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POBdb crashes on concurrent write, c++ linux/osx
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5919206
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2011-05-07T04:57:01.973
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2011-05-13T09:39:29.867
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I am having issues with bdb and there locking mechanisms. The following code results in either a seg fault, or what looks like a deadlock/endless loop <pre><code>#include <iostream> #include "db_cxx.h" #include <boost/thread.hpp> using namespace std; void thread_instance(Db* db, double start){ double s = start; double finish = start + 5000; for(int x=s; x < finish ; x++){ Dbt key(&x, sizeof(double)); Dbt ddata(&x, sizeof(double)); db->put(NULL, &key, &ddata, 0); } } int compare_double(DB *dbp, const DBT *a,const DBT *b){ double ai, bi; memcpy(&ai, a->data, sizeof(double)); memcpy(&bi, b->data, sizeof(double)); return (ai > bi ? 1 : ((ai < bi) ? -1 : 0)); } int main(){ system("rm data/*"); u_int32_t env_flags = DB_CREATE | DB_INIT_MPOOL | DB_INIT_CDB; DbEnv* env = new DbEnv(0); env->set_cachesize(0, 2000000, 1); u_int32_t m = 0; env->open("data/", env_flags, 0); Db* db = new Db(env, 0); db->set_bt_compare(compare_double); db->set_flags(DB_DUPSORT); db->set_pagesize(32768); db->set_dup_compare(compare_double); u_int32_t oFlags = DB_CREATE; try { db->open(NULL, "db", NULL, DB_BTREE, oFlags, 0); } catch (DbException &e) { } catch (std::exception &e) { } vector<boost::thread*> threads; for(int x=0; x < 3; x++){ threads.push_back(new boost::thread(boost::bind(&thread_instance, db, (x *5000)))); } for(int x=0; x < threads.size(); x++){ threads[x]->join(); } }; </code></pre> I have tried DB_INIT_LOCK as well, but with the same results. The stack track: <pre><code>Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000019 [Switching to process 34816] 0x00000001002e36a7 in __bamc_put () (gdb) ba #0 0x00000001002e36a7 in __bamc_put () #1 0x0000000100386689 in __dbc_iput () #2 0x0000000100387a6c in __dbc_put () #3 0x0000000100383092 in __db_put () #4 0x0000000100397888 in __db_put_pp () #5 0x00000001002cee59 in Db::put () #6 0x0000000100001f88 in thread_instance (db=0x1007006c0, start=5000) at src/main.cpp:16 #7 0x0000000100698254 in thread_proxy () #8 0x00007fff80cb9456 in _pthread_start () #9 0x00007fff80cb9309 in thread_start () </code></pre> Does anyone know what could be going on here ? 
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<berkeley-db>
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Bdb crashes on concurrent write, c++ linux/osx
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