Memory Allocation

These functions provide support for allocating and freeing memory.

If any call to allocate memory using functions g_new(), g_new0(), g_renew(), g_malloc(), g_malloc0(), g_malloc0_n(), g_realloc() and g_realloc_n() fails, the application is terminated. This also means that there is no need to check if the call succeeded.

On the other hand, the g_try_…() family of functions returns NULL on failure that can be used as a check for unsuccessful memory allocation. The application is not terminated in this case.

As all GLib functions and data structures use g_malloc() internally, unless otherwise specified, any allocation failure will result in the application being terminated.

It’s important to match g_malloc() (and wrappers such as g_new()) with g_free(), g_slice_alloc() (and wrappers such as g_slice_new()) with g_slice_free(), plain malloc() with free(), and (if you’re using C++) new with delete and new[] with delete[]. Otherwise bad things can happen, since these allocators may use different memory pools (and new/delete call constructors and destructors).

Since GLib 2.46, g_malloc() is hardcoded to always use the system malloc implementation.

Struct Allocations

• g_new()
• g_new0()
• g_renew()
• g_try_new()
• g_try_new0()
• g_try_renew()

Block Allocations

• g_malloc()
• g_malloc0()
• g_realloc()
• g_try_malloc()
• g_try_malloc0()
• g_try_realloc()
• g_malloc_n()
• g_malloc0_n()
• g_realloc_n()
• g_try_malloc_n()
• g_try_malloc0_n()
• g_try_realloc_n()

Free Functions

• g_free()
• g_free_sized()
• g_clear_pointer()
• g_steal_pointer()

In addition, the g_mem_gc_friendly exported variable will be true if GLib has been run with G_DEBUG=gc-friendly. If so, memory to be freed will be cleared to zero before being freed.

Stack Allocations

• g_alloca()
• g_alloca0()
• g_newa()
• g_newa0()

Aligned Allocations

• g_aligned_alloc()
• g_aligned_alloc0()
• g_aligned_free()
• g_aligned_free_sized()

Copies and Moves

• g_memmove()
• g_memdup2()

Deprecated API

• g_memdup()
• GMemVTable
• g_mem_set_vtable()
• g_mem_is_system_malloc()
• glib_mem_profiler_table exported variable
• g_mem_profile()