diff options
| -rw-r--r-- | src/core/async.c | 109 |
1 files changed, 74 insertions, 35 deletions
diff --git a/src/core/async.c b/src/core/async.c index 26b27f0b3..20be7f565 100644 --- a/src/core/async.c +++ b/src/core/async.c @@ -125,8 +125,15 @@ aid_t async_init ( struct async *async, struct async_operations *aop, * async). */ void async_uninit ( struct async *async ) { - if ( async->parent ) + + assert ( async != NULL ); + + if ( async->parent ) { + assert ( list_empty ( &async->children ) ); + + DBGC ( async, "ASYNC %p uninitialising\n", async ); list_del ( &async->siblings ); + } } /** @@ -238,6 +245,51 @@ void async_signal_children ( struct async *async, enum signal signal ) { } /** + * Reap default handler + * + * @v async Asynchronous operation + */ +static void async_reap_default ( struct async *async ) { + + DBGC ( async, "ASYNC %p ignoring REAP\n", async ); + + assert ( async != NULL ); + + /* Nothing to do */ +} + +/** + * Reap asynchronous operation + * + * @v async Asynchronous operation + * + * Note that the asynchronous operation should have been freed by + * calling this function; you may not dereference @c async after this + * call. + */ +static void async_reap ( struct async *async ) { + + DBGC ( async, "ASYNC %p being reaped, exit status %d (%s)\n", + async, async->rc, strerror ( async->rc ) ); + + assert ( async != NULL ); + assert ( async->aop != NULL ); + assert ( list_empty ( &async->children ) ); + + /* Unlink from hierarchy */ + if ( async->parent ) + list_del ( &async->siblings ); + async->parent = NULL; + + /* Release all resources */ + if ( async->aop->reap ) { + async->aop->reap ( async ); + } else { + async_reap_default ( async ); + } +} + +/** * Mark asynchronous operation as complete * * @v async Asynchronous operation @@ -248,6 +300,8 @@ void async_signal_children ( struct async *async, enum signal signal ) { * having its reap() method called. */ void async_done ( struct async *async, int rc ) { + struct async *child; + struct async *tmp; DBGC ( async, "ASYNC %p completing with status %d (%s)\n", async, rc, strerror ( rc ) ); @@ -259,23 +313,22 @@ void async_done ( struct async *async, int rc ) { /* Store return status code */ async->rc = rc; - /* Send SIGCHLD to parent. Guard against NULL pointer dereferences */ - if ( async->parent ) - async_signal ( async->parent, SIGCHLD ); -} - -/** - * Reap default handler - * - * @v async Asynchronous operation - */ -static void async_reap_default ( struct async *async ) { - - DBGC ( async, "ASYNC %p ignoring REAP\n", async ); - - assert ( async != NULL ); + /* Disown all of our children */ + list_for_each_entry_safe ( child, tmp, &async->children, siblings ) { + DBGC ( async, "ASYNC %p disowning child ASYNC %p\n", + async, child ); + list_del ( &child->siblings ); + child->parent = NULL; + } - /* Nothing to do */ + /* Send SIGCHLD to parent. If we don't have a parent then we + * have to take care of our own funeral arrangements. + */ + if ( async->parent ) { + async_signal ( async->parent, SIGCHLD ); + } else { + async_reap ( async ); + } } /** @@ -319,25 +372,11 @@ aid_t async_wait ( struct async *async, int *rc, int block ) { *rc = child->rc; child_aid = child->aid; - DBGC ( async, "ASYNC %p reaping child ASYNC %p (ID " - "%ld), exit status %d (%s)\n", async, child, - child_aid, child->rc, strerror ( child->rc ) ); - - /* Reap the child */ - assert ( child->aop != NULL ); - assert ( list_empty ( &child->children ) ); - - /* Unlink from operations hierarchy */ - list_del ( &child->siblings ); - child->parent = NULL; - - /* Release all resources */ - if ( child->aop->reap ) { - child->aop->reap ( child ); - } else { - async_reap_default ( child ); - } + DBGC ( async, "ASYNC %p reaping child ASYNC %p " + "(ID %ld)\n", async, child, child_aid ); + /* Reap the child and return */ + async_reap ( child ); return child_aid; } |