Thread: global structures

ok..so my program uses threads..but the basics are this...lets say i have file1.c, file2.c and file3.c..

atm, i have defined the struct in a file called struct_definitions.h... so basically file1 creates the threads and then the thread is located in file2. the structure is passed to the thread through the thread creation argument. the thread in file2.c writes a value to the struct and ends..then the thread in file3 is supposed to read and print that value.

the reading of the value is ok, as soon after the read i print it and its correct. but when i print it out in the other function, the value comes as 0, which means that it is clearly wrong.

struct definition in struct_definitions.h

Code:

struct analog_input
{
	float analog_input_value;
};

since everything works ok, i will post only the problematic read function which is supposed to read the struct

Code:

void *analog_printfunction0 (void *analogin0struct)
{
struct analog_input *ptr = (struct analog_input*) &analogin0struct;

printf("Analog In 0 value : %f\n",ptr->analog_input_value);
}

hope someone can help me!

Also, the use of the type cast is not really needed. The use of void * should be okay to assign to anything without errors.

That is

struct analog_input *ptr = analogin0struct;

should be allowed.

i made the changes as suggested and removed the address operator. but still its the same result..

in the main file where the thread which writes to the struct is created ive done this

Code:

struct analog_input analogin0struct;

//and then create the thread to write to it. write is successful

also in the file where the struct is read i have included the file with the struct definitions and added

Code:

extern struct analog_input analogin0struct;

would it be easier if i create a global struct in the main file and then read it from the output file?but how do you do that?