[PATCH 1/3] bthread: remove thread exit codes
Ahmad Fatoum
a.fatoum at pengutronix.de
Mon Jun 28 00:07:30 PDT 2021
Follow-up commit will replace blocking bthread_stop with non-blocking
bthread_cancel. Prepare for this by dropping exit codes. This is not
much of a loss, because most users of bthreads will only call
bthread_stop at cleanup time. bthread command is an exception, so have
it take manual care of passing around exit codes.
As we touch the bthread_stop prototype anyway, rename it to
__bthread_stop. This will make it clearer in the future, that it's not
meant for driver use.
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
commands/bthread.c | 48 ++++++++++++++++++-----------
common/bthread.c | 20 ++++++------
drivers/usb/gadget/f_mass_storage.c | 12 +++-----
include/bthread.h | 5 +--
4 files changed, 47 insertions(+), 38 deletions(-)
diff --git a/commands/bthread.c b/commands/bthread.c
index 0c9c221884e8..446fe9c37ac3 100644
--- a/commands/bthread.c
+++ b/commands/bthread.c
@@ -33,12 +33,10 @@ static int bthread_time(void)
return i;
}
-static int bthread_infinite(void *data)
+static void bthread_infinite(void *data)
{
while (!bthread_should_stop())
;
-
- return 0;
}
static int bthread_isolated_time(void)
@@ -62,14 +60,20 @@ static int bthread_isolated_time(void)
i += 2;
}
- bthread_stop(bthread);
+ __bthread_stop(bthread);
bthread_free(bthread);
return i;
}
-static int bthread_printer(void *arg)
+struct arg {
+ unsigned long in;
+ long out;
+};
+
+static void bthread_printer(void *_arg)
{
+ struct arg *arg = _arg;
volatile u64 start;
volatile unsigned long i = 0;
start = get_time_ns();
@@ -78,28 +82,30 @@ static int bthread_printer(void *arg)
if (!is_timeout_non_interruptible(start, 225 * MSECOND))
continue;
- if ((unsigned long)arg == i++)
+ if (arg->in == i++)
printf("%s yield #%lu\n", bthread_name(current), i);
start = get_time_ns();
}
- return i;
+ arg->out = i;
}
static int yields;
-static int bthread_spawner(void *arg)
+static void bthread_spawner(void *_spawner_arg)
{
+ struct arg *arg, *spawner_arg = _spawner_arg;
struct bthread *bthread[4];
volatile u64 start;
volatile unsigned long i = 0;
int ret = 0;
- int ecode;
start = get_time_ns();
for (i = 0; i < ARRAY_SIZE(bthread); i++) {
- bthread[i] = bthread_run(bthread_printer, (void *)(long)i,
+ arg = malloc(sizeof(*arg));
+ arg->in = i;
+ bthread[i] = bthread_run(bthread_printer, arg,
"%s-bthread%u", bthread_name(current), i+1);
if (!bthread[i]) {
ret = -ENOMEM;
@@ -112,14 +118,16 @@ static int bthread_spawner(void *arg)
cleanup:
while (i--) {
- ecode = bthread_stop(bthread[i]);
+ arg = bthread_data(bthread[i]);
+ __bthread_stop(bthread[i]);
bthread_free(bthread[i]);
- if (!ret && (ecode != 4 || yields < ecode))
+ if (!ret && (arg->out != 4 || yields < arg->out))
ret = -EIO;
+ free(arg);
}
- return ret;
+ spawner_arg->out = ret;
}
struct spawn {
@@ -132,8 +140,9 @@ static int do_bthread(int argc, char *argv[])
LIST_HEAD(spawners);
struct spawn *spawner, *tmp;
int ret = 0;
- int ecode, opt, i = 0;
+ int opt, i = 0;
bool time = false;
+ struct arg *arg;
while ((opt = getopt(argc, argv, "itcv")) > 0) {
switch (opt) {
@@ -146,7 +155,8 @@ static int do_bthread(int argc, char *argv[])
break;
case 'v':
spawner = xzalloc(sizeof(*spawner));
- spawner->bthread = bthread_run(bthread_spawner, NULL,
+ arg = malloc(sizeof(*arg));
+ spawner->bthread = bthread_run(bthread_spawner, arg,
"spawner%u", ++i);
if (!spawner->bthread) {
free(spawner);
@@ -172,10 +182,12 @@ static int do_bthread(int argc, char *argv[])
cleanup:
list_for_each_entry_safe(spawner, tmp, &spawners, list) {
- ecode = bthread_stop(spawner->bthread);
+ arg = bthread_data(spawner->bthread);
+ __bthread_stop(spawner->bthread);
bthread_free(spawner->bthread);
- if (!ret && ecode)
- ret = ecode;
+ if (!ret && arg->out)
+ ret = arg->out;
+ free(arg);
free(spawner);
}
diff --git a/common/bthread.c b/common/bthread.c
index 80651344da64..48248dfad41a 100644
--- a/common/bthread.c
+++ b/common/bthread.c
@@ -20,11 +20,8 @@
#endif
static struct bthread {
- int (*threadfn)(void *);
- union {
- void *data;
- int ret;
- };
+ void (*threadfn)(void *);
+ void *data;
char *name;
jmp_buf jmp_buf;
void *stack;
@@ -54,7 +51,7 @@ static void __noreturn bthread_trampoline(void)
finish_switch_fiber(current);
bthread_reschedule();
- current->ret = current->threadfn(current->data);
+ current->threadfn(current->data);
bthread_suspend(current);
current->has_stopped = true;
@@ -81,7 +78,7 @@ const char *bthread_name(struct bthread *bthread)
return bthread->name;
}
-struct bthread *bthread_create(int (*threadfn)(void *), void *data,
+struct bthread *bthread_create(void (*threadfn)(void *), void *data,
const char *namefmt, ...)
{
struct bthread *bthread;
@@ -117,6 +114,11 @@ err:
return NULL;
}
+void *bthread_data(struct bthread *bthread)
+{
+ return bthread->data;
+}
+
void bthread_wake(struct bthread *bthread)
{
if (bthread->awake)
@@ -133,14 +135,12 @@ void bthread_suspend(struct bthread *bthread)
list_del(&bthread->list);
}
-int bthread_stop(struct bthread *bthread)
+void __bthread_stop(struct bthread *bthread)
{
bthread->should_stop = true;
while (!bthread->has_stopped)
bthread_reschedule();
-
- return bthread->ret;
}
int bthread_should_stop(void)
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 4894f91fa6ef..0033a95f68f3 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -2335,7 +2335,7 @@ static void handle_exception(struct fsg_common *common)
/*-------------------------------------------------------------------------*/
-static int fsg_main_thread(void *common_)
+static void fsg_main_thread(void *common_)
{
struct fsg_common *common = common_;
int ret = 0;
@@ -2374,12 +2374,8 @@ static int fsg_main_thread(void *common_)
common->state = FSG_STATE_IDLE;
}
- if (ret && ret != -ERESTARTSYS) {
+ if (ret && ret != -ERESTARTSYS)
pr_warn("%s: error %pe\n", __func__, ERR_PTR(ret));
- return ret;
- }
-
- return 0;
}
static void fsg_common_release(struct fsg_common *common);
@@ -2541,7 +2537,7 @@ static void fsg_common_release(struct fsg_common *common)
/* If the thread isn't already dead, tell it to exit now */
if (common->state != FSG_STATE_TERMINATED) {
raise_exception(common, FSG_STATE_EXIT);
- bthread_stop(thread_task);
+ __bthread_stop(thread_task);
bthread_free(thread_task);
}
@@ -2568,7 +2564,7 @@ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
fsg->common->new_fsg = NULL;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
- bthread_stop(thread_task);
+ __bthread_stop(thread_task);
while (common->fsg == fsg)
bthread_reschedule();
}
diff --git a/include/bthread.h b/include/bthread.h
index e3871fb11555..407aa830a835 100644
--- a/include/bthread.h
+++ b/include/bthread.h
@@ -12,14 +12,15 @@ struct bthread;
extern struct bthread *current;
-struct bthread *bthread_create(int (*threadfn)(void *), void *data, const char *namefmt, ...);
+struct bthread *bthread_create(void (*threadfn)(void *), void *data, const char *namefmt, ...);
void bthread_free(struct bthread *bthread);
void bthread_schedule(struct bthread *);
void bthread_wake(struct bthread *bthread);
void bthread_suspend(struct bthread *bthread);
int bthread_should_stop(void);
-int bthread_stop(struct bthread *bthread);
+void __bthread_stop(struct bthread *bthread);
+void *bthread_data(struct bthread *bthread);
void bthread_info(void);
const char *bthread_name(struct bthread *bthread);
bool bthread_is_main(struct bthread *bthread);
--
2.30.2
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