cpython/Python/dynload_aix.c
Nick Coghlan d5cacbb1d9 PEP 489: Multi-phase extension module initialization
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.
2015-05-23 22:24:10 +10:00

185 lines
5.7 KiB
C

/* Support for dynamic loading of extension modules */
#include "Python.h"
#include "importdl.h"
#include <errno.h> /* for global errno */
#include <string.h> /* for strerror() */
#include <stdlib.h> /* for malloc(), free() */
#include <sys/ldr.h>
#ifdef AIX_GENUINE_CPLUSPLUS
#include <load.h>
#define aix_load loadAndInit
#else
#define aix_load load
#endif
extern char *Py_GetProgramName(void);
typedef struct Module {
struct Module *next;
void *entry;
} Module, *ModulePtr;
const char *_PyImport_DynLoadFiletab[] = {".so", NULL};
static int
aix_getoldmodules(void **modlistptr)
{
ModulePtr modptr, prevmodptr;
struct ld_info *ldiptr;
char *ldibuf;
int errflag, bufsize = 1024;
unsigned int offset;
char *progname = Py_GetProgramName();
/*
-- Get the list of loaded modules into ld_info structures.
*/
if ((ldibuf = malloc(bufsize)) == NULL) {
PyErr_SetString(PyExc_ImportError, strerror(errno));
return -1;
}
while ((errflag = loadquery(L_GETINFO, ldibuf, bufsize)) == -1
&& errno == ENOMEM) {
free(ldibuf);
bufsize += 1024;
if ((ldibuf = malloc(bufsize)) == NULL) {
PyErr_SetString(PyExc_ImportError, strerror(errno));
return -1;
}
}
if (errflag == -1) {
PyErr_SetString(PyExc_ImportError, strerror(errno));
return -1;
}
/*
-- Make the modules list from the ld_info structures.
*/
ldiptr = (struct ld_info *)ldibuf;
prevmodptr = NULL;
do {
if (strstr(progname, ldiptr->ldinfo_filename) == NULL &&
strstr(ldiptr->ldinfo_filename, "python") == NULL) {
/*
-- Extract only the modules belonging to the main
-- executable + those containing "python" as a
-- substring (like the "python[version]" binary or
-- "libpython[version].a" in case it's a shared lib).
*/
offset = (unsigned int)ldiptr->ldinfo_next;
ldiptr = (struct ld_info *)((char*)ldiptr + offset);
continue;
}
if ((modptr = (ModulePtr)malloc(sizeof(Module))) == NULL) {
PyErr_SetString(PyExc_ImportError, strerror(errno));
while (*modlistptr) {
modptr = (ModulePtr)*modlistptr;
*modlistptr = (void *)modptr->next;
free(modptr);
}
return -1;
}
modptr->entry = ldiptr->ldinfo_dataorg;
modptr->next = NULL;
if (prevmodptr == NULL)
*modlistptr = (void *)modptr;
else
prevmodptr->next = modptr;
prevmodptr = modptr;
offset = (unsigned int)ldiptr->ldinfo_next;
ldiptr = (struct ld_info *)((char*)ldiptr + offset);
} while (offset);
free(ldibuf);
return 0;
}
static void
aix_loaderror(const char *pathname)
{
char *message[1024], errbuf[1024];
PyObject *pathname_ob = NULL;
PyObject *errbuf_ob = NULL;
int i,j;
struct errtab {
int errNo;
char *errstr;
} load_errtab[] = {
{L_ERROR_TOOMANY, "too many errors, rest skipped."},
{L_ERROR_NOLIB, "can't load library:"},
{L_ERROR_UNDEF, "can't find symbol in library:"},
{L_ERROR_RLDBAD,
"RLD index out of range or bad relocation type:"},
{L_ERROR_FORMAT, "not a valid, executable xcoff file:"},
{L_ERROR_MEMBER,
"file not an archive or does not contain requested member:"},
{L_ERROR_TYPE, "symbol table mismatch:"},
{L_ERROR_ALIGN, "text alignment in file is wrong."},
{L_ERROR_SYSTEM, "System error:"},
{L_ERROR_ERRNO, NULL}
};
#define ERRBUF_APPEND(s) strncat(errbuf, s, sizeof(errbuf)-strlen(errbuf)-1)
PyOS_snprintf(errbuf, sizeof(errbuf), "from module %.200s ", pathname);
if (!loadquery(L_GETMESSAGES, &message[0], sizeof(message))) {
ERRBUF_APPEND(strerror(errno));
ERRBUF_APPEND("\n");
}
for(i = 0; message[i] && *message[i]; i++) {
int nerr = atoi(message[i]);
for (j=0; j < Py_ARRAY_LENGTH(load_errtab); j++) {
if (nerr == load_errtab[j].errNo && load_errtab[j].errstr)
ERRBUF_APPEND(load_errtab[j].errstr);
}
while (Py_ISDIGIT(Py_CHARMASK(*message[i]))) message[i]++ ;
ERRBUF_APPEND(message[i]);
ERRBUF_APPEND("\n");
}
errbuf[strlen(errbuf)-1] = '\0'; /* trim off last newline */
pathname_ob = PyUnicode_FromString(pathname);
errbuf_ob = PyUnicode_FromString(errbuf);
PyErr_SetImportError(errbuf_ob, NULL, pathname);
Py_DECREF(pathname_ob);
Py_DECREF(errbuf_ob);
return;
}
dl_funcptr _PyImport_FindSharedFuncptr(const char *prefix,
const char *shortname,
const char *pathname, FILE *fp)
{
dl_funcptr p;
/*
-- Invoke load() with L_NOAUTODEFER leaving the imported symbols
-- of the shared module unresolved. Thus we have to resolve them
-- explicitly with loadbind. The new module is loaded, then we
-- resolve its symbols using the list of already loaded modules
-- (only those that belong to the python executable). Get these
-- with loadquery(L_GETINFO).
*/
static void *staticmodlistptr = NULL;
if (!staticmodlistptr)
if (aix_getoldmodules(&staticmodlistptr) == -1)
return NULL;
p = (dl_funcptr) aix_load((char *)pathname, L_NOAUTODEFER, 0);
if (p == NULL) {
aix_loaderror(pathname);
return NULL;
}
return p;
}