Re: [Jsoncpp-devel] Potential memory leaks in jsoncpp

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Oops, I removed the list's mailing address by mistake. Resending to the original list.

From: P, Chandrasekhar
Sent: Wednesday, March 23, 2011 3:15 PM
To: 'Amit Rao'
Subject: RE: [Jsoncpp-devel] Potential memory leaks in jsoncpp

Hi Amit,
                Ran few valgrind tests and found no memory leaks reported. Can u attach the sample code that is reporting this leak?

Thanks,
Sekhar.

From: P, Chandrasekhar
Sent: Monday, March 21, 2011 11:13 AM
To: 'Amit Rao'
Subject: RE: [Jsoncpp-devel] Potential memory leaks in jsoncpp

Hi Amit,
                Thanks for reporting this. So far, I'm not aware of any memory leaks in JSONCPP. However, from the stack trace you've provided below it looks Json::Value copy constructor is being invoked. A review of the code looks like a valid issue to me. In the code snippet below, value_.string_ should have been freed before being assigned.

435      if ( other.value_.string_ )
436      {
437         value_.string_ = valueAllocator()->duplicateStringValue( other.value_.string_ );
438         allocated_ = true;
439      }
440      else
441         value_.string_ = 0;

Thanks,
Sekhar.

From: Amit Rao [mailto:am...@ya...]
Sent: Tuesday, March 08, 2011 6:17 AM
To: jso...@li...
Cc: Amit Rao
Subject: [Jsoncpp-devel] Potential memory leaks in jsoncpp

Hi jsoncpp-devel,

I am developing application code that uses jsoncpp-0.5.0 on a  freebsd6 server compiled with gcc version 2.95.3 20010315 (release). I am seeing that the heap memory of the process is constantly growing when a large json stucture with several thousands of entries is parsed.  The process grows to over 500 MB in size and eventually dumps core with a seg fault. Memory leak detection tools are reporting a memory leak with the following stack trace. The application code's entry point to the jsoncpp library is through the Json::Reader::parse() call. It seems that the underlying std::map under Value::Value is not deleted properly in this case.

|   allocation size per-call (min max avg): 4 94 27
|   most recent stack trace:
#0  0x213caea5 in malloc () from /usr/lib32/compat/libc.so.4
#1  0x234810a3 in Json::DefaultValueAllocator::duplicateStringValue (
    this=0x23491f9c, value=0x12c4eb0 "address", length=4294967295)
    at json_value.cpp:85
#2  0x23479917 in Json::Value::Value (this=0xffffb6a0, other=@0xffffb6ec)
    at json_value.cpp:437
#3  0x23479d73 in Json::Value::operator= (this=0x11d6130, other=@0xffffb6ec)
    at json_value.cpp:510
#4  0x23470484 in Json::Reader::decodeString (this=0x113f53c,
    token=@0xffffb744) at json_reader.cpp:652
#5  0x2346dbee in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:220
#6  0x2346ec97 in Json::Reader::readObject (this=0x113f53c,
    tokenStart=@0xffffb814) at json_reader.cpp:510
#7  0x2346dbc1 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:211
#8  0x2346f2c7 in Json::Reader::readArray (this=0x113f53c,
    tokenStart=@0xffffb8b4) at json_reader.cpp:554
#9  0x2346dbd0 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:214
#10 0x2346ec97 in Json::Reader::readObject (this=0x113f53c,
    tokenStart=@0xffffb984) at json_reader.cpp:510
#11 0x2346dbc1 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:211
#12 0x2346f2c7 in Json::Reader::readArray (this=0x113f53c,
    tokenStart=@0xffffba24) at json_reader.cpp:554
#13 0x2346dbd0 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:214
#14 0x2346ec97 in Json::Reader::readObject (this=0x113f53c,
    tokenStart=@0xffffbaf4) at json_reader.cpp:510
#15 0x2346dbc1 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:211
#16 0x2346ec97 in Json::Reader::readObject (this=0x113f53c,
    tokenStart=@0xffffbbc4) at json_reader.cpp:510
#17 0x2346dbc1 in Json::Reader::readValue (this=0x113f53c)
    at json_reader.cpp:211
#18 0x2346d8d6 in Json::Reader::parse (this=0x113f53c,
    beginDoc=0x14fc010 "{\"contacts\":{\"start\":0,\"count\":618,\"total\":618,\"uri\":\"http://social.yahooapis.com/v1/user/3N74ASGDFNOAJUBXOFSDDZZEYQ/contacts\",\"contact\":[{\"uri\":\"http://social.yahooapis.com/v1/user/3N74ASGDFNOAJUBXOF"..., endDoc=0x1599ebd "", root=@0xffffbdf0, collectComments=true)
    at json_reader.cpp:172
#19 0x2346d696 in Json::Reader::parse (this=0x113f53c, document=@0xffffbd1c,
    root=@0xffffbdf0, collectComments=true) at json_reader.cpp:129
#20 0x231cff6e in ymmaddbk::AddressBookClient::parseContactsInJson (
    this=0x113f500, text=@0xffffbd1c, root=@0xffffbdf0)
    at AddressBookClient.cc:582
#21 0x231c3a21 in ymmaddbk::AddressBookClient::getAllRecords (this=0x113f500,
    ytcookie=@0x10f7688, root=@0xffffbdf0) at AddressBookClient.cc:144
#22 0x231c70c2 in ymmaddbk::AddressBookClient::getNickNames (this=0x113f500,
    ytcookie=@0x10f7688, nickNames=@0xffffbf4c) at AddressBookClient.cc:313
#23 0x231e4df3 in ymmaddbk::ymmab::getNickNames (this=0xffffbf58,
    ytcookie=@0x10f7688, nickNames=@0xffffbf4c) at ymmab.cc:347
#24 0x22c8dac0 in push::pushNotify::valAndInitialize (this=0x10f7680,
    rawData=@0xffffc060, len=@0xffffc04c) at PushNotifier.cc:384
#25 0x22c8a696 in push::pushNotifyWrapper::valAndInitialize (this=0x113e220,
    rawData=@0xffffc060, len=@0xffffc04c) at PushNotifier.cc:182
#26 0x22c9425a in MsgrPushNotifyProcess (
    consumer=0x1064838 "MsgrPushNotify.so /home/y/conf/ymmpush/pushConsumerApns.xml", entry=0x1048d10) at PushNotifier.cc:653
#27 0x2114fca2 in yreplLogConsSO::callProcess (this=0x10dd3c0,
    consumer=0x1064838 "MsgrPushNotify.so /home/y/conf/ymmpush/pushConsumerApns.xml", entry=0x1048d10) at logConsSO.cc:135
#28 0x01023212 in processEntry (entry=0x1048cd0) at txLogReader.cc:1533
#29 0x010195a5 in flushEntryBuffer (unreadLast=false) at txLogReader.cc:335
#30 0x0101a271 in addEntryToBuffer (entry=0x11790a0) at txLogReader.cc:512
#31 0x0101d9db in main (argc=2, argv=0xffffc330) at txLogReader.cc:10

Is this a known issue?  Has anyone encountered memory leaks with jsoncpp-0.5.0? If someone on the mailing list
Has run into this problem please let me know.

Thanks,
amit

Here is some additional data about the server...
FreeBSD cache101a.a1.rest.msg.sp1.yahoo.com 6.3-YAHOO-20080603 FreeBSD 6.3-YAHOO-20080603 #0: Wed Jun  4 08:19:43 PDT 2008        jh...@fb...:/home/src/sys/amd64/compile/YAHOO amd64

Re: [Jsoncpp-devel] Potential memory leaks in jsoncpp

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Re: [Jsoncpp-devel] Potential memory leaks in jsoncpp