rocksdb/file
mrambacher 3dff28cf9b Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033)
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>.  The shared ptr has some performance degradation on certain hardware classes.

For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere.  For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it.  The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.

There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold.  In those cases, the shared pointer was preserved.

Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:

6.17: readrandom   :      28.046 micros/op 854902 ops/sec;   61.3 MB/s (355999 of 355999 found)
6.18: readrandom   :      32.615 micros/op 735306 ops/sec;   52.7 MB/s (290999 of 290999 found)
PR: readrandom   :      27.500 micros/op 871909 ops/sec;   62.5 MB/s (367999 of 367999 found)

(Note that the times for 6.18 are prior to revert of the SystemClock).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033

Reviewed By: pdillinger

Differential Revision: D27014563

Pulled By: mrambacher

fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
2021-03-15 04:34:11 -07:00
..
delete_scheduler.cc Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
delete_scheduler.h Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
delete_scheduler_test.cc Add a SystemClock class to capture the time functions of an Env (#7858) 2021-01-25 22:09:11 -08:00
file_prefetch_buffer.cc Fix typo: replace readadhead with readahead (#7953) 2021-02-18 14:31:20 -08:00
file_prefetch_buffer.h Fix typo: replace readadhead with readahead (#7953) 2021-02-18 14:31:20 -08:00
file_util.cc Fix typo: replace readadhead with readahead (#7953) 2021-02-18 14:31:20 -08:00
file_util.h Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
filename.cc Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
filename.h Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
line_file_reader.cc Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
line_file_reader.h Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
prefetch_test.cc Make BlockBasedTable::kMaxAutoReadAheadSize configurable (#7951) 2021-02-23 16:54:08 -08:00
random_access_file_reader.cc Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
random_access_file_reader.h Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
random_access_file_reader_test.cc Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
read_write_util.cc Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
read_write_util.h Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
readahead_raf.cc Make StringEnv, StringSink, StringSource use FS classes (#7786) 2021-01-04 16:01:01 -08:00
readahead_raf.h Make StringEnv, StringSink, StringSource use FS classes (#7786) 2021-01-04 16:01:01 -08:00
sequence_file_reader.cc Remove Legacy and Custom FileWrapper classes from header files (#7851) 2021-01-28 22:10:32 -08:00
sequence_file_reader.h Remove Legacy and Custom FileWrapper classes from header files (#7851) 2021-01-28 22:10:32 -08:00
sst_file_manager_impl.cc Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
sst_file_manager_impl.h Add a SystemClock class to capture the time functions of an Env (#7858) 2021-01-25 22:09:11 -08:00
writable_file_writer.cc Handoff checksum Implementation (#7523) 2021-02-10 22:20:32 -08:00
writable_file_writer.h Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00