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Instead of embedding a lock bit in rtree leaf elements, we associate extents with a small set of mutexes. This gets us two things: - We can use the system mutexes. This (hypothetically) protects us from priority inversion, and lets us stop doing a backoff/sleep loop, instead opting for precise wakeups from the mutex. - Cuts down on the number of mutex acquisitions we have to do (from 4 in the worst case to two). We end up simplifying most of the rtree code (which no longer has to deal with locking or concurrency at all), at the cost of additional complexity in the extent code: since the mutex protecting the rtree leaf elements is determined by reading the extent out of those elements, the initial read is racy, so that we may acquire an out of date mutex. We re-check the extent in the leaf after acquiring the mutex to protect us from this race. |
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| bin | ||
| build-aux | ||
| doc | ||
| include | ||
| m4 | ||
| msvc | ||
| scripts | ||
| src | ||
| test | ||
| .appveyor.yml | ||
| .autom4te.cfg | ||
| .gitattributes | ||
| .gitignore | ||
| .travis.yml | ||
| autogen.sh | ||
| ChangeLog | ||
| config.stamp.in | ||
| configure.ac | ||
| COPYING | ||
| INSTALL.md | ||
| jemalloc.pc.in | ||
| Makefile.in | ||
| README | ||
| run_tests.sh | ||
jemalloc is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support. jemalloc first came into use as the FreeBSD libc allocator in 2005, and since then it has found its way into numerous applications that rely on its predictable behavior. In 2010 jemalloc development efforts broadened to include developer support features such as heap profiling and extensive monitoring/tuning hooks. Modern jemalloc releases continue to be integrated back into FreeBSD, and therefore versatility remains critical. Ongoing development efforts trend toward making jemalloc among the best allocators for a broad range of demanding applications, and eliminating/mitigating weaknesses that have practical repercussions for real world applications. The COPYING file contains copyright and licensing information. The INSTALL file contains information on how to configure, build, and install jemalloc. The ChangeLog file contains a brief summary of changes for each release. URL: http://jemalloc.net/