X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-qsbr.c;h=06e81c7bbbbe47ad5eb4b0b40bf81be55d8bb9b7;hp=1dc99792d7a49f2f6f3614693e34cde239312bfb;hb=541d828d3101283ccdb1e25fa5a885e1d1743c1a;hpb=a128aeb4a7b1a05c9ddbc8b0239c93ca00984f4a diff --git a/urcu-qsbr.c b/urcu-qsbr.c index 1dc9979..06e81c7 100644 --- a/urcu-qsbr.c +++ b/urcu-qsbr.c @@ -39,6 +39,7 @@ #include "urcu/map/urcu-qsbr.h" #define BUILD_QSBR_LIB #include "urcu/static/urcu-qsbr.h" +#include "urcu-pointer.h" /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */ #undef _LGPL_SOURCE @@ -208,21 +209,17 @@ void synchronize_rcu(void) was_online = rcu_reader.ctr; /* All threads should read qparity before accessing data structure - * where new ptr points to. - */ - /* Write new ptr before changing the qparity */ - cmm_smp_mb(); - - /* + * where new ptr points to. In the "then" case, rcu_thread_offline + * includes a memory barrier. + * * Mark the writer thread offline to make sure we don't wait for * our own quiescent state. This allows using synchronize_rcu() * in threads registered as readers. */ - if (was_online) { - CMM_STORE_SHARED(rcu_reader.ctr, 0); - cmm_smp_mb(); /* write rcu_reader.ctr before read futex */ - wake_up_gp(); - } + if (was_online) + rcu_thread_offline(); + else + cmm_smp_mb(); mutex_lock(&rcu_gp_lock); @@ -263,9 +260,9 @@ out: * freed. */ if (was_online) - _CMM_STORE_SHARED(rcu_reader.ctr, - CMM_LOAD_SHARED(rcu_gp_ctr)); - cmm_smp_mb(); + rcu_thread_online(); + else + cmm_smp_mb(); } #else /* !(CAA_BITS_PER_LONG < 64) */ void synchronize_rcu(void) @@ -279,12 +276,10 @@ void synchronize_rcu(void) * our own quiescent state. This allows using synchronize_rcu() * in threads registered as readers. */ - cmm_smp_mb(); - if (was_online) { - CMM_STORE_SHARED(rcu_reader.ctr, 0); - cmm_smp_mb(); /* write rcu_reader.ctr before read futex */ - wake_up_gp(); - } + if (was_online) + rcu_thread_offline(); + else + cmm_smp_mb(); mutex_lock(&rcu_gp_lock); if (cds_list_empty(®istry)) @@ -294,9 +289,9 @@ out: mutex_unlock(&rcu_gp_lock); if (was_online) - _CMM_STORE_SHARED(rcu_reader.ctr, - CMM_LOAD_SHARED(rcu_gp_ctr)); - cmm_smp_mb(); + rcu_thread_online(); + else + cmm_smp_mb(); } #endif /* !(CAA_BITS_PER_LONG < 64) */ @@ -354,8 +349,14 @@ void rcu_unregister_thread(void) void rcu_exit(void) { - assert(cds_list_empty(®istry)); + /* + * Assertion disabled because call_rcu threads are now rcu + * readers, and left running at exit. + * assert(cds_list_empty(®istry)); + */ } +DEFINE_RCU_FLAVOR() + #include "urcu-call-rcu-impl.h" #include "urcu-defer-impl.h"