Hi list, recently I wrote app on LMDB, found that for every write , lmdb lock a global lock when transaction is created , and release this lock in mdb_txn_commit, on Ubuntu, this lock is implemented by pthread_mutext_t. in my app, I create write transaction in a thread, then commit this write transaction in another thread, since lmdb use pthread_mutex_unlock to release this lock, according to manual , attempting to unlock the mutex if it was not locked by the calling thread results in undefined behavior, then my app cannot create write transaction . So does this issue known to community or is there any way to work around?
Cheers, xinxin
Shu, Xinxin wrote:
Hi list, recently I wrote app on LMDB, found that for every write , lmdb lock a global lock when transaction is created , and release this lock in mdb_txn_commit, on Ubuntu, this lock is implemented by pthread_mutext_t. in my app, I create write transaction in a thread, then commit this write transaction in another thread, since lmdb use pthread_mutex_unlock to release this lock, according to manual , attempting to unlock the mutex if it was not locked by the calling thread results in undefined behavior, then my app cannot create write transaction . So does this issue known to community or is there any way to work around?
This is already documented.
http://symas.com/mdb/doc/group__mdb.html#gad7ea55da06b77513609efebd44b26920
Thanks for pointing me out
-----Original Message----- From: Howard Chu [mailto:hyc@symas.com] Sent: Tuesday, August 4, 2015 9:46 AM To: Shu, Xinxin; openldap-technical@openldap.org Subject: Re: question on write transaction
Shu, Xinxin wrote:
Hi list, recently I wrote app on LMDB, found that for every write , lmdb lock a global lock when transaction is created , and release this lock in mdb_txn_commit, on Ubuntu, this lock is implemented by pthread_mutext_t. in my app, I create write transaction in a thread, then commit this write transaction in another thread, since lmdb use pthread_mutex_unlock to release this lock, according to manual , attempting to unlock the mutex if it was not locked by the calling thread results in undefined behavior, then my app cannot create write transaction . So does this issue known to community or is there any way to work around?
This is already documented.
http://symas.com/mdb/doc/group__mdb.html#gad7ea55da06b77513609efebd44b26920
openldap-technical@openldap.org
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Howard Chu -
Shu, Xinxin