static sexp sexp_get_env_cell (sexp ctx, sexp self, sexp_sint_t n, sexp env, sexp id, sexp createp) {
sexp cell;
sexp_assert_type(ctx, sexp_envp, SEXP_ENV, env);
cell = sexp_env_cell(ctx, env, id, 0);
if (! cell) {
if (sexp_synclop(id)) {
env = sexp_synclo_env(id);
id = sexp_synclo_expr(id);
}
cell = sexp_env_cell(ctx, env, id, 0);
if (!cell && createp)
cell = sexp_env_cell_define(ctx, env, id, SEXP_UNDEF, NULL);
}
return cell ? cell : SEXP_FALSE;
}
static sexp sexp_get_env_cell (sexp ctx, sexp self, sexp_sint_t n, sexp env, sexp id) {
sexp cell;
sexp_assert_type(ctx, sexp_envp, SEXP_ENV, env);
cell = sexp_env_cell(env, id, 0);
while ((! cell) && sexp_synclop(id)) {
env = sexp_synclo_env(id);
id = sexp_synclo_expr(id);
}
return cell ? cell : SEXP_FALSE;
}
sexp run_main (int argc, char **argv) {
#if SEXP_USE_MODULES
char *impmod;
#endif
char *arg;
const char *prefix=NULL, *suffix=NULL, *main_symbol=NULL, *main_module=NULL;
sexp_sint_t i, j, c, quit=0, print=0, init_loaded=0, mods_loaded=0,
fold_case=SEXP_DEFAULT_FOLD_CASE_SYMS, nonblocking=0;
sexp_uint_t heap_size=0, heap_max_size=SEXP_MAXIMUM_HEAP_SIZE;
sexp out=SEXP_FALSE, ctx=NULL, ls;
sexp_gc_var4(tmp, sym, args, env);
args = SEXP_NULL;
env = NULL;
/* SRFI 22: invoke `main` procedure by default if the interpreter is */
/* invoked as `scheme-r7rs`. */
arg = strrchr(argv[0], '/');
if (strncmp((arg == NULL ? argv[0] : arg + 1), "scheme-r7rs", strlen("scheme-r7rs")) == 0) {
main_symbol = "main";
/* skip option parsing since we can't pass `--` before the name of script */
/* to avoid misinterpret the name as options when the interpreter is */
/* executed via `#!/usr/env/bin scheme-r7rs` shebang. */
i = 1;
goto done_options;
}
/* parse options */
for (i=1; i < argc && argv[i][0] == '-'; i++) {
switch ((c=argv[i][1])) {
case 'D':
init_context();
arg = (argv[i][2] == '\0') ? argv[++i] : argv[i]+2;
sym = sexp_intern(ctx, arg, -1);
ls = sexp_global(ctx, SEXP_G_FEATURES);
if (sexp_pairp(ls)) {
for (; sexp_pairp(sexp_cdr(ls)); ls=sexp_cdr(ls))
;
sexp_cdr(ls) = sexp_cons(ctx, sym, SEXP_NULL);
}
break;
case 'e':
case 'p':
mods_loaded = 1;
load_init(0);
print = (argv[i][1] == 'p');
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
check_nonull_arg('e', arg);
tmp = check_exception(ctx, sexp_eval_string(ctx, arg, -1, env));
if (print) {
if (! sexp_oportp(out))
out = sexp_eval_string(ctx, "(current-output-port)", -1, env);
sexp_write(ctx, tmp, out);
sexp_write_char(ctx, '\n', out);
}
quit = 1;
break;
case 'l':
mods_loaded = 1;
load_init(0);
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
check_nonull_arg('l', arg);
check_exception(ctx, sexp_load_module_file(ctx, arg, env));
break;
case 'x':
prefix = sexp_environment_prefix;
suffix = sexp_environment_suffix;
case 'm':
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
if (c == 'x') {
if (strcmp(arg, "chibi.primitive") == 0) {
goto load_primitive;
} else if (strcmp(arg, "scheme.small") == 0) {
load_init(0);
break;
}
} else {
prefix = sexp_import_prefix;
suffix = sexp_import_suffix;
}
mods_loaded = 1;
load_init(c == 'x');
#if SEXP_USE_MODULES
check_nonull_arg(c, arg);
impmod = make_import(prefix, arg, suffix);
tmp = check_exception(ctx, sexp_eval_string(ctx, impmod, -1, (c=='x' ? sexp_global(ctx, SEXP_G_META_ENV) : env)));
free(impmod);
if (c == 'x') {
sexp_set_parameter(ctx, sexp_global(ctx, SEXP_G_META_ENV), sexp_global(ctx, SEXP_G_INTERACTION_ENV_SYMBOL), tmp);
sexp_context_env(ctx) = env = tmp;
sexp_add_import_binding(ctx, env);
tmp = sexp_param_ref(ctx, env, sexp_global(ctx, SEXP_G_CUR_OUT_SYMBOL));
if (tmp != NULL && !sexp_oportp(tmp)) {
sexp_load_standard_ports(ctx, env, stdin, stdout, stderr, 0);
}
}
#endif
break;
load_primitive:
case 'Q':
init_context();
mods_loaded = 1;
if (! init_loaded++)
sexp_load_standard_ports(ctx, env, stdin, stdout, stderr, 0);
handle_noarg();
break;
case 'q':
argv[i--] = (char*)"-xchibi";
break;
case 'A':
init_context();
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
check_nonull_arg('A', arg);
sexp_add_module_directory(ctx, tmp=sexp_c_string(ctx,arg,-1), SEXP_TRUE);
break;
case 'I':
init_context();
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
check_nonull_arg('I', arg);
sexp_add_module_directory(ctx, tmp=sexp_c_string(ctx,arg,-1), SEXP_FALSE);
break;
#if SEXP_USE_GREEN_THREADS
case 'b':
nonblocking = 1;
break;
#endif
case '-':
if (argv[i][2] == '\0') {
i++;
goto done_options;
}
sexp_usage(1);
case 'h':
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
check_nonull_arg('h', arg);
#if ! SEXP_USE_BOEHM
heap_size = strtoul(arg, &arg, 0);
if (sexp_isalpha((unsigned char)*arg)) heap_size *= multiplier(*arg++);
if (*arg == '/') {
heap_max_size = strtoul(arg+1, &arg, 0);
if (sexp_isalpha((unsigned char)*arg)) heap_max_size *= multiplier(*arg++);
}
#endif
break;
#if SEXP_USE_IMAGE_LOADING
case 'i':
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
if (ctx) {
fprintf(stderr, "-:i <file>: image files must be loaded first\n");
exit_failure();
}
ctx = sexp_load_image(arg, 0, heap_size, heap_max_size);
if (!ctx || !sexp_contextp(ctx)) {
fprintf(stderr, "-:i <file>: couldn't open image file for reading: %s\n", arg);
fprintf(stderr, " %s\n", sexp_load_image_err());
ctx = NULL;
} else {
env = sexp_load_standard_params(ctx, sexp_context_env(ctx), nonblocking);
init_loaded++;
}
break;
case 'd':
if (! init_loaded++) {
init_context();
env = sexp_load_standard_env(ctx, env, SEXP_SEVEN);
}
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
if (sexp_save_image(ctx, arg) != SEXP_TRUE) {
fprintf(stderr, "-d <file>: couldn't save image to file: %s\n", arg);
fprintf(stderr, " %s\n", sexp_load_image_err());
exit_failure();
}
quit = 1;
break;
#endif
case 'V':
load_init(1);
if (! sexp_oportp(out))
out = sexp_eval_string(ctx, "(current-output-port)", -1, env);
sexp_write_string(ctx, sexp_version_string, out);
tmp = sexp_env_ref(ctx, env, sym=sexp_intern(ctx, "*features*", -1), SEXP_NULL);
sexp_write(ctx, tmp, out);
sexp_newline(ctx, out);
return SEXP_TRUE;
#if SEXP_USE_FOLD_CASE_SYMS
case 'f':
fold_case = 1;
init_context();
sexp_global(ctx, SEXP_G_FOLD_CASE_P) = SEXP_TRUE;
handle_noarg();
break;
#endif
case 'R':
main_module = argv[i][2] != '\0' ? argv[i]+2 :
(i+1 < argc && argv[i+1][0] != '-') ? argv[++i] : "chibi.repl";
if (main_symbol == NULL) main_symbol = "main";
break;
case 'r':
main_symbol = argv[i][2] == '\0' ? "main" : argv[i]+2;
break;
case 's':
init_context(); sexp_global(ctx, SEXP_G_STRICT_P) = SEXP_TRUE;
handle_noarg();
break;
case 'T':
init_context(); sexp_global(ctx, SEXP_G_NO_TAIL_CALLS_P) = SEXP_TRUE;
handle_noarg();
break;
case 't':
mods_loaded = 1;
load_init(1);
arg = ((argv[i][2] == '\0') ? argv[++i] : argv[i]+2);
#if SEXP_USE_MODULES
check_nonull_arg('t', arg);
suffix = strrchr(arg, '.');
sym = sexp_intern(ctx, suffix + 1, -1);
*(char*)suffix = '\0';
impmod = make_import(sexp_trace_prefix, arg, sexp_trace_suffix);
tmp = check_exception(ctx, sexp_eval_string(ctx, impmod, -1, sexp_meta_env(ctx)));
if (!(tmp && sexp_envp(tmp))) {
fprintf(stderr, "couldn't find library to trace: %s\n", impmod);
} else if (!((sym = sexp_env_cell(ctx, tmp, sym, 0)))) {
fprintf(stderr, "couldn't find binding to trace: %s in %s\n", suffix + 1, impmod);
} else {
sym = sexp_list1(ctx, sym);
tmp = check_exception(ctx, sexp_eval_string(ctx, "(environment '(chibi trace))", -1, sexp_meta_env(ctx)));
tmp = sexp_env_ref(ctx, tmp, sexp_intern(ctx, "trace-cell", -1), 0);
if (tmp && sexp_procedurep(tmp))
check_exception(ctx, sexp_apply(ctx, tmp, sym));
}
free(impmod);
#endif
break;
default:
fprintf(stderr, "unknown option: %s\n", argv[i]);
/* ... FALLTHROUGH ... */
case '?':
sexp_usage(1);
}
}
done_options:
if (!quit || main_symbol != NULL) {
init_context();
/* build argument list */
if (i < argc)
for (j=argc-1; j>=i; j--)
args = sexp_cons(ctx, tmp=sexp_c_string(ctx,argv[j],-1), args);
if (i >= argc || main_symbol != NULL)
args = sexp_cons(ctx, tmp=sexp_c_string(ctx,argv[0],-1), args);
load_init(i < argc || main_symbol != NULL);
sexp_set_parameter(ctx, sexp_meta_env(ctx), sym=sexp_intern(ctx, sexp_argv_symbol, -1), args);
if (i >= argc && main_symbol == NULL) {
/* no script or main, run interactively */
repl(ctx, env);
} else {
#if SEXP_USE_MODULES
/* load the module or script */
if (main_module != NULL) {
impmod = make_import("(load-module '(", main_module, "))");
env = check_exception(ctx, sexp_eval_string(ctx, impmod, -1, sexp_meta_env(ctx)));
if (sexp_vectorp(env)) env = sexp_vector_ref(env, SEXP_ONE);
free(impmod);
check_exception(ctx, env);
if (!sexp_envp(env)) {
fprintf(stderr, "couldn't find module: %s\n", main_module);
exit_failure();
}
} else
#endif
if (i < argc) { /* script usage */
#if SEXP_USE_MODULES
/* reset the environment to have only the `import' and */
/* `cond-expand' bindings */
if (!mods_loaded) {
env = sexp_make_env(ctx);
sexp_set_parameter(ctx, sexp_meta_env(ctx),
sexp_global(ctx, SEXP_G_INTERACTION_ENV_SYMBOL), env);
sexp_context_env(ctx) = env;
sym = sexp_intern(ctx, "repl-import", -1);
tmp = sexp_env_ref(ctx, sexp_meta_env(ctx), sym, SEXP_VOID);
sym = sexp_intern(ctx, "import", -1);
check_exception(ctx, sexp_env_define(ctx, env, sym, tmp));
sym = sexp_intern(ctx, "cond-expand", -1);
tmp = sexp_env_cell(ctx, sexp_meta_env(ctx), sym, 0);
#if SEXP_USE_RENAME_BINDINGS
sexp_env_rename(ctx, env, sym, tmp);
#endif
sexp_env_define(ctx, env, sym, sexp_cdr(tmp));
}
#endif
sexp_context_tracep(ctx) = 1;
tmp = sexp_env_bindings(env);
#if SEXP_USE_MODULES
/* use scheme load if possible for better stack traces */
sym = sexp_intern(ctx, "load", -1);
tmp = sexp_env_ref(ctx, sexp_meta_env(ctx), sym, SEXP_FALSE);
if (sexp_procedurep(tmp)) {
sym = sexp_c_string(ctx, argv[i], -1);
sym = sexp_list2(ctx, sym, env);
tmp = check_exception(ctx, sexp_apply(ctx, tmp, sym));
} else
#endif
tmp = check_exception(ctx, sexp_load(ctx, sym=sexp_c_string(ctx, argv[i], -1), env));
#if SEXP_USE_WARN_UNDEFS
sexp_warn_undefs(ctx, env, tmp, SEXP_VOID);
#endif
#ifdef EMSCRIPTEN
if (sexp_applicablep(tmp)) {
sexp_resume_ctx = ctx;
sexp_resume_proc = tmp;
sexp_preserve_object(ctx, sexp_resume_proc);
emscripten_exit_with_live_runtime();
}
#endif
}
/* SRFI-22: run main if specified */
if (main_symbol) {
sym = sexp_intern(ctx, main_symbol, -1);
tmp = sexp_env_ref(ctx, env, sym, SEXP_FALSE);
if (sexp_procedurep(tmp)) {
args = sexp_list1(ctx, sexp_cdr(args));
check_exception(ctx, sexp_apply(ctx, tmp, args));
} else {
fprintf(stderr, "couldn't find main binding: %s in %s\n", main_symbol, main_module ? main_module : argv[i]);
}
}
}
}
sexp_gc_release4(ctx);
if (sexp_destroy_context(ctx) == SEXP_FALSE) {
fprintf(stderr, "destroy_context error\n");
return SEXP_FALSE;
}
return SEXP_TRUE;
}
sexp sexp_scheduler (sexp ctx, sexp self, sexp_sint_t n, sexp root_thread) {
int i, k;
struct timeval tval;
struct pollfd *pfds;
useconds_t usecs = 0;
sexp res, ls1, ls2, evt, runner, paused, front, pollfds;
sexp_gc_var1(tmp);
sexp_gc_preserve1(ctx, tmp);
front = sexp_global(ctx, SEXP_G_THREADS_FRONT);
paused = sexp_global(ctx, SEXP_G_THREADS_PAUSED);
/* check signals */
if (sexp_global(ctx, SEXP_G_THREADS_SIGNALS) != SEXP_ZERO) {
runner = sexp_global(ctx, SEXP_G_THREADS_SIGNAL_RUNNER);
if (! sexp_contextp(runner)) { /* ensure the runner exists */
if (sexp_envp(runner)) {
tmp = sexp_env_cell(runner, (tmp=sexp_intern(ctx, "signal-runner", -1)), 0);
if (sexp_pairp(tmp) && sexp_procedurep(sexp_cdr(tmp))) {
runner = sexp_make_thread(ctx, self, 2, sexp_cdr(tmp), SEXP_FALSE);
sexp_global(ctx, SEXP_G_THREADS_SIGNAL_RUNNER) = runner;
sexp_thread_start(ctx, self, 1, runner);
if (!sexp_pairp(front))
front = sexp_global(ctx, SEXP_G_THREADS_FRONT);
}
}
} else if (sexp_context_waitp(runner)) { /* wake it if it's sleeping */
sexp_context_waitp(runner) = 0;
sexp_thread_start(ctx, self, 1, runner);
}
}
/* check blocked fds */
pollfds = sexp_global(ctx, SEXP_G_THREADS_POLL_FDS);
if (sexp_pollfdsp(ctx, pollfds) && sexp_pollfds_num_fds(pollfds) > 0) {
pfds = sexp_pollfds_fds(pollfds);
k = poll(sexp_pollfds_fds(pollfds), sexp_pollfds_num_fds(pollfds), 0);
for (i=sexp_pollfds_num_fds(pollfds)-1; i>=0 && k>0; --i) {
if (pfds[i].revents > 0) { /* free all threads blocked on this fd */
k--;
/* maybe unblock the current thread */
evt = sexp_context_event(ctx);
if ((sexp_portp(evt) && (sexp_port_fileno(evt) == pfds[i].fd))
|| (sexp_fixnump(evt) && (sexp_unbox_fixnum(evt) == pfds[i].fd))) {
sexp_context_waitp(ctx) = 0;
sexp_context_timeoutp(ctx) = 0;
sexp_context_event(ctx) = SEXP_FALSE;
}
/* maybe unblock paused threads */
for (ls1=SEXP_NULL, ls2=paused; sexp_pairp(ls2); ) {
/* TODO: distinguish input and output on the same fd? */
evt = sexp_context_event(sexp_car(ls2));
if ((sexp_portp(evt) && sexp_port_fileno(evt) == pfds[i].fd)
|| (sexp_fixnump(evt) && sexp_unbox_fixnum(evt) == pfds[i].fd)) {
sexp_context_waitp(sexp_car(ls2)) = 0;
sexp_context_timeoutp(sexp_car(ls2)) = 0;
sexp_context_event(sexp_car(ls2)) = SEXP_FALSE;
if (ls1==SEXP_NULL)
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = sexp_cdr(ls2);
else
sexp_cdr(ls1) = sexp_cdr(ls2);
tmp = sexp_cdr(ls2);
sexp_cdr(ls2) = SEXP_NULL;
if (sexp_car(ls2) != ctx) {
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = ls2;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = ls2;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls2;
}
ls2 = tmp;
} else {
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
}
if (i < (sexp_pollfds_num_fds(pollfds) - 1)) {
pfds[i] = pfds[sexp_pollfds_num_fds(pollfds) - 1];
}
sexp_pollfds_num_fds(pollfds) -= 1;
}
}
}
/* if we've terminated, check threads joining us */
if (sexp_context_refuel(ctx) <= 0) {
for (ls1=SEXP_NULL, ls2=paused; sexp_pairp(ls2); ) {
if (sexp_context_event(sexp_car(ls2)) == ctx) {
sexp_context_waitp(sexp_car(ls2)) = 0;
sexp_context_timeoutp(sexp_car(ls2)) = 0;
if (ls1==SEXP_NULL)
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = sexp_cdr(ls2);
else
sexp_cdr(ls1) = sexp_cdr(ls2);
tmp = sexp_cdr(ls2);
sexp_cdr(ls2) = SEXP_NULL;
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = ls2;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = ls2;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls2;
ls2 = tmp;
} else {
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
}
}
/* check timeouts */
if (sexp_pairp(paused)) {
if (gettimeofday(&tval, NULL) == 0) {
ls1 = SEXP_NULL;
ls2 = paused;
while (sexp_pairp(ls2) && sexp_context_before(sexp_car(ls2), tval)) {
sexp_context_timeoutp(sexp_car(ls2)) = 1;
sexp_context_waitp(sexp_car(ls2)) = 0;
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
if (sexp_pairp(ls1)) {
sexp_cdr(ls1) = SEXP_NULL;
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = paused;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = paused;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls1;
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = ls2;
}
}
}
/* dequeue next thread */
if (sexp_pairp(front)) {
res = sexp_car(front);
if ((sexp_context_refuel(ctx) <= 0) || sexp_context_waitp(ctx)) {
/* orig ctx is either terminated or paused */
sexp_global(ctx, SEXP_G_THREADS_FRONT) = sexp_cdr(front);
if (! sexp_pairp(sexp_cdr(front)))
sexp_global(ctx, SEXP_G_THREADS_BACK) = SEXP_NULL;
if (sexp_context_refuel(ctx) > 0 && sexp_not(sexp_memq(ctx, ctx, paused)))
sexp_insert_timed(ctx, ctx, SEXP_FALSE);
paused = sexp_global(ctx, SEXP_G_THREADS_PAUSED);
} else {
/* swap with front of queue */
sexp_car(sexp_global(ctx, SEXP_G_THREADS_FRONT)) = ctx;
/* rotate front of queue to back */
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK))
= sexp_global(ctx, SEXP_G_THREADS_FRONT);
sexp_global(ctx, SEXP_G_THREADS_FRONT)
= sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_FRONT));
sexp_global(ctx, SEXP_G_THREADS_BACK)
= sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK));
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = SEXP_NULL;
}
} else {
/* no threads to dequeue */
res = ctx;
/* prefer a thread we can wait on instead of spinning */
if (sexp_context_refuel(ctx) <= 0) {
for (ls1=paused; sexp_pairp(ls1); ls1=sexp_cdr(ls1)) {
evt = sexp_context_event(sexp_car(ls1));
if (sexp_fixnump(evt) || sexp_portp(evt)) {
res = sexp_car(ls1);
break;
}
}
}
}
if (sexp_context_waitp(res)) {
/* the only thread available was waiting */
if (sexp_pairp(paused)
&& sexp_context_before(sexp_car(paused), sexp_context_timeval(res))) {
tmp = res;
res = sexp_car(paused);
paused = sexp_global(ctx, SEXP_G_THREADS_PAUSED) = sexp_cdr(paused);
if (sexp_not(sexp_memq(ctx, tmp, paused)))
sexp_insert_timed(ctx, tmp, tmp);
} else {
sexp_delete_list(ctx, SEXP_G_THREADS_PAUSED, res);
}
paused = sexp_global(ctx, SEXP_G_THREADS_PAUSED);
usecs = 0;
if ((sexp_context_timeval(res).tv_sec == 0)
&& (sexp_context_timeval(res).tv_usec == 0)) {
/* no timeout, wait for default 10ms */
usecs = 10*1000;
} else {
/* wait until the next timeout */
gettimeofday(&tval, NULL);
if (tval.tv_sec <= sexp_context_timeval(res).tv_sec) {
usecs = (sexp_context_timeval(res).tv_sec - tval.tv_sec) * 1000000;
if (tval.tv_usec < sexp_context_timeval(res).tv_usec || usecs > 0)
usecs += sexp_context_timeval(res).tv_usec - tval.tv_usec;
}
}
/* take a nap to avoid busy looping */
usleep(usecs);
sexp_context_waitp(res) = 0;
sexp_context_timeoutp(res) = 1;
}
sexp_gc_release1(ctx);
return res;
}
sexp sexp_scheduler (sexp ctx, sexp self, sexp_sint_t n, sexp root_thread) {
int i, k;
struct timeval tval;
struct pollfd *pfds;
useconds_t usecs = 0;
sexp res, ls1, ls2, runner, paused, front, pollfds;
sexp_gc_var1(tmp);
sexp_gc_preserve1(ctx, tmp);
front = sexp_global(ctx, SEXP_G_THREADS_FRONT);
paused = sexp_global(ctx, SEXP_G_THREADS_PAUSED);
/* check signals */
if (sexp_global(ctx, SEXP_G_THREADS_SIGNALS) != SEXP_ZERO) {
runner = sexp_global(ctx, SEXP_G_THREADS_SIGNAL_RUNNER);
if (! sexp_contextp(runner)) { /* ensure the runner exists */
if (sexp_envp(runner)) {
tmp = sexp_env_cell(runner, (tmp=sexp_intern(ctx, "signal-runner", -1)), 0);
if (sexp_pairp(tmp) && sexp_procedurep(sexp_cdr(tmp))) {
runner = sexp_make_thread(ctx, self, 2, sexp_cdr(tmp), SEXP_FALSE);
sexp_global(ctx, SEXP_G_THREADS_SIGNAL_RUNNER) = runner;
sexp_thread_start(ctx, self, 1, runner);
}
}
} else if (sexp_context_waitp(runner)) { /* wake it if it's sleeping */
sexp_context_waitp(runner) = 0;
sexp_thread_start(ctx, self, 1, runner);
}
}
/* check blocked fds */
pollfds = sexp_global(ctx, SEXP_G_THREADS_POLL_FDS);
if (sexp_pollfdsp(ctx, pollfds) && sexp_pollfds_num_fds(pollfds) > 0) {
pfds = sexp_pollfds_fds(pollfds);
k = poll(sexp_pollfds_fds(pollfds), sexp_pollfds_num_fds(pollfds), 0);
unblock_io_threads:
for (i=sexp_pollfds_num_fds(pollfds)-1; i>=0 && k>0; --i) {
if (pfds[i].revents > 0) { /* free all threads blocked on this fd */
k--;
pfds[i].events = 0; /* FIXME: delete from queue completely */
for (ls1=SEXP_NULL, ls2=paused; sexp_pairp(ls2); ) {
/* FIXME distinguish input and output on the same fd */
if (sexp_portp(sexp_context_event(sexp_car(ls2)))
&& sexp_port_fileno(sexp_context_event(sexp_car(ls2))) == pfds[i].fd) {
sexp_context_waitp(sexp_car(ls2)) = 0;
sexp_context_timeoutp(sexp_car(ls2)) = 0;
if (ls1==SEXP_NULL)
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = sexp_cdr(ls2);
else
sexp_cdr(ls1) = sexp_cdr(ls2);
tmp = sexp_cdr(ls2);
sexp_cdr(ls2) = SEXP_NULL;
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = ls2;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = ls2;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls2;
ls2 = tmp;
} else {
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
}
}
}
}
/* if we've terminated, check threads joining us */
if (sexp_context_refuel(ctx) <= 0) {
for (ls1=SEXP_NULL, ls2=paused; sexp_pairp(ls2); ) {
if (sexp_context_event(sexp_car(ls2)) == ctx) {
sexp_context_waitp(sexp_car(ls2)) = 0;
sexp_context_timeoutp(sexp_car(ls2)) = 0;
if (ls1==SEXP_NULL)
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = sexp_cdr(ls2);
else
sexp_cdr(ls1) = sexp_cdr(ls2);
tmp = sexp_cdr(ls2);
sexp_cdr(ls2) = SEXP_NULL;
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = ls2;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = ls2;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls2;
ls2 = tmp;
} else {
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
}
}
/* check timeouts */
if (sexp_pairp(paused)) {
if (gettimeofday(&tval, NULL) == 0) {
ls1 = SEXP_NULL;
ls2 = paused;
while (sexp_pairp(ls2) && sexp_context_before(sexp_car(ls2), tval)) {
sexp_context_timeoutp(sexp_car(ls2)) = 1;
sexp_context_waitp(ctx) = 0;
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
if (sexp_pairp(ls1)) {
sexp_cdr(ls1) = SEXP_NULL;
if (! sexp_pairp(sexp_global(ctx, SEXP_G_THREADS_BACK))) {
sexp_global(ctx, SEXP_G_THREADS_FRONT) = front = paused;
} else {
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = paused;
}
sexp_global(ctx, SEXP_G_THREADS_BACK) = ls1;
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = paused = ls2;
}
}
}
/* dequeue next thread */
if (sexp_pairp(front)) {
res = sexp_car(front);
if ((sexp_context_refuel(ctx) <= 0) || sexp_context_waitp(ctx)) {
/* either terminated or paused */
sexp_global(ctx, SEXP_G_THREADS_FRONT) = sexp_cdr(front);
if (! sexp_pairp(sexp_cdr(front)))
sexp_global(ctx, SEXP_G_THREADS_BACK) = SEXP_NULL;
} else {
/* swap with front of queue */
sexp_car(sexp_global(ctx, SEXP_G_THREADS_FRONT)) = ctx;
/* rotate front of queue to back */
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK))
= sexp_global(ctx, SEXP_G_THREADS_FRONT);
sexp_global(ctx, SEXP_G_THREADS_FRONT)
= sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_FRONT));
sexp_global(ctx, SEXP_G_THREADS_BACK)
= sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK));
sexp_cdr(sexp_global(ctx, SEXP_G_THREADS_BACK)) = SEXP_NULL;
}
} else {
res = ctx;
}
if (sexp_context_waitp(res)) {
/* the only thread available was waiting */
if (sexp_pairp(paused)
&& sexp_context_before(sexp_car(paused), sexp_context_timeval(res))) {
tmp = res;
res = sexp_car(paused);
sexp_global(ctx, SEXP_G_THREADS_PAUSED) = sexp_cdr(paused);
if (sexp_not(sexp_memq(ctx, tmp, paused)))
sexp_insert_timed(ctx, tmp, tmp);
}
usecs = 0;
if ((sexp_context_timeval(res).tv_sec == 0)
&& (sexp_context_timeval(res).tv_usec == 0)) {
/* no timeout, wait for default 10ms */
usecs = 10*1000;
} else {
/* wait until the next timeout */
gettimeofday(&tval, NULL);
if (tval.tv_sec <= sexp_context_timeval(res).tv_sec) {
usecs = (sexp_context_timeval(res).tv_sec - tval.tv_sec) * 1000000;
if (tval.tv_usec < sexp_context_timeval(res).tv_usec || usecs > 0)
usecs += sexp_context_timeval(res).tv_usec - tval.tv_usec;
}
}
/* either wait on an fd, or just sleep */
pollfds = sexp_global(res, SEXP_G_THREADS_POLL_FDS);
if (sexp_portp(sexp_context_event(res)) && sexp_pollfdsp(ctx, pollfds)) {
if ((k = poll(sexp_pollfds_fds(pollfds), sexp_pollfds_num_fds(pollfds), usecs/1000)) > 0) {
pfds = sexp_pollfds_fds(pollfds);
goto unblock_io_threads;
}
} else {
usleep(usecs);
sexp_context_waitp(res) = 0;
sexp_context_timeoutp(res) = 1;
}
}
sexp_gc_release1(ctx);
return res;
}
