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cstructbytesizeofvxworks

Can sizeof() ever return a different value for the same type?

In C, on the VxWorks operating system, I am experiencing different return values on sizeof for the same input parameter.

I have only one declaration of a particular structure:

typedef struct Data{
    //contains ints, floats, int[], and float[]
} Data;

With two separate spawned tasks, each calling: 

sizeof(Data);

the size appears different among the two calls.
One of the values returned back is smaller than it should be.

What could be causing this?
Why would sizeof return a different number of bytes on the same type declaration?

Solution

  • Despite only having one declaration of the struct, the arrays inside the struct had their size specified by a macro. The macro was re-defined in another file.