diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/obmalloc.c | 121 |
1 files changed, 115 insertions, 6 deletions
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index 16d5bcb..bea4ea8 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -7,6 +7,7 @@ #include "pycore_pyerrors.h" // _Py_FatalErrorFormat() #include "pycore_pymem.h" #include "pycore_pystate.h" // _PyInterpreterState_GET +#include "pycore_obmalloc_init.h" #include <stdlib.h> // malloc() #include <stdbool.h> @@ -1016,6 +1017,13 @@ static int running_on_valgrind = -1; typedef struct _obmalloc_state OMState; +/* obmalloc state for main interpreter and shared by all interpreters without + * their own obmalloc state. By not explicitly initalizing this structure, it + * will be allocated in the BSS which is a small performance win. The radix + * tree arrays are fairly large but are sparsely used. */ +static struct _obmalloc_state obmalloc_state_main; +static bool obmalloc_state_initialized; + static inline int has_own_state(PyInterpreterState *interp) { @@ -1028,10 +1036,8 @@ static inline OMState * get_state(void) { PyInterpreterState *interp = _PyInterpreterState_GET(); - if (!has_own_state(interp)) { - interp = _PyInterpreterState_Main(); - } - return &interp->obmalloc; + assert(interp->obmalloc != NULL); // otherwise not initialized or freed + return interp->obmalloc; } // These macros all rely on a local "state" variable. @@ -1094,7 +1100,11 @@ _PyInterpreterState_GetAllocatedBlocks(PyInterpreterState *interp) "the interpreter doesn't have its own allocator"); } #endif - OMState *state = &interp->obmalloc; + OMState *state = interp->obmalloc; + + if (state == NULL) { + return 0; + } Py_ssize_t n = raw_allocated_blocks; /* add up allocated blocks for used pools */ @@ -1116,6 +1126,8 @@ _PyInterpreterState_GetAllocatedBlocks(PyInterpreterState *interp) return n; } +static void free_obmalloc_arenas(PyInterpreterState *interp); + void _PyInterpreterState_FinalizeAllocatedBlocks(PyInterpreterState *interp) { @@ -1124,10 +1136,20 @@ _PyInterpreterState_FinalizeAllocatedBlocks(PyInterpreterState *interp) return; } #endif - if (has_own_state(interp)) { + if (has_own_state(interp) && interp->obmalloc != NULL) { Py_ssize_t leaked = _PyInterpreterState_GetAllocatedBlocks(interp); assert(has_own_state(interp) || leaked == 0); interp->runtime->obmalloc.interpreter_leaks += leaked; + if (_PyMem_obmalloc_state_on_heap(interp) && leaked == 0) { + // free the obmalloc arenas and radix tree nodes. If leaked > 0 + // then some of the memory allocated by obmalloc has not been + // freed. It might be safe to free the arenas in that case but + // it's possible that extension modules are still using that + // memory. So, it is safer to not free and to leak. Perhaps there + // should be warning when this happens. It should be possible to + // use a tool like "-fsanitize=address" to track down these leaks. + free_obmalloc_arenas(interp); + } } } @@ -2717,9 +2739,96 @@ _PyDebugAllocatorStats(FILE *out, (void)printone(out, buf2, num_blocks * sizeof_block); } +// Return true if the obmalloc state structure is heap allocated, +// by PyMem_RawCalloc(). For the main interpreter, this structure +// allocated in the BSS. Allocating that way gives some memory savings +// and a small performance win (at least on a demand paged OS). On +// 64-bit platforms, the obmalloc structure is 256 kB. Most of that +// memory is for the arena_map_top array. Since normally only one entry +// of that array is used, only one page of resident memory is actually +// used, rather than the full 256 kB. +bool _PyMem_obmalloc_state_on_heap(PyInterpreterState *interp) +{ +#if WITH_PYMALLOC + return interp->obmalloc && interp->obmalloc != &obmalloc_state_main; +#else + return false; +#endif +} + +#ifdef WITH_PYMALLOC +static void +init_obmalloc_pools(PyInterpreterState *interp) +{ + // initialize the obmalloc->pools structure. This must be done + // before the obmalloc alloc/free functions can be called. + poolp temp[OBMALLOC_USED_POOLS_SIZE] = + _obmalloc_pools_INIT(interp->obmalloc->pools); + memcpy(&interp->obmalloc->pools.used, temp, sizeof(temp)); +} +#endif /* WITH_PYMALLOC */ + +int _PyMem_init_obmalloc(PyInterpreterState *interp) +{ +#ifdef WITH_PYMALLOC + /* Initialize obmalloc, but only for subinterpreters, + since the main interpreter is initialized statically. */ + if (_Py_IsMainInterpreter(interp) + || _PyInterpreterState_HasFeature(interp, + Py_RTFLAGS_USE_MAIN_OBMALLOC)) { + interp->obmalloc = &obmalloc_state_main; + if (!obmalloc_state_initialized) { + init_obmalloc_pools(interp); + obmalloc_state_initialized = true; + } + } else { + interp->obmalloc = PyMem_RawCalloc(1, sizeof(struct _obmalloc_state)); + if (interp->obmalloc == NULL) { + return -1; + } + init_obmalloc_pools(interp); + } +#endif /* WITH_PYMALLOC */ + return 0; // success +} + #ifdef WITH_PYMALLOC +static void +free_obmalloc_arenas(PyInterpreterState *interp) +{ + OMState *state = interp->obmalloc; + for (uint i = 0; i < maxarenas; ++i) { + // free each obmalloc memory arena + struct arena_object *ao = &allarenas[i]; + _PyObject_Arena.free(_PyObject_Arena.ctx, + (void *)ao->address, ARENA_SIZE); + } + // free the array containing pointers to all arenas + PyMem_RawFree(allarenas); +#if WITH_PYMALLOC_RADIX_TREE +#ifdef USE_INTERIOR_NODES + // Free the middle and bottom nodes of the radix tree. These are allocated + // by arena_map_mark_used() but not freed when arenas are freed. + for (int i1 = 0; i1 < MAP_TOP_LENGTH; i1++) { + arena_map_mid_t *mid = arena_map_root.ptrs[i1]; + if (mid == NULL) { + continue; + } + for (int i2 = 0; i2 < MAP_MID_LENGTH; i2++) { + arena_map_bot_t *bot = arena_map_root.ptrs[i1]->ptrs[i2]; + if (bot == NULL) { + continue; + } + PyMem_RawFree(bot); + } + PyMem_RawFree(mid); + } +#endif +#endif +} + #ifdef Py_DEBUG /* Is target in the list? The list is traversed via the nextpool pointers. * The list may be NULL-terminated, or circular. Return 1 if target is in |