Introduce linux only futex contention resolution btree2v.c

[btree] / README.md

diff --git a/README.md b/README.md
index 7b2ba8494ba565b07a52c87c3cbc0ef2c3b398e6..b1206be147916fcfc467d7327bec2c2574955758 100644 (file)
--- a/README.md
+++ b/README.md
@@ -3,17 +3,21 @@ Btree-source-code
 
 A working project for High-concurrency B-tree source code in C
 
-There are three major code sets in the btree source code:
+There are seven files in the btree source code:
 
-btree2q.c       Single Threaded/MultiProcess with latching supplied by advisory file locking.  Works with network file systems.
-threads2h.c     Multi-Threaded/Multi-Process with latching implemented with test & set locks in the btree pages.
-threads2i.c     Multi-Threaded/Multi-Process with latching implemented with test & set locks in the btree pages with Linux futex system calls for contention.
+btree2s.c       Single Threaded/MultiProcess version that removes keys all the way back to an original empty btree, placing removed nodes on a free list.  Operates under either memory mapping or file I/O.  Recommended btrees hosted on network file systems.
 
-The Foster set includes three types of latching:
+btree2t.c       Single Threaded/MultiProcess version similar to btree2s except that fcntl locking has been replaced by test & set latches in the first few btree pages.  Uses either memory mapping or file I/O.
 
-Fosterbtreee.c  Multi-Threaded/Single Process with latches hosted by the buffer pool manager
-Fosterbtreef.c  Multi-Threaded/Multi-Process with latches hosted by a latch manager using the first few pages of the btree.
-Fosterbtreeg.c  Multi-Threaded/Multi-Process with latches implemented with test & set locks in the btree pages.
+btree2u.c              Single Threaded/MultiProcess version that implements a traditional buffer pool manager in the first n pages of the btree file.  The buffer pool accesses its pages with mmap.  Evicted pages are written back to the btree file from the buffer pool pages with pwrite. Recommended for linux.
+
+btree2v.c              Single Threaded/MultiProcess version based on btree2u that utilizes linux only futex calls for latch contention.
+
+threads2h.c     Multi-Threaded/Multi-Process with latching implemented by a latch manager with pthreads/SRW latches in the first few btree pages. Recommended for Windows.
+
+threads2i.c     Multi-Threaded/Multi-Process with latching implemented by a latch manager with test & set latches in the first few btree pages with thread yield system calls during contention.
+
+threads2j.c     Multi-Threaded/Multi-Process with latching implemented by a latch manager with test & set locks in the first few btree pages with Linux futex system calls during contention.
 
 Compilation is achieved on linux or Windows by:
 
@@ -21,6 +25,6 @@ gcc -D STANDALONE threads2h.c -lpthread
 
 or
 
-cl /D STANDALONE threads2h.c
+cl /Ox /D STANDALONE threads2h.c
 
-Please see the project wiki page for documentation
+Please see the project wiki page for additional documentation