Issue #14785: Add sys._debugmallocstats() to help debug low-level memory allocation issues
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 9cd6a50..9254821 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -523,12 +523,10 @@
/* Number of arenas allocated that haven't been free()'d. */
static size_t narenas_currently_allocated = 0;
-#ifdef PYMALLOC_DEBUG
/* Total number of times malloc() called to allocate an arena. */
static size_t ntimes_arena_allocated = 0;
/* High water mark (max value ever seen) for narenas_currently_allocated. */
static size_t narenas_highwater = 0;
-#endif
/* Allocate a new arena. If we run out of memory, return NULL. Else
* allocate a new arena, and return the address of an arena_object
@@ -545,7 +543,7 @@
#ifdef PYMALLOC_DEBUG
if (Py_GETENV("PYTHONMALLOCSTATS"))
- _PyObject_DebugMallocStats();
+ _PyObject_DebugMallocStats(stderr);
#endif
if (unused_arena_objects == NULL) {
uint i;
@@ -613,11 +611,9 @@
arenaobj->address = (uptr)address;
++narenas_currently_allocated;
-#ifdef PYMALLOC_DEBUG
++ntimes_arena_allocated;
if (narenas_currently_allocated > narenas_highwater)
narenas_highwater = narenas_currently_allocated;
-#endif
arenaobj->freepools = NULL;
/* pool_address <- first pool-aligned address in the arena
nfreepools <- number of whole pools that fit after alignment */
@@ -1723,17 +1719,19 @@
}
}
+#endif /* PYMALLOC_DEBUG */
+
static size_t
-printone(const char* msg, size_t value)
+printone(FILE *out, const char* msg, size_t value)
{
int i, k;
char buf[100];
size_t origvalue = value;
- fputs(msg, stderr);
+ fputs(msg, out);
for (i = (int)strlen(msg); i < 35; ++i)
- fputc(' ', stderr);
- fputc('=', stderr);
+ fputc(' ', out);
+ fputc('=', out);
/* Write the value with commas. */
i = 22;
@@ -1754,17 +1752,33 @@
while (i >= 0)
buf[i--] = ' ';
- fputs(buf, stderr);
+ fputs(buf, out);
return origvalue;
}
-/* Print summary info to stderr about the state of pymalloc's structures.
+void
+_PyDebugAllocatorStats(FILE *out,
+ const char *block_name, int num_blocks, size_t sizeof_block)
+{
+ char buf1[128];
+ char buf2[128];
+ PyOS_snprintf(buf1, sizeof(buf1),
+ "%d %ss * %zd bytes each",
+ num_blocks, block_name, sizeof_block);
+ PyOS_snprintf(buf2, sizeof(buf2),
+ "%48s ", buf1);
+ (void)printone(out, buf2, num_blocks * sizeof_block);
+}
+
+#ifdef WITH_PYMALLOC
+
+/* Print summary info to "out" about the state of pymalloc's structures.
* In Py_DEBUG mode, also perform some expensive internal consistency
* checks.
*/
void
-_PyObject_DebugMallocStats(void)
+_PyObject_DebugMallocStats(FILE *out)
{
uint i;
const uint numclasses = SMALL_REQUEST_THRESHOLD >> ALIGNMENT_SHIFT;
@@ -1793,7 +1807,7 @@
size_t total;
char buf[128];
- fprintf(stderr, "Small block threshold = %d, in %u size classes.\n",
+ fprintf(out, "Small block threshold = %d, in %u size classes.\n",
SMALL_REQUEST_THRESHOLD, numclasses);
for (i = 0; i < numclasses; ++i)
@@ -1847,10 +1861,10 @@
}
assert(narenas == narenas_currently_allocated);
- fputc('\n', stderr);
+ fputc('\n', out);
fputs("class size num pools blocks in use avail blocks\n"
"----- ---- --------- ------------- ------------\n",
- stderr);
+ out);
for (i = 0; i < numclasses; ++i) {
size_t p = numpools[i];
@@ -1861,7 +1875,7 @@
assert(b == 0 && f == 0);
continue;
}
- fprintf(stderr, "%5u %6u "
+ fprintf(out, "%5u %6u "
"%11" PY_FORMAT_SIZE_T "u "
"%15" PY_FORMAT_SIZE_T "u "
"%13" PY_FORMAT_SIZE_T "u\n",
@@ -1871,35 +1885,36 @@
pool_header_bytes += p * POOL_OVERHEAD;
quantization += p * ((POOL_SIZE - POOL_OVERHEAD) % size);
}
- fputc('\n', stderr);
- (void)printone("# times object malloc called", serialno);
-
- (void)printone("# arenas allocated total", ntimes_arena_allocated);
- (void)printone("# arenas reclaimed", ntimes_arena_allocated - narenas);
- (void)printone("# arenas highwater mark", narenas_highwater);
- (void)printone("# arenas allocated current", narenas);
+ fputc('\n', out);
+#ifdef PYMALLOC_DEBUG
+ (void)printone(out, "# times object malloc called", serialno);
+#endif
+ (void)printone(out, "# arenas allocated total", ntimes_arena_allocated);
+ (void)printone(out, "# arenas reclaimed", ntimes_arena_allocated - narenas);
+ (void)printone(out, "# arenas highwater mark", narenas_highwater);
+ (void)printone(out, "# arenas allocated current", narenas);
PyOS_snprintf(buf, sizeof(buf),
"%" PY_FORMAT_SIZE_T "u arenas * %d bytes/arena",
narenas, ARENA_SIZE);
- (void)printone(buf, narenas * ARENA_SIZE);
+ (void)printone(out, buf, narenas * ARENA_SIZE);
- fputc('\n', stderr);
+ fputc('\n', out);
- total = printone("# bytes in allocated blocks", allocated_bytes);
- total += printone("# bytes in available blocks", available_bytes);
+ total = printone(out, "# bytes in allocated blocks", allocated_bytes);
+ total += printone(out, "# bytes in available blocks", available_bytes);
PyOS_snprintf(buf, sizeof(buf),
"%u unused pools * %d bytes", numfreepools, POOL_SIZE);
- total += printone(buf, (size_t)numfreepools * POOL_SIZE);
+ total += printone(out, buf, (size_t)numfreepools * POOL_SIZE);
- total += printone("# bytes lost to pool headers", pool_header_bytes);
- total += printone("# bytes lost to quantization", quantization);
- total += printone("# bytes lost to arena alignment", arena_alignment);
- (void)printone("Total", total);
+ total += printone(out, "# bytes lost to pool headers", pool_header_bytes);
+ total += printone(out, "# bytes lost to quantization", quantization);
+ total += printone(out, "# bytes lost to arena alignment", arena_alignment);
+ (void)printone(out, "Total", total);
}
-#endif /* PYMALLOC_DEBUG */
+#endif /* #ifdef WITH_PYMALLOC */
#ifdef Py_USING_MEMORY_DEBUGGER
/* Make this function last so gcc won't inline it since the definition is