diff options
Diffstat (limited to 'debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch')
| -rw-r--r-- | debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch | 345 |
1 files changed, 0 insertions, 345 deletions
diff --git a/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch b/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch deleted file mode 100644 index e03a61f7..00000000 --- a/debian/patches/0003-libports-lock-less-reference-counting-for-port_info-.patch +++ /dev/null @@ -1,345 +0,0 @@ -From c860c73eb7baf5d3846da968969d3b2ef7a541ac Mon Sep 17 00:00:00 2001 -From: Justus Winter <4winter@informatik.uni-hamburg.de> -Date: Sat, 3 May 2014 01:02:35 +0200 -Subject: [PATCH 03/11] libports: lock-less reference counting for port_info - objects - -* libports/ports.h (struct port_info): Use the new type. -* libports/lookup-port.c: No need to lock _ports_lock anymore. -* libports/bucket-iterate.c: Likewise. -* libports/complete-deallocate.c: Check if someone reacquired a -reference through a hash table lookup. -* libports/create-internal.c: Use the new reference counting primitives. -* libports/get-right.c: Likewise. -* libports/import-port.c: Likewise. -* libports/port-deref-weak.c: Likewise. -* libports/port-deref.c: Likewise. -* libports/port-ref-weak.c: Likewise. -* libports/port-ref.c: Likewise. -* libports/reallocate-from-external.c: Likewise. -* libports/transfer-right.c: Likewise. -* utils/rpctrace.c: Likewise. ---- - libports/bucket-iterate.c | 4 +--- - libports/complete-deallocate.c | 15 +++++++++++++++ - libports/create-internal.c | 3 +-- - libports/get-right.c | 2 +- - libports/import-port.c | 3 +-- - libports/lookup-port.c | 6 ++---- - libports/port-deref-weak.c | 10 +++------- - libports/port-deref.c | 34 ++++++++++++++++------------------ - libports/port-ref-weak.c | 8 +++----- - libports/port-ref.c | 8 +++----- - libports/ports.h | 4 ++-- - libports/reallocate-from-external.c | 2 +- - libports/transfer-right.c | 2 +- - utils/rpctrace.c | 10 ++++++++-- - 14 files changed, 58 insertions(+), 53 deletions(-) - -diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c -index d5f590e..2a2b2b6 100644 ---- a/libports/bucket-iterate.c -+++ b/libports/bucket-iterate.c -@@ -35,7 +35,6 @@ _ports_bucket_class_iterate (struct port_bucket *bucket, - size_t i, n, nr_items; - error_t err; - -- pthread_mutex_lock (&_ports_lock); - pthread_mutex_lock (&_ports_htable_lock); - - if (_ports_htable.nr_items == 0) -@@ -60,13 +59,12 @@ _ports_bucket_class_iterate (struct port_bucket *bucket, - if ((bucket == NULL || pi->bucket == bucket) - && (class == NULL || pi->class == class)) - { -- pi->refcnt++; -+ refcounts_ref (&pi->refcounts, NULL); - p[n] = pi; - n++; - } - } - pthread_mutex_unlock (&_ports_htable_lock); -- pthread_mutex_unlock (&_ports_lock); - - if (n == 0) - { -diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c -index 1371d92..6c9074a 100644 ---- a/libports/complete-deallocate.c -+++ b/libports/complete-deallocate.c -@@ -29,14 +29,29 @@ _ports_complete_deallocate (struct port_info *pi) - - if (pi->port_right) - { -+ struct references result; -+ - pthread_mutex_lock (&_ports_htable_lock); -+ -+ refcounts_references (&pi->refcounts, &result); -+ if (result.hard > 0 || result.weak > 0) -+ { -+ /* A reference was reacquired through a hash table lookup. -+ It's fine, we didn't touch anything yet. */ -+ pthread_mutex_unlock (&_ports_htable_lock); -+ return; -+ } -+ - hurd_ihash_locp_remove (&_ports_htable, pi->hentry); - pthread_mutex_unlock (&_ports_htable_lock); -+ - mach_port_mod_refs (mach_task_self (), pi->port_right, - MACH_PORT_RIGHT_RECEIVE, -1); - pi->port_right = MACH_PORT_NULL; - } - -+ pthread_mutex_lock (&_ports_lock); -+ - pi->bucket->count--; - pi->class->count--; - -diff --git a/libports/create-internal.c b/libports/create-internal.c -index e773dd6..9e3824d 100644 ---- a/libports/create-internal.c -+++ b/libports/create-internal.c -@@ -54,8 +54,7 @@ _ports_create_port_internal (struct port_class *class, - } - - pi->class = class; -- pi->refcnt = 1; -- pi->weakrefcnt = 0; -+ refcounts_init (&pi->refcounts, 1, 0); - pi->cancel_threshold = 0; - pi->mscount = 0; - pi->flags = 0; -diff --git a/libports/get-right.c b/libports/get-right.c -index 89050c6..8681f46 100644 ---- a/libports/get-right.c -+++ b/libports/get-right.c -@@ -41,7 +41,7 @@ ports_get_right (void *port) - if ((pi->flags & PORT_HAS_SENDRIGHTS) == 0) - { - pi->flags |= PORT_HAS_SENDRIGHTS; -- pi->refcnt++; -+ refcounts_ref (&pi->refcounts, NULL); - err = mach_port_request_notification (mach_task_self (), - pi->port_right, - MACH_NOTIFY_NO_SENDERS, -diff --git a/libports/import-port.c b/libports/import-port.c -index d0b2ea4..e250b0e 100644 ---- a/libports/import-port.c -+++ b/libports/import-port.c -@@ -48,8 +48,7 @@ ports_import_port (struct port_class *class, struct port_bucket *bucket, - return ENOMEM; - - pi->class = class; -- pi->refcnt = 1 + !!stat.mps_srights; -- pi->weakrefcnt = 0; -+ refcounts_init (&pi->refcounts, 1 + !!stat.mps_srights, 0); - pi->cancel_threshold = 0; - pi->mscount = stat.mps_mscount; - pi->flags = stat.mps_srights ? PORT_HAS_SENDRIGHTS : 0; -diff --git a/libports/lookup-port.c b/libports/lookup-port.c -index fbb13ef..1bf012f 100644 ---- a/libports/lookup-port.c -+++ b/libports/lookup-port.c -@@ -28,7 +28,6 @@ ports_lookup_port (struct port_bucket *bucket, - { - struct port_info *pi; - -- pthread_mutex_lock (&_ports_lock); - pthread_mutex_lock (&_ports_htable_lock); - - pi = hurd_ihash_find (&_ports_htable, port); -@@ -38,10 +37,9 @@ ports_lookup_port (struct port_bucket *bucket, - pi = 0; - - if (pi) -- pi->refcnt++; -+ ports_port_ref (pi); - - pthread_mutex_unlock (&_ports_htable_lock); -- pthread_mutex_unlock (&_ports_lock); -- -+ - return pi; - } -diff --git a/libports/port-deref-weak.c b/libports/port-deref-weak.c -index beb4842..8432660 100644 ---- a/libports/port-deref-weak.c -+++ b/libports/port-deref-weak.c -@@ -25,12 +25,8 @@ void - ports_port_deref_weak (void *portstruct) - { - struct port_info *pi = portstruct; -- -- pthread_mutex_lock (&_ports_lock); -- assert (pi->weakrefcnt); -- pi->weakrefcnt--; -- if (pi->refcnt == 0 && pi->weakrefcnt == 0) -+ struct references result; -+ refcounts_deref_weak (&pi->refcounts, &result); -+ if (result.hard == 0 && result.weak == 0) - _ports_complete_deallocate (pi); -- else -- pthread_mutex_unlock (&_ports_lock); - } -diff --git a/libports/port-deref.c b/libports/port-deref.c -index cf9b238..dd38f55 100644 ---- a/libports/port-deref.c -+++ b/libports/port-deref.c -@@ -25,26 +25,24 @@ void - ports_port_deref (void *portstruct) - { - struct port_info *pi = portstruct; -- int trieddroppingweakrefs = 0; -- -- retry: -- -- pthread_mutex_lock (&_ports_lock); -- -- if (pi->refcnt == 1 && pi->weakrefcnt -- && pi->class->dropweak_routine && !trieddroppingweakrefs) -+ struct references result; -+ -+ /* If we need to call the dropweak routine, we need to hold one -+ reference while doing so. We use a weak reference for this -+ purpose, which we acquire before we release our hard reference. -+ The order is important here to prevent a race. */ -+ if (pi->class->dropweak_routine) -+ refcounts_ref_weak (&pi->refcounts, NULL); -+ -+ refcounts_deref (&pi->refcounts, &result); -+ -+ if (pi->class->dropweak_routine) - { -- pthread_mutex_unlock (&_ports_lock); -- (*pi->class->dropweak_routine) (pi); -- trieddroppingweakrefs = 1; -- goto retry; -+ if (result.hard == 0 && result.weak > 1) -+ (*pi->class->dropweak_routine) (pi); -+ refcounts_deref_weak (&pi->refcounts, &result); - } -- -- assert (pi->refcnt); - -- pi->refcnt--; -- if (pi->refcnt == 0 && pi->weakrefcnt == 0) -+ if (result.hard == 0 && result.weak == 0) - _ports_complete_deallocate (pi); -- else -- pthread_mutex_unlock (&_ports_lock); - } -diff --git a/libports/port-ref-weak.c b/libports/port-ref-weak.c -index c7d3c69..e4b7fc8 100644 ---- a/libports/port-ref-weak.c -+++ b/libports/port-ref-weak.c -@@ -25,9 +25,7 @@ void - ports_port_ref_weak (void *portstruct) - { - struct port_info *pi = portstruct; -- -- pthread_mutex_lock (&_ports_lock); -- assert (pi->refcnt || pi->weakrefcnt); -- pi->weakrefcnt++; -- pthread_mutex_unlock (&_ports_lock); -+ struct references result; -+ refcounts_ref_weak (&pi->refcounts, &result); -+ assert (result.hard > 0 || result.weak > 1); - } -diff --git a/libports/port-ref.c b/libports/port-ref.c -index 92b7118..761c50f 100644 ---- a/libports/port-ref.c -+++ b/libports/port-ref.c -@@ -25,9 +25,7 @@ void - ports_port_ref (void *portstruct) - { - struct port_info *pi = portstruct; -- -- pthread_mutex_lock (&_ports_lock); -- assert (pi->refcnt || pi->weakrefcnt); -- pi->refcnt++; -- pthread_mutex_unlock (&_ports_lock); -+ struct references result; -+ refcounts_ref (&pi->refcounts, &result); -+ assert (result.hard > 1 || result.weak > 0); - } -diff --git a/libports/ports.h b/libports/ports.h -index 9c5f14d..116e920 100644 ---- a/libports/ports.h -+++ b/libports/ports.h -@@ -27,6 +27,7 @@ - #include <hurd/ihash.h> - #include <mach/notify.h> - #include <pthread.h> -+#include <refcount.h> - - /* These are global values for common flags used in the various structures. - Not all of these are meaningful in all flag fields. */ -@@ -39,8 +40,7 @@ - struct port_info - { - struct port_class *class; -- int refcnt; -- int weakrefcnt; -+ refcounts_t refcounts; - mach_port_mscount_t mscount; - mach_msg_seqno_t cancel_threshold; - int flags; -diff --git a/libports/reallocate-from-external.c b/libports/reallocate-from-external.c -index bbcf9ba..5ee579d 100644 ---- a/libports/reallocate-from-external.c -+++ b/libports/reallocate-from-external.c -@@ -55,7 +55,7 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive) - else if (((pi->flags & PORT_HAS_SENDRIGHTS) == 0) && stat.mps_srights) - { - pi->flags |= PORT_HAS_SENDRIGHTS; -- pi->refcnt++; -+ refcounts_ref (&pi->refcounts, NULL); - } - - pi->port_right = receive; -diff --git a/libports/transfer-right.c b/libports/transfer-right.c -index 5a7653d..d3ff0f4 100644 ---- a/libports/transfer-right.c -+++ b/libports/transfer-right.c -@@ -70,7 +70,7 @@ ports_transfer_right (void *tostruct, - else if (((topi->flags & PORT_HAS_SENDRIGHTS) == 0) && hassendrights) - { - topi->flags |= PORT_HAS_SENDRIGHTS; -- topi->refcnt++; -+ refcounts_ref (&topi->refcounts, NULL); - } - } - -diff --git a/utils/rpctrace.c b/utils/rpctrace.c -index fc913e3..b11fea4 100644 ---- a/utils/rpctrace.c -+++ b/utils/rpctrace.c -@@ -431,7 +431,9 @@ destroy_receiver_info (struct receiver_info *info) - while (send_wrapper) - { - struct sender_info *next = send_wrapper->next; -- assert (TRACED_INFO (send_wrapper)->pi.refcnt == 1); -+ assert ( -+ refcounts_hard_references (&TRACED_INFO (send_wrapper)->pi.refcounts) -+ == 1); - /* Reset the receive_right of the send wrapper in advance to avoid - * destroy_receiver_info is called when the port info is destroyed. */ - send_wrapper->receive_right = NULL; -@@ -848,7 +850,11 @@ rewrite_right (mach_port_t *right, mach_msg_type_name_t *type, - hurd_ihash_locp_remove (&traced_names, receiver_info->locp); - - send_wrapper2 = get_send_wrapper (receiver_info, dest, &rr); -- assert (TRACED_INFO (send_wrapper2)->pi.refcnt == 1); -+ assert ( -+ refcounts_hard_references ( -+ &TRACED_INFO (send_wrapper2)->pi.refcounts) -+ == 1); -+ - name = TRACED_INFO (send_wrapper2)->name; - TRACED_INFO (send_wrapper2)->name = NULL; - /* send_wrapper2 isn't destroyed normally, so we need to unlink --- -2.0.0.rc0 - |