diff --git a/src/fiber.cc b/src/fiber.cc
index b6436e8bc1780928b56fcc477abbe7a48ba98cdb..2fd689d1535fe69727c172c002df0ffc87671980 100644
--- a/src/fiber.cc
+++ b/src/fiber.cc
@@ -38,7 +38,6 @@
#include "assoc.h"
#include "memory.h"
#include "trigger.h"
-#include <typeinfo>
#include "third_party/pmatomic.h"
/*
@@ -47,16 +46,16 @@
* implement cord_cojoin.
*/
struct cord_on_exit {
- void (*callback) (void*);
+ void (*callback)(void*);
void *argument;
};
/*
- * The special value distinct from any valid pointer to cord_on_exit
- * structure AND NULL). This value is stored in cord()->on_exit by the
- * thread func prior to a thread termination.
+ * A special value distinct from any valid pointer to cord_on_exit
+ * structure AND NULL. This value is stored in cord()->on_exit by the
+ * thread function prior to thread termination.
*/
-#define CORD_ON_EXIT_WONT_RUN ((struct cord_on_exit*)1)
+static const struct cord_on_exit CORD_ON_EXIT_WONT_RUN = { NULL, NULL };
static struct cord main_cord;
__thread struct cord *cord_ptr = NULL;
@@ -652,22 +651,20 @@ void *cord_thread_func(void *p)
res = NULL;
}
/*
- * cord()->on_exit initially holds a NULL value. This field is
+ * cord()->on_exit initially holds NULL. This field is
* change-once.
- * Either a handler installation suceeds (in cord_cojoin) or prior
- * to thread exit the thread func discovers that no handler was installed
- * so far and it stores CORD_ON_EXIT_WONT_RUN to prevent a future
- * handler installation (since a handler won't run anyway).
+ * Either handler installation succeeds (in cord_cojoin())
+ * or prior to thread exit the thread function discovers
+ * that no handler was installed so far and it stores
+ * CORD_ON_EXIT_WONT_RUN to prevent a future handler
+ * installation (since a handler won't run anyway).
*/
struct cord_on_exit *handler = NULL; /* expected value */
bool rc = pm_atomic_compare_exchange_strong(&cord()->on_exit,
&handler,
- CORD_ON_EXIT_WONT_RUN);
- if (!rc) {
- assert(handler);
- assert(handler->callback);
+ &CORD_ON_EXIT_WONT_RUN);
+ if (rc == 0)
handler->callback(handler->argument);
- }
return res;
}
@@ -711,37 +708,36 @@ cord_join(struct cord *cord)
return res;
}
-struct cord_cojoin_state
+/** The state of the waiter for a thread to complete. */
+struct cord_cojoin_ctx
{
struct ev_loop *loop;
+ /** Waiting fiber. */
struct fiber *fiber;
+ /*
+ * This event is signalled when the subject thread is
+ * about to die.
+ */
struct ev_async async;
- bool task_complete;
};
static void
cord_cojoin_on_exit(void *arg)
{
- struct cord_cojoin_state *b =
- (struct cord_cojoin_state *)arg;
+ struct cord_cojoin_ctx *ctx = (struct cord_cojoin_ctx *)arg;
- assert(b->loop);
- ev_async_send(b->loop, &b->async);
+ ev_async_send(ctx->loop, &ctx->async);
}
static void
cord_cojoin_wakeup(struct ev_loop *loop, struct ev_async *ev, int revents)
{
- assert(ev);
- assert(ev->data);
(void)loop;
(void)revents;
- struct cord_cojoin_state *b = (cord_cojoin_state *)ev->data;
+ struct cord_cojoin_ctx *ctx = (struct cord_cojoin_ctx *)ev->data;
- assert(b->fiber);
- b->task_complete = true;
- fiber_wakeup(b->fiber);
+ fiber_wakeup(ctx->fiber);
}
int
@@ -749,16 +745,15 @@ cord_cojoin(struct cord *cord)
{
assert(cord() != cord); /* Can't join self. */
- struct cord_cojoin_state b;
- b.loop = loop();
- b.fiber = fiber();
- b.task_complete = false;
+ struct cord_cojoin_ctx ctx;
+ ctx.loop = loop();
+ ctx.fiber = fiber();
- ev_async_init(&b.async, cord_cojoin_wakeup);
- b.async.data = &b;
- ev_async_start(loop(), &b.async);
+ ev_async_init(&ctx.async, cord_cojoin_wakeup);
+ ctx.async.data = &ctx;
+ ev_async_start(loop(), &ctx.async);
- struct cord_on_exit handler = { cord_cojoin_on_exit, &b };
+ struct cord_on_exit handler = { cord_cojoin_on_exit, &ctx };
/*
* cord->on_exit initially holds a NULL value. This field is
@@ -771,25 +766,26 @@ cord_cojoin(struct cord *cord)
* A handler installation fails either if the thread did exit or
* if someone is already joining this cord (BUG).
*/
- if (!rc) {
+ if (rc == 0) {
/* Assume cord's thread already exited. */
- assert(prev_handler == CORD_ON_EXIT_WONT_RUN);
+ assert(prev_handler == &CORD_ON_EXIT_WONT_RUN);
} else {
/*
- * Wait until the thread exits. Prior to exit the thread invokes
- * cord_cojoin_on_exit, signaling ev_async, making the event loop
- * call cord_cojoin_wakeup, waking up this fiber again.
+ * Wait until the thread exits. Prior to exit the
+ * thread invokes cord_cojoin_on_exit, signaling
+ * ev_async, making the event loop call
+ * cord_cojoin_wakeup, waking up this fiber again.
*
- * The fiber is non-cancellable during the wait to avoid
- * invalidating the state struct on stack.
+ * The fiber is non-cancellable during the wait to
+ * avoid invalidating of the cord_cojoin_ctx
+ * object declared on stack.
*/
bool cancellable = fiber_set_cancellable(false);
fiber_yield();
- assert(b.task_complete);
fiber_set_cancellable(cancellable);
}
- ev_async_stop(loop(), &b.async);
+ ev_async_stop(loop(), &ctx.async);
return cord_join(cord);
}
diff --git a/third_party/pmatomic.h b/third_party/pmatomic.h
index 8797f71b1dd56142d751f6a7b46a1c50ad7e0317..57078717ec4b184ef74af9e213d0018e4cfb39c5 100644
--- a/third_party/pmatomic.h
+++ b/third_party/pmatomic.h
@@ -4,7 +4,7 @@
* Borrowed from FreeBSD (original copyright follows).
*
* Standard atomic facilities in stdatomic.h are great, unless you are
- * stuck with an old compiler, or you attemt to compile a code using
+ * stuck with an old compiler, or you attempt to compile code using
* stdatomic.h in C++ mode [gcc 4.9], or if you were desperate enough to
* enable OpenMP in C mode [gcc 4.9].
*
@@ -42,7 +42,7 @@
* reason we comment unused code regions with #if 0 instead of removing
* them.
*
- * Renames are carried out by a scipt generating the final header.
+ * Renames are carried out by a script generating the final header.
*/
/*-