Pros of rpmalloc

• Simpler implementation, making it easier to understand and maintain
• Lower memory overhead for small allocations
• Better performance on some benchmarks, particularly for small allocations

Cons of rpmalloc

• Less focus on security features compared to snmalloc
• May not perform as well for large allocations or high-concurrency scenarios
• Less extensive documentation and community support

Code Comparison

rpmalloc:

static void* _rpmalloc_allocate_large(size_t size) {
    size_t total_size = size + SPAN_HEADER_SIZE;
    size_t num_spans = total_size >> _memory_span_size_shift;
    if (total_size & (_memory_span_size - 1))
        ++num_spans;
    size_t span_count = (size_t)num_spans;
    span_t* span = _rpmalloc_heap_allocate_spans(heap, span_count);
    return pointer_offset(span, SPAN_HEADER_SIZE);
}

snmalloc:

void* Alloc::alloc_large(size_t size)
{
  size = round_size(size);
  auto sizeclass = size_to_sizeclass(size);
  auto rsize = sizeclass_to_size(sizeclass);
  auto span = large_allocator.alloc(rsize);
  if (span == nullptr)
    return nullptr;
  return span->start;
}

Both allocators use similar approaches for large allocations, but snmalloc's implementation is more abstracted and uses higher-level constructs.

Pros of jemalloc

• Widely adopted and battle-tested in large-scale production environments
• Extensive performance tuning options and customization capabilities
• Strong support for multi-threaded applications and scalability

Cons of jemalloc

• More complex codebase, potentially harder to maintain or modify
• Higher memory overhead in some scenarios due to its sophisticated management structures
• May require more fine-tuning to achieve optimal performance in specific use cases

Code Comparison

jemalloc:

void *ptr = malloc(size);
free(ptr);

snmalloc:

void *ptr = snmalloc::ThreadAlloc::get().alloc(size);
snmalloc::ThreadAlloc::get().dealloc(ptr);

Key Differences

• snmalloc is designed with a focus on security and memory isolation
• jemalloc offers more extensive statistics and debugging features
• snmalloc has a simpler codebase, potentially easier to integrate and maintain
• jemalloc provides better support for fragmentation reduction in long-running applications

Both allocators aim to improve performance and memory efficiency, but they take different approaches. snmalloc emphasizes security and simplicity, while jemalloc focuses on scalability and extensive customization options. The choice between them depends on specific project requirements and use cases.

Pros of tcmalloc

• Highly optimized for multi-threaded applications
• Extensive performance profiling and debugging tools
• Wider adoption and longer history of use in production environments

Cons of tcmalloc

• More complex implementation, potentially harder to maintain
• May have higher memory overhead for small allocations
• Less focus on security features compared to snmalloc

Code Comparison

snmalloc:

void* alloc = snmalloc::ThreadAlloc::get().alloc(size);
snmalloc::ThreadAlloc::get().dealloc(alloc);

tcmalloc:

void* alloc = tc_malloc(size);
tc_free(alloc);

Both libraries provide similar APIs for allocation and deallocation, but snmalloc uses a thread-local allocator object, while tcmalloc uses global functions.

snmalloc focuses on simplicity and security, with features like randomized allocation and memory zeroing. tcmalloc emphasizes performance and scalability, particularly for multi-threaded applications.

tcmalloc offers more advanced profiling and debugging tools, which can be beneficial for large-scale projects. However, snmalloc's simpler design may make it easier to integrate and maintain in smaller projects or those with specific security requirements.

Pros of mimalloc

• Higher performance in multi-threaded scenarios
• More extensive documentation and benchmarks
• Wider adoption and community support

Cons of mimalloc

• Slightly larger memory footprint
• More complex implementation, potentially harder to maintain

Code comparison

mimalloc:

#include <mimalloc.h>

void* p = mi_malloc(sizeof(int));
mi_free(p);

snmalloc:

#include <snmalloc.h>

void* p = snmalloc::malloc(sizeof(int));
snmalloc::free(p);

Key differences

• mimalloc uses a global API, while snmalloc requires namespace usage
• mimalloc focuses on performance optimizations for common allocation patterns
• snmalloc emphasizes memory isolation and security features

Performance

• mimalloc generally outperforms snmalloc in multi-threaded scenarios
• snmalloc may have an edge in single-threaded applications

Memory usage

• snmalloc typically has a smaller memory footprint
• mimalloc trades some memory overhead for improved performance

Compatibility

• Both allocators can be used as drop-in replacements for standard malloc
• mimalloc has broader platform support and more extensive testing

Community and development

• mimalloc has a larger user base and more frequent updates
• snmalloc focuses on specific use cases and security features