int
getdtablesize (void)
{
if (dtablesize == 0)
{
/* We are looking for the number N such that the valid file descriptors
are 0..N-1. It can be obtained through a loop as follows:
{
int fd;
for (fd = 3; fd < 65536; fd++)
if (dup2 (0, fd) == -1)
break;
return fd;
}
On Windows XP, the result is 2048.
The drawback of this loop is that it allocates memory for a libc
internal array that is never freed.
The number N can also be obtained as the upper bound for
_getmaxstdio (). _getmaxstdio () returns the maximum number of open
FILE objects. The sanity check in _setmaxstdio reveals the maximum
number of file descriptors. This too allocates memory, but it is
freed when we call _setmaxstdio with the original value. */
int orig_max_stdio = _getmaxstdio ();
unsigned int bound;
for (bound = 0x10000; _setmaxstdio (bound) < 0; bound = bound / 2)
;
_setmaxstdio (orig_max_stdio);
dtablesize = bound;
}
return dtablesize;
}
ccReturn ccSysinfoInitialize(void)
{
SYSTEM_INFO sysinfo;
MEMORYSTATUSEX memstat;
memstat.dwLength = sizeof(MEMORYSTATUSEX);
GlobalMemoryStatusEx(&memstat);
ccAssert(_ccSysinfo == NULL);
ccMalloc(_ccSysinfo, sizeof(ccSysinfo));
if(GetPhysicallyInstalledSystemMemory(&_ccSysinfo->ramTotal) == FALSE) goto fail;
_ccSysinfo->ramTotal <<= 10;
GetSystemInfo(&sysinfo);
_ccSysinfo->processorCount = sysinfo.dwNumberOfProcessors;
_ccSysinfo->fileMaxOpen = _getmaxstdio();
return CC_SUCCESS;
fail:
free(_ccSysinfo);
return CC_FAIL;
}
/* --------------------------------------------------------- init_globals --- */
void
RTcmix::init_globals(bool fromMain, const char *defaultDSOPath)
{
Option::init();
if (defaultDSOPath && defaultDSOPath[0])
Option::dsoPathPrepend(defaultDSOPath);
if (fromMain) {
#ifndef MAXMSP
Option::readConfigFile(Option::rcName());
Option::exitOnError(true); // we do this no matter what is in config file
#else
Option::exitOnError(false);
#endif
rtInteractive = 0;
}
else {
SR = 44100.0; // what the heck...
Option::print(0);
Option::reportClipping(false);
}
RTBUFSAMPS = (int) Option::bufferFrames(); /* modifiable with rtsetparams */
rtHeap = new heap;
rtQueue = new RTQueue[MAXBUS*3];
#ifdef MULTI_THREAD
taskManager = new TaskManager;
mixVector.reserve(MAXBUS);
#endif
for (int i = 0; i < MAXBUS; i++) {
AuxToAuxPlayList[i] = -1; /* The playback order for AUX buses */
ToOutPlayList[i] = -1; /* The playback order for AUX buses */
ToAuxPlayList[i] =-1; /* The playback order for AUX buses */
}
#ifdef MINGW
max_input_fds = _getmaxstdio();
#else
max_input_fds = sysconf(_SC_OPEN_MAX);
#endif
if (max_input_fds == -1) // call failed
max_input_fds = 128; // what we used to hardcode
else
max_input_fds -= RESERVE_INPUT_FDS;
inputFileTable = new InputFile[max_input_fds];
init_buf_ptrs();
if (Option::autoLoad()) {
const char *dsoPath = Option::dsoPath();
if (strlen(dsoPath) == 0)
registerDSOs(SHAREDLIBDIR);
else
registerDSOs(dsoPath);
}
}
/**
* Described in header.
*/
void closefrom(int lowfd)
{
char fd_dir[PATH_MAX];
int maxfd, fd, len;
/* try to close only open file descriptors on Linux... */
len = snprintf(fd_dir, sizeof(fd_dir), "/proc/%u/fd", getpid());
if (len > 0 && len < sizeof(fd_dir) && access(fd_dir, F_OK) == 0)
{
enumerator_t *enumerator = enumerator_create_directory(fd_dir);
if (enumerator)
{
char *rel;
while (enumerator->enumerate(enumerator, &rel, NULL, NULL))
{
fd = atoi(rel);
if (fd >= lowfd)
{
close(fd);
}
}
enumerator->destroy(enumerator);
return;
}
}
/* ...fall back to closing all fds otherwise */
#ifdef WIN32
maxfd = _getmaxstdio();
#else
maxfd = (int)sysconf(_SC_OPEN_MAX);
#endif
if (maxfd < 0)
{
maxfd = 256;
}
for (fd = lowfd; fd < maxfd; fd++)
{
close(fd);
}
}
int getdtablesize() { return _getmaxstdio(); }
void testMaxHandlersOfFiles()
{
printf( "maxstdio: %d\n", _getmaxstdio());
_setmaxstdio(2048);
printf( "maxstdio: %d\n", _getmaxstdio());
}
/**
* Described in header.
*/
void closefrom(int low_fd)
{
int max_fd, dir_fd, fd;
/* try to close only open file descriptors on Linux... */
#if defined(__linux__) && defined(HAVE_SYS_SYSCALL_H)
/* By directly using a syscall we avoid any calls that might be unsafe after
* fork() (e.g. malloc()). */
char buffer[sizeof(struct linux_dirent64)];
struct linux_dirent64 *entry;
int offset, len;
dir_fd = open("/proc/self/fd", O_RDONLY);
if (dir_fd != -1)
{
while ((len = syscall(SYS_getdents64, dir_fd, buffer,
sizeof(buffer))) > 0)
{
for (offset = 0; offset < len; offset += entry->d_reclen)
{
entry = (struct linux_dirent64*)(buffer + offset);
if (!isdigit(entry->d_name[0]))
{
continue;
}
fd = atoi(entry->d_name);
if (fd != dir_fd && fd >= low_fd)
{
close(fd);
}
}
}
close(dir_fd);
return;
}
#else /* !defined(__linux__) || !defined(HAVE_SYS_SYSCALL_H) */
/* This is potentially unsafe when called after fork() in multi-threaded
* applications. In particular opendir() will require an allocation.
* Depends on how the malloc() implementation handles such situations. */
DIR *dir;
struct dirent *entry;
#ifndef HAVE_DIRFD
/* if we don't have dirfd() lets close the lowest FD and hope it gets reused
* by opendir() */
close(low_fd);
dir_fd = low_fd++;
#endif
dir = opendir(FD_DIR);
if (dir)
{
#ifdef HAVE_DIRFD
dir_fd = dirfd(dir);
#endif
while ((entry = readdir(dir)))
{
if (!isdigit(entry->d_name[0]))
{
continue;
}
fd = atoi(entry->d_name);
if (fd != dir_fd && fd >= low_fd)
{
close(fd);
}
}
closedir(dir);
return;
}
#endif /* defined(__linux__) && defined(HAVE_SYS_SYSCALL_H) */
/* ...fall back to closing all fds otherwise */
#ifdef WIN32
max_fd = _getmaxstdio();
#else
max_fd = (int)sysconf(_SC_OPEN_MAX);
#endif
if (max_fd < 0)
{
max_fd = 256;
}
for (fd = low_fd; fd < max_fd; fd++)
{
close(fd);
}
}
static PyObject *
winutil_get_max_stdio(PyObject *self, PyObject *args) {
return Py_BuildValue("i", _getmaxstdio());
}
int
pdc_get_maxfilehandles(void)
{
return _getmaxstdio();
}
