[glib/wip/mutexes] Rework GPrivate
- From: Ryan Lortie <ryanl src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [glib/wip/mutexes] Rework GPrivate
- Date: Sun, 18 Sep 2011 16:02:30 +0000 (UTC)
commit fd808dbde9a849dc432049192a02484d89316702
Author: Ryan Lortie <desrt desrt ca>
Date: Sat Sep 17 22:00:27 2011 -0400
Rework GPrivate
- expose the structure types for GLib internal use only
- avoid infinite recursion hazards by ensuring that GPrivate never
calls back into any other part of GLib
- substantially rework the Windows implementation so that it never
holds locks, contains no arbitrary limits and doesn't waste
100*sizeof(void*) per thread
We have to keep the macro hacks for the time being since some code
inside libglib depends on it.
glib/glib.symbols | 3 +
glib/gthread-posix.c | 81 ++++++++++++---------
glib/gthread-win32.c | 192 +++++++++++++++++++++++--------------------------
glib/gthread.h | 5 ++
glib/gthreadprivate.h | 12 +++
5 files changed, 155 insertions(+), 138 deletions(-)
---
diff --git a/glib/glib.symbols b/glib/glib.symbols
index 33b72de..30fd422 100644
--- a/glib/glib.symbols
+++ b/glib/glib.symbols
@@ -1610,3 +1610,6 @@ g_mutex_lock
g_mutex_new
g_mutex_trylock
g_mutex_unlock
+g_private_new
+g_private_get
+g_private_set
diff --git a/glib/gthread-posix.c b/glib/gthread-posix.c
index 1102630..e85a719 100644
--- a/glib/gthread-posix.c
+++ b/glib/gthread-posix.c
@@ -27,8 +27,8 @@
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
-/* The GMutex and GCond implementations in this file are some of the
- * lowest-level code in GLib. All other parts of GLib (messages,
+/* The GMutex, GCond and GPrivate implementations in this file are some
+ * of the lowest-level code in GLib. All other parts of GLib (messages,
* memory, slices, etc) assume that they can freely use these facilities
* without risking recursion.
*
@@ -42,6 +42,7 @@
#include "config.h"
#include "gthread.h"
+#include "gthreadprivate.h"
#include <pthread.h>
#include <stdlib.h>
@@ -205,6 +206,45 @@ g_cond_timedwait (GCond *cond,
/* {{{1 GPrivate */
+GPrivate *
+(g_private_new) (GDestroyNotify notify)
+{
+ GPrivate *key;
+
+ key = malloc (sizeof (GPrivate));
+ if G_UNLIKELY (key == NULL)
+ g_thread_abort (errno, "malloc");
+ g_private_init (key, notify);
+
+ return key;
+}
+
+void
+g_private_init (GPrivate *key,
+ GDestroyNotify notify)
+{
+ pthread_key_create (&key->key, notify);
+}
+
+gpointer
+(g_private_get) (GPrivate *key)
+{
+ /* quote POSIX: No errors are returned from pthread_getspecific(). */
+ return pthread_getspecific (key->key);
+}
+
+void
+(g_private_set) (GPrivate *key,
+ gpointer value)
+{
+ gint status;
+
+ if G_UNLIKELY ((status = pthread_setspecific (key->key, value)) != 0)
+ g_thread_abort (status, "pthread_setspecific");
+}
+
+/* {{{1 GThread */
+
#include "glib.h"
#include "gthreadprivate.h"
@@ -320,37 +360,6 @@ _g_thread_impl_init(void)
#endif /* HAVE_PRIORITIES */
}
-static GPrivate *
-g_private_new_posix_impl (GDestroyNotify destructor)
-{
- GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
- posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
- return result;
-}
-
-/* NOTE: the functions g_private_get and g_private_set may not use
- functions from gmem.c and gmessages.c */
-
-static void
-g_private_set_posix_impl (GPrivate * private_key, gpointer value)
-{
- if (!private_key)
- return;
- pthread_setspecific (*(pthread_key_t *) private_key, value);
-}
-
-static gpointer
-g_private_get_posix_impl (GPrivate * private_key)
-{
- if (!private_key)
- return NULL;
-
- return pthread_getspecific (*(pthread_key_t *) private_key);
-}
-
-/* {{{1 GThread */
-
-
static void
g_thread_create_posix_impl (GThreadFunc thread_func,
gpointer arg,
@@ -475,9 +484,9 @@ GThreadFunctions g_thread_functions_for_glib_use =
g_cond_wait,
g_cond_timed_wait,
g_cond_free,
- g_private_new_posix_impl,
- g_private_get_posix_impl,
- g_private_set_posix_impl,
+ g_private_new,
+ g_private_get,
+ g_private_set,
g_thread_create_posix_impl,
g_thread_yield_posix_impl,
g_thread_join_posix_impl,
diff --git a/glib/gthread-win32.c b/glib/gthread-win32.c
index b826918..81fd7de 100644
--- a/glib/gthread-win32.c
+++ b/glib/gthread-win32.c
@@ -43,8 +43,8 @@
#include "config.h"
#include "gthread.h"
+#include "gthreadprivate.h"
-#define _WIN32_WINDOWS 0x0401 /* to get IsDebuggerPresent */
#include <windows.h>
#include <process.h>
@@ -234,6 +234,64 @@ g_cond_timed_wait (GCond *cond,
/* {{{1 GPrivate */
+typedef struct _GPrivateDestructor GPrivateDestructor;
+
+struct _GPrivateDestructor
+{
+ DWORD index;
+ GDestroyNotify notify;
+ GPrivateDestructor *next;
+};
+
+static GPrivateDestructor * volatile g_private_destructors;
+
+GPrivate *
+(g_private_new) (GDestroyNotify notify)
+{
+ GPrivate *key;
+
+ key = malloc (sizeof (GPrivate));
+ if G_UNLIKELY (key == NULL)
+ g_thread_abort (errno, "malloc");
+ g_private_init (key, notify);
+
+ return key;
+}
+
+void
+g_private_init (GPrivate *key,
+ GDestroyNotify notify)
+{
+ GPrivateDestructor *destructor;
+
+ key->index = TlsAlloc ();
+
+ destructor = malloc (sizeof (GPrivateDestructor));
+ if G_UNLIKELY (destructor == NULL)
+ g_thread_abort (errno, "malloc");
+ destructor->index = key->index;
+ destructor->notify = notify;
+
+ do
+ destructor->next = g_private_destructors;
+ while (InterlockedCompareExchangePointer (&g_private_destructors, destructor->next, destructor) != destructor->next);
+}
+
+gpointer
+(g_private_get) (GPrivate *key)
+{
+ return TlsGetValue (key->index);
+}
+
+void
+(g_private_set) (GPrivate *key,
+ gpointer value)
+{
+ TlsSetValue (key->index, value);
+}
+
+/* {{{1 GThread */
+
#include "glib.h"
#include "gthreadprivate.h"
@@ -248,18 +306,9 @@ g_cond_timed_wait (GCond *cond,
static DWORD g_thread_self_tls;
static DWORD g_private_tls;
-static CRITICAL_SECTION g_thread_global_spinlock;
typedef BOOL (__stdcall *GTryEnterCriticalSectionFunc) (CRITICAL_SECTION *);
-/* As noted in the docs, GPrivate is a limited resource, here we take
- * a rather low maximum to save memory, use GStaticPrivate instead. */
-#define G_PRIVATE_MAX 100
-
-static GDestroyNotify g_private_destructors[G_PRIVATE_MAX];
-
-static guint g_private_next = 0;
-
typedef struct _GThreadData GThreadData;
struct _GThreadData
{
@@ -269,64 +318,6 @@ struct _GThreadData
gboolean joinable;
};
-static GPrivate *
-g_private_new_win32_impl (GDestroyNotify destructor)
-{
- GPrivate *result;
- EnterCriticalSection (&g_thread_global_spinlock);
- if (g_private_next >= G_PRIVATE_MAX)
- {
- char buf[100];
- sprintf (buf,
- "Too many GPrivate allocated. Their number is limited to %d.",
- G_PRIVATE_MAX);
- MessageBox (NULL, buf, NULL, MB_ICONERROR|MB_SETFOREGROUND);
- if (IsDebuggerPresent ())
- G_BREAKPOINT ();
- abort ();
- }
- g_private_destructors[g_private_next] = destructor;
- result = GUINT_TO_POINTER (g_private_next);
- g_private_next++;
- LeaveCriticalSection (&g_thread_global_spinlock);
-
- return result;
-}
-
-/* NOTE: the functions g_private_get and g_private_set may not use
- functions from gmem.c and gmessages.c */
-
-static void
-g_private_set_win32_impl (GPrivate * private_key, gpointer value)
-{
- gpointer* array = TlsGetValue (g_private_tls);
- guint index = GPOINTER_TO_UINT (private_key);
-
- if (index >= G_PRIVATE_MAX)
- return;
-
- if (!array)
- {
- array = (gpointer*) calloc (G_PRIVATE_MAX, sizeof (gpointer));
- TlsSetValue (g_private_tls, array);
- }
-
- array[index] = value;
-}
-
-static gpointer
-g_private_get_win32_impl (GPrivate * private_key)
-{
- gpointer* array = TlsGetValue (g_private_tls);
- guint index = GPOINTER_TO_UINT (private_key);
-
- if (index >= G_PRIVATE_MAX || !array)
- return NULL;
-
- return array[index];
-}
-
-/* {{{1 GThread */
static void
g_thread_set_priority_win32_impl (gpointer thread, GThreadPriority priority)
@@ -386,38 +377,36 @@ static void
g_thread_exit_win32_impl (void)
{
GThreadData *self = TlsGetValue (g_thread_self_tls);
- guint i, private_max;
- gpointer *array = TlsGetValue (g_private_tls);
-
- EnterCriticalSection (&g_thread_global_spinlock);
- private_max = g_private_next;
- LeaveCriticalSection (&g_thread_global_spinlock);
+ gboolean dtors_called;
- if (array)
+ do
{
- gboolean some_data_non_null;
-
- do {
- some_data_non_null = FALSE;
- for (i = 0; i < private_max; i++)
- {
- GDestroyNotify destructor = g_private_destructors[i];
- GDestroyNotify data = array[i];
-
- if (data)
- some_data_non_null = TRUE;
-
- array[i] = NULL;
-
- if (destructor && data)
- destructor (data);
- }
- } while (some_data_non_null);
-
- free (array);
-
- win32_check_for_error (TlsSetValue (g_private_tls, NULL));
+ GPrivateDestructor *dtor;
+
+ /* We go by the POSIX book on this one.
+ *
+ * If we call a destructor then there is a chance that some new
+ * TLS variables got set by code called in that destructor.
+ *
+ * Loop until nothing is left.
+ */
+ dtors_called = FALSE;
+
+ for (dtor = g_private_destructors; dtor; dtor = dtor->next)
+ {
+ gpointer value;
+
+ value = TlsGetValue (dtor->index);
+ if (value != NULL && dtor->notify != NULL)
+ {
+ /* POSIX says to clear this before the call */
+ TlsSetValue (dtor->index, NULL);
+ dtor->notify (value);
+ dtors_called = TRUE;
+ }
+ }
}
+ while (dtors_called);
if (self)
{
@@ -514,8 +503,8 @@ g_thread_join_win32_impl (gpointer thread)
/* {{{1 SRWLock and CONDITION_VARIABLE emulation (for Windows XP) */
-static DWORD g_thread_xp_waiter_tls;
static CRITICAL_SECTION g_thread_xp_lock;
+static DWORD g_thread_xp_waiter_tls;
/* {{{2 GThreadWaiter utility class for CONDITION_VARIABLE emulation */
typedef struct _GThreadXpWaiter GThreadXpWaiter;
@@ -807,9 +796,9 @@ GThreadFunctions g_thread_functions_for_glib_use =
g_cond_wait,
g_cond_timed_wait,
g_cond_free,
- g_private_new_win32_impl, /* private thread data */
- g_private_get_win32_impl,
- g_private_set_win32_impl,
+ g_private_new, /* private thread data */
+ g_private_get,
+ g_private_set,
g_thread_create_win32_impl, /* thread */
g_thread_yield_win32_impl,
g_thread_join_win32_impl,
@@ -834,7 +823,6 @@ _g_thread_impl_init (void)
(g_thread_self_tls = TlsAlloc ()));
win32_check_for_error (TLS_OUT_OF_INDEXES !=
(g_private_tls = TlsAlloc ()));
- InitializeCriticalSection (&g_thread_global_spinlock);
}
static gboolean
diff --git a/glib/gthread.h b/glib/gthread.h
index 14da02b..77afc4e 100644
--- a/glib/gthread.h
+++ b/glib/gthread.h
@@ -408,6 +408,11 @@ void g_mutex_free (GMutex
GCond * g_cond_new (void);
void g_cond_free (GCond *cond);
+GPrivate * (g_private_new) (GDestroyNotify notify);
+gpointer (g_private_get) (GPrivate *key);
+void (g_private_set) (GPrivate *key,
+ gpointer value);
+
G_END_DECLS
#endif /* __G_THREAD_H__ */
diff --git a/glib/gthreadprivate.h b/glib/gthreadprivate.h
index 3887519..4b9c2f4 100644
--- a/glib/gthreadprivate.h
+++ b/glib/gthreadprivate.h
@@ -55,6 +55,18 @@ G_GNUC_INTERNAL void _g_messages_thread_init_nomessage (void);
/* full fledged initializers */
G_GNUC_INTERNAL void _g_thread_impl_init (void);
+struct _GPrivate
+{
+#ifdef G_OS_WIN32
+ gint index;
+#else
+ pthread_key_t key;
+#endif
+};
+
+G_GNUC_INTERNAL void g_private_init (GPrivate *key,
+ GDestroyNotify notify);
+
G_END_DECLS
#endif /* __G_THREADPRIVATE_H__ */
[
Date Prev][
Date Next] [
Thread Prev][
Thread Next]
[
Thread Index]
[
Date Index]
[
Author Index]
