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memory-managementgocgo

Garbage collection in cgo

I have the following code in Go which uses cgo:

  func foo() {
       bar := new(C.struct_bar)
       ...
  }

Will bar be garbage collected after the function finishes its execution or I need to explicitly call free?

Solution

  • Yes, even though the struct_bar is a C type, the memory is allocated by Go, and will be collected by Go.

    Any memory allocated in C however is not tracked by the Go GC. The C code should manage this on it's own, but in cases like C.CString where Go triggers the allocation, you must manually free the memory with C.free.