From 7f3d5c8166e5205e9d9bf8b4b2f31d44387a8006 Mon Sep 17 00:00:00 2001 From: Behdad Esfahbod Date: Thu, 6 Aug 2009 13:33:51 -0400 Subject: [PATCH] [HB] Fix blob to use a actual mutex --- src/hb-blob.c | 125 +++++++++++++++++++++++++++++++++++------------- src/hb-object-private.h | 4 +- src/hb-private.h | 20 +++++--- 3 files changed, 106 insertions(+), 43 deletions(-) diff --git a/src/hb-blob.c b/src/hb-blob.c index 428e7d0..c2c557a 100644 --- a/src/hb-blob.c +++ b/src/hb-blob.c @@ -36,24 +36,31 @@ struct _hb_blob_t { hb_reference_count_t ref_count; - hb_reference_count_t lock; - - const char *data; 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; + hb_destroy_func_t destroy; void *user_data; }; static hb_blob_t _hb_blob_nil = { HB_REFERENCE_COUNT_INVALID, /* ref_count */ - HB_REFERENCE_COUNT_INVALID, /* lock */ - - NULL, /* data */ 0, /* length */ + + HB_MUTEX_INIT, /* lock */ + + 0, /* lock_count */ HB_MEMORY_MODE_READONLY_NEVER_DUPLICATE, /* mode */ + NULL, /* data */ + 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; } diff --git a/src/hb-object-private.h b/src/hb-object-private.h index 86ab82b..4f4c3de 100644 --- a/src/hb-object-private.h +++ b/src/hb-object-private.h @@ -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)) diff --git a/src/hb-private.h b/src/hb-private.h index fe13b7e..5cb2f56 100644 --- a/src/hb-private.h +++ b/src/hb-private.h @@ -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 /* 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" -- 2.7.4