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/*
* Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Routines common to all platforms.
*/
#ifdef PSUTIL_POSIX
#include <sys/types.h>
#include <signal.h>
#endif
#include <Python.h>
/*
* Set OSError(errno=ESRCH, strerror="No such process") Python exception.
*/
PyObject *
NoSuchProcess(void) {
PyObject *exc;
char *msg = strerror(ESRCH);
exc = PyObject_CallFunction(PyExc_OSError, "(is)", ESRCH, msg);
PyErr_SetObject(PyExc_OSError, exc);
Py_XDECREF(exc);
return NULL;
}
/*
* Set OSError(errno=EACCES, strerror="Permission denied") Python exception.
*/
PyObject *
AccessDenied(void) {
PyObject *exc;
char *msg = strerror(EACCES);
exc = PyObject_CallFunction(PyExc_OSError, "(is)", EACCES, msg);
PyErr_SetObject(PyExc_OSError, exc);
Py_XDECREF(exc);
return NULL;
}
#ifdef PSUTIL_POSIX
/*
* Check if PID exists. Return values:
* 1: exists
* 0: does not exist
* -1: error (Python exception is set)
*/
int
psutil_pid_exists(long pid) {
int ret;
// No negative PID exists, plus -1 is an alias for sending signal
// too all processes except system ones. Not what we want.
if (pid < 0)
return 0;
// As per "man 2 kill" PID 0 is an alias for sending the signal to
// every process in the process group of the calling process.
// Not what we want. Some platforms have PID 0, some do not.
// We decide that at runtime.
if (pid == 0) {
#if defined(PSUTIL_LINUX) || defined(PSUTIL_FREEBSD)
return 0;
#else
return 1;
#endif
}
#if defined(PSUTIL_OSX)
ret = kill((pid_t)pid , 0);
#else
ret = kill(pid , 0);
#endif
if (ret == 0)
return 1;
else {
if (errno == ESRCH) {
// ESRCH == No such process
return 0;
}
else if (errno == EPERM) {
// EPERM clearly indicates there's a process to deny
// access to.
return 1;
}
else {
// According to "man 2 kill" possible error values are
// (EINVAL, EPERM, ESRCH) therefore we should never get
// here. If we do let's be explicit in considering this
// an error.
PyErr_SetFromErrno(PyExc_OSError);
return -1;
}
}
}
/*
* Utility used for those syscalls which do not return a meaningful
* error that we can translate into an exception which makes sense.
* As such, we'll have to guess.
* On UNIX, if errno is set, we return that one (OSError).
* Else, if PID does not exist we assume the syscall failed because
* of that so we raise NoSuchProcess.
* If none of this is true we giveup and raise RuntimeError(msg).
* This will always set a Python exception and return NULL.
*/
int
psutil_raise_for_pid(long pid, char *msg) {
// Set exception to AccessDenied if pid exists else NoSuchProcess.
if (errno != 0) {
PyErr_SetFromErrno(PyExc_OSError);
return 0;
}
if (psutil_pid_exists(pid) == 0)
NoSuchProcess();
else
PyErr_SetString(PyExc_RuntimeError, msg);
return 0;
}
#endif
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