From 40aac94801f86355bd86cf5b340481ee2f501d3c Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Fri, 27 Aug 2004 22:33:54 -0400 Subject: [PATCH] re PR c++/13684 (local static object variable constructed once but ctors and dtors called multiple times on same memory when called in multiple threads) PR c++/13684 * cp/decl.c (expand_static_init): Use thread-safety API. (register_dtor_fn): Return the call, don't expand it. * cp/tree.c (add_stmt_to_compound): New fn. (stabilize_call): Use it. * gimplify.c (gimplify_cleanup_point_expr): Handle CLEANUP_EH_ONLY. (gimple_push_cleanup): Add eh_only parm. (gimplify_target_expr): Pass it. * c.opt (-fno-threadsafe-statics): New option. * c-opts.c (c_common_handle_option): Handle it. * c-common.h (flag_threadsafe_statics): Declare it. * c-common.c (flag_threadsafe_statics): Record it. * doc/invoke.texi: Document it. * tsystem.h (_GNU_SOURCE): Define. * gthr-posix.h (__gthread_recursive_mutex_t): New typedef. (__GTHREAD_RECURSIVE_MUTEX_INIT): New macro. (__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION): New macro. (__gthread_recursive_mutex_init_function): New fn. (__gthread_recursive_mutex_lock): New fn. (__gthread_recursive_mutex_trylock): New fn. (__gthread_recursive_mutex_unlock): New fn. * gthr-solaris.h, gthr-single.h, gthr-dce.h: Likewise. * gthr-win32.h, gthr-vxworks.h: Likewise. * gthr.h: Document. * libsupc++/guard.cc (static_mutex): Internal class implementing a recursive mutex which controls initialization of local statics. (__gnu_cxx::recursive_init): New exception class. (__cxa_guard_acquire): Deal with locking and recursion detection. (acquire_1, __cxa_guard_abort, __cxa_guard_release): Likewise. From-SVN: r86687 --- gcc/ChangeLog | 23 ++++++ gcc/c-common.c | 5 ++ gcc/c-common.h | 5 ++ gcc/c-opts.c | 4 + gcc/c.opt | 4 + gcc/config/i386/gthr-win32.c | 70 ++++++++++++++++ gcc/cp/ChangeLog | 8 ++ gcc/cp/cp-tree.h | 3 +- gcc/cp/decl.c | 119 +++++++++++++++++++--------- gcc/cp/decl2.c | 2 +- gcc/cp/tree.c | 20 +++-- gcc/doc/invoke.texi | 9 ++- gcc/gimplify.c | 14 +++- gcc/gthr-dce.h | 41 +++++++++- gcc/gthr-posix.h | 47 +++++++++++ gcc/gthr-single.h | 19 +++++ gcc/gthr-solaris.h | 20 +++++ gcc/gthr-vxworks.h | 27 +++++++ gcc/gthr-win32.h | 113 ++++++++++++++++++++++++++ gcc/gthr.h | 8 ++ gcc/tsystem.h | 3 + libstdc++-v3/ChangeLog | 9 +++ libstdc++-v3/libsupc++/guard.cc | 136 +++++++++++++++++++++++++++++++- 23 files changed, 655 insertions(+), 54 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 54d4c5f1a25f..74a6b13be166 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,26 @@ +2004-08-27 Jason Merrill + + PR c++/13684 + * gimplify.c (gimplify_cleanup_point_expr): Handle CLEANUP_EH_ONLY. + (gimple_push_cleanup): Add eh_only parm. + (gimplify_target_expr): Pass it. + * c.opt (-fno-threadsafe-statics): New option. + * c-opts.c (c_common_handle_option): Handle it. + * c-common.h (flag_threadsafe_statics): Declare it. + * c-common.c (flag_threadsafe_statics): Record it. + * doc/invoke.texi: Document it. + * tsystem.h (_GNU_SOURCE): Define. + * gthr-posix.h (__gthread_recursive_mutex_t): New typedef. + (__GTHREAD_RECURSIVE_MUTEX_INIT): New macro. + (__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION): New macro. + (__gthread_recursive_mutex_init_function): New fn. + (__gthread_recursive_mutex_lock): New fn. + (__gthread_recursive_mutex_trylock): New fn. + (__gthread_recursive_mutex_unlock): New fn. + * gthr-solaris.h, gthr-single.h, gthr-dce.h: Likewise. + * gthr-win32.h, gthr-vxworks.h: Likewise. + * gthr.h: Document. + 2004-08-27 David Edelsohn * config/rs6000/rs6000.c (rs6000_override_options): Increase diff --git a/gcc/c-common.c b/gcc/c-common.c index 03531d3ca035..bd8ea6c32c38 100644 --- a/gcc/c-common.c +++ b/gcc/c-common.c @@ -459,6 +459,11 @@ int flag_permissive; int flag_enforce_eh_specs = 1; +/* Nonzero means to generate thread-safe code for initializing local + statics. */ + +int flag_threadsafe_statics = 1; + /* Nonzero means warn about implicit declarations. */ int warn_implicit = 1; diff --git a/gcc/c-common.h b/gcc/c-common.h index e9a91d50fdd7..b2da85d81885 100644 --- a/gcc/c-common.h +++ b/gcc/c-common.h @@ -571,6 +571,11 @@ extern int flag_permissive; extern int flag_enforce_eh_specs; +/* Nonzero (the default) means to generate thread-safe code for + initializing local statics. */ + +extern int flag_threadsafe_statics; + /* Nonzero means warn about implicit declarations. */ extern int warn_implicit; diff --git a/gcc/c-opts.c b/gcc/c-opts.c index 92a6c7273a36..31bbb48d9b05 100644 --- a/gcc/c-opts.c +++ b/gcc/c-opts.c @@ -773,6 +773,10 @@ c_common_handle_option (size_t scode, const char *arg, int value) flag_weak = value; break; + case OPT_fthreadsafe_statics: + flag_threadsafe_statics = value; + break; + case OPT_fzero_link: flag_zero_link = value; break; diff --git a/gcc/c.opt b/gcc/c.opt index b84c5ba84081..c93fe7e895a5 100644 --- a/gcc/c.opt +++ b/gcc/c.opt @@ -675,6 +675,10 @@ C++ ObjC++ Joined RejectNegative UInteger fthis-is-variable C++ ObjC++ +fthreadsafe-statics +C++ ObjC++ +-fno-threadsafe-statics Do not generate thread-safe code for initializing local statics. + funsigned-bitfields C ObjC C++ ObjC++ When \"signed\" or \"unsigned\" is not given make the bitfield unsigned diff --git a/gcc/config/i386/gthr-win32.c b/gcc/config/i386/gthr-win32.c index c53369bca50c..6fb3cf8853d5 100644 --- a/gcc/config/i386/gthr-win32.c +++ b/gcc/config/i386/gthr-win32.c @@ -182,3 +182,73 @@ __gthr_win32_mutex_unlock (__gthread_mutex_t *mutex) else return 0; } + +void +__gthr_win32_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex) +{ + mutex->counter = -1; + mutex->depth = 0; + mutex->owner = 0; + mutex->sema = CreateSemaphore (NULL, 0, 65535, NULL); +} + +int +__gthr_win32_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + DWORD me = GetCurrentThreadId(); + if (InterlockedIncrement (&mutex->counter) == 0) + { + mutex->depth = 1; + mutex->owner = me; + } + else if (mutex->owner == me) + { + InterlockedDecrement (&mx->lock_idx); + ++(mutex->depth); + } + else if (WaitForSingleObject (mutex->sema, INFINITE) == WAIT_OBJECT_0) + { + mutex->depth = 1; + mutex->owner = me; + } + else + { + /* WaitForSingleObject returns WAIT_FAILED, and we can only do + some best-effort cleanup here. */ + InterlockedDecrement (&mutex->counter); + return 1; + } + return 0; +} + +int +__gthr_win32_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + DWORD me = GetCurrentThreadId(); + if (__GTHR_W32_InterlockedCompareExchange (&mutex->counter, 0, -1) < 0) + { + mutex->depth = 1; + mutex->owner = me; + } + else if (mutex->owner == me) + ++(mutex->depth); + else + return 1; + + return 0; +} + +int +__gthr_win32_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + --(mutex->depth); + if (mutex->depth == 0) + { + mutex->owner = 0; + + if (InterlockedDecrement (&mutex->counter) >= 0) + return ReleaseSemaphore (mutex->sema, 1, NULL) ? 0 : 1; + } + + return 0; +} diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index afd820fb2224..f1cac07a8036 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,11 @@ +2004-08-27 Jason Merrill + + PR c++/13684 + * decl.c (expand_static_init): Use thread-safety API. + (register_dtor_fn): Return the call, don't expand it. + * tree.c (add_stmt_to_compound): New fn. + (stabilize_call): Use it. + 2004-08-27 Richard Henderson * cp-tree.def (OFFSETOF_EXPR): New. diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 4597b45ff81c..2eba7a316e42 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -3801,7 +3801,7 @@ extern tree build_target_expr_with_type (tree, tree); extern int local_variable_p (tree); extern int nonstatic_local_decl_p (tree); extern tree declare_global_var (tree, tree); -extern void register_dtor_fn (tree); +extern tree register_dtor_fn (tree); extern tmpl_spec_kind current_tmpl_spec_kind (int); extern tree cp_fname_init (const char *, tree *); extern tree builtin_function (const char *name, tree type, @@ -4198,6 +4198,7 @@ extern void lang_check_failed (const char *, int, extern tree stabilize_expr (tree, tree *); extern void stabilize_call (tree, tree *); extern bool stabilize_init (tree, tree *); +extern tree add_stmt_to_compound (tree, tree); extern tree cxx_maybe_build_cleanup (tree); extern void init_tree (void); extern int pod_type_p (tree); diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index 95cf0f5e7178..c746e336fbac 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -5081,7 +5081,7 @@ end_cleanup_fn (void) /* Generate code to handle the destruction of DECL, an object with static storage duration. */ -void +tree register_dtor_fn (tree decl) { tree cleanup; @@ -5090,7 +5090,7 @@ register_dtor_fn (tree decl) tree fcall; if (TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (decl))) - return; + return void_zero_node; /* Call build_cleanup before we enter the anonymous function so that any access checks will be done relative to the current scope, @@ -5129,7 +5129,7 @@ register_dtor_fn (tree decl) } else args = tree_cons (NULL_TREE, cleanup, NULL_TREE); - finish_expr_stmt (build_function_call (get_atexit_node (), args)); + return build_function_call (get_atexit_node (), args); } /* DECL is a VAR_DECL with static storage duration. INIT, if present, @@ -5151,36 +5151,42 @@ expand_static_init (tree decl, tree init) if (DECL_FUNCTION_SCOPE_P (decl)) { /* Emit code to perform this initialization but once. */ - tree if_stmt; - tree then_clause; - tree assignment; - tree guard; - tree guard_init; + tree if_stmt, inner_if_stmt; + tree then_clause, inner_then_clause; + tree guard, guard_addr, guard_addr_list; + tree acquire_fn, release_fn, abort_fn; + tree flag, begin; /* Emit code to perform this initialization but once. This code looks like: - static int guard = 0; - if (!guard) { - // Do initialization. - guard = 1; - // Register variable for destruction at end of program. + static guard; + if (!guard.first_byte) { + if (__cxa_guard_acquire (&guard)) { + bool flag = false; + try { + // Do initialization. + flag = true; __cxa_guard_release (&guard); + // Register variable for destruction at end of program. + } catch { + if (!flag) __cxa_guard_abort (&guard); + } } - Note that the `temp' variable is only set to 1 *after* the + Note that the `flag' variable is only set to 1 *after* the initialization is complete. This ensures that an exception, thrown during the construction, will cause the variable to reinitialized when we pass through this code again, as per: [stmt.dcl] - If the initialization exits by throwing an exception, the + If the initialization exits by throwing an exception, the initialization is not complete, so it will be tried again the next time control enters the declaration. - In theory, this process should be thread-safe, too; multiple - threads should not be able to initialize the variable more - than once. We don't yet attempt to ensure thread-safety. */ + This process should be thread-safe, too; multiple threads + should not be able to initialize the variable more than + once. */ /* Create the guard variable. */ guard = get_guard (decl); @@ -5188,29 +5194,68 @@ expand_static_init (tree decl, tree init) /* Begin the conditional initialization. */ if_stmt = begin_if_stmt (); finish_if_stmt_cond (get_guard_cond (guard), if_stmt); - then_clause = begin_compound_stmt (0); - - /* Do the initialization itself. */ - assignment = init ? init : NULL_TREE; - - /* Once the assignment is complete, set TEMP to 1. Since the - construction of the static object is complete at this point, - we want to make sure TEMP is set to 1 even if a temporary - constructed during the initialization throws an exception - when it is destroyed. So, we combine the initialization and - the assignment to TEMP into a single expression, ensuring - that when we call finish_expr_stmt the cleanups will not be - run until after TEMP is set to 1. */ - guard_init = set_guard (guard); - if (assignment) - assignment = build_compound_expr (assignment, guard_init); + then_clause = begin_compound_stmt (BCS_NO_SCOPE); + + if (flag_threadsafe_statics) + { + guard_addr = build_address (guard); + guard_addr_list = build_tree_list (NULL_TREE, guard_addr); + + acquire_fn = get_identifier ("__cxa_guard_acquire"); + release_fn = get_identifier ("__cxa_guard_release"); + abort_fn = get_identifier ("__cxa_guard_abort"); + if (!get_global_value_if_present (acquire_fn, &acquire_fn)) + { + tree argtypes = tree_cons (NULL_TREE, TREE_TYPE (guard_addr), + void_list_node); + tree vfntype = build_function_type (void_type_node, argtypes); + acquire_fn = push_library_fn + (acquire_fn, build_function_type (integer_type_node, argtypes)); + release_fn = push_library_fn (release_fn, vfntype); + abort_fn = push_library_fn (abort_fn, vfntype); + } + else + { + release_fn = identifier_global_value (release_fn); + abort_fn = identifier_global_value (abort_fn); + } + + inner_if_stmt = begin_if_stmt (); + finish_if_stmt_cond (build_call (acquire_fn, guard_addr_list), + inner_if_stmt); + + inner_then_clause = begin_compound_stmt (BCS_NO_SCOPE); + begin = get_target_expr (boolean_false_node); + flag = TARGET_EXPR_SLOT (begin); + + TARGET_EXPR_CLEANUP (begin) + = build (COND_EXPR, void_type_node, flag, + void_zero_node, + build_call (abort_fn, guard_addr_list)); + CLEANUP_EH_ONLY (begin) = 1; + + /* Do the initialization itself. */ + init = add_stmt_to_compound (begin, init); + init = add_stmt_to_compound + (init, build (MODIFY_EXPR, void_type_node, flag, boolean_true_node)); + init = add_stmt_to_compound + (init, build_call (release_fn, guard_addr_list)); + } else - assignment = guard_init; - finish_expr_stmt (assignment); + init = add_stmt_to_compound (init, set_guard (guard)); /* Use atexit to register a function for destroying this static variable. */ - register_dtor_fn (decl); + init = add_stmt_to_compound (init, register_dtor_fn (decl)); + + finish_expr_stmt (init); + + if (flag_threadsafe_statics) + { + finish_compound_stmt (inner_then_clause); + finish_then_clause (inner_if_stmt); + finish_if_stmt (inner_if_stmt); + } finish_compound_stmt (then_clause); finish_then_clause (if_stmt); diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c index 5da240f6075c..2d852f714810 100644 --- a/gcc/cp/decl2.c +++ b/gcc/cp/decl2.c @@ -2446,7 +2446,7 @@ do_static_initialization (tree decl, tree init) /* If we're using __cxa_atexit, register a a function that calls the destructor for the object. */ if (flag_use_cxa_atexit) - register_dtor_fn (decl); + finish_expr_stmt (register_dtor_fn (decl)); /* Finish up. */ finish_static_initialization_or_destruction (guard_if_stmt); diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c index 4bdadad690d9..99334678a7c2 100644 --- a/gcc/cp/tree.c +++ b/gcc/cp/tree.c @@ -2254,6 +2254,19 @@ stabilize_expr (tree exp, tree* initp) return exp; } +/* Add NEW, an expression whose value we don't care about, after the + similar expression ORIG. */ + +tree +add_stmt_to_compound (tree orig, tree new) +{ + if (!new || !TREE_SIDE_EFFECTS (new)) + return orig; + if (!orig || !TREE_SIDE_EFFECTS (orig)) + return new; + return build2 (COMPOUND_EXPR, void_type_node, orig, new); +} + /* Like stabilize_expr, but for a call whose args we want to pre-evaluate. */ @@ -2275,12 +2288,7 @@ stabilize_call (tree call, tree *initp) { tree init; TREE_VALUE (t) = stabilize_expr (TREE_VALUE (t), &init); - if (!init) - /* Nothing. */; - else if (inits) - inits = build2 (COMPOUND_EXPR, void_type_node, inits, init); - else - inits = init; + inits = add_stmt_to_compound (inits, init); } *initp = inits; diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 25acc613c8e8..e5e176f4dfda 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -182,7 +182,7 @@ in the following sections. -fno-nonansi-builtins -fno-operator-names @gol -fno-optional-diags -fpermissive @gol -frepo -fno-rtti -fstats -ftemplate-depth-@var{n} @gol --fuse-cxa-atexit -fno-weak -nostdinc++ @gol +-fno-threadsafe-statics -fuse-cxa-atexit -fno-weak -nostdinc++ @gol -fno-default-inline -fvisibility-inlines-hidden @gol -Wabi -Wctor-dtor-privacy @gol -Wnon-virtual-dtor -Wreorder @gol @@ -1470,6 +1470,13 @@ A limit on the template instantiation depth is needed to detect endless recursions during template class instantiation. ANSI/ISO C++ conforming programs must not rely on a maximum depth greater than 17. +@item -fno-threadsafe-statics +@opindex fno-threadsafe-statics +Do not emit the extra code to use the routines specified in the C++ +ABI for thread-safe initialization of local statics. You can use this +option to reduce code size slightly in code that doesn't need to be +thread-safe. + @item -fuse-cxa-atexit @opindex fuse-cxa-atexit Register destructors for objects with static storage duration with the diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 323df3617733..2de6cf6e091e 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -3271,9 +3271,15 @@ gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p) else { tree sl, tfe; + enum tree_code code; + + if (CLEANUP_EH_ONLY (wce)) + code = TRY_CATCH_EXPR; + else + code = TRY_FINALLY_EXPR; sl = tsi_split_statement_list_after (&iter); - tfe = build (TRY_FINALLY_EXPR, void_type_node, sl, NULL_TREE); + tfe = build (code, void_type_node, sl, NULL_TREE); append_to_statement_list (TREE_OPERAND (wce, 0), &TREE_OPERAND (tfe, 1)); *wce_p = tfe; @@ -3301,7 +3307,7 @@ gimplify_cleanup_point_expr (tree *expr_p, tree *pre_p) is the cleanup action required. */ static void -gimple_push_cleanup (tree var, tree cleanup, tree *pre_p) +gimple_push_cleanup (tree var, tree cleanup, bool eh_only, tree *pre_p) { tree wce; @@ -3352,6 +3358,7 @@ gimple_push_cleanup (tree var, tree cleanup, tree *pre_p) else { wce = build (WITH_CLEANUP_EXPR, void_type_node, cleanup); + CLEANUP_EH_ONLY (wce) = eh_only; append_to_statement_list (wce, pre_p); } @@ -3399,7 +3406,8 @@ gimplify_target_expr (tree *expr_p, tree *pre_p, tree *post_p) if (TARGET_EXPR_CLEANUP (targ)) { gimplify_stmt (&TARGET_EXPR_CLEANUP (targ)); - gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), pre_p); + gimple_push_cleanup (temp, TARGET_EXPR_CLEANUP (targ), + CLEANUP_EH_ONLY (targ), pre_p); } /* Only expand this once. */ diff --git a/gcc/gthr-dce.h b/gcc/gthr-dce.h index 563754ea4401..ccdf82dead8f 100644 --- a/gcc/gthr-dce.h +++ b/gcc/gthr-dce.h @@ -1,4 +1,4 @@ - +/* Threads compatibility routines for libgcc2 and libobjc. */ /* Compile this one with gcc. */ /* Copyright (C) 1997, 1999, 2000, 2001 Free Software Foundation, Inc. @@ -52,10 +52,12 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA typedef pthread_key_t __gthread_key_t; typedef pthread_once_t __gthread_once_t; typedef pthread_mutex_t __gthread_mutex_t; +typedef pthread_mutex_t __gthread_recursive_mutex_t; #define __GTHREAD_ONCE_INIT pthread_once_init #define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function +#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function #define __GTHREAD_MUTEX_INIT_DEFAULT pthread_once_init @@ -481,6 +483,43 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return 0; } +static inline int +__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + { + pthread_mutexattr_t attr; + int r; + + r = pthread_mutexattr_create (&attr); + if (!r) + r = pthread_mutexattr_setkind_np (&attr, MUTEX_RECURSIVE_NP); + if (!r) + r = pthread_mutex_init (mutex, attr); + if (!r) + r = pthread_mutexattr_delete (&attr); + return r; + } +} + +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_lock (mutex); +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_trylock (mutex); +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_unlock (mutex); +} + #endif /* _LIBOBJC */ #undef UNUSED diff --git a/gcc/gthr-posix.h b/gcc/gthr-posix.h index e2b5a5739990..91204104658c 100644 --- a/gcc/gthr-posix.h +++ b/gcc/gthr-posix.h @@ -46,9 +46,17 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA typedef pthread_key_t __gthread_key_t; typedef pthread_once_t __gthread_once_t; typedef pthread_mutex_t __gthread_mutex_t; +typedef pthread_mutex_t __gthread_recursive_mutex_t; #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT +#if defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER) +#define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER +#elif defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP) +#define __GTHREAD_RECURSIVE_MUTEX_INIT PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP +#else +#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function +#endif #if SUPPORTS_WEAK && GTHREAD_USE_WEAK @@ -516,6 +524,45 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return 0; } +#ifndef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP +static inline int +__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + { + pthread_mutexattr_t attr; + int r; + + r = pthread_mutexattr_init (&attr); + if (!r) + r = pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE); + if (!r) + r = pthread_mutex_init (mutex, &attr); + if (!r) + r = pthread_mutexattr_destroy (&attr); + return r; + } +} +#endif + +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_lock (mutex); +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_trylock (mutex); +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_unlock (mutex); +} + #endif /* _LIBOBJC */ #endif /* ! GCC_GTHR_POSIX_H */ diff --git a/gcc/gthr-single.h b/gcc/gthr-single.h index 0bb4682615db..d42ee15becc2 100644 --- a/gcc/gthr-single.h +++ b/gcc/gthr-single.h @@ -32,6 +32,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA /* Just provide compatibility for mutex handling. */ typedef int __gthread_mutex_t; +typedef int __gthread_recursive_mutex_t; #define __GTHREAD_MUTEX_INIT 0 @@ -232,6 +233,24 @@ __gthread_mutex_unlock (__gthread_mutex_t * UNUSED(mutex)) return 0; } +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_lock (mutex); +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_trylock (mutex); +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_unlock (mutex); +} + #endif /* _LIBOBJC */ #undef UNUSED diff --git a/gcc/gthr-solaris.h b/gcc/gthr-solaris.h index 33ddf7a363ca..b44a4de26bf5 100644 --- a/gcc/gthr-solaris.h +++ b/gcc/gthr-solaris.h @@ -44,9 +44,11 @@ typedef struct { int once; } __gthread_once_t; typedef mutex_t __gthread_mutex_t; +typedef mutex_t __gthread_recursive_mutex_t; #define __GTHREAD_ONCE_INIT { DEFAULTMUTEX, 0 } #define __GTHREAD_MUTEX_INIT DEFAULTMUTEX +#define __GTHREAD_RECURSIVE_MUTEX_INIT RECURSIVE_ERRORCHECKMUTEX #if SUPPORTS_WEAK && GTHREAD_USE_WEAK @@ -466,6 +468,24 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return 0; } +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_lock (mutex); +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_trylock (mutex); +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_unlock (mutex); +} + #endif /* _LIBOBJC */ #endif /* ! GCC_GTHR_SOLARIS_H */ diff --git a/gcc/gthr-vxworks.h b/gcc/gthr-vxworks.h index 4fb3b09404aa..0f3ad23412ad 100644 --- a/gcc/gthr-vxworks.h +++ b/gcc/gthr-vxworks.h @@ -45,7 +45,10 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include typedef SEM_ID __gthread_mutex_t; +/* All VxWorks mutexes are recursive. */ +typedef SEM_ID __gthread_recursive_mutex_t; #define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function +#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function static inline void __gthread_mutex_init_function (__gthread_mutex_t *mutex) @@ -71,6 +74,30 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return semGive (*mutex); } +static inline void +__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex) +{ + __gthread_mutex_init_function (mutex); +} + +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_lock (mutex); +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_trylock (mutex); +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + return __gthread_mutex_unlock (mutex); +} + /* pthread_once is complicated enough that it's implemented out-of-line. See config/vxlib.c. */ diff --git a/gcc/gthr-win32.h b/gcc/gthr-win32.h index b76180484301..3e1aac7fce09 100644 --- a/gcc/gthr-win32.h +++ b/gcc/gthr-win32.h @@ -343,9 +343,18 @@ typedef struct { void *sema; } __gthread_mutex_t; +typedef struct { + long counter; + long depth; + DWORD owner; + void *sema; +} __gthread_recursive_mutex_t; + #define __GTHREAD_ONCE_INIT {0, -1} #define __GTHREAD_MUTEX_INIT_FUNCTION __gthread_mutex_init_function #define __GTHREAD_MUTEX_INIT_DEFAULT {-1, 0} +#define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_mutex_init_function +#define __GTHREAD_RECURSIVE_MUTEX_INIT_DEFAULT {-1, 0} #if __MINGW32_MAJOR_VERSION >= 1 || \ (__MINGW32_MAJOR_VERSION == 0 && __MINGW32_MINOR_VERSION > 2) @@ -472,6 +481,33 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return 0; } +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + return __gthr_win32_recursive_mutex_lock (mutex); + else + return 0; +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + return __gthr_win32_recursive_mutex_trylock (mutex); + else + return 0; +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + return __gthr_win32_recursive_mutex_unlock (mutex); + else + return 0; +} + #else /* ! __GTHREAD_HIDE_WIN32API */ #include @@ -610,6 +646,83 @@ __gthread_mutex_unlock (__gthread_mutex_t *mutex) return 0; } +static inline void +__gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex) +{ + mutex->counter = -1; + mutex->depth = 0; + mutex->owner = 0; + mutex->sema = CreateSemaphore (NULL, 0, 65535, NULL); +} + +static inline int +__gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + { + DWORD me = GetCurrentThreadId(); + if (InterlockedIncrement (&mutex->counter) == 0) + { + mutex->depth = 1; + mutex->owner = me; + } + else if (mutex->owner == me) + { + InterlockedDecrement (&mx->lock_idx); + ++(mutex->depth); + } + else if (WaitForSingleObject (mutex->sema, INFINITE) == WAIT_OBJECT_0) + { + mutex->depth = 1; + mutex->owner = me; + } + else + { + /* WaitForSingleObject returns WAIT_FAILED, and we can only do + some best-effort cleanup here. */ + InterlockedDecrement (&mutex->counter); + return 1; + } + } + return 0; +} + +static inline int +__gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + { + DWORD me = GetCurrentThreadId(); + if (__GTHR_W32_InterlockedCompareExchange (&mutex->counter, 0, -1) < 0) + { + mutex->depth = 1; + mutex->owner = me; + } + else if (mutex->owner == me) + ++(mutex->depth); + else + return 1; + } + return 0; +} + +static inline int +__gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex) +{ + if (__gthread_active_p ()) + { + --(mutex->depth); + if (mutex->depth == 0) + { + mutex->owner = 0; + + if (InterlockedDecrement (&mutex->counter) >= 0) + return ReleaseSemaphore (mutex->sema, 1, NULL) ? 0 : 1; + } + } + return 0; +} + #endif /* __GTHREAD_HIDE_WIN32API */ #ifdef __cplusplus diff --git a/gcc/gthr.h b/gcc/gthr.h index 22b2ecd0ca44..42f4d1a4d3ad 100644 --- a/gcc/gthr.h +++ b/gcc/gthr.h @@ -42,6 +42,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA __gthread_key_t __gthread_once_t __gthread_mutex_t + __gthread_recursive_mutex_t The threads interface must define the following macros: @@ -56,6 +57,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA function which looks like this: void __GTHREAD_MUTEX_INIT_FUNCTION (__gthread_mutex_t *) Don't define __GTHREAD_MUTEX_INIT in this case + __GTHREAD_RECURSIVE_MUTEX_INIT + __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION + as above, but for a recursive mutex. The threads interface must define the following static functions: @@ -71,6 +75,10 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA int __gthread_mutex_trylock (__gthread_mutex_t *mutex); int __gthread_mutex_unlock (__gthread_mutex_t *mutex); + int __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex); + int __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex); + int __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex); + All functions returning int should return zero on success or the error number. If the operation is not supported, -1 is returned. diff --git a/gcc/tsystem.h b/gcc/tsystem.h index f24bab78cc5e..d7f1ebc9a5cc 100644 --- a/gcc/tsystem.h +++ b/gcc/tsystem.h @@ -40,6 +40,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #define HAVE_DECL_GETOPT 1 #endif +/* We want everything from the glibc headers. */ +#define _GNU_SOURCE 1 + /* GCC supplies these headers. */ #include #include diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index d96a583e89ad..c77647b7e6a9 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,12 @@ +2004-08-27 Jason Merrill + + PR c++/13684 + * libsupc++/guard.cc (static_mutex): Internal class implementing a + recursive mutex which controls initialization of local statics. + (__gnu_cxx::recursive_init): New exception class. + (__cxa_guard_acquire): Deal with locking and recursion detection. + (acquire_1, __cxa_guard_abort, __cxa_guard_release): Likewise. + 2004-08-27 Matthias Klose * configure.host: For mips*-*-linux* update cpu_include_dir diff --git a/libstdc++-v3/libsupc++/guard.cc b/libstdc++-v3/libsupc++/guard.cc index 255108f5f7e8..a9280bccdc54 100644 --- a/libstdc++-v3/libsupc++/guard.cc +++ b/libstdc++-v3/libsupc++/guard.cc @@ -29,26 +29,154 @@ // Written by Mark Mitchell, CodeSourcery LLC, #include +#include +#include +#include // The IA64/generic ABI uses the first byte of the guard variable. // The ARM EABI uses the least significant bit. +// Thread-safe static local initialization support. +#ifdef __GTHREADS +namespace +{ + // static_mutex is a single mutex controlling all static initializations. + // This is a static class--the need for a static initialization function + // to pass to __gthread_once precludes creating multiple instances, though + // I suppose you could achieve the same effect with a template. + class static_mutex + { + static __gthread_recursive_mutex_t mutex; + +#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION + static void init(); +#endif + + public: + static void lock(); + static void unlock(); + }; + + __gthread_recursive_mutex_t static_mutex::mutex +#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT + = __GTHREAD_RECURSIVE_MUTEX_INIT +#endif + ; + +#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION + void static_mutex::init() + { + __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION (&mutex); + } +#endif + + void static_mutex::lock() + { +#ifdef __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION + static __gthread_once_t once = __GTHREAD_ONCE_INIT; + __gthread_once (&once, init); +#endif + __gthread_recursive_mutex_lock (&mutex); + } + + void static_mutex::unlock () + { + __gthread_recursive_mutex_unlock (&mutex); + } +} +#endif + +namespace __gnu_cxx +{ + // 6.7[stmt.dcl]/4: If control re-enters the declaration (recursively) + // while the object is being initialized, the behavior is undefined. + + // Since we already have a library function to handle locking, we might + // as well check for this situation and throw an exception. + // We use the second byte of the guard variable to remember that we're + // in the middle of an initialization. + class recursive_init: public std::exception + { + public: + recursive_init() throw() { } + virtual ~recursive_init() throw (); + }; + + recursive_init::~recursive_init() throw() { } +} + namespace __cxxabiv1 { + static int + acquire_1 (__guard *g) + { + if (_GLIBCXX_GUARD_ACQUIRE (g)) + { + if (((char *)g)[1]++) + { +#ifdef __EXCEPTIONS + throw __gnu_cxx::recursive_init(); +#else + abort (); +#endif + } + return 1; + } + return 0; + } + extern "C" int __cxa_guard_acquire (__guard *g) { - return _GLIBCXX_GUARD_ACQUIRE (g); +#ifdef __GTHREADS + if (__gthread_active_p ()) + { + // Simple wrapper for exception safety. + struct mutex_wrapper + { + bool unlock; + mutex_wrapper (): unlock(true) + { + static_mutex::lock (); + } + ~mutex_wrapper () + { + if (unlock) + static_mutex::unlock (); + } + } mw; + + if (acquire_1 (g)) + { + mw.unlock = false; + return 1; + } + + return 0; + } +#endif + + return acquire_1 (g); } extern "C" - void __cxa_guard_release (__guard *g) + void __cxa_guard_abort (__guard *g) { - _GLIBCXX_GUARD_RELEASE (g); + ((char *)g)[1]--; +#ifdef __GTHREADS + if (__gthread_active_p ()) + static_mutex::unlock (); +#endif } extern "C" - void __cxa_guard_abort (__guard *) + void __cxa_guard_release (__guard *g) { + ((char *)g)[1]--; + _GLIBCXX_GUARD_RELEASE (g); +#ifdef __GTHREADS + if (__gthread_active_p ()) + static_mutex::unlock (); +#endif } } -- 2.43.5