From c1014a812c90bab3c9c989863e4ebb129e987de6 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 18 Apr 2018 00:16:12 -0400 Subject: [PATCH] refactor flockfile not to duplicate lock mechanism logic --- src/stdio/flockfile.c | 11 ++++------- src/stdio/ftrylockfile.c | 15 ++++++++++----- 2 files changed, 14 insertions(+), 12 deletions(-) diff --git a/src/stdio/flockfile.c b/src/stdio/flockfile.c index 6b574cf0..6806cf8b 100644 --- a/src/stdio/flockfile.c +++ b/src/stdio/flockfile.c @@ -1,14 +1,11 @@ #include "stdio_impl.h" #include "pthread_impl.h" -#define MAYBE_WAITERS 0x40000000 +void __register_locked_file(FILE *, pthread_t); void flockfile(FILE *f) { - while (ftrylockfile(f)) { - int owner = f->lock; - if (!owner) continue; - a_cas(&f->lock, owner, owner|MAYBE_WAITERS); - __futexwait(&f->lock, owner|MAYBE_WAITERS, 1); - } + if (!ftrylockfile(f)) return; + __lockfile(f); + __register_locked_file(f, __pthread_self()); } diff --git a/src/stdio/ftrylockfile.c b/src/stdio/ftrylockfile.c index 3b1d5f20..3b97807a 100644 --- a/src/stdio/ftrylockfile.c +++ b/src/stdio/ftrylockfile.c @@ -20,6 +20,15 @@ void __unlist_locked_file(FILE *f) } } +void __register_locked_file(FILE *f, pthread_t self) +{ + f->lockcount = 1; + f->prev_locked = 0; + f->next_locked = self->stdio_locks; + if (f->next_locked) f->next_locked->prev_locked = f; + self->stdio_locks = f; +} + int ftrylockfile(FILE *f) { pthread_t self = __pthread_self(); @@ -34,10 +43,6 @@ int ftrylockfile(FILE *f) if (owner < 0) f->lock = owner = 0; if (owner || a_cas(&f->lock, 0, tid)) return -1; - f->lockcount = 1; - f->prev_locked = 0; - f->next_locked = self->stdio_locks; - if (f->next_locked) f->next_locked->prev_locked = f; - self->stdio_locks = f; + __register_locked_file(f, self); return 0; } -- 2.25.1