make execCmd exception-safe
This commit is contained in:
dockes
parent
cb344d7493
commit
f920d2ce3e
@ -1,5 +1,5 @@
|
||||
#ifndef lint
|
||||
static char rcsid[] = "@(#$Id: execmd.cpp,v 1.13 2006-01-24 12:22:20 dockes Exp $ (C) 2004 J.F.Dockes";
|
||||
static char rcsid[] = "@(#$Id: execmd.cpp,v 1.14 2006-01-26 17:44:51 dockes Exp $ (C) 2004 J.F.Dockes";
|
||||
#endif
|
||||
/*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
@ -49,6 +49,49 @@ void ExecCmd::putenv(const string &ea)
|
||||
m_env.push_back(ea);
|
||||
}
|
||||
|
||||
/** A resource manager to ensure that execcmd cleans up if an exception is
|
||||
* raised in the callback */
|
||||
class ExecCmdRsrc {
|
||||
public:
|
||||
int pipein[2];
|
||||
int pipeout[2];
|
||||
pid_t pid;
|
||||
ExecCmdRsrc() {
|
||||
reset();
|
||||
}
|
||||
void reset() {
|
||||
pipein[0] = pipein[1] = pipeout[0] = pipeout[1] = -1;
|
||||
pid = -1;
|
||||
}
|
||||
~ExecCmdRsrc() {
|
||||
int status;
|
||||
if (pid > 0) {
|
||||
LOGDEB(("ExecCmd: killing cmd\n"));
|
||||
if (kill(pid, SIGTERM) == 0) {
|
||||
for (int i = 0; i < 3; i++) {
|
||||
(void)waitpid(pid, &status, WNOHANG);
|
||||
if (kill(pid, 0) != 0)
|
||||
break;
|
||||
sleep(1);
|
||||
if (i == 2) {
|
||||
LOGDEB(("ExecCmd: killing (KILL) cmd\n"));
|
||||
kill(pid, SIGKILL);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
if (pipein[0] >= 0)
|
||||
close(pipein[0]);
|
||||
if (pipein[1] >= 0)
|
||||
close(pipein[1]);
|
||||
if (pipeout[0] >= 0)
|
||||
close(pipeout[0]);
|
||||
if (pipeout[1] >= 0)
|
||||
close(pipeout[1]);
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
const string *inputstring, string *output)
|
||||
{
|
||||
@ -63,35 +106,31 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
const char *input = inputstring ? inputstring->data() : 0;
|
||||
unsigned int inputlen = inputstring ? inputstring->length() : 0;
|
||||
|
||||
int pipein[2]; // subproc input
|
||||
int pipeout[2]; // subproc output
|
||||
pipein[0] = pipein[1] = pipeout[0] = pipeout[1] = -1;
|
||||
ExecCmdRsrc e;
|
||||
|
||||
if (input && pipe(pipein) < 0) {
|
||||
if (input && pipe(e.pipein) < 0) {
|
||||
LOGERR(("ExecCmd::doexec: pipe(2) failed. errno %d\n", errno));
|
||||
return -1;
|
||||
}
|
||||
if (output && pipe(pipeout) < 0) {
|
||||
if (output && pipe(e.pipeout) < 0) {
|
||||
LOGERR(("ExecCmd::doexec: pipe(2) failed. errno %d\n", errno));
|
||||
if (pipein[0] >= 0) close(pipein[0]);
|
||||
if (pipein[1] >= 0) close(pipein[1]);
|
||||
return -1;
|
||||
}
|
||||
|
||||
pid_t pid = fork();
|
||||
if (pid < 0) {
|
||||
e.pid = fork();
|
||||
if (e.pid < 0) {
|
||||
LOGERR(("ExecCmd::doexec: fork(2) failed. errno %d\n", errno));
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (pid) {
|
||||
if (e.pid) {
|
||||
if (input) {
|
||||
close(pipein[0]);
|
||||
pipein[0] = -1;
|
||||
close(e.pipein[0]);
|
||||
e.pipein[0] = -1;
|
||||
}
|
||||
if (output) {
|
||||
close(pipeout[1]);
|
||||
pipeout[1] = -1;
|
||||
close(e.pipeout[1]);
|
||||
e.pipeout[1] = -1;
|
||||
}
|
||||
fd_set readfds, writefds;
|
||||
struct timeval tv;
|
||||
@ -100,25 +139,25 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
|
||||
if (input || output) {
|
||||
if (input)
|
||||
fcntl(pipein[1], F_SETFL, O_NONBLOCK);
|
||||
fcntl(e.pipein[1], F_SETFL, O_NONBLOCK);
|
||||
if (output)
|
||||
fcntl(pipeout[0], F_SETFL, O_NONBLOCK);
|
||||
fcntl(e.pipeout[0], F_SETFL, O_NONBLOCK);
|
||||
unsigned int nwritten = 0;
|
||||
int nfds = MAX(pipein[1], pipeout[0]) + 1;
|
||||
int nfds = MAX(e.pipein[1], e.pipeout[0]) + 1;
|
||||
for(; nfds > 0;) {
|
||||
if (m_cancelRequest)
|
||||
break;
|
||||
|
||||
FD_ZERO(&writefds);
|
||||
FD_ZERO(&readfds);
|
||||
if (pipein[1] >= 0)
|
||||
FD_SET(pipein[1], &writefds);
|
||||
if (pipeout[0] >= 0)
|
||||
FD_SET(pipeout[0], &readfds);
|
||||
nfds = MAX(pipein[1], pipeout[0]) + 1;
|
||||
if (e.pipein[1] >= 0)
|
||||
FD_SET(e.pipein[1], &writefds);
|
||||
if (e.pipeout[0] >= 0)
|
||||
FD_SET(e.pipeout[0], &readfds);
|
||||
nfds = MAX(e.pipein[1], e.pipeout[0]) + 1;
|
||||
//struct timeval to; to.tv_sec = 1;to.tv_usec=0;
|
||||
//cerr << "pipein[1] "<< pipein[1] << " pipeout[0] " <<
|
||||
//pipeout[0] << " nfds " << nfds << endl;
|
||||
//cerr << "e.pipein[1] "<< e.pipein[1] << " e.pipeout[0] " <<
|
||||
//e.pipeout[0] << " nfds " << nfds << endl;
|
||||
int ss;
|
||||
if ((ss = select(nfds, &readfds, &writefds, 0, &tv)) <= 0) {
|
||||
if (ss == 0) {
|
||||
@ -129,8 +168,8 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
errno));
|
||||
break;
|
||||
}
|
||||
if (pipein[1] >= 0 && FD_ISSET(pipein[1], &writefds)) {
|
||||
int n = write(pipein[1], input + nwritten,
|
||||
if (e.pipein[1] >= 0 && FD_ISSET(e.pipein[1], &writefds)) {
|
||||
int n = write(e.pipein[1], input + nwritten,
|
||||
inputlen - nwritten);
|
||||
if (n < 0) {
|
||||
LOGERR(("ExecCmd::doexec: write(2) failed. errno %d\n",
|
||||
@ -140,13 +179,13 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
nwritten += n;
|
||||
if (nwritten == inputlen) {
|
||||
// cerr << "Closing output" << endl;
|
||||
close(pipein[1]);
|
||||
pipein[1] = -1;
|
||||
close(e.pipein[1]);
|
||||
e.pipein[1] = -1;
|
||||
}
|
||||
}
|
||||
if (pipeout[0] > 0 && FD_ISSET(pipeout[0], &readfds)) {
|
||||
if (e.pipeout[0] > 0 && FD_ISSET(e.pipeout[0], &readfds)) {
|
||||
char buf[8192];
|
||||
int n = read(pipeout[0], buf, 8192);
|
||||
int n = read(e.pipeout[0], buf, 8192);
|
||||
if (n == 0) {
|
||||
goto out;
|
||||
} else if (n < 0) {
|
||||
@ -165,30 +204,11 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
|
||||
out:
|
||||
int status = -1;
|
||||
|
||||
if (m_cancelRequest) {
|
||||
// If we were canceled, need to cleanup
|
||||
LOGDEB1(("Killing cmd\n"));
|
||||
kill(pid, SIGTERM);
|
||||
for (int i = 0; i < 3; i++) {
|
||||
if (kill(pid, 0) != 0)
|
||||
break;
|
||||
sleep(1);
|
||||
if (i == 2) {
|
||||
LOGDEB1(("Killing (KILL) cmd\n"));
|
||||
kill(pid, SIGKILL);
|
||||
}
|
||||
}
|
||||
if (!m_cancelRequest) {
|
||||
LOGDEB(("Execmd: canceled\n"));
|
||||
(void)waitpid(e.pid, &status, 0);
|
||||
e.pid = -1;
|
||||
}
|
||||
(void)waitpid(pid, &status, 0);
|
||||
if (pipein[0] >= 0)
|
||||
close(pipein[0]);
|
||||
if (pipein[1] >= 0)
|
||||
close(pipein[1]);
|
||||
if (pipeout[0] >= 0)
|
||||
close(pipeout[0]);
|
||||
if (pipeout[1] >= 0)
|
||||
close(pipeout[1]);
|
||||
LOGDEB1(("ExecCmd::doexec: father got status 0x%x\n", status));
|
||||
return status;
|
||||
|
||||
@ -196,38 +216,36 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
// In child process. Set up pipes, environment, and exec command
|
||||
|
||||
if (input) {
|
||||
close(pipein[1]);
|
||||
pipein[1] = -1;
|
||||
if (pipein[0] != 0) {
|
||||
dup2(pipein[0], 0);
|
||||
close(pipein[0]);
|
||||
pipein[0] = -1;
|
||||
close(e.pipein[1]);
|
||||
e.pipein[1] = -1;
|
||||
if (e.pipein[0] != 0) {
|
||||
dup2(e.pipein[0], 0);
|
||||
close(e.pipein[0]);
|
||||
e.pipein[0] = -1;
|
||||
}
|
||||
}
|
||||
if (output) {
|
||||
close(pipeout[0]);
|
||||
pipeout[0] = -1;
|
||||
if (pipeout[1] != 1) {
|
||||
if (dup2(pipeout[1], 1) < 0) {
|
||||
close(e.pipeout[0]);
|
||||
e.pipeout[0] = -1;
|
||||
if (e.pipeout[1] != 1) {
|
||||
if (dup2(e.pipeout[1], 1) < 0) {
|
||||
LOGERR(("ExecCmd::doexec: dup2(2) failed. errno %d\n",
|
||||
errno));
|
||||
}
|
||||
if (close(pipeout[1]) < 0) {
|
||||
if (close(e.pipeout[1]) < 0) {
|
||||
LOGERR(("ExecCmd::doexec: close(2) failed. errno %d\n",
|
||||
errno));
|
||||
}
|
||||
pipeout[1] = -1;
|
||||
e.pipeout[1] = -1;
|
||||
}
|
||||
}
|
||||
|
||||
// Count args
|
||||
list<string>::const_iterator it;
|
||||
int i = 0;
|
||||
for (it = args.begin(); it != args.end(); it++) i++;
|
||||
e.reset();
|
||||
|
||||
// Allocate arg vector (2 more for arg0 + final 0)
|
||||
typedef const char *Ccharp;
|
||||
Ccharp *argv;
|
||||
argv = (Ccharp *)malloc((i+2) * sizeof(char *));
|
||||
argv = (Ccharp *)malloc((args.size()+2) * sizeof(char *));
|
||||
if (argv == 0) {
|
||||
LOGERR(("ExecCmd::doexec: malloc() failed. errno %d\n",
|
||||
errno));
|
||||
@ -236,7 +254,8 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
|
||||
// Fill up argv
|
||||
argv[0] = path_getsimple(cmd).c_str();
|
||||
i = 1;
|
||||
int i = 1;
|
||||
list<string>::const_iterator it;
|
||||
for (it = args.begin(); it != args.end(); it++) {
|
||||
argv[i++] = it->c_str();
|
||||
}
|
||||
@ -254,7 +273,6 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
::putenv(it->c_str());
|
||||
#endif
|
||||
}
|
||||
|
||||
execvp(cmd.c_str(), (char *const*)argv);
|
||||
// Hu ho
|
||||
LOGERR(("ExecCmd::doexec: execvp(%s) failed. errno %d\n", cmd.c_str(),
|
||||
@ -269,6 +287,8 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
|
||||
#include <iostream>
|
||||
#include <list>
|
||||
#include "debuglog.h"
|
||||
#include "cancelcheck.h"
|
||||
|
||||
using namespace std;
|
||||
|
||||
#include "execmd.h"
|
||||
@ -277,8 +297,14 @@ const char *data = "Une ligne de donnees\n";
|
||||
class MEAdv : public ExecCmdAdvise {
|
||||
public:
|
||||
ExecCmd *cmd;
|
||||
void newData() {cerr << "New Data!" << endl;cmd->setCancel();}
|
||||
void newData() {
|
||||
cerr << "New Data!" << endl;
|
||||
CancelCheck::instance().setCancel();
|
||||
CancelCheck::instance().checkCancel();
|
||||
// cmd->setCancel();
|
||||
}
|
||||
};
|
||||
|
||||
int main(int argc, const char **argv)
|
||||
{
|
||||
DebugLog::getdbl()->setloglevel(DEBDEB1);
|
||||
@ -304,7 +330,12 @@ int main(int argc, const char **argv)
|
||||
mexec.putenv("TESTVARIABLE2=TESTVALUE2");
|
||||
mexec.putenv("TESTVARIABLE3=TESTVALUE3");
|
||||
|
||||
int status = mexec.doexec(cmd, l, ip, &output);
|
||||
int status = -1;
|
||||
try {
|
||||
status = mexec.doexec(cmd, l, ip, &output);
|
||||
} catch (CancelExcept) {
|
||||
cerr << "CANCELED" << endl;
|
||||
}
|
||||
|
||||
fprintf(stderr, "Status: 0x%x\n", status);
|
||||
cout << "Output:" << output << endl;
|
||||
|
||||
@ -1,6 +1,6 @@
|
||||
#ifndef _EXECMD_H_INCLUDED_
|
||||
#define _EXECMD_H_INCLUDED_
|
||||
/* @(#$Id: execmd.h,v 1.5 2006-01-24 12:22:20 dockes Exp $ (C) 2004 J.F.Dockes */
|
||||
/* @(#$Id: execmd.h,v 1.6 2006-01-26 17:44:51 dockes Exp $ (C) 2004 J.F.Dockes */
|
||||
|
||||
#include <string>
|
||||
#include <list>
|
||||
@ -19,10 +19,15 @@ class ExecCmdAdvise {
|
||||
class ExecCmd {
|
||||
public:
|
||||
/**
|
||||
* Execute command. Both input and output can be specified, and
|
||||
* Execute command.
|
||||
*
|
||||
* Both input and output can be specified, and
|
||||
* asynchronous io is used to prevent blocking. This wont work if
|
||||
* input and output need to be synchronized (ie: Q/A), but ok for
|
||||
* filtering.
|
||||
* The function is exception-safe. In case an exception occurs in the
|
||||
* advise callback, fds and pids will be cleaned-up properly.
|
||||
*
|
||||
* @param cmd the program to execute. This must be an absolute file name
|
||||
* or exist in the PATH.
|
||||
* @param args the argument list (NOT including argv[0]).
|
||||
@ -44,7 +49,10 @@ class ExecCmd {
|
||||
/** Set function object to call whenever new data is available */
|
||||
void setAdvise(ExecCmdAdvise *adv) {m_advise = adv;}
|
||||
|
||||
/** Cancel exec. This can be called from another thread or from newData */
|
||||
/** Cancel exec. This can be called from another thread or from the
|
||||
* advise callback, which could also raise an exception to accomplish
|
||||
* the same thing
|
||||
*/
|
||||
void setCancel() {m_cancelRequest = true;}
|
||||
|
||||
ExecCmd() : m_advise(0), m_cancelRequest(false) {}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user