diff options
Diffstat (limited to 'debian/patches')
3 files changed, 1003 insertions, 0 deletions
diff --git a/debian/patches/0001-libports-use-a-global-hash-table-for-the-lookups.patch b/debian/patches/0001-libports-use-a-global-hash-table-for-the-lookups.patch new file mode 100644 index 00000000..ca25ebd3 --- /dev/null +++ b/debian/patches/0001-libports-use-a-global-hash-table-for-the-lookups.patch @@ -0,0 +1,660 @@ +From 9c12cb8e9474692b35f658643d278816bd524355 Mon Sep 17 00:00:00 2001 +From: Justus Winter <4winter@informatik.uni-hamburg.de> +Date: Sat, 3 May 2014 03:53:41 +0200 +Subject: [PATCH 1/2] libports: use a global hash table for the lookups + +Previously, libports used a hash table per port bucket. This makes +looking up a port difficult if one does not know the port bucket, as +one has to iterate over all buckets and do a hash table lookup each. + +Having to iterate over the buckets makes it necessary to keep a list +of all buckets, which has to be updated and protected by a lock as +well. + +Also, the current code in _ports_bucket_class_iterate iterates over +the hash table associated with the bucket given. When +ports_class_iterate calls this common function, it obtains a reference +to the bucket from one of the ports in the given class. This will not +work if a class contains ports in different port buckets. This +limitation is not documented as far as I can see. Again, having to +maintain this list has its cost and requires serialization. + +Use a global hash table for lookups instead. Keep the per-bucket hash +tables for efficient iteration over buckets. Furthermore, serialize +access to all hash tables using a separate lock. Remove the linked +lists of all buckets and all ports in a class. + +* libports/bucket-iterate.c (ports_bucket_iterate): Acquire +_ports_htable_lock. Also, generalize ports_bucket_iterate so that it +takes a pointer to a hash table as first argument. +(ports_bucket_iterate): Ajust call to former function accordingly. +* libports/class-iterate.c (ports_class_iterate): Just call the +generalized _ports_bucket_class_iterate with the global hash table as +argument. +* libports/ports.h (struct port_info): Remove the port class links. +(struct port_bucket): Remove the hash table, and the all buckets link. +(_ports_all_buckets): Remove declaration. +(_ports_htable): New global hash table. +(_ports_htable_lock): Protected by this lock. +* libports/claim-right.c: Adjust accordingly. +* libports/complete-deallocate.c: Likewise. +* libports/create-bucket.c: Likewise. +* libports/create-class.c: Likewise. +* libports/create-internal.c: Likewise. +* libports/destroy-right.c: Likewise. +* libports/import-port.c: Likewise. +* libports/lookup-port.c: Likewise. +* libports/reallocate-from-external.c: Likewise. +* libports/reallocate-port.c: Likewise. +* libports/transfer-right.c: Likewise. +* libports/inhibit-all-rpcs.c: Iterate over the hash table. +* libports/inhibit-bucket-rpcs.c: Likewise, but filter using bucket. +* libports/inhibit-class-rpcs.c: Likewise, but filter using class. +* libports/init.c (_ports_htable): Initialize. +(_ports_htable_lock): Likewise. +--- + libports/bucket-iterate.c | 16 +++++++++------- + libports/claim-right.c | 5 ++++- + libports/class-iterate.c | 10 +--------- + libports/complete-deallocate.c | 7 +++---- + libports/create-bucket.c | 6 ------ + libports/create-class.c | 1 - + libports/create-internal.c | 19 +++++++++++++------ + libports/destroy-right.c | 5 +++-- + libports/import-port.c | 19 +++++++++++++------ + libports/inhibit-all-rpcs.c | 27 +++++++++++++-------------- + libports/inhibit-bucket-rpcs.c | 3 ++- + libports/inhibit-class-rpcs.c | 27 ++++++++++++++++++--------- + libports/init.c | 7 ++++++- + libports/lookup-port.c | 23 +++++++++-------------- + libports/ports.h | 22 +++++++++++++++++----- + libports/reallocate-from-external.c | 15 +++++++++++---- + libports/reallocate-port.c | 9 ++++++++- + libports/transfer-right.c | 18 ++++++++++++++---- + 18 files changed, 144 insertions(+), 95 deletions(-) + +diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c +index 2d1b00d..79b6d72 100644 +--- a/libports/bucket-iterate.c ++++ b/libports/bucket-iterate.c +@@ -25,7 +25,7 @@ + /* Internal entrypoint for both ports_bucket_iterate and ports_class_iterate. + If CLASS is non-null, call FUN only for ports in that class. */ + error_t +-_ports_bucket_class_iterate (struct port_bucket *bucket, ++_ports_bucket_class_iterate (struct hurd_ihash *ht, + struct port_class *class, + error_t (*fun)(void *)) + { +@@ -36,23 +36,24 @@ _ports_bucket_class_iterate (struct port_bucket *bucket, + error_t err; + + pthread_mutex_lock (&_ports_lock); ++ pthread_rwlock_rdlock (&_ports_htable_lock); + +- if (bucket->htable.nr_items == 0) ++ if (ht->nr_items == 0) + { +- pthread_mutex_unlock (&_ports_lock); ++ pthread_rwlock_unlock (&_ports_htable_lock); + return 0; + } + +- nr_items = bucket->htable.nr_items; ++ nr_items = ht->nr_items; + p = malloc (nr_items * sizeof *p); + if (p == NULL) + { +- pthread_mutex_unlock (&_ports_lock); ++ pthread_rwlock_unlock (&_ports_htable_lock); + return ENOMEM; + } + + n = 0; +- HURD_IHASH_ITERATE (&bucket->htable, arg) ++ HURD_IHASH_ITERATE (ht, arg) + { + struct port_info *const pi = arg; + +@@ -63,6 +64,7 @@ _ports_bucket_class_iterate (struct port_bucket *bucket, + n++; + } + } ++ pthread_rwlock_unlock (&_ports_htable_lock); + pthread_mutex_unlock (&_ports_lock); + + if (n != 0 && n != nr_items) +@@ -89,5 +91,5 @@ error_t + ports_bucket_iterate (struct port_bucket *bucket, + error_t (*fun)(void *)) + { +- return _ports_bucket_class_iterate (bucket, 0, fun); ++ return _ports_bucket_class_iterate (&bucket->htable, NULL, fun); + } +diff --git a/libports/claim-right.c b/libports/claim-right.c +index 4851ea3..85592ff 100644 +--- a/libports/claim-right.c ++++ b/libports/claim-right.c +@@ -34,10 +34,13 @@ ports_claim_right (void *portstruct) + if (ret == MACH_PORT_NULL) + return ret; + +- pthread_mutex_lock (&_ports_lock); ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); ++ pthread_rwlock_unlock (&_ports_htable_lock); + err = mach_port_move_member (mach_task_self (), ret, MACH_PORT_NULL); + assert_perror (err); ++ pthread_mutex_lock (&_ports_lock); + pi->port_right = MACH_PORT_NULL; + if (pi->flags & PORT_HAS_SENDRIGHTS) + { +diff --git a/libports/class-iterate.c b/libports/class-iterate.c +index 1f8878a..df33818 100644 +--- a/libports/class-iterate.c ++++ b/libports/class-iterate.c +@@ -23,13 +23,5 @@ error_t + ports_class_iterate (struct port_class *class, + error_t (*fun)(void *)) + { +- pthread_mutex_lock (&_ports_lock); +- if (class->ports != 0) +- { +- struct port_bucket *bucket = class->ports->bucket; +- pthread_mutex_unlock (&_ports_lock); +- return _ports_bucket_class_iterate (bucket, class, fun); +- } +- pthread_mutex_unlock (&_ports_lock); +- return 0; ++ return _ports_bucket_class_iterate (&_ports_htable, class, fun); + } +diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c +index 8ce095b..4768dab 100644 +--- a/libports/complete-deallocate.c ++++ b/libports/complete-deallocate.c +@@ -29,16 +29,15 @@ _ports_complete_deallocate (struct port_info *pi) + + if (pi->port_right) + { ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); ++ pthread_rwlock_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; + } + +- *pi->prevp = pi->next; +- if (pi->next) +- pi->next->prevp = pi->prevp; +- + pi->bucket->count--; + pi->class->count--; + +diff --git a/libports/create-bucket.c b/libports/create-bucket.c +index 52d50c3..2c5f1b6 100644 +--- a/libports/create-bucket.c ++++ b/libports/create-bucket.c +@@ -48,11 +48,5 @@ ports_create_bucket () + + hurd_ihash_init (&ret->htable, offsetof (struct port_info, hentry)); + ret->rpcs = ret->flags = ret->count = 0; +- +- pthread_mutex_lock (&_ports_lock); +- ret->next = _ports_all_buckets; +- _ports_all_buckets = ret; +- pthread_mutex_unlock (&_ports_lock); +- + return ret; + } +diff --git a/libports/create-class.c b/libports/create-class.c +index 12c8add..782f52b 100644 +--- a/libports/create-class.c ++++ b/libports/create-class.c +@@ -39,7 +39,6 @@ ports_create_class (void (*clean_routine)(void *), + cl->dropweak_routine = dropweak_routine; + cl->flags = 0; + cl->rpcs = 0; +- cl->ports = NULL; + cl->count = 0; + cl->uninhibitable_rpcs = ports_default_uninhibitable_rpcs; + +diff --git a/libports/create-internal.c b/libports/create-internal.c +index 8551297..8543986 100644 +--- a/libports/create-internal.c ++++ b/libports/create-internal.c +@@ -81,15 +81,22 @@ _ports_create_port_internal (struct port_class *class, + goto loop; + } + ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ err = hurd_ihash_add (&_ports_htable, port, pi); ++ if (err) ++ { ++ pthread_rwlock_unlock (&_ports_htable_lock); ++ goto lose; ++ } + err = hurd_ihash_add (&bucket->htable, port, pi); + if (err) +- goto lose; ++ { ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); ++ pthread_rwlock_unlock (&_ports_htable_lock); ++ goto lose; ++ } ++ pthread_rwlock_unlock (&_ports_htable_lock); + +- pi->next = class->ports; +- pi->prevp = &class->ports; +- if (class->ports) +- class->ports->prevp = &pi->next; +- class->ports = pi; + bucket->count++; + class->count++; + pthread_mutex_unlock (&_ports_lock); +diff --git a/libports/destroy-right.c b/libports/destroy-right.c +index 65e19c7..448b379 100644 +--- a/libports/destroy-right.c ++++ b/libports/destroy-right.c +@@ -30,12 +30,13 @@ ports_destroy_right (void *portstruct) + + if (pi->port_right != MACH_PORT_NULL) + { +- pthread_mutex_lock (&_ports_lock); ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); ++ pthread_rwlock_unlock (&_ports_htable_lock); + err = mach_port_mod_refs (mach_task_self (), pi->port_right, + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); +- pthread_mutex_unlock (&_ports_lock); + + pi->port_right = MACH_PORT_NULL; + +diff --git a/libports/import-port.c b/libports/import-port.c +index 226f47e..2660672 100644 +--- a/libports/import-port.c ++++ b/libports/import-port.c +@@ -75,15 +75,22 @@ ports_import_port (struct port_class *class, struct port_bucket *bucket, + goto loop; + } + ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ err = hurd_ihash_add (&_ports_htable, port, pi); ++ if (err) ++ { ++ pthread_rwlock_unlock (&_ports_htable_lock); ++ goto lose; ++ } + err = hurd_ihash_add (&bucket->htable, port, pi); + if (err) +- goto lose; ++ { ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); ++ pthread_rwlock_unlock (&_ports_htable_lock); ++ goto lose; ++ } ++ pthread_rwlock_unlock (&_ports_htable_lock); + +- pi->next = class->ports; +- pi->prevp = &class->ports; +- if (class->ports) +- class->ports->prevp = &pi->next; +- class->ports = pi; + bucket->count++; + class->count++; + pthread_mutex_unlock (&_ports_lock); +diff --git a/libports/inhibit-all-rpcs.c b/libports/inhibit-all-rpcs.c +index d4a54ba..27e2ec5 100644 +--- a/libports/inhibit-all-rpcs.c ++++ b/libports/inhibit-all-rpcs.c +@@ -36,24 +36,23 @@ ports_inhibit_all_rpcs () + struct port_bucket *bucket; + int this_one = 0; + +- for (bucket = _ports_all_buckets; bucket; bucket = bucket->next) ++ pthread_rwlock_rdlock (&_ports_htable_lock); ++ HURD_IHASH_ITERATE (&_ports_htable, portstruct) + { +- HURD_IHASH_ITERATE (&bucket->htable, portstruct) ++ struct rpc_info *rpc; ++ struct port_info *pi = portstruct; ++ ++ for (rpc = pi->current_rpcs; rpc; rpc = rpc->next) + { +- struct rpc_info *rpc; +- struct port_info *pi = portstruct; +- +- for (rpc = pi->current_rpcs; rpc; rpc = rpc->next) +- { +- /* Avoid cancelling the calling thread if it's currently +- handling a RPC. */ +- if (rpc->thread == hurd_thread_self ()) +- this_one = 1; +- else +- hurd_thread_cancel (rpc->thread); +- } ++ /* Avoid cancelling the calling thread if it's currently ++ handling a RPC. */ ++ if (rpc->thread == hurd_thread_self ()) ++ this_one = 1; ++ else ++ hurd_thread_cancel (rpc->thread); + } + } ++ pthread_rwlock_unlock (&_ports_htable_lock); + + while (_ports_total_rpcs > this_one) + { +diff --git a/libports/inhibit-bucket-rpcs.c b/libports/inhibit-bucket-rpcs.c +index 965aa03..82efdf5 100644 +--- a/libports/inhibit-bucket-rpcs.c ++++ b/libports/inhibit-bucket-rpcs.c +@@ -35,6 +35,7 @@ ports_inhibit_bucket_rpcs (struct port_bucket *bucket) + { + int this_one = 0; + ++ pthread_rwlock_rdlock (&_ports_htable_lock); + HURD_IHASH_ITERATE (&bucket->htable, portstruct) + { + struct rpc_info *rpc; +@@ -49,7 +50,7 @@ ports_inhibit_bucket_rpcs (struct port_bucket *bucket) + hurd_thread_cancel (rpc->thread); + } + } +- ++ pthread_rwlock_unlock (&_ports_htable_lock); + + while (bucket->rpcs > this_one) + { +diff --git a/libports/inhibit-class-rpcs.c b/libports/inhibit-class-rpcs.c +index 7ee8653..9a87a5f 100644 +--- a/libports/inhibit-class-rpcs.c ++++ b/libports/inhibit-class-rpcs.c +@@ -36,15 +36,24 @@ ports_inhibit_class_rpcs (struct port_class *class) + struct rpc_info *rpc; + int this_one = 0; + +- for (pi = class->ports; pi; pi = pi->next) +- for (rpc = pi->current_rpcs; rpc; rpc = rpc->next) +- { +- /* Avoid cancelling the calling thread. */ +- if (rpc->thread == hurd_thread_self ()) +- this_one = 1; +- else +- hurd_thread_cancel (rpc->thread); +- } ++ pthread_rwlock_rdlock (&_ports_htable_lock); ++ HURD_IHASH_ITERATE (&_ports_htable, portstruct) ++ { ++ struct rpc_info *rpc; ++ struct port_info *pi = portstruct; ++ if (pi->class != class) ++ continue; ++ ++ for (rpc = pi->current_rpcs; rpc; rpc = rpc->next) ++ { ++ /* Avoid cancelling the calling thread. */ ++ if (rpc->thread == hurd_thread_self ()) ++ this_one = 1; ++ else ++ hurd_thread_cancel (rpc->thread); ++ } ++ } ++ pthread_rwlock_unlock (&_ports_htable_lock); + + while (class->rpcs > this_one) + { +diff --git a/libports/init.c b/libports/init.c +index 3ef5388..4a68cb8 100644 +--- a/libports/init.c ++++ b/libports/init.c +@@ -19,9 +19,14 @@ + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + + #include "ports.h" ++#include <stddef.h> + + pthread_mutex_t _ports_lock = PTHREAD_MUTEX_INITIALIZER; + pthread_cond_t _ports_block = PTHREAD_COND_INITIALIZER; +-struct port_bucket *_ports_all_buckets; ++ ++struct hurd_ihash _ports_htable = ++ HURD_IHASH_INITIALIZER (offsetof (struct port_info, ports_htable_entry)); ++pthread_rwlock_t _ports_htable_lock = PTHREAD_RWLOCK_INITIALIZER; ++ + int _ports_total_rpcs; + int _ports_flags; +diff --git a/libports/lookup-port.c b/libports/lookup-port.c +index f79f6f0..858ee11 100644 +--- a/libports/lookup-port.c ++++ b/libports/lookup-port.c +@@ -26,27 +26,22 @@ ports_lookup_port (struct port_bucket *bucket, + mach_port_t port, + struct port_class *class) + { +- struct port_info *pi = 0; +- ++ struct port_info *pi; ++ + pthread_mutex_lock (&_ports_lock); ++ pthread_rwlock_rdlock (&_ports_htable_lock); + +- if (bucket) +- pi = hurd_ihash_find (&bucket->htable, port); +- else +- for (bucket = _ports_all_buckets; bucket; bucket = bucket->next) +- { +- pi = hurd_ihash_find (&bucket->htable, port); +- if (pi) +- break; +- } +- +- if (pi && class && pi->class != class) ++ pi = hurd_ihash_find (&_ports_htable, port); ++ if (pi ++ && ((class && pi->class != class) ++ || (bucket && pi->bucket != bucket))) + pi = 0; + + if (pi) + pi->refcnt++; + ++ pthread_rwlock_unlock (&_ports_htable_lock); + pthread_mutex_unlock (&_ports_lock); +- ++ + return pi; + } +diff --git a/libports/ports.h b/libports/ports.h +index 7f13124..6922162 100644 +--- a/libports/ports.h ++++ b/libports/ports.h +@@ -48,7 +48,7 @@ struct port_info + struct rpc_info *current_rpcs; + struct port_bucket *bucket; + hurd_ihash_locp_t hentry; +- struct port_info *next, **prevp; /* links on port_class list */ ++ hurd_ihash_locp_t ports_htable_entry; + }; + typedef struct port_info *port_info_t; + +@@ -61,11 +61,12 @@ typedef struct port_info *port_info_t; + struct port_bucket + { + mach_port_t portset; ++ /* Per-bucket hash table used for fast iteration. Access must be ++ serialized using _ports_htable_lock. */ + struct hurd_ihash htable; + int rpcs; + int flags; + int count; +- struct port_bucket *next; + }; + /* FLAGS above are the following: */ + #define PORT_BUCKET_INHIBITED PORTS_INHIBITED +@@ -78,7 +79,6 @@ struct port_class + { + int flags; + int rpcs; +- struct port_info *ports; + int count; + void (*clean_routine) (void *); + void (*dropweak_routine) (void *); +@@ -277,7 +277,7 @@ error_t ports_class_iterate (struct port_class *class, + error_t (*fun)(void *port)); + + /* Internal entrypoint for above two. */ +-error_t _ports_bucket_class_iterate (struct port_bucket *bucket, ++error_t _ports_bucket_class_iterate (struct hurd_ihash *ht, + struct port_class *class, + error_t (*fun)(void *port)); + +@@ -402,7 +402,19 @@ extern kern_return_t + /* Private data */ + extern pthread_mutex_t _ports_lock; + extern pthread_cond_t _ports_block; +-extern struct port_bucket *_ports_all_buckets; ++ ++/* A global hash table mapping port names to port_info objects. This ++ table is used for port lookups and to iterate over classes. ++ ++ A port in this hash table carries an implicit light reference. ++ When the reference counts reach zero, we call ++ _ports_complete_deallocate. There we reacquire our lock ++ momentarily to check whether someone else reacquired a reference ++ through the hash table. */ ++extern struct hurd_ihash _ports_htable; ++/* Access to the hash table is protected by this lock. */ ++extern pthread_rwlock_t _ports_htable_lock; ++ + extern int _ports_total_rpcs; + extern int _ports_flags; + #define _PORTS_INHIBITED PORTS_INHIBITED +diff --git a/libports/reallocate-from-external.c b/libports/reallocate-from-external.c +index 8cccb2a..9944b39 100644 +--- a/libports/reallocate-from-external.c ++++ b/libports/reallocate-from-external.c +@@ -43,8 +43,11 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive) + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); + ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); +- ++ pthread_rwlock_unlock (&_ports_htable_lock); ++ + if ((pi->flags & PORT_HAS_SENDRIGHTS) && !stat.mps_srights) + { + dropref = 1; +@@ -59,11 +62,15 @@ ports_reallocate_from_external (void *portstruct, mach_port_t receive) + pi->port_right = receive; + pi->cancel_threshold = 0; + pi->mscount = stat.mps_mscount; +- +- err = hurd_ihash_add (&pi->bucket->htable, receive, pi); ++ ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ err = hurd_ihash_add (&_ports_htable, receive, pi); + assert_perror (err); ++ err = hurd_ihash_add (&pi->bucket->htable, receive, pi); ++ pthread_rwlock_unlock (&_ports_htable_lock); + pthread_mutex_unlock (&_ports_lock); +- ++ assert_perror (err); ++ + mach_port_move_member (mach_task_self (), receive, pi->bucket->portset); + + if (stat.mps_srights) +diff --git a/libports/reallocate-port.c b/libports/reallocate-port.c +index d2adaeb..cc534eb 100644 +--- a/libports/reallocate-port.c ++++ b/libports/reallocate-port.c +@@ -36,7 +36,10 @@ ports_reallocate_port (void *portstruct) + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); + ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, pi->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); ++ pthread_rwlock_unlock (&_ports_htable_lock); + + err = mach_port_allocate (mach_task_self (), MACH_PORT_RIGHT_RECEIVE, + &pi->port_right); +@@ -48,9 +51,13 @@ ports_reallocate_port (void *portstruct) + } + pi->cancel_threshold = 0; + pi->mscount = 0; +- err = hurd_ihash_add (&pi->bucket->htable, pi->port_right, pi); ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ err = hurd_ihash_add (&_ports_htable, pi->port_right, pi); + assert_perror (err); ++ err = hurd_ihash_add (&pi->bucket->htable, pi->port_right, pi); ++ pthread_rwlock_unlock (&_ports_htable_lock); + pthread_mutex_unlock (&_ports_lock); ++ assert_perror (err); + + err = mach_port_move_member (mach_task_self (), pi->port_right, + pi->bucket->portset); +diff --git a/libports/transfer-right.c b/libports/transfer-right.c +index 72488a9..3f48290 100644 +--- a/libports/transfer-right.c ++++ b/libports/transfer-right.c +@@ -41,7 +41,10 @@ ports_transfer_right (void *tostruct, + port = frompi->port_right; + if (port != MACH_PORT_NULL) + { ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, frompi->ports_htable_entry); + hurd_ihash_locp_remove (&frompi->bucket->htable, frompi->hentry); ++ pthread_rwlock_unlock (&_ports_htable_lock); + frompi->port_right = MACH_PORT_NULL; + if (frompi->flags & PORT_HAS_SENDRIGHTS) + { +@@ -54,7 +57,10 @@ ports_transfer_right (void *tostruct, + /* Destroy the existing right in TOPI. */ + if (topi->port_right != MACH_PORT_NULL) + { ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ hurd_ihash_locp_remove (&_ports_htable, topi->ports_htable_entry); + hurd_ihash_locp_remove (&topi->bucket->htable, topi->hentry); ++ pthread_rwlock_unlock (&_ports_htable_lock); + err = mach_port_mod_refs (mach_task_self (), topi->port_right, + MACH_PORT_RIGHT_RECEIVE, -1); + assert_perror (err); +@@ -74,10 +80,16 @@ ports_transfer_right (void *tostruct, + topi->port_right = port; + topi->cancel_threshold = frompi->cancel_threshold; + topi->mscount = frompi->mscount; +- ++ ++ pthread_mutex_unlock (&_ports_lock); ++ + if (port) + { ++ pthread_rwlock_wrlock (&_ports_htable_lock); ++ err = hurd_ihash_add (&_ports_htable, port, topi); ++ assert_perror (err); + err = hurd_ihash_add (&topi->bucket->htable, port, topi); ++ pthread_rwlock_unlock (&_ports_htable_lock); + assert_perror (err); + if (topi->bucket != frompi->bucket) + { +@@ -86,9 +98,7 @@ ports_transfer_right (void *tostruct, + assert_perror (err); + } + } +- +- pthread_mutex_unlock (&_ports_lock); +- ++ + /* Take care of any lowered reference counts. */ + if (dereffrompi) + ports_port_deref (frompi); +-- +2.1.0 + diff --git a/debian/patches/0002-libports-lock-less-reference-counting-for-port_info-.patch b/debian/patches/0002-libports-lock-less-reference-counting-for-port_info-.patch new file mode 100644 index 00000000..151815b3 --- /dev/null +++ b/debian/patches/0002-libports-lock-less-reference-counting-for-port_info-.patch @@ -0,0 +1,340 @@ +From f496af4ca56392434655668035f912350f37261b 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 2/2] 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 | 14 ++++++++++++++ + libports/create-internal.c | 3 +-- + libports/get-right.c | 2 +- + libports/import-port.c | 3 +-- + libports/lookup-port.c | 4 +--- + libports/port-deref-weak.c | 10 +++------- + libports/port-deref.c | 34 ++++++++++++++++------------------ + libports/port-ref-weak.c | 6 +----- + libports/port-ref.c | 6 +----- + libports/ports.h | 4 ++-- + libports/reallocate-from-external.c | 2 +- + libports/transfer-right.c | 2 +- + utils/rpctrace.c | 10 ++++++++-- + 14 files changed, 52 insertions(+), 52 deletions(-) + +diff --git a/libports/bucket-iterate.c b/libports/bucket-iterate.c +index 79b6d72..b021b99 100644 +--- a/libports/bucket-iterate.c ++++ b/libports/bucket-iterate.c +@@ -35,7 +35,6 @@ _ports_bucket_class_iterate (struct hurd_ihash *ht, + size_t i, n, nr_items; + error_t err; + +- pthread_mutex_lock (&_ports_lock); + pthread_rwlock_rdlock (&_ports_htable_lock); + + if (ht->nr_items == 0) +@@ -59,13 +58,12 @@ _ports_bucket_class_iterate (struct hurd_ihash *ht, + + if (class == 0 || pi->class == class) + { +- pi->refcnt++; ++ refcounts_ref (&pi->refcounts, NULL); + p[n] = pi; + n++; + } + } + pthread_rwlock_unlock (&_ports_htable_lock); +- pthread_mutex_unlock (&_ports_lock); + + if (n != 0 && n != nr_items) + { +diff --git a/libports/complete-deallocate.c b/libports/complete-deallocate.c +index 4768dab..0d852f5 100644 +--- a/libports/complete-deallocate.c ++++ b/libports/complete-deallocate.c +@@ -29,15 +29,29 @@ _ports_complete_deallocate (struct port_info *pi) + + if (pi->port_right) + { ++ struct references result; ++ + pthread_rwlock_wrlock (&_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->ports_htable_entry); + hurd_ihash_locp_remove (&pi->bucket->htable, pi->hentry); + pthread_rwlock_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 8543986..2d85931 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 2660672..c337c85 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 858ee11..2f0eee9 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_rwlock_rdlock (&_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++; ++ refcounts_unsafe_ref (&pi->refcounts, NULL); + + pthread_rwlock_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..b97dd13 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 (pi->class->dropweak_routine) + { +- pthread_mutex_unlock (&_ports_lock); +- (*pi->class->dropweak_routine) (pi); +- trieddroppingweakrefs = 1; +- goto retry; ++ /* 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 by demoting our hard reference to a ++ weak one. */ ++ refcounts_demote (&pi->refcounts, &result); ++ ++ if (result.hard == 0 && result.weak > 1) ++ (*pi->class->dropweak_routine) (pi); ++ ++ refcounts_deref_weak (&pi->refcounts, &result); + } +- +- assert (pi->refcnt); ++ else ++ refcounts_deref (&pi->refcounts, &result); + +- 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..3f62dfe 100644 +--- a/libports/port-ref-weak.c ++++ b/libports/port-ref-weak.c +@@ -25,9 +25,5 @@ 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); ++ refcounts_ref_weak (&pi->refcounts, NULL); + } +diff --git a/libports/port-ref.c b/libports/port-ref.c +index 92b7118..9a1c71e 100644 +--- a/libports/port-ref.c ++++ b/libports/port-ref.c +@@ -25,9 +25,5 @@ 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); ++ refcounts_ref (&pi->refcounts, NULL); + } +diff --git a/libports/ports.h b/libports/ports.h +index 6922162..40d3b43 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 9944b39..7205bd9 100644 +--- a/libports/reallocate-from-external.c ++++ b/libports/reallocate-from-external.c +@@ -56,7 +56,7 @@ 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 3f48290..776a8d2 100644 +--- a/libports/transfer-right.c ++++ b/libports/transfer-right.c +@@ -72,7 +72,7 @@ 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 +-- +2.1.0 + diff --git a/debian/patches/series b/debian/patches/series index 58c6c811..53978055 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -55,3 +55,6 @@ mount-bind.patch xkb-compat.patch mach-defpager-protected-payload.patch + +0001-libports-use-a-global-hash-table-for-the-lookups.patch +0002-libports-lock-less-reference-counting-for-port_info-.patch |