@ -872,40 +872,27 @@ static void daemonLoop()
printMsg(lvlInfo, format("accepted connection from pid %1%, uid %2%") % clientPid % clientUid);
/* Fork a child to handle the connection. */
- pid_t child;
- child = fork();
-
- switch (child) {
-
- case -1:
- throw SysError("unable to fork");
-
- case 0:
- try { /* child */
-
- /* Background the daemon. */
- if (setsid() == -1)
- throw SysError(format("creating a new session"));
-
- /* Restore normal handling of SIGCHLD. */
- setSigChldAction(false);
-
- /* For debugging, stuff the pid into argv[1]. */
- if (clientPid != -1 && argvSaved[1]) {
- string processName = int2String(clientPid);
- strncpy(argvSaved[1], processName.c_str(), strlen(argvSaved[1]));
- }
+ startProcess([&]() {
+ /* Background the daemon. */
+ if (setsid() == -1)
+ throw SysError(format("creating a new session"));
+
+ /* Restore normal handling of SIGCHLD. */
+ setSigChldAction(false);
+
+ /* For debugging, stuff the pid into argv[1]. */
+ if (clientPid != -1 && argvSaved[1]) {
+ string processName = int2String(clientPid);
+ strncpy(argvSaved[1], processName.c_str(), strlen(argvSaved[1]));
+ }
- /* Handle the connection. */
- from.fd = remote;
- to.fd = remote;
- processConnection(trusted);
+ /* Handle the connection. */
+ from.fd = remote;
+ to.fd = remote;
+ processConnection(trusted);
- } catch (std::exception & e) {
- writeToStderr("unexpected Nix daemon error: " + string(e.what()) + "\n");
- }
- exit(0);
- }
+ _exit(0);
+ }, "unexpected Nix daemon error: ");
} catch (Interrupted & e) {
throw;
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index bb5a9e2e0..28b205b1f 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -939,27 +939,14 @@ static void opServe(Strings opFlags, Strings opArgs)
Pipe fromDecompressor;
fromDecompressor.create();
- Pid pid;
- pid = fork();
-
- switch (pid) {
-
- case -1:
- throw SysError("unable to fork");
-
- case 0: /* child */
- try {
- fromDecompressor.readSide.close();
- if (dup2(fromDecompressor.writeSide, STDOUT_FILENO) == -1)
- throw SysError("dupping stdout");
- // FIXME: use absolute path.
- execlp(compression.c_str(), compression.c_str(), "-d", NULL);
- throw SysError(format("executing `%1%'") % compression);
- } catch (std::exception & e) {
- std::cerr << "error: " << e.what() << std::endl;
- }
- _exit(1);
- }
+ Pid pid = startProcess([&]() {
+ fromDecompressor.readSide.close();
+ if (dup2(fromDecompressor.writeSide, STDOUT_FILENO) == -1)
+ throw SysError("dupping stdout");
+ // FIXME: use absolute path.
+ execlp(compression.c_str(), compression.c_str(), "-d", NULL);
+ throw SysError(format("executing `%1%'") % compression);
+ });
fromDecompressor.writeSide.close();
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 02:42:37 +0000