tris/recoll
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

make execCmd exception-safe

Browse Source
This commit is contained in:
dockes 2006-01-26 17:44:51 +00:00
parent cb344d7493
commit f920d2ce3e
2 changed files with 117 additions and 78 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

181
src/utils/execmd.cpp
View File

@ -1,5 +1,5 @@
#ifndef lint #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 #endif
/* /*
* This program is free software; you can redistribute it and/or modify * 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); 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, int ExecCmd::doexec(const string &cmd, const list<string>& args,
const string *inputstring, string *output) 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; const char *input = inputstring ? inputstring->data() : 0;
unsigned int inputlen = inputstring ? inputstring->length() : 0; unsigned int inputlen = inputstring ? inputstring->length() : 0;
int pipein[2]; // subproc input ExecCmdRsrc e;
int pipeout[2]; // subproc output
pipein[0] = pipein[1] = pipeout[0] = pipeout[1] = -1;
if (input && pipe(pipein) < 0) { if (input && pipe(e.pipein) < 0) {
LOGERR(("ExecCmd::doexec: pipe(2) failed. errno %d\n", errno)); LOGERR(("ExecCmd::doexec: pipe(2) failed. errno %d\n", errno));
return -1; return -1;
} }
if (output && pipe(pipeout) < 0) { if (output && pipe(e.pipeout) < 0) {
LOGERR(("ExecCmd::doexec: pipe(2) failed. errno %d\n", errno)); 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; return -1;
} }
pid_t pid = fork(); e.pid = fork();
if (pid < 0) { if (e.pid < 0) {
LOGERR(("ExecCmd::doexec: fork(2) failed. errno %d\n", errno)); LOGERR(("ExecCmd::doexec: fork(2) failed. errno %d\n", errno));
return -1; return -1;
} }
if (pid) { if (e.pid) {
if (input) { if (input) {
close(pipein[0]); close(e.pipein[0]);
pipein[0] = -1; e.pipein[0] = -1;
} }
if (output) { if (output) {
close(pipeout[1]); close(e.pipeout[1]);
pipeout[1] = -1; e.pipeout[1] = -1;
} }
fd_set readfds, writefds; fd_set readfds, writefds;
struct timeval tv; struct timeval tv;
@ -100,25 +139,25 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
if (input || output) { if (input || output) {
if (input) if (input)
fcntl(pipein[1], F_SETFL, O_NONBLOCK); fcntl(e.pipein[1], F_SETFL, O_NONBLOCK);
if (output) if (output)
fcntl(pipeout[0], F_SETFL, O_NONBLOCK); fcntl(e.pipeout[0], F_SETFL, O_NONBLOCK);
unsigned int nwritten = 0; 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;) { for(; nfds > 0;) {
if (m_cancelRequest) if (m_cancelRequest)
break; break;
FD_ZERO(&writefds); FD_ZERO(&writefds);
FD_ZERO(&readfds); FD_ZERO(&readfds);
if (pipein[1] >= 0) if (e.pipein[1] >= 0)
FD_SET(pipein[1], &writefds); FD_SET(e.pipein[1], &writefds);
if (pipeout[0] >= 0) if (e.pipeout[0] >= 0)
FD_SET(pipeout[0], &readfds); FD_SET(e.pipeout[0], &readfds);
nfds = MAX(pipein[1], pipeout[0]) + 1; nfds = MAX(e.pipein[1], e.pipeout[0]) + 1;
//struct timeval to; to.tv_sec = 1;to.tv_usec=0; //struct timeval to; to.tv_sec = 1;to.tv_usec=0;
//cerr << "pipein[1] "<< pipein[1] << " pipeout[0] " << //cerr << "e.pipein[1] "<< e.pipein[1] << " e.pipeout[0] " <<
//pipeout[0] << " nfds " << nfds << endl; //e.pipeout[0] << " nfds " << nfds << endl;
int ss; int ss;
if ((ss = select(nfds, &readfds, &writefds, 0, &tv)) <= 0) { if ((ss = select(nfds, &readfds, &writefds, 0, &tv)) <= 0) {
if (ss == 0) { if (ss == 0) {
@ -129,8 +168,8 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
errno)); errno));
break; break;
} }
if (pipein[1] >= 0 && FD_ISSET(pipein[1], &writefds)) { if (e.pipein[1] >= 0 && FD_ISSET(e.pipein[1], &writefds)) {
int n = write(pipein[1], input + nwritten, int n = write(e.pipein[1], input + nwritten,
inputlen - nwritten); inputlen - nwritten);
if (n < 0) { if (n < 0) {
LOGERR(("ExecCmd::doexec: write(2) failed. errno %d\n", 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; nwritten += n;
if (nwritten == inputlen) { if (nwritten == inputlen) {
// cerr << "Closing output" << endl; // cerr << "Closing output" << endl;
close(pipein[1]); close(e.pipein[1]);
pipein[1] = -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]; char buf[8192];
int n = read(pipeout[0], buf, 8192); int n = read(e.pipeout[0], buf, 8192);
if (n == 0) { if (n == 0) {
goto out; goto out;
} else if (n < 0) { } else if (n < 0) {
@ -165,30 +204,11 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
out: out:
int status = -1; int status = -1;
if (!m_cancelRequest) {
if (m_cancelRequest) { LOGDEB(("Execmd: canceled\n"));
// If we were canceled, need to cleanup (void)waitpid(e.pid, &status, 0);
LOGDEB1(("Killing cmd\n")); e.pid = -1;
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);
}
}
} }
(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)); LOGDEB1(("ExecCmd::doexec: father got status 0x%x\n", status));
return 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 // In child process. Set up pipes, environment, and exec command
if (input) { if (input) {
close(pipein[1]); close(e.pipein[1]);
pipein[1] = -1; e.pipein[1] = -1;
if (pipein[0] != 0) { if (e.pipein[0] != 0) {
dup2(pipein[0], 0); dup2(e.pipein[0], 0);
close(pipein[0]); close(e.pipein[0]);
pipein[0] = -1; e.pipein[0] = -1;
} }
} }
if (output) { if (output) {
close(pipeout[0]); close(e.pipeout[0]);
pipeout[0] = -1; e.pipeout[0] = -1;
if (pipeout[1] != 1) { if (e.pipeout[1] != 1) {
if (dup2(pipeout[1], 1) < 0) { if (dup2(e.pipeout[1], 1) < 0) {
LOGERR(("ExecCmd::doexec: dup2(2) failed. errno %d\n", LOGERR(("ExecCmd::doexec: dup2(2) failed. errno %d\n",
errno)); errno));
} }
if (close(pipeout[1]) < 0) { if (close(e.pipeout[1]) < 0) {
LOGERR(("ExecCmd::doexec: close(2) failed. errno %d\n", LOGERR(("ExecCmd::doexec: close(2) failed. errno %d\n",
errno)); errno));
} }
pipeout[1] = -1; e.pipeout[1] = -1;
} }
} }
// Count args e.reset();
list<string>::const_iterator it;
int i = 0;
for (it = args.begin(); it != args.end(); it++) i++;
// Allocate arg vector (2 more for arg0 + final 0) // Allocate arg vector (2 more for arg0 + final 0)
typedef const char *Ccharp; typedef const char *Ccharp;
Ccharp *argv; Ccharp *argv;
argv = (Ccharp *)malloc((i+2) * sizeof(char *)); argv = (Ccharp *)malloc((args.size()+2) * sizeof(char *));
if (argv == 0) { if (argv == 0) {
LOGERR(("ExecCmd::doexec: malloc() failed. errno %d\n", LOGERR(("ExecCmd::doexec: malloc() failed. errno %d\n",
errno)); errno));
@ -236,7 +254,8 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
// Fill up argv // Fill up argv
argv[0] = path_getsimple(cmd).c_str(); 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++) { for (it = args.begin(); it != args.end(); it++) {
argv[i++] = it->c_str(); argv[i++] = it->c_str();
} }
@ -254,7 +273,6 @@ int ExecCmd::doexec(const string &cmd, const list<string>& args,
::putenv(it->c_str()); ::putenv(it->c_str());
#endif #endif
} }
execvp(cmd.c_str(), (char *const*)argv); execvp(cmd.c_str(), (char *const*)argv);
// Hu ho // Hu ho
LOGERR(("ExecCmd::doexec: execvp(%s) failed. errno %d\n", cmd.c_str(), 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 <iostream>
#include <list> #include <list>
#include "debuglog.h" #include "debuglog.h"
#include "cancelcheck.h"
using namespace std; using namespace std;
#include "execmd.h" #include "execmd.h"
@ -277,8 +297,14 @@ const char *data = "Une ligne de donnees\n";
class MEAdv : public ExecCmdAdvise { class MEAdv : public ExecCmdAdvise {
public: public:
ExecCmd *cmd; 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) int main(int argc, const char **argv)
{ {
DebugLog::getdbl()->setloglevel(DEBDEB1); DebugLog::getdbl()->setloglevel(DEBDEB1);
@ -304,7 +330,12 @@ int main(int argc, const char **argv)
mexec.putenv("TESTVARIABLE2=TESTVALUE2"); mexec.putenv("TESTVARIABLE2=TESTVALUE2");
mexec.putenv("TESTVARIABLE3=TESTVALUE3"); 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); fprintf(stderr, "Status: 0x%x\n", status);
cout << "Output:" << output << endl; cout << "Output:" << output << endl;

14
src/utils/execmd.h
View File

@ -1,6 +1,6 @@
#ifndef _EXECMD_H_INCLUDED_ #ifndef _EXECMD_H_INCLUDED_
#define _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 <string>
#include <list> #include <list>
@ -19,10 +19,15 @@ class ExecCmdAdvise {
class ExecCmd { class ExecCmd {
public: 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 * asynchronous io is used to prevent blocking. This wont work if
* input and output need to be synchronized (ie: Q/A), but ok for * input and output need to be synchronized (ie: Q/A), but ok for
* filtering. * 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 * @param cmd the program to execute. This must be an absolute file name
* or exist in the PATH. * or exist in the PATH.
* @param args the argument list (NOT including argv[0]). * @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 */ /** Set function object to call whenever new data is available */
void setAdvise(ExecCmdAdvise *adv) {m_advise = adv;} 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;} void setCancel() {m_cancelRequest = true;}
ExecCmd() : m_advise(0), m_cancelRequest(false) {} ExecCmd() : m_advise(0), m_cancelRequest(false) {}