levelDB-LAB1-pzy_ckx

小组成员：曹可心-10223903406 朴祉燕-10224602413

costan 05709fb43e Remove InitOnce from the port API. This is not an API-breaking change, because it reduces the API that the leveldb embedder must implement. The project will build just fine against ports that still implement InitOnce. C++11 guarantees thread-safe initialization of static variables inside functions. This is a more restricted form of std::call_once or pthread_once_t (e.g., single call site), so the compiler might be able to generate better code [1]. Equally important, having less code in port_example.h makes it easier to port to other platforms. Due to the change above, this CL introduces a new approach for storing the singleton BytewiseComparatorImpl instance returned by BytewiseComparator(). The new approach avoids a dynamic memory allocation, which eliminates the false positive from LeakSanitizer reported in https://github.com/google/leveldb/issues/200 [1] https://stackoverflow.com/a/27206650/ ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=212348004			6 роки тому
..
win	reverting disastrous MOE commit, returning to r21	删除	13 роки тому
README	Replace port_posix with port_stdcxx.		6 роки тому
atomic_pointer.h	Take <atomic> for granted in port/atomic_pointer.h.		6 роки тому
port.h	Replace port_posix with port_stdcxx.		6 роки тому
port_config.h.in	Take <atomic> for granted in port/atomic_pointer.h.		6 роки тому
port_example.h	Remove InitOnce from the port API.		6 роки тому
port_stdcxx.h	Remove InitOnce from the port API.		6 роки тому
thread_annotations.h	Enable thread safety annotations in open source version.		6 роки тому

README

This directory contains interfaces and implementations that isolate the
rest of the package from platform details.

Code in the rest of the package includes "port.h" from this directory.
"port.h" in turn includes a platform specific "port_<platform>.h" file
that provides the platform specific implementation.

See port_stdcxx.h for an example of what must be provided in a platform
specific header file.