Programming PHP

The struct looks like this in the php_foo.h header file:
ZEND_BEGIN_MODULE_GLOBALS(foo)
int some_integer;
char *some_string;
ZEND_END_MODULE_GLOBALS(foo)
#ifdef ZTS
# define FOO_G(v) TSRMG(foo_globals_id, zend_foo_globals *, v)
#else
# define FOO_G(v) (foo_globals.v)
#endif
The ext_skel tool creates most of this for you. You simply have to uncomment the
right sections.
In the main extension file, foo.c, you need to declare that your extension has globals
and define a function to initialize each member of your global struct:
ZEND_DECLARE_MODULE_GLOBALS(foo)
static void php_foo_init_globals(zend_foo_globals *foo_globals)
{
foo_globals->some_integer = 0;
foo_globals->some_string = NULL;
}
To have your initialization function called on module initialization, add this inside
the PHP_MINIT_FUNCTION( ):
ZEND_INIT_MODULE_GLOBALS(foo, php_foo_init_globals, NULL);
To access one of these globals, some_integer or some_string, use FOO_G(some_
integer) or FOO_G(some_string). Note that the struct must be available in the function
in order to use the FOO_G( ) macro. For all standard PHP functions, the global
struct is automatically and invisibly passed in.
However, if you write your own utility functions that need to access the global values,
you’ll have to pass in the struct yourself. The TSRMLS_CC macro does this for you,
so calls to your utility functions look like:
foo_utility_function(my_arg TSRMLS_CC);
When you declare foo_utility_function( ), use the TSRMLS_DC macro to receive the
global struct:
static void foo_utility_function(int my_arg TSRMLS_DC);
Creating Variables
As we saw in the previous section, the symbol_table and active_symbol_table hashes
contain user-accessible variables. You can inject new variables or change existing
ones in these hashes.
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Creating Variables | 345