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-rw-r--r--src/internal/pthread_impl.h3
-rw-r--r--src/thread/pthread_key_create.c105
-rw-r--r--src/thread/pthread_key_delete.c14
3 files changed, 104 insertions, 18 deletions
diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index 052a5475..26e6e1df 100644
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -148,6 +148,9 @@ hidden void __do_cleanup_push(struct __ptcb *);
hidden void __do_cleanup_pop(struct __ptcb *);
hidden void __pthread_tsd_run_dtors();
+hidden void __pthread_key_delete_synccall(void (*)(void *), void *);
+hidden int __pthread_key_delete_impl(pthread_key_t);
+
extern hidden volatile int __block_new_threads;
extern hidden volatile size_t __pthread_tsd_size;
extern hidden void *__pthread_tsd_main[];
diff --git a/src/thread/pthread_key_create.c b/src/thread/pthread_key_create.c
index a78e507a..e26f199c 100644
--- a/src/thread/pthread_key_create.c
+++ b/src/thread/pthread_key_create.c
@@ -3,54 +3,123 @@
volatile size_t __pthread_tsd_size = sizeof(void *) * PTHREAD_KEYS_MAX;
void *__pthread_tsd_main[PTHREAD_KEYS_MAX] = { 0 };
-static void (*volatile keys[PTHREAD_KEYS_MAX])(void *);
+static void (*keys[PTHREAD_KEYS_MAX])(void *);
+
+static pthread_rwlock_t key_lock = PTHREAD_RWLOCK_INITIALIZER;
+
+static pthread_key_t next_key;
static void nodtor(void *dummy)
{
}
+static void dirty(void *dummy)
+{
+}
+
+struct cleanup_args {
+ pthread_t caller;
+ int ret;
+};
+
+static void clean_dirty_tsd_callback(void *p)
+{
+ struct cleanup_args *args = p;
+ pthread_t self = __pthread_self();
+ pthread_key_t i;
+ for (i=0; i<PTHREAD_KEYS_MAX; i++) {
+ if (keys[i] == dirty && self->tsd[i])
+ self->tsd[i] = 0;
+ }
+ /* Arbitrary choice to avoid data race. */
+ if (args->caller == self) args->ret = 0;
+}
+
+static int clean_dirty_tsd(void)
+{
+ struct cleanup_args args = {
+ .caller = __pthread_self(),
+ .ret = EAGAIN
+ };
+ __pthread_key_delete_synccall(clean_dirty_tsd_callback, &args);
+ return args.ret;
+}
+
int __pthread_key_create(pthread_key_t *k, void (*dtor)(void *))
{
- unsigned i = (uintptr_t)&k / 16 % PTHREAD_KEYS_MAX;
- unsigned j = i;
+ pthread_key_t j = next_key;
pthread_t self = __pthread_self();
+ int found_dirty = 0;
/* This can only happen in the main thread before
* pthread_create has been called. */
if (!self->tsd) self->tsd = __pthread_tsd_main;
+ /* Purely a sentinel value since null means slot is free. */
if (!dtor) dtor = nodtor;
+
+ pthread_rwlock_wrlock(&key_lock);
do {
- if (!a_cas_p(keys+j, 0, (void *)dtor)) {
- *k = j;
+ if (!keys[j]) {
+ keys[next_key = *k = j] = dtor;
+ pthread_rwlock_unlock(&key_lock);
return 0;
+ } else if (keys[j] == dirty) {
+ found_dirty = 1;
}
- } while ((j=(j+1)%PTHREAD_KEYS_MAX) != i);
- return EAGAIN;
+ } while ((j=(j+1)%PTHREAD_KEYS_MAX) != next_key);
+
+ /* It's possible that all slots are in use or __synccall fails. */
+ if (!found_dirty || clean_dirty_tsd()) {
+ pthread_rwlock_unlock(&key_lock);
+ return EAGAIN;
+ }
+
+ /* If this point is reached there is necessarily a newly-cleaned
+ * slot to allocate to satisfy the caller's request. Find it and
+ * mark any additional previously-dirty slots clean. */
+ for (j=0; j<PTHREAD_KEYS_MAX; j++) {
+ if (keys[j] == dirty) {
+ if (dtor) {
+ keys[next_key = *k = j] = dtor;
+ dtor = 0;
+ } else {
+ keys[j] = 0;
+ }
+ }
+ }
+
+ pthread_rwlock_unlock(&key_lock);
+ return 0;
}
-int __pthread_key_delete(pthread_key_t k)
+int __pthread_key_delete_impl(pthread_key_t k)
{
- keys[k] = 0;
+ pthread_rwlock_wrlock(&key_lock);
+ keys[k] = dirty;
+ pthread_rwlock_unlock(&key_lock);
return 0;
}
void __pthread_tsd_run_dtors()
{
pthread_t self = __pthread_self();
- int i, j, not_finished = self->tsd_used;
- for (j=0; not_finished && j<PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
- not_finished = 0;
+ int i, j;
+ for (j=0; self->tsd_used && j<PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
+ pthread_rwlock_rdlock(&key_lock);
+ self->tsd_used = 0;
for (i=0; i<PTHREAD_KEYS_MAX; i++) {
- if (self->tsd[i] && keys[i]) {
- void *tmp = self->tsd[i];
- self->tsd[i] = 0;
- keys[i](tmp);
- not_finished = 1;
+ void *val = self->tsd[i];
+ void (*dtor)(void *) = keys[i];
+ self->tsd[i] = 0;
+ if (val && dtor && dtor != nodtor && dtor != dirty) {
+ pthread_rwlock_unlock(&key_lock);
+ dtor(val);
+ pthread_rwlock_rdlock(&key_lock);
}
}
+ pthread_rwlock_unlock(&key_lock);
}
}
-weak_alias(__pthread_key_delete, pthread_key_delete);
weak_alias(__pthread_key_create, pthread_key_create);
diff --git a/src/thread/pthread_key_delete.c b/src/thread/pthread_key_delete.c
new file mode 100644
index 00000000..012fe2da
--- /dev/null
+++ b/src/thread/pthread_key_delete.c
@@ -0,0 +1,14 @@
+#include "pthread_impl.h"
+#include "libc.h"
+
+void __pthread_key_delete_synccall(void (*f)(void *), void *p)
+{
+ __synccall(f, p);
+}
+
+int __pthread_key_delete(pthread_key_t k)
+{
+ return __pthread_key_delete_impl(k);
+}
+
+weak_alias(__pthread_key_delete, pthread_key_delete);