mirror of
https://git.proxmox.com/git/wasi-libc
synced 2025-10-17 06:45:26 +00:00
21d93b927d
* Add a check to command modules to ensure that they're only started once. Wasm command modules should only be called once per instance, because the programming model doesn't leave linear memory in a reusable state when the program exits. As use cases arise for loading wasm modules in environments that want to treat them like reactors, add a safety check to ensure that command modules are used according to their expectations.
35 lines
1.0 KiB
C
35 lines
1.0 KiB
C
#include <wasi/api.h>
|
|
extern void __wasm_call_ctors(void);
|
|
extern int __main_void(void);
|
|
extern void __wasm_call_dtors(void);
|
|
|
|
// Commands should only be called once per instance. This simple check ensures
|
|
// that the `_start` function isn't started more than once.
|
|
static volatile int started = 0;
|
|
|
|
__attribute__((export_name("_start")))
|
|
void _start(void) {
|
|
// Don't allow the program to be called multiple times.
|
|
if (started != 0) {
|
|
__builtin_trap();
|
|
}
|
|
started = 1;
|
|
|
|
// The linker synthesizes this to call constructors.
|
|
__wasm_call_ctors();
|
|
|
|
// Call `__main_void` which will either be the application's zero-argument
|
|
// `__main_void` function or a libc routine which obtains the command-line
|
|
// arguments and calls `__main_argv_argc`.
|
|
int r = __main_void();
|
|
|
|
// Call atexit functions, destructors, stdio cleanup, etc.
|
|
__wasm_call_dtors();
|
|
|
|
// If main exited successfully, just return, otherwise call
|
|
// `__wasi_proc_exit`.
|
|
if (r != 0) {
|
|
__wasi_proc_exit(r);
|
|
}
|
|
}
|