#Jemallocator: Rust jemalloc Memory Allocator

jemallocator is a library linked with the jemalloc memory allocator, providing the Jemalloc unit type that implements the allocator API and can be set as #[global_allocator].

tikv-jemallocator is the successor to jemallocator. These two crates are identical except for their names. For new projects, it is recommended to use the tikv-xxx version.

#The jemalloc Ecosystem

The jemalloc support ecosystem consists of the following crates:

• tikv-jemalloc-sys: Builds and links to jemalloc, exposing raw C bindings to it.
• tikv-jemallocator: Provides the Jemalloc type, which implements the GlobalAlloc and Alloc traits.
• tikv-jemalloc-ctl: A high-level wrapper for jemalloc's control and introspection APIs (the mallctl*() function family and MALLCTL NAMESPACE).

#Usage

#Adding Dependencies

To use tikv-jemallocator, add it as a dependency:

[dependencies]  

[target.'cfg(not(target_env = "msvc"))'.dependencies]  
tikv-jemallocator = "0.5"

#Setting as the Global Allocator

To set tikv_jemallocator::Jemalloc as the global allocator, add the following code to your project:

#[cfg(not(target_env = "msvc"))]  
use tikv_jemallocator::Jemalloc;  

#[cfg(not(target_env = "msvc"))]  
#[global_allocator]  
static GLOBAL: Jemalloc = Jemalloc;

That's it! Once this static variable is defined, jemalloc will be used for all memory allocations requested by Rust code in the same program.

#Advantages

jemalloc is a general-purpose malloc implementation that focuses on:

• Reducing memory fragmentation
• Scalability in high-concurrency scenarios
• Providing rich introspection and control capabilities

It is particularly useful in the following scenarios:

• Long-running applications
• Memory-intensive workloads
• High-performance services requiring fine-grained memory management

#Compatibility Notes

jemalloc does not support the MSVC target environment and is therefore unavailable when using the MSVC toolchain on Windows. This is why the cfg(not(target_env = "msvc")) condition is included in the example code.