From 1100f84983f22e570a5081cbe79b0ef8fe4952d7 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 10 Oct 2006 00:51:29 +0000 Subject: Jakub Jelinek Implement reference counting of scope records. * elf/dl-close.c (_dl_close): Remove all scopes from removed objects from the list in objects which remain. Always allocate new scope record. * elf/dl-open.c (dl_open_worker): When growing array for scopes, don't resize, allocate a new one. * elf/dl-runtime.c: Update reference counters before using a scope array. * elf/dl-sym.c: Likewise. * elf/dl-libc.c: Adjust for l_scope name change. * elf/dl-load.c: Likewise. * elf/dl-object.c: Likewise. * elf/rtld.c: Likewise. * include/link.h: Inlcude . Define struct r_scoperec. Replace r_scope with pointer to r_scoperec structure. Add l_scoperec_lock. * sysdeps/generic/ldsodefs.h: Include . * sysdeps/generic/rtld-lowlevel.h: New file. * include/atomic.h: Rename atomic_and to atomic_and_val and atomic_or to atomic_or_val. Define new macros atomic_and and atomic_or which do not return values. * sysdeps/x86_64/bits/atomic.h: Define atomic_and and atomic_or. Various cleanups. * sysdeps/i386/i486/bits/atomic.h: Likewise. --- include/atomic.h | 38 +++++++++++++++++++++++++++++++++++++- include/link.h | 35 ++++++++++++++++++++++++++++++++--- 2 files changed, 69 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/atomic.h b/include/atomic.h index a1598e3850..bd2e2f13f7 100644 --- a/include/atomic.h +++ b/include/atomic.h @@ -273,9 +273,27 @@ __oldval & __mask; }) #endif -/* Atomically *mem &= mask and return the old value of *mem. */ +/* Atomically *mem &= mask. */ #ifndef atomic_and # define atomic_and(mem, mask) \ + do { \ + __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __mask = (mask); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + & __mask, \ + __oldval), \ + 0)); \ + } while (0) +#endif + +/* Atomically *mem &= mask and return the old value of *mem. */ +#ifndef atomic_and_val +# define atomic_and_val(mem, mask) \ ({ __typeof (*(mem)) __oldval; \ __typeof (mem) __memp = (mem); \ __typeof (*(mem)) __mask = (mask); \ @@ -294,6 +312,24 @@ /* Atomically *mem |= mask and return the old value of *mem. */ #ifndef atomic_or # define atomic_or(mem, mask) \ + do { \ + __typeof (*(mem)) __oldval; \ + __typeof (mem) __memp = (mem); \ + __typeof (*(mem)) __mask = (mask); \ + \ + do \ + __oldval = (*__memp); \ + while (__builtin_expect (atomic_compare_and_exchange_bool_acq (__memp, \ + __oldval \ + | __mask, \ + __oldval), \ + 0)); \ + } while (0) +#endif + +/* Atomically *mem |= mask and return the old value of *mem. */ +#ifndef atomic_or_val +# define atomic_or_val(mem, mask) \ ({ __typeof (*(mem)) __oldval; \ __typeof (mem) __memp = (mem); \ __typeof (*(mem)) __mask = (mask); \ diff --git a/include/link.h b/include/link.h index 0d6b66100e..4b2f07e862 100644 --- a/include/link.h +++ b/include/link.h @@ -43,6 +43,8 @@ extern unsigned int la_objopen (struct link_map *__map, Lmid_t __lmid, #include #include #include /* Defines USE_TLS. */ +#include +#include /* Some internal data structures of the dynamic linker used in the @@ -73,6 +75,18 @@ struct r_search_path_struct }; +/* Structure for a scope. Each such data structure has a lock. The + lock allows many readers. It can be invalidated by setting bit 31 + which means that no more lockers are allowe */ +struct r_scoperec +{ + bool remove_after_use; + bool notify; + int nusers; + struct r_scope_elem *scope[0]; +}; + + /* Structure describing a loaded shared object. The `l_next' and `l_prev' members form a chain of all the shared objects loaded at startup. @@ -120,7 +134,7 @@ struct link_map are indexed by DT_ADDRTAGIDX(tagvalue), see . */ ElfW(Dyn) *l_info[DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM - + DT_EXTRANUM + DT_VALNUM + DT_ADDRNUM]; + + DT_EXTRANUM + DT_VALNUM + DT_ADDRNUM]; const ElfW(Phdr) *l_phdr; /* Pointer to program header table in core. */ ElfW(Addr) l_entry; /* Entry point location. */ ElfW(Half) l_phnum; /* Number of program header entries. */ @@ -212,12 +226,27 @@ struct link_map ElfW(Addr) l_text_end; /* Default array for 'l_scope'. */ - struct r_scope_elem *l_scope_mem[4]; + union + { + struct r_scoperec l_scoperec_mem; + struct + { + struct r_scoperec scoperec_struct; + /* XXX This number should be increased once the scope memory + handling has been tested. */ + struct r_scope_elem *scope_elems[4]; +#define NINIT_SCOPE_ELEMS(map) \ + (sizeof ((map)->l_scope_realmem.scope_elems) \ + / sizeof ((map)->l_scope_realmem.scope_elems[0])) + } l_scope_realmem; + }; /* Size of array allocated for 'l_scope'. */ size_t l_scope_max; /* This is an array defining the lookup scope for this link map. There are initially at most three different scope lists. */ - struct r_scope_elem **l_scope; + struct r_scoperec *l_scoperec; + /* We need to protect using the SCOPEREC. */ + __rtld_mrlock_define (, l_scoperec_lock) /* A similar array, this time only with the local scope. This is used occasionally. */ -- cgit v1.2.3