From 19f5eebff80d9eeacc6ccf74b7bfa7718e3f7ea2 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Fri, 12 Aug 2011 04:47:00 -0700 Subject: [PATCH] Better defs for locker structures --- libraries/libmdb/mdb.c | 119 ++++++++++++++++++++++------------------- 1 file changed, 63 insertions(+), 56 deletions(-) diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c index b0b572dfef..1bffce58fb 100644 --- a/libraries/libmdb/mdb.c +++ b/libraries/libmdb/mdb.c @@ -83,44 +83,51 @@ typedef uint16_t indx_t; #define DEFAULT_MAPSIZE 1048576 /* Lock descriptor stuff */ -#define RXBODY \ - ULONG mr_txnid; \ - pid_t mr_pid; \ - pthread_t mr_tid -typedef struct MDB_rxbody { - RXBODY; -} MDB_rxbody; - #ifndef CACHELINE -# ifdef __APPLE__ -# define CACHELINE 128 /* 64 is too small to contain a mutex */ -# else -# define CACHELINE 64 /* most CPUs. Itanium uses 128 */ -# endif +#define CACHELINE 64 /* most CPUs. Itanium uses 128 */ #endif +typedef struct MDB_rxbody { + ULONG mrb_txnid; + pid_t mrb_pid; + pthread_t mrb_tid; +} MDB_rxbody; + typedef struct MDB_reader { - RXBODY; - /* cache line alignment */ - char pad[CACHELINE-sizeof(MDB_rxbody)]; + union { + MDB_rxbody mrx; +#define mr_txnid mru.mrx.mrb_txnid +#define mr_pid mru.mrx.mrb_pid +#define mr_tid mru.mrx.mrb_tid + /* cache line alignment */ + char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)]; + } mru; } MDB_reader; -#define TXBODY \ - uint32_t mt_magic; \ - uint32_t mt_version; \ - pthread_mutex_t mt_mutex; \ - ULONG mt_txnid; \ - uint32_t mt_numreaders typedef struct MDB_txbody { - TXBODY; + uint32_t mtb_magic; + uint32_t mtb_version; + pthread_mutex_t mtb_mutex; + ULONG mtb_txnid; + uint32_t mtb_numreaders; } MDB_txbody; typedef struct MDB_txninfo { - TXBODY; - char pad[CACHELINE-sizeof(MDB_txbody)]; - pthread_mutex_t mt_wmutex; - char pad2[CACHELINE-sizeof(pthread_mutex_t)]; - MDB_reader mt_readers[1]; + union { + MDB_txbody mtb; +#define mti_magic mt1.mtb.mtb_magic +#define mti_version mt1.mtb.mtb_version +#define mti_mutex mt1.mtb.mtb_mutex +#define mti_txnid mt1.mtb.mtb_txnid +#define mti_numreaders mt1.mtb.mtb_numreaders + char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)]; + } mt1; + union { + pthread_mutex_t mt2_wmutex; +#define mti_wmutex mt2.mt2_wmutex + char pad[(sizeof(pthread_mutex_t)+CACHELINE-1) & ~(CACHELINE-1)]; + } mt2; + MDB_reader mti_readers[1]; } MDB_txninfo; /* Common header for all page types. Overflow pages @@ -524,11 +531,11 @@ mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num) } if (txn->mt_env->me_pghead) { unsigned int i; - for (i=0; imt_env->me_txns->mt_numreaders; i++) { - ULONG mr = txn->mt_env->me_txns->mt_readers[i].mr_txnid; + for (i=0; imt_env->me_txns->mti_numreaders; i++) { + ULONG mr = txn->mt_env->me_txns->mti_readers[i].mr_txnid; if (!mr) continue; if (mr < oldest) - oldest = txn->mt_env->me_txns->mt_readers[i].mr_txnid; + oldest = txn->mt_env->me_txns->mti_readers[i].mr_txnid; } if (oldest > txn->mt_env->me_pghead->mo_txnid) { MDB_oldpages *mop = txn->mt_env->me_pghead; @@ -636,32 +643,32 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret) } STAILQ_INIT(txn->mt_u.dirty_queue); - pthread_mutex_lock(&env->me_txns->mt_wmutex); - env->me_txns->mt_txnid++; + pthread_mutex_lock(&env->me_txns->mti_wmutex); + env->me_txns->mti_txnid++; txn->mt_free_pgs = env->me_free_pgs; txn->mt_free_pgs[0] = 0; } - txn->mt_txnid = env->me_txns->mt_txnid; + txn->mt_txnid = env->me_txns->mti_txnid; if (rdonly) { MDB_reader *r = pthread_getspecific(env->me_txkey); if (!r) { unsigned int i; - pthread_mutex_lock(&env->me_txns->mt_mutex); - for (i=0; ime_txns->mt_numreaders; i++) - if (env->me_txns->mt_readers[i].mr_pid == 0) + pthread_mutex_lock(&env->me_txns->mti_mutex); + for (i=0; ime_txns->mti_numreaders; i++) + if (env->me_txns->mti_readers[i].mr_pid == 0) break; if (i == env->me_maxreaders) { pthread_mutex_unlock(&env->me_txns->mti_mutex); return ENOSPC; } - env->me_txns->mt_readers[i].mr_pid = getpid(); - env->me_txns->mt_readers[i].mr_tid = pthread_self(); - r = &env->me_txns->mt_readers[i]; + env->me_txns->mti_readers[i].mr_pid = getpid(); + env->me_txns->mti_readers[i].mr_tid = pthread_self(); + r = &env->me_txns->mti_readers[i]; pthread_setspecific(env->me_txkey, r); - if (i >= env->me_txns->mt_numreaders) - env->me_txns->mt_numreaders = i+1; - pthread_mutex_unlock(&env->me_txns->mt_mutex); + if (i >= env->me_txns->mti_numreaders) + env->me_txns->mti_numreaders = i+1; + pthread_mutex_unlock(&env->me_txns->mti_mutex); } r->mr_txnid = txn->mt_txnid; txn->mt_u.reader = r; @@ -733,10 +740,10 @@ mdb_txn_abort(MDB_txn *txn) } env->me_txn = NULL; - env->me_txns->mt_txnid--; + env->me_txns->mti_txnid--; for (i=2; ime_numdbs; i++) env->me_dbxs[i].md_dirty = 0; - pthread_mutex_unlock(&env->me_txns->mt_wmutex); + pthread_mutex_unlock(&env->me_txns->mti_wmutex); } free(txn); @@ -937,7 +944,7 @@ mdb_txn_commit(MDB_txn *txn) free(txn->mt_dbs); } - pthread_mutex_unlock(&env->me_txns->mt_wmutex); + pthread_mutex_unlock(&env->me_txns->mti_wmutex); free(txn->mt_u.dirty_queue); free(txn); txn = NULL; @@ -1219,7 +1226,7 @@ mdb_env_share_locks(MDB_env *env) { struct flock lock_info; - env->me_txns->mt_txnid = env->me_meta->mm_txnid; + env->me_txns->mti_txnid = env->me_meta->mm_txnid; memset((void *)&lock_info, 0, sizeof(lock_info)); lock_info.l_type = F_RDLCK; @@ -1284,22 +1291,22 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl) pthread_mutexattr_init(&mattr); pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED); - pthread_mutex_init(&env->me_txns->mt_mutex, &mattr); - pthread_mutex_init(&env->me_txns->mt_wmutex, &mattr); - env->me_txns->mt_version = MDB_VERSION; - env->me_txns->mt_magic = MDB_MAGIC; - env->me_txns->mt_txnid = 0; - env->me_txns->mt_numreaders = 0; + pthread_mutex_init(&env->me_txns->mti_mutex, &mattr); + pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr); + env->me_txns->mti_version = MDB_VERSION; + env->me_txns->mti_magic = MDB_MAGIC; + env->me_txns->mti_txnid = 0; + env->me_txns->mti_numreaders = 0; } else { - if (env->me_txns->mt_magic != MDB_MAGIC) { + if (env->me_txns->mti_magic != MDB_MAGIC) { DPRINTF("lock region has invalid magic"); rc = EINVAL; goto fail; } - if (env->me_txns->mt_version != MDB_VERSION) { + if (env->me_txns->mti_version != MDB_VERSION) { DPRINTF("lock region is version %u, expected version %u", - env->me_txns->mt_version, MDB_VERSION); + env->me_txns->mti_version, MDB_VERSION); rc = MDB_VERSION_MISMATCH; goto fail; } -- 2.39.2