diff options
Diffstat (limited to 'libdw/libdwP.h')
| -rw-r--r-- | libdw/libdwP.h | 80 |
1 files changed, 45 insertions, 35 deletions
diff --git a/libdw/libdwP.h b/libdw/libdwP.h index ad2599eb..36c2acd9 100644 --- a/libdw/libdwP.h +++ b/libdw/libdwP.h @@ -149,17 +149,6 @@ enum #include "dwarf_sig8_hash.h" -/* Structure for internal memory handling. This is basically a simplified - reimplementation of obstacks. Unfortunately the standard obstack - implementation is not usable in libraries. */ -struct libdw_memblock -{ - size_t size; - size_t remaining; - struct libdw_memblock *prev; - char mem[0]; -}; - /* This is the structure representing the debugging state. */ struct Dwarf { @@ -231,11 +220,22 @@ struct Dwarf /* Similar for addrx/constx, which will come from .debug_addr section. */ struct Dwarf_CU *fake_addr_cu; - /* Internal memory handling. Each thread allocates separately and only - allocates from its own blocks, while all the blocks are pushed atomically - onto a unified stack for easy deallocation. */ - pthread_key_t mem_key; - atomic_uintptr_t mem_tail; + /* Supporting lock for internal memory handling. Ensures threads that have + an entry in the mem_tails array are not disturbed by new threads doing + allocations for this Dwarf. */ + pthread_rwlock_t mem_rwl; + + /* Internal memory handling. This is basically a simplified thread-local + reimplementation of obstacks. Unfortunately the standard obstack + implementation is not usable in libraries. */ + size_t mem_stacks; + struct libdw_memblock + { + size_t size; + size_t remaining; + struct libdw_memblock *prev; + char mem[0]; + } **mem_tails; /* Default size of allocated memory blocks. */ size_t mem_default_size; @@ -578,34 +578,44 @@ libdw_valid_user_form (int form) extern void __libdw_seterrno (int value) internal_function; -/* Memory handling, the easy parts. This macro does not do nor need to do any - locking for proper concurrent operation. */ +/* Memory handling, the easy parts. */ #define libdw_alloc(dbg, type, tsize, cnt) \ - ({ struct libdw_memblock *_tail = pthread_getspecific (dbg->mem_key); \ - size_t _req = (tsize) * (cnt); \ - type *_result; \ - if (unlikely (_tail == NULL)) \ - _result = (type *) __libdw_allocate (dbg, _req, __alignof (type)); \ + ({ struct libdw_memblock *_tail = __libdw_alloc_tail(dbg); \ + size_t _required = (tsize) * (cnt); \ + type *_result = (type *) (_tail->mem + (_tail->size - _tail->remaining));\ + size_t _padding = ((__alignof (type) \ + - ((uintptr_t) _result & (__alignof (type) - 1))) \ + & (__alignof (type) - 1)); \ + if (unlikely (_tail->remaining < _required + _padding)) \ + _result = (type *) __libdw_allocate (dbg, _required, __alignof (type));\ else \ { \ - _result = (type *) (_tail->mem + (_tail->size - _tail->remaining)); \ - size_t _padding = ((__alignof (type) \ - - ((uintptr_t) _result & (__alignof (type) - 1))) \ - & (__alignof (type) - 1)); \ - if (unlikely (_tail->remaining < _req + _padding)) \ - _result = (type *) __libdw_allocate (dbg, _req, __alignof (type)); \ - else \ - { \ - _req += _padding; \ - _result = (type *) ((char *) _result + _padding); \ - _tail->remaining -= _req; \ - } \ + _required += _padding; \ + _result = (type *) ((char *) _result + _padding); \ + _tail->remaining -= _required; \ } \ _result; }) #define libdw_typed_alloc(dbg, type) \ libdw_alloc (dbg, type, sizeof (type), 1) +/* Can only be used to undo the last libdw_alloc. */ +#define libdw_unalloc(dbg, type, tsize, cnt) \ + ({ struct libdw_memblock *_tail = __libdw_thread_tail (dbg); \ + size_t _required = (tsize) * (cnt); \ + /* We cannot know the padding, it is lost. */ \ + _tail->remaining += _required; }) \ + +#define libdw_typed_unalloc(dbg, type) \ + libdw_unalloc (dbg, type, sizeof (type), 1) + +/* Callback to choose a thread-local memory allocation stack. */ +extern struct libdw_memblock *__libdw_alloc_tail (Dwarf* dbg) + __nonnull_attribute__ (1); + +extern struct libdw_memblock *__libdw_thread_tail (Dwarf* dbg) + __nonnull_attribute__ (1); + /* Callback to allocate more. */ extern void *__libdw_allocate (Dwarf *dbg, size_t minsize, size_t align) __attribute__ ((__malloc__)) __nonnull_attribute__ (1); |