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499f306859
Arena 0 have a dedicated initialization path, which differs from
initialization path of other arenas. The main difference for the purpose
of this change is that we initialize arena 0 before we initialize
background threads. HPA shard options have `deferral_allowed` flag which
should be equal to `background_thread_enabled()` return value, but it
wasn't the case before this change, because for arena 0
`background_thread_enabled()` was initialized correctly after arena 0
initialization phase already ended.
Below is initialization sequence for arena 0 after this commit to
illustrate everything still should be initialized correctly.
* `hpa_central_init` initializes HPA Central, before we initialize every
HPA shard (including arena's 0).
* `background_thread_boot1` initializes `background_thread_enabled()`
return value.
* `pa_shard_enable_hpa` initializes arena 0 HPA shard.
```
malloc_init_hard -------------
/ / \
/ / \
/ / \
malloc_init_hard_a0_locked background_thread_boot1 pa_shard_enable_hpa
/ / \
/ / \
/ / \
arena_boot background_thread_enabled_seta hpa_shard_init
|
|
pa_central_init
|
|
hpa_central_init
```
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: https://jemalloc.net/