Call _PyTraceMalloc_Init() at Python startup

So TABLES_LOCK() can be called in _PyMem_DumpTraceback() even if
tracemalloc is not tracing.

Author: vstinner

Include/internal/pycore_tracemalloc.h

@@ -144,7 +144,7 @@ extern PyObject* _PyTraceMalloc_GetTraces(void);
 extern PyObject* _PyTraceMalloc_GetObjectTraceback(PyObject *obj);
 
 /* Initialize tracemalloc */
-extern int _PyTraceMalloc_Init(void);
+extern PyStatus _PyTraceMalloc_Init(void);
 
 /* Start tracemalloc */
 extern int _PyTraceMalloc_Start(int max_nframe);

Modules/_tracemalloc.c

@@ -223,10 +223,5 @@ PyInit__tracemalloc(void)
     PyUnstable_Module_SetGIL(m, Py_MOD_GIL_NOT_USED);
 #endif
 
-    if (_PyTraceMalloc_Init() < 0) {
-        Py_DECREF(m);
-        return NULL;
-    }
-
     return m;
 }

Python/pylifecycle.c

@@ -706,6 +706,11 @@ pycore_create_interpreter(_PyRuntimeState *runtime,
         return  _PyStatus_NO_MEMORY();
     }
 
+    status = _PyTraceMalloc_Init();
+    if (_PyStatus_EXCEPTION(status)) {
+        return status;
+    }
+
     PyThreadState *tstate = _PyThreadState_New(interp,
                                                _PyThreadState_WHENCE_INIT);
     if (tstate == NULL) {

Python/tracemalloc.c

@@ -2,6 +2,7 @@
 #include "pycore_fileutils.h"     // _Py_write_noraise()
 #include "pycore_gc.h"            // PyGC_Head
 #include "pycore_hashtable.h"     // _Py_hashtable_t
+#include "pycore_initconfig.h"    // _PyStatus_NO_MEMORY()
 #include "pycore_object.h"        // _PyType_PreHeaderSize()
 #include "pycore_pymem.h"         // _Py_tracemalloc_config
 #include "pycore_runtime.h"       // _Py_ID()
@@ -815,37 +816,24 @@ tracemalloc_clear_traces_unlocked(void)
 }
 
 
-int
+PyStatus
 _PyTraceMalloc_Init(void)
 {
-    if (tracemalloc_config.initialized == TRACEMALLOC_FINALIZED) {
-        PyErr_SetString(PyExc_RuntimeError,
-                        "the tracemalloc module has been unloaded");
-        return -1;
-    }
-
-    if (tracemalloc_config.initialized == TRACEMALLOC_INITIALIZED)
-        return 0;
+    assert(tracemalloc_config.initialized == TRACEMALLOC_NOT_INITIALIZED);
 
     PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
 
 #ifdef REENTRANT_THREADLOCAL
     if (PyThread_tss_create(&tracemalloc_reentrant_key) != 0) {
-#ifdef MS_WINDOWS
-        PyErr_SetFromWindowsErr(0);
-#else
-        PyErr_SetFromErrno(PyExc_OSError);
-#endif
-        return -1;
+        return _PyStatus_NO_MEMORY();
     }
 #endif
 
 #if defined(TRACE_RAW_MALLOC)
     if (tables_lock == NULL) {
         tables_lock = PyThread_allocate_lock();
         if (tables_lock == NULL) {
-            PyErr_SetString(PyExc_RuntimeError, "cannot allocate lock");
-            return -1;
+            return _PyStatus_NO_MEMORY();
         }
     }
 #endif
@@ -862,9 +850,9 @@ _PyTraceMalloc_Init(void)
     tracemalloc_domains = tracemalloc_create_domains_table();
 
     if (tracemalloc_filenames == NULL || tracemalloc_tracebacks == NULL
-       || tracemalloc_traces == NULL || tracemalloc_domains == NULL) {
-        PyErr_NoMemory();
-        return -1;
+       || tracemalloc_traces == NULL || tracemalloc_domains == NULL)
+    {
+        return _PyStatus_NO_MEMORY();
     }
 
     tracemalloc_empty_traceback.nframe = 1;
@@ -875,7 +863,7 @@ _PyTraceMalloc_Init(void)
     tracemalloc_empty_traceback.hash = traceback_hash(&tracemalloc_empty_traceback);
 
     tracemalloc_config.initialized = TRACEMALLOC_INITIALIZED;
-    return 0;
+    return _PyStatus_OK();
 }
 
 
@@ -920,10 +908,6 @@ _PyTraceMalloc_Start(int max_nframe)
         return -1;
     }
 
-    if (_PyTraceMalloc_Init() < 0) {
-        return -1;
-    }
-
     if (PyRefTracer_SetTracer(_PyTraceMalloc_TraceRef, NULL) < 0) {
         return -1;
     }