Seg Fault

[xinthose]

Hello. I am getting a segmentation fault and do not know why. The C++ code is simply this:

std::string test = "{\"Val\":7}";           
document.Parse(test.c_str()).HasParseError()

I know it works elsewhere for me, so it could be in how I'm compiling and linking. This function is in a Boost thread and I also use Boost global logging. Thank you.

gdb output

----------------------------------------------------------------
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb659fb40 (LWP 3618)]
0x0806d697 in rapidjson::GenericValue<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator> >::GenericValue (this=0x10, s=0xb5a12600 "Val", length=3, allocator=...) at /usr/local/include/rapidjson/document.h:558
558     GenericValue(const Ch* s, SizeType length, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s, length), allocator); }
------------------------------------
(gdb) list
553 
554     //! Constructor for constant string (i.e. do not make a copy of string)
555     explicit GenericValue(StringRefType s) RAPIDJSON_NOEXCEPT : data_(), flags_() { SetStringRaw(s); }
556 
557     //! Constructor for copy-string (i.e. do make a copy of string)
558     GenericValue(const Ch* s, SizeType length, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s, length), allocator); }
559 
560     //! Constructor for copy-string (i.e. do make a copy of string)
561     GenericValue(const Ch*s, Allocator& allocator) : data_(), flags_() { SetStringRaw(StringRef(s), allocator); }
562 
------------------------------------
(gdb) bt
#0  0x0806d697 in rapidjson::GenericValue<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator> >::GenericValue (this=0x10, s=0xb5a12600 "Val", length=3, allocator=...) at /usr/local/include/rapidjson/document.h:558
#1  0x0806cecf in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::String (this=0x80cab24 <_system_rapidjson+4>, str=0xb5a12600 "Val", length=3, copy=true)
    at /usr/local/include/rapidjson/document.h:2023
#2  0x0806ce21 in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::Key (this=0x80cab24 <_system_rapidjson+4>, str=0xb5a12600 "Val", length=3, copy=true)
    at /usr/local/include/rapidjson/document.h:2031
#3  0x0806b5b5 in rapidjson::GenericReader<rapidjson::UTF8<char>, rapidjson::UTF8<char>, rapidjson::CrtAllocator>::ParseString<0u, rapidjson::GenericStringStream<rapidjson::UTF8<char> >, rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator> > (this=0xb659ee8c, is=..., handler=..., isKey=true)
    at /usr/local/include/rapidjson/reader.h:657
#4  0x0806b874 in rapidjson::GenericReader<rapidjson::UTF8<char>, rapidjson::UTF8<char>, rapidjson::CrtAllocator>::ParseObject<0u, rapidjson::GenericStringStream<rapidjson::UTF8<char> >, rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator> > (this=0xb659ee8c, is=..., handler=...)
    at /usr/local/include/rapidjson/reader.h:487
#5  0x0806a8ec in rapidjson::GenericReader<rapidjson::UTF8<char>, rapidjson::UTF8<char>, rapidjson::CrtAllocator>::ParseValue<0u, rapidjson::GenericStringStream<rapidjson::UTF8<char> >, rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator> > (this=0xb659ee8c, is=..., handler=...)
    at /usr/local/include/rapidjson/reader.h:993
#6  0x0806a2ab in rapidjson::GenericReader<rapidjson::UTF8<char>, rapidjson::UTF8<char>, rapidjson::CrtAllocator>::Parse<0u, rapidjson::GenericStringStream<rapidjson::UTF8<char> >, rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator> > (this=0xb659ee8c, is=..., handler=...)
    at /usr/local/include/rapidjson/reader.h:408
#7  0x08069c95 in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::ParseStream<0u, rapidjson::UTF8<char>, rapidjson::GenericStringStream<rapidjson::UTF8<char> > > (
    this=0x80cab24 <_system_rapidjson+4>, is=...) at /usr/local/include/rapidjson/document.h:1892
#8  0x08069593 in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::Parse<0u, rapidjson::UTF8<char> > (this=0x80cab24 <_system_rapidjson+4>, 
    str=0xb5a13054 "{\"Val\":7}") at /usr/local/include/rapidjson/document.h:1957
#9  0x08068e9a in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::Parse<0u> (this=0x80cab24 <_system_rapidjson+4>, str=0xb5a13054 "{\"Val\":7}")
    at /usr/local/include/rapidjson/document.h:1966
#10 0x080687a6 in rapidjson::GenericDocument<rapidjson::UTF8<char>, rapidjson::MemoryPoolAllocator<rapidjson::CrtAllocator>, rapidjson::CrtAllocator>::Parse (this=0x80cab24 <_system_rapidjson+4>, str=0xb5a13054 "{\"Val\":7}")
    at /usr/local/include/rapidjson/document.h:1973
#11 0x080679c1 in system_rapidjson::read_json_str (this=0x80cab20 <_system_rapidjson>, 
    json_str="{\"Description\":\"DATABASE TASK MODE VALUE\",\"Name\":\"TASK\",\"Val\":0,\"addID\":0,\"CreatedAt\":\"2015-08-12T17:57:03.954Z\",\"ModifiedAt\":\"2015-08-19T21:26:02.354Z\",\"CreatedBy\":\"00000000-0000-0000-0000-0000000000"...)
    at src/rapidjson.cpp:64
#12 0x0808b041 in check_task () at src/main.cpp:68
#13 0x08095dc3 in boost::detail::thread_data<void (*)()>::run (this=0x80f8728)
---Type <return> to continue, or q <return> to quit---
    at /usr/include/boost/thread/detail/thread.hpp:117
#14 0xb7fb1f16 in ?? () from /usr/lib/i386-linux-gnu/libboost_thread.so.1.55.0
#15 0xb7d03d97 in start_thread (arg=0xb659fb40) at pthread_create.c:309
#16 0xb76d2dfe in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:129

[xinthose]

I already gave up. string.find () works just as well. I just want to extract "Val" 's from JSON

[miloyip]

I cannot diagnose the problem from the information.
Will it be possible that your program using more than one version of RapidJSON?

[ImmortalDragonm]

Is RapidJSON thread safe?

[xinthose]

I am having weird problems in my code elsewhere. I wasn't sure if the gdb output could help at all. I only installed it once. I found boost property tree works well for me in a threaded environment: http://tiny.cc/25eb2x ; Thank you.

[miloyip]

@ImmortalDragonm
RapidJSON is not thread-safe per se. But different instances of RapidJSON objects does not interfere each other. No global/static-member variable is used.