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[HB] Fix blob to use a actual mutex

This commit is contained in:
Behdad Esfahbod 2009-08-06 13:33:51 -04:00
parent a794ebf4be
commit 7f3d5c8166
3 changed files with 106 additions and 43 deletions
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125
src/hb-blob.c
View File

@ -36,11 +36,15 @@
struct _hb_blob_t {
hb_reference_count_t ref_count;
hb_reference_count_t lock;
unsigned int length;
hb_mutex_t lock;
/* the rest are protected by lock */
unsigned int lock_count;
hb_memory_mode_t mode;
const char *data;
unsigned int length;
hb_memory_mode_t mode;
hb_destroy_func_t destroy;
void *user_data;
@ -48,11 +52,14 @@ struct _hb_blob_t {
static hb_blob_t _hb_blob_nil = {
HB_REFERENCE_COUNT_INVALID, /* ref_count */
HB_REFERENCE_COUNT_INVALID, /* lock */
0, /* length */
HB_MUTEX_INIT, /* lock */
0, /* lock_count */
HB_MEMORY_MODE_READONLY_NEVER_DUPLICATE, /* mode */
NULL, /* data */
0, /* length */
HB_MEMORY_MODE_READONLY_NEVER_DUPLICATE, /* mode */
NULL, /* destroy */
NULL /* user_data */
@ -90,7 +97,8 @@ hb_blob_create (const char *data,
return &_hb_blob_nil;
}
HB_REFERENCE_COUNT_INIT (blob->lock, 0);
hb_mutex_init (blob->lock);
blob->lock_count = 0;
blob->data = data;
blob->length = length;
@ -125,7 +133,10 @@ hb_blob_create_sub_blob (hb_blob_t *parent,
blob->data = pdata + offset;
blob->length = MIN (length, parent->length - offset);
hb_mutex_lock (parent->lock);
blob->mode = parent->mode;
hb_mutex_unlock (parent->lock);
blob->destroy = (hb_destroy_func_t) _hb_blob_unlock_and_destroy;
blob->user_data = hb_blob_reference (parent);
@ -170,53 +181,80 @@ hb_blob_get_length (hb_blob_t *blob)
const char *
hb_blob_lock (hb_blob_t *blob)
{
if (!HB_OBJECT_IS_INERT (blob))
(void) hb_reference_count_inc (blob->lock);
if (HB_OBJECT_IS_INERT (blob))
return NULL;
hb_mutex_lock (blob->lock);
blob->lock_count++;
#if HB_DEBUG
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
blob->lock_count, blob->data);
#endif
hb_mutex_unlock (blob->lock);
return blob->data;
}
void
hb_blob_unlock (hb_blob_t *blob)
{
if (!HB_OBJECT_IS_INERT (blob)) {
int old_lock = hb_reference_count_dec (blob->lock);
assert (old_lock > 0);
}
if (HB_OBJECT_IS_INERT (blob))
return;
hb_mutex_lock (blob->lock);
assert (blob->lock_count > 0);
blob->lock_count--;
#if HB_DEBUG
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
hb_atomic_int_get (blob->lock_count), blob->data);
#endif
hb_mutex_unlock (blob->lock);
}
hb_bool_t
hb_blob_is_writeable (hb_blob_t *blob)
{
return blob->mode == HB_MEMORY_MODE_WRITEABLE;
hb_memory_mode_t mode;
if (HB_OBJECT_IS_INERT (blob))
return FALSE;
hb_mutex_lock (blob->lock);
mode = blob->mode;
hb_mutex_unlock (blob->lock);
return mode == HB_MEMORY_MODE_WRITEABLE;
}
hb_bool_t
hb_blob_try_writeable_inplace (hb_blob_t *blob)
{
hb_memory_mode_t mode;
if (HB_OBJECT_IS_INERT (blob))
return FALSE;
hb_mutex_lock (blob->lock);
if (blob->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITEABLE) {
unsigned int pagesize, mask, length;
const char *addr;
#if HB_DEBUG
fprintf (stderr, "%p %s: making writeable\n", blob, __FUNCTION__);
fprintf (stderr, "%p %s: making writeable\n", blob, __FUNCTION__);
#endif
pagesize = (unsigned int) sysconf(_SC_PAGE_SIZE);
if ((unsigned int) -1 == pagesize) {
#if HB_DEBUG
fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
#endif
return FALSE;
goto done;
}
#if HB_DEBUG
fprintf (stderr, "%p %s: pagesize is %u\n", blob, __FUNCTION__, pagesize);
@ -232,12 +270,13 @@ hb_blob_try_writeable_inplace (hb_blob_t *blob)
#endif
if (-1 == mprotect ((void *) addr, length, PROT_READ | PROT_WRITE)) {
#if HB_DEBUG
fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
#endif
return FALSE;
goto done;
}
blob->mode = HB_MEMORY_MODE_WRITEABLE;
#if HB_DEBUG
fprintf (stderr, "%p %s: successfully made [%p..%p] (%d bytes) writeable\n",
blob, __FUNCTION__,
@ -245,25 +284,38 @@ hb_blob_try_writeable_inplace (hb_blob_t *blob)
#endif
}
return blob->mode == HB_MEMORY_MODE_WRITEABLE;
done:
mode = blob->mode;
hb_mutex_unlock (blob->lock);
return mode == HB_MEMORY_MODE_WRITEABLE;
}
hb_bool_t
hb_blob_try_writeable (hb_blob_t *blob)
{
if (blob->mode == HB_MEMORY_MODE_READONLY_NEVER_DUPLICATE)
hb_memory_mode_t mode;
if (HB_OBJECT_IS_INERT (blob))
return FALSE;
hb_mutex_lock (blob->lock);
if (blob->mode == HB_MEMORY_MODE_READONLY_NEVER_DUPLICATE)
goto done;
if (blob->mode == HB_MEMORY_MODE_READONLY)
{
char *new_data;
#if HB_DEBUG
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
blob->lock_count, blob->data);
#endif
if (HB_REFERENCE_COUNT_HAS_REFERENCE (blob->lock))
return FALSE;
if (blob->lock_count)
goto done;
new_data = malloc (blob->length);
if (new_data) {
@ -274,11 +326,16 @@ hb_blob_try_writeable (hb_blob_t *blob)
blob->data = new_data;
blob->mode = HB_MEMORY_MODE_WRITEABLE;
_hb_blob_destroy_user_data (blob);
return TRUE;
} else
return FALSE;
}
}
return
hb_blob_try_writeable_inplace (blob);
done:
mode = blob->mode;
hb_mutex_unlock (blob->lock);
if (blob->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITEABLE)
return hb_blob_try_writeable_inplace (blob);
return mode == HB_MEMORY_MODE_WRITEABLE;
}

4
src/hb-object-private.h
View File

@ -36,8 +36,8 @@ typedef struct {
hb_atomic_int_t ref_count;
} hb_reference_count_t;
#define hb_reference_count_inc(RC) hb_atomic_fetch_and_add ((RC).ref_count, 1)
#define hb_reference_count_dec(RC) hb_atomic_fetch_and_add ((RC).ref_count, -1)
#define hb_reference_count_inc(RC) hb_atomic_int_fetch_and_add ((RC).ref_count, 1)
#define hb_reference_count_dec(RC) hb_atomic_int_fetch_and_add ((RC).ref_count, -1)
#define HB_REFERENCE_COUNT_INIT(RC, VALUE) ((RC).ref_count = (VALUE))

20
src/hb-private.h
View File

@ -51,8 +51,6 @@
#define hb_be_uint16(v) ((uint16_t) hb_be_int16 ((uint16_t) v))
#define hb_be_uint32(v) ((uint32_t) hb_be_int32 ((uint32_t) v))
typedef int hb_atomic_int_t;
/* We need external help for these */
#if HAVE_GLIB
@ -60,12 +58,20 @@ typedef int hb_atomic_int_t;
#include <glib.h>
/* Macros to convert to/from BigEndian */
#define hb_be_int16(v) GINT16_FROM_BE (v)
#define hb_be_int32(v) GINT32_FROM_BE (v)
#define hb_be_int16(v) GINT16_FROM_BE (v)
#define hb_be_int32(v) GINT32_FROM_BE (v)
#define hb_atomic_fetch_and_add(AI, V) g_atomic_int_exchange_and_add (&(AI), V)
#define hb_atomic_int_get(AI) g_atomic_int_get (&(AI))
#define hb_atomic_int_set(AI, V) g_atomic_int_set (&(AI), V)
typedef int hb_atomic_int_t;
#define hb_atomic_int_fetch_and_add(AI, V) g_atomic_int_exchange_and_add (&(AI), V)
#define hb_atomic_int_get(AI) g_atomic_int_get (&(AI))
#define hb_atomic_int_set(AI, V) g_atomic_int_set (&(AI), V)
typedef GStaticMutex hb_mutex_t;
#define HB_MUTEX_INIT G_STATIC_MUTEX_INIT
#define hb_mutex_init(M) g_static_mutex_init (&M)
#define hb_mutex_lock(M) g_static_mutex_lock (&M)
#define hb_mutex_trylock(M) g_static_mutex_trylock (&M)
#define hb_mutex_unlock(M) g_static_mutex_unlock (&M)
#else
#error "Could not find any system to define platform macros, see hb-private.h"