From a4d106c70e87ee8e5d8aa3a0e3d44218703f1d04 Mon Sep 17 00:00:00 2001 From: Marius Vollmer Date: Mon, 7 Mar 2005 21:30:24 +0000 Subject: [PATCH] * threads.h, async.h, threads.c (SCM_CRITICAL_SECTION_START, SCM_CRITICAL_SECTION_END): Moved here from threads.h since now they also block/unblock execution of asyncs and call scm_async_click which is declared in async.h but threads.h can not include async.h since async.h already includes threads.h. (scm_i_critical_section_level): New, for checking mistakes in the use of the SCM_CRITICAL_SECTION_* macros. (scm_i_critical_section_mutex): Make it a recursive mutex so that critical sections can be nested. * threads.h, threads.c (scm_frame_lock_mutex): New. (scm_frame_critical_section): Take mutex as argument. (framed_critical_section_mutex): New, used as default for above. (scm_init_threads): Initialize it. (scm_threads_prehistory): Do not initialize thread_admin_mutex and scm_i_critical_section_mutex; both are initialized statically. --- libguile/async.h | 26 ++++++++++++++++++++++++++ libguile/threads.c | 27 ++++++++++++++++++++++----- libguile/threads.h | 15 ++------------- 3 files changed, 50 insertions(+), 18 deletions(-) diff --git a/libguile/async.h b/libguile/async.h index fca230382..e6d71520e 100644 --- a/libguile/async.h +++ b/libguile/async.h @@ -51,6 +51,32 @@ void *scm_c_call_with_unblocked_asyncs (void *(*p) (void *d), void *d); void scm_frame_block_asyncs (void); void scm_frame_unblock_asyncs (void); +/* Critical sections */ + +/* XXX - every critical section needs to be examined whether the + requirements for SCM_CRITICAL_SECTION_START/END are fulfilled. See + the manual. +*/ + +/* Defined in threads.c. scm_i_critical_section_level is only used + for error checking and will go away eventually. */ +extern scm_i_pthread_mutex_t scm_i_critical_section_mutex; +extern int scm_i_critical_section_level; + +#define SCM_CRITICAL_SECTION_START \ + do { \ + scm_i_pthread_mutex_lock (&scm_i_critical_section_mutex);\ + SCM_I_CURRENT_THREAD->block_asyncs++; \ + scm_i_critical_section_level++; \ + } while (0) +#define SCM_CRITICAL_SECTION_END \ + do { \ + scm_i_critical_section_level--; \ + SCM_I_CURRENT_THREAD->block_asyncs--; \ + scm_i_pthread_mutex_unlock (&scm_i_critical_section_mutex); \ + scm_async_click (); \ + } while (0) + SCM_API void scm_init_async (void); #if (SCM_ENABLE_DEPRECATED == 1) diff --git a/libguile/threads.c b/libguile/threads.c index 19fdc0004..05ea1e774 100644 --- a/libguile/threads.c +++ b/libguile/threads.c @@ -876,6 +876,15 @@ SCM_DEFINE (scm_lock_mutex, "lock-mutex", 1, 0, 0, } #undef FUNC_NAME +void +scm_frame_lock_mutex (SCM mutex) +{ + scm_frame_unwind_handler_with_scm ((void(*)(SCM))scm_unlock_mutex, mutex, + SCM_F_WIND_EXPLICITLY); + scm_frame_rewind_handler_with_scm ((void(*)(SCM))scm_lock_mutex, mutex, + SCM_F_WIND_EXPLICITLY); +} + static char * fat_mutex_trylock (fat_mutex *m, int *resp) { @@ -1490,13 +1499,20 @@ scm_i_frame_single_threaded () scm_frame_unwind_handler (wake_up, NULL, SCM_F_WIND_EXPLICITLY); } +/* This mutex is used by SCM_CRITICAL_SECTION_START/END. + */ scm_i_pthread_mutex_t scm_i_critical_section_mutex = - SCM_I_PTHREAD_MUTEX_INITIALIZER; + SCM_I_PTHREAD_RECURSIVE_MUTEX_INITIALIZER; +int scm_i_critical_section_level = 0; + +static SCM framed_critical_section_mutex; void -scm_frame_critical_section () +scm_frame_critical_section (SCM mutex) { - scm_i_frame_pthread_mutex_lock (&scm_i_critical_section_mutex); + if (scm_is_false (mutex)) + mutex = framed_critical_section_mutex; + scm_frame_lock_mutex (mutex); scm_frame_block_asyncs (); } @@ -1508,10 +1524,8 @@ scm_i_pthread_mutex_t scm_i_misc_mutex; void scm_threads_prehistory (SCM_STACKITEM *base) { - scm_i_pthread_mutex_init (&thread_admin_mutex, NULL); scm_i_pthread_mutex_init (&scm_i_misc_mutex, NULL); scm_i_pthread_cond_init (&wake_up_cond, NULL); - scm_i_pthread_mutex_init (&scm_i_critical_section_mutex, NULL); scm_i_pthread_key_create (&scm_i_freelist, NULL); scm_i_pthread_key_create (&scm_i_freelist2, NULL); @@ -1544,6 +1558,9 @@ scm_init_threads () scm_i_default_dynamic_state = SCM_BOOL_F; guilify_self_2 (SCM_BOOL_F); threads_initialized_p = 1; + + framed_critical_section_mutex = + scm_permanent_object (scm_make_recursive_mutex ()); } void diff --git a/libguile/threads.h b/libguile/threads.h index ad38653ed..8dda68f06 100644 --- a/libguile/threads.h +++ b/libguile/threads.h @@ -132,18 +132,6 @@ SCM_API void *scm_with_guile (void *(*func)(void *), void *data); SCM_API void *scm_i_with_guile_and_parent (void *(*func)(void *), void *data, SCM parent); -/* Critical sections */ - -/* XXX - every critical section needs to be examined and protected - with scm_frame_critical_section, say. -*/ - -extern scm_i_pthread_mutex_t scm_i_critical_section_mutex; - -#define SCM_CRITICAL_SECTION_START \ - scm_i_pthread_mutex_lock (&scm_i_critical_section_mutex) -#define SCM_CRITICAL_SECTION_END \ - scm_i_pthread_mutex_unlock (&scm_i_critical_section_mutex) extern int scm_i_thread_go_to_sleep; @@ -174,6 +162,7 @@ SCM_API SCM scm_join_thread (SCM t); SCM_API SCM scm_make_mutex (void); SCM_API SCM scm_make_recursive_mutex (void); SCM_API SCM scm_lock_mutex (SCM m); +SCM_API void scm_frame_lock_mutex (SCM mutex); SCM_API SCM scm_try_mutex (SCM m); SCM_API SCM scm_unlock_mutex (SCM m); @@ -190,7 +179,7 @@ SCM_API SCM scm_all_threads (void); SCM_API int scm_c_thread_exited_p (SCM thread); SCM_API SCM scm_thread_exited_p (SCM thread); -SCM_API void scm_frame_critical_section (void); +SCM_API void scm_frame_critical_section (SCM mutex); #define SCM_I_CURRENT_THREAD \ ((scm_i_thread *) scm_i_pthread_getspecific (scm_i_thread_key)) -- 2.20.1