Summary:
Abstract out FlushProcess and take it out of DBImpl.
This also includes taking DeletionState outside of DBImpl.

Currently this diff is only doing the refactoring. Future work includes:
1. Decoupling flush_process.cc, make it depend on less state
2. Write flush_process_test, which will mock out everything that FlushProcess depends on and test it in isolation

Test Plan: make check

Reviewers: rven, yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27561

Summary:
Now this gives us the real deal stack trace:

    Assertion failed: (false), function GetProperty, file db/db_impl.cc, line 4072.
    Received signal 6 (Abort trap: 6)
    #0   0x7fff57ce39b9
    #1   abort (in libsystem_c.dylib) + 125
    #2   basename (in libsystem_c.dylib) + 0
    #3   rocksdb::DBImpl::GetProperty(rocksdb::ColumnFamilyHandle*, rocksdb::Slice const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*) (in db_test) (db_impl.cc:4072)
    #4   rocksdb::_Test_Empty::_Run() (in db_test) (testharness.h:68)
    #5   rocksdb::_Test_Empty::_RunIt() (in db_test) (db_test.cc:1005)
    #6   rocksdb::test::RunAllTests() (in db_test) (testharness.cc:60)
    #7   main (in db_test) (db_test.cc:6697)
    #8   start (in libdyld.dylib) + 1

Test Plan: added artificial assert, saw great stack trace

Reviewers: haobo, dhruba, ljin

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18309

Summary: Sometimes, our tests fail because of normal `assert` call. It would be helpful to see stack trace in that case, too.

Test Plan: Added `assert(false)` and verified it prints out stack trace

Reviewers: haobo, dhruba, sdong, ljin, yhchiang

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18291

Summary: While debugging Mac-only issue with ThreadLocalPtr, this was very useful. Let's print out stack trace in MAC OS, too.

Test Plan: Verified that somewhat useful stack trace was generated on mac. Will run PrintStack() on linux, too.

Reviewers: ljin, haobo

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18189

Summary:
This will help me a lot! When we hit an assertion in unittest, we get the whole stack trace now.

Also, changed stack trace a bit, we now include actual demangled C++ class::function symbols!

Test Plan: Added ASSERT_TRUE(false) to a test, observed a stack trace

Reviewers: haobo, dhruba, kailiu

Reviewed By: kailiu

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14499

Summary:
Add appropriate LICENSE and Copyright message.

Test Plan:
make check

Reviewers:

CC:

Task ID: #

Blame Rev:

Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.

Test Plan: compile rocksdb

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13287

Summary: Some scripts (like regression_build_test.sh) redirect stdio to a tmp file and delete it on exit. This would miss the stack trace output on segfault. Output to stderr would hopefully show us the stack trace in the continuous build output.

Test Plan: ./signal_test, make check

Reviewers: dhruba

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10485

Summary:
This diff provides the ability to print out a stacktrace when the process receives certain signals.
Currently, we enable this for the following signals (program error related):
SIGILL SIGSEGV SIGBUS SIGABRT
Application simply #include "util/stack_trace.h" and call leveldb::InstallStackTraceHandler() during initialization, if signal handler is needed. It's not done automatically when openning db, because it's the application(process)'s responsibility to install signal handler and some applications might already have their own (like fbcode).

Sample output:
Received signal 11 (Segmentation fault)
#0  0x408ff0 ./signal_test() [0x408ff0] /home/haobo/rocksdb/util/signal_test.cc:4
#1  0x40827d ./signal_test() [0x40827d] /home/haobo/rocksdb/util/signal_test.cc:24
#2  0x7f8bb183172e /usr/local/fbcode/gcc-4.7.1-glibc-2.14.1/lib/libc.so.6(__libc_start_main+0x10e) [0x7f8bb183172e] ??:0
#3  0x408ebc ./signal_test() [0x408ebc] /home/engshare/third-party/src/glibc/glibc-2.14.1/glibc-2.14.1/csu/../sysdeps/x86_64/elf/start.S:113
Segmentation fault (core dumped)

For each frame, we print the raw pointer, the symbol provided by backtrace_symbols (still not good enough), and the source file/line. Note that address translation is done by directly shell out to addr2line. ??:0 means addr2line fails to do the translation. Hacky, but I think it's good for now.

Test Plan: signal_test.cc

Reviewers: dhruba, MarkCallaghan

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D10173