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				synced 2025-11-03 07:01:21 +00:00 
			
		
		
		
	Known limitations of the current implementation: - documentation changes are incomplete - there's a reference leak I haven't tracked down yet The leak is most visible by running: ./python -m test -R3:3 test_importlib However, you can also see it by running: ./python -X showrefcount Importing the array or _testmultiphase modules, and then deleting them from both sys.modules and the local namespace shows significant increases in the total number of active references each cycle. By contrast, with _testcapi (which continues to use single-phase initialisation) the global refcounts stabilise after a couple of cycles.
		
			
				
	
	
		
			128 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
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/* Support for dynamic loading of extension modules */
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#include "Python.h"
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#include "importdl.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#if defined(__NetBSD__)
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#include <sys/param.h>
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#if (NetBSD < 199712)
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#include <nlist.h>
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#include <link.h>
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#define dlerror() "error in dynamic linking"
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#endif
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#endif /* NetBSD */
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#ifdef HAVE_DLFCN_H
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#include <dlfcn.h>
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#endif
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#if (defined(__OpenBSD__) || defined(__NetBSD__)) && !defined(__ELF__)
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#define LEAD_UNDERSCORE "_"
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#else
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#define LEAD_UNDERSCORE ""
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#endif
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/* The .so extension module ABI tag, supplied by the Makefile via
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   Makefile.pre.in and configure.  This is used to discriminate between
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   incompatible .so files so that extensions for different Python builds can
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   live in the same directory.  E.g. foomodule.cpython-32.so
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*/
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const char *_PyImport_DynLoadFiletab[] = {
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#ifdef __CYGWIN__
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    ".dll",
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#else  /* !__CYGWIN__ */
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    "." SOABI ".so",
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    ".abi" PYTHON_ABI_STRING ".so",
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    ".so",
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#endif  /* __CYGWIN__ */
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    NULL,
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};
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static struct {
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    dev_t dev;
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    ino_t ino;
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    void *handle;
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} handles[128];
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static int nhandles = 0;
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dl_funcptr
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_PyImport_FindSharedFuncptr(const char *prefix,
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                            const char *shortname,
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                            const char *pathname, FILE *fp)
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{
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    dl_funcptr p;
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    void *handle;
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    char funcname[258];
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    char pathbuf[260];
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    int dlopenflags=0;
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    if (strchr(pathname, '/') == NULL) {
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        /* Prefix bare filename with "./" */
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        PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
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        pathname = pathbuf;
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    }
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    PyOS_snprintf(funcname, sizeof(funcname),
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                  LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
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    if (fp != NULL) {
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        int i;
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        struct _Py_stat_struct status;
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        if (_Py_fstat(fileno(fp), &status) == -1)
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            return NULL;
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        for (i = 0; i < nhandles; i++) {
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            if (status.st_dev == handles[i].dev &&
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                status.st_ino == handles[i].ino) {
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                p = (dl_funcptr) dlsym(handles[i].handle,
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                                       funcname);
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                return p;
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            }
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        }
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        if (nhandles < 128) {
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            handles[nhandles].dev = status.st_dev;
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            handles[nhandles].ino = status.st_ino;
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        }
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    }
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    dlopenflags = PyThreadState_GET()->interp->dlopenflags;
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    handle = dlopen(pathname, dlopenflags);
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    if (handle == NULL) {
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        PyObject *mod_name;
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        PyObject *path;
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        PyObject *error_ob;
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        const char *error = dlerror();
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        if (error == NULL)
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            error = "unknown dlopen() error";
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        error_ob = PyUnicode_FromString(error);
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        if (error_ob == NULL)
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            return NULL;
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        mod_name = PyUnicode_FromString(shortname);
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        if (mod_name == NULL) {
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            Py_DECREF(error_ob);
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            return NULL;
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        }
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        path = PyUnicode_FromString(pathname);
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        if (path == NULL) {
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            Py_DECREF(error_ob);
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            Py_DECREF(mod_name);
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            return NULL;
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        }
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        PyErr_SetImportError(error_ob, mod_name, path);
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        Py_DECREF(error_ob);
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        Py_DECREF(mod_name);
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        Py_DECREF(path);
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        return NULL;
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    }
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    if (fp != NULL && nhandles < 128)
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        handles[nhandles++].handle = handle;
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    p = (dl_funcptr) dlsym(handle, funcname);
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    return p;
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}
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