factor/vm/os-unix.c

#include "master.h"

static void *null_dll;

s64 current_millis(void)
{
	struct timeval t;
	gettimeofday(&t,NULL);
	return (s64)t.tv_sec * 1000 + t.tv_usec / 1000;
}

void sleep_millis(CELL msec)
{
	usleep(msec * 1000);
}

void init_ffi(void)
{
	/* NULL_DLL is "libfactor.dylib" for OS X and NULL for generic unix */
	null_dll = dlopen(NULL_DLL,RTLD_LAZY);
}

void ffi_dlopen(F_DLL *dll)
{
	dll->dll = dlopen(alien_offset(dll->path), RTLD_LAZY);
}

void *ffi_dlsym(F_DLL *dll, F_SYMBOL *symbol)
{
	void *handle = (dll == NULL ? null_dll : dll->dll);
	return dlsym(handle,symbol);
}

void ffi_dlclose(F_DLL *dll)
{
	if(dlclose(dll->dll))
	{
		general_error(ERROR_FFI,tag_object(
			from_char_string(dlerror())),F,NULL);
	}
	dll->dll = NULL;
}

DEFINE_PRIMITIVE(existsp)
{
	struct stat sb;
	box_boolean(stat(unbox_char_string(),&sb) >= 0);
}

/* Allocates memory */
CELL parse_dir_entry(struct dirent *file)
{
	CELL name = tag_object(from_char_string(file->d_name));
	if(UNKNOWN_TYPE_P(file))
		return name;
	else
	{
		CELL dirp = tag_boolean(DIRECTORY_P(file));
		return allot_array_2(name,dirp);
	}
}

DEFINE_PRIMITIVE(read_dir)
{
	DIR* dir = opendir(unbox_char_string());
	GROWABLE_ARRAY(result);
	REGISTER_ROOT(result);

	if(dir != NULL)
	{
		struct dirent* file;

		while((file = readdir(dir)) != NULL)
		{
			CELL pair = parse_dir_entry(file);
			GROWABLE_ADD(result,pair);
		}

		closedir(dir);
	}

	UNREGISTER_ROOT(result);
	GROWABLE_TRIM(result);

	dpush(result);
}

DEFINE_PRIMITIVE(os_envs)
{
	GROWABLE_ARRAY(result);
	REGISTER_ROOT(result);
	char **env = environ;

	while(*env)
	{
		CELL string = tag_object(from_char_string(*env));
		GROWABLE_ADD(result,string);
		env++;
	}

	UNREGISTER_ROOT(result);
	GROWABLE_TRIM(result);
	dpush(result);
}

DEFINE_PRIMITIVE(set_os_envs)
{
	F_ARRAY *array = untag_array(dpop());
	CELL size = array_capacity(array);

	/* Memory leak */
	char **env = calloc(size + 1,sizeof(CELL));

	CELL i;
	for(i = 0; i < size; i++)
	{
		F_STRING *string = untag_string(array_nth(array,i));
		CELL length = to_fixnum(string->length);

		char *chars = malloc(length + 1);
		char_string_to_memory(string,chars);
		chars[length] = '\0';
		env[i] = chars;
	}

	environ = env;
}

F_SEGMENT *alloc_segment(CELL size)
{
	int pagesize = getpagesize();

	char *array = mmap(NULL,pagesize + size + pagesize,
		PROT_READ | PROT_WRITE | PROT_EXEC,
		MAP_ANON | MAP_PRIVATE,-1,0);

	if(array == (char*)-1)
		fatal_error("Out of memory in alloc_segment",0);

	if(mprotect(array,pagesize,PROT_NONE) == -1)
		fatal_error("Cannot protect low guard page",(CELL)array);

	if(mprotect(array + pagesize + size,pagesize,PROT_NONE) == -1)
		fatal_error("Cannot protect high guard page",(CELL)array);

	F_SEGMENT *retval = safe_malloc(sizeof(F_SEGMENT));

	retval->start = (CELL)(array + pagesize);
	retval->size = size;
	retval->end = retval->start + size;

	return retval;
}

void dealloc_segment(F_SEGMENT *block)
{
	int pagesize = getpagesize();

	int retval = munmap((void*)(block->start - pagesize),
		pagesize + block->size + pagesize);
	
	if(retval)
		fatal_error("dealloc_segment failed",0);

	free(block);
}
  
INLINE F_STACK_FRAME *uap_stack_pointer(void *uap)
{
	/* There is a race condition here, but in practice a signal
	delivered during stack frame setup/teardown or while transitioning
	from Factor to C is a sign of things seriously gone wrong, not just
	a divide by zero or stack underflow in the listener */
	if(in_code_heap_p(UAP_PROGRAM_COUNTER(uap)))
	{
		F_STACK_FRAME *ptr = ucontext_stack_pointer(uap);
		if(!ptr)
			critical_error("Invalid uap",(CELL)uap);
		return ptr;
	}
	else
		return NULL;
}

void memory_signal_handler(int signal, siginfo_t *siginfo, void *uap)
{
	signal_fault_addr = (CELL)siginfo->si_addr;
	signal_callstack_top = uap_stack_pointer(uap);
	UAP_PROGRAM_COUNTER(uap) = (CELL)memory_signal_handler_impl;
}

void misc_signal_handler(int signal, siginfo_t *siginfo, void *uap)
{
	signal_number = signal;
	signal_callstack_top = uap_stack_pointer(uap);
	UAP_PROGRAM_COUNTER(uap) = (CELL)misc_signal_handler_impl;
}

static void sigaction_safe(int signum, const struct sigaction *act, struct sigaction *oldact)
{
	int ret;
	do
	{
		ret = sigaction(signum, act, oldact);
	}
	while(ret == -1 && errno == EINTR);

	if(ret == -1)
		fatal_error("sigaction failed", 0);
}

void unix_init_signals(void)
{
	struct sigaction memory_sigaction;
	struct sigaction misc_sigaction;
	struct sigaction ignore_sigaction;

	memset(&memory_sigaction,0,sizeof(struct sigaction));
	sigemptyset(&memory_sigaction.sa_mask);
	memory_sigaction.sa_sigaction = memory_signal_handler;
	memory_sigaction.sa_flags = SA_SIGINFO;

	sigaction_safe(SIGBUS,&memory_sigaction,NULL);
	sigaction_safe(SIGSEGV,&memory_sigaction,NULL);

	memset(&misc_sigaction,0,sizeof(struct sigaction));
	sigemptyset(&misc_sigaction.sa_mask);
	misc_sigaction.sa_sigaction = misc_signal_handler;
	misc_sigaction.sa_flags = SA_SIGINFO;

	sigaction_safe(SIGABRT,&misc_sigaction,NULL);
	sigaction_safe(SIGFPE,&misc_sigaction,NULL);
	sigaction_safe(SIGQUIT,&misc_sigaction,NULL);
	sigaction_safe(SIGILL,&misc_sigaction,NULL);

	memset(&ignore_sigaction,0,sizeof(struct sigaction));
	sigemptyset(&ignore_sigaction.sa_mask);
	ignore_sigaction.sa_handler = SIG_IGN;
	sigaction_safe(SIGPIPE,&ignore_sigaction,NULL);
}

void reset_stdio(void)
{
	fcntl(0,F_SETFL,0);
	fcntl(1,F_SETFL,0);
}

void open_console(void) { }