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- Fixed warnings

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- Fixed deadlock in xsi_sem_undo - RecordUndo
- Fixed issue in xsi_sem_undo: if the semaphore set does not exist
anymore, ignore the request but do remove the process from the sUndoList,
which wasn't previously done.
- free() in ClearUndos was called with interrupts disabled
- when a semaphore set ends to exist, remove all it's sem_undo request as it's ID
will be reused in the future.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26727 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Salvatore Benedetto
2008-08-02 11:30:55 +00:00
parent 64ea0b9f74
commit 51daeb7147
4 changed files with 53 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files
headers/private/kernel/posix/xsi_semaphore.h
+1 -9
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@@ -11,15 +11,7 @@
#include <OS.h>
#include <kernel.h>
// TODO: move into a system/posix/xsi_semaphore_defs.h file to be shared with
// xsi_sem.cpp in libroot!
union semun {
int val;
struct semid_ds *buf;
unsigned short *array;
};
#include <posix/xsi_semaphore_defs.h>
__BEGIN_DECLS
headers/private/system/posix/xsi_semaphore_defs.h
+18
View File
@@ -0,0 +1,18 @@
/*
* Copyright 2008, Salvatore Benedetto, [email protected].
* Distributed under the terms of the MIT License.
*/
#ifndef SYSTEM_XSI_SEM_H
#define SYSTEM_XSI_SEM_H
/*
* Shared union used by the semctl option argument.
* The user should declare it explicitly
*/
union semun {
int val;
struct semid_ds *buf;
unsigned short *array;
};
#endif
src/system/kernel/posix/xsi_semaphore.cpp
+33 -22
View File
@@ -133,7 +133,7 @@ public:
int RecordUndo(int semaphoreSetID, short semaphoreNumber, short value);
// Implemented after sUndoListLock is declared
int RemoveUndo(int semaphoreSetID, short semaphoreNumber, short value);
void RemoveUndo(int semaphoreSetID, short semaphoreNumber, short value);
void Revert(short value)
{
@@ -256,6 +256,10 @@ public:
~XsiSemaphoreSet()
{
// Clear all sem_undo left, as our ID will be reused
// by another set.
for (uint32 i = 0; i < fNumberOfSemaphores; i++)
fSemaphores[i].ClearUndos(fID, i);
UnsetID();
delete []fSemaphores;
}
@@ -493,16 +497,20 @@ XsiSemaphore::ClearUndos(int semaphoreSetID, short semaphoreNumber)
// the global undo list, plus decrementing the related
// team xsi_sem_undo_requests field.
// This happens only on semctl SETVAL and SETALL.
TRACE(("XsiSemaphore::ClearUndos: semaphoreSetID = %d, "
"semaphoreNumber = %d\n", semaphoreSetID, semaphoreNumber));
MutexLocker _(sUndoListLock);
DoublyLinkedList<sem_undo>::Iterator iterator = sUndoList.GetIterator();
while (iterator.HasNext()) {
struct sem_undo *current = iterator.Next();
if (current->semaphore_set_id == semaphoreSetID
&& current->semaphore_number == semaphoreNumber) {
InterruptsSpinLocker _(team_spinlock);
InterruptsSpinLocker lock(team_spinlock);
if (current->team)
current->team->xsi_sem_undo_requests--;
iterator.Remove();
// Restore interrupts before calling free
lock.Unlock();
free(current);
}
}
@@ -526,7 +534,8 @@ XsiSemaphore::RecordUndo(int semaphoreSetID, short semaphoreNumber, short value)
// Update its undo value
TRACE(("XsiSemaphore::RecordUndo: found record. Team = %d, "
"semaphoreSetID = %d, semaphoreNumber = %d, value = %d\n",
team->id, semaphoreSetID, semaphoreNumber, current->undo_value));
(int)team->id, semaphoreSetID, semaphoreNumber,
current->undo_value));
int newValue = current->undo_value + value;
if (newValue > USHRT_MAX || newValue < -USHRT_MAX) {
TRACE_ERROR(("XsiSemaphore::RecordUndo: newValue %d out of range\n",
@@ -559,13 +568,14 @@ XsiSemaphore::RecordUndo(int semaphoreSetID, short semaphoreNumber, short value)
sUndoList.Add(request);
TRACE(("XsiSemaphore::RecordUndo: new record added. Team = %d, "
"semaphoreSetID = %d, semaphoreNumber = %d, value = %d\n",
team->id, semaphoreSetID, semaphoreNumber, request->undo_value));
(int)team->id, semaphoreSetID, semaphoreNumber,
request->undo_value));
}
return B_OK;
}
int
void
XsiSemaphore::RemoveUndo(int semaphoreSetID, short semaphoreNumber, short value)
{
// This can be called only when RecordUndo fails.
@@ -643,6 +653,9 @@ xsi_sem_undo(team_id teamID, int32 numberOfUndos)
if (numberOfUndos <= 0)
return;
// We must hold the set mutex before the sem_undo
// one in order to avoid deadlock with RecordUndo
MutexLocker lock(sXsiSemaphoreSetLock);
MutexLocker _(sUndoListLock);
DoublyLinkedList<sem_undo>::Iterator iterator = sUndoList.GetIterator();
// Look for all sem_undo request from this team
@@ -651,21 +664,21 @@ xsi_sem_undo(team_id teamID, int32 numberOfUndos)
if (current->team->id == teamID) {
// Check whether the semaphore set still exist
int semaphoreSetID = current->semaphore_set_id;
MutexLocker _(sXsiSemaphoreSetLock);
XsiSemaphoreSet *semaphoreSet
= sSemaphoreHashTable.Lookup(semaphoreSetID);
if (semaphoreSet == NULL) {
if (semaphoreSet != NULL) {
// Revert the changes done by this process
XsiSemaphore *semaphore
= semaphoreSet->Semaphore(current->semaphore_number);
TRACE(("xsi_do_undo: TeamID = %d, SemaphoreSetID = %d, "
"SemaphoreNumber = %d, undo value = %d\n", (int)teamID,
semaphoreSetID, current->semaphore_number,
current->undo_value));
semaphore->Revert(current->undo_value);
} else
TRACE(("xsi_do_undo: semaphore set %d does not exist "
"anymore. Ignore record.\n", semaphoreSetID));
continue;
}
// Revert the changes done by this process
XsiSemaphore *semaphore
= semaphoreSet->Semaphore(current->semaphore_number);
TRACE(("xsi_do_undo: TeamID = %d, SemaphoreSetID = %d, "
"SemaphoreNumber = %d, undo value = %d\n", teamID,
semaphoreSetID, current->semaphore_number, current->undo_value));
semaphore->Revert(current->undo_value);
// Remove and free the sem_undo structure from sUndoList
iterator.Remove();
free(current);
@@ -976,7 +989,7 @@ _user_xsi_semctl(int semaphoreID, int semaphoreNumber, int command,
status_t
_user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
{
TRACE(("xsi_semop: semaphoreID = %d, ops = %p, numOps = %d\n",
TRACE(("xsi_semop: semaphoreID = %d, ops = %p, numOps = %ld\n",
semaphoreID, ops, numOps));
MutexLocker lock(sXsiSemaphoreSetLock);
XsiSemaphoreSet *semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
@@ -1021,14 +1034,13 @@ _user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
while (notDone) {
XsiSemaphore *semaphore = NULL;
short numberOfSemaphores = semaphoreSet->NumberOfSemaphores();
// TODO: Perhaps lock the set itself?
bool goToSleep = false;
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
if (semaphoreNumber >= numberOfSemaphores) {
TRACE_ERROR(("xsi_semop: %d invalid semaphore number\n", i));
TRACE_ERROR(("xsi_semop: %ld invalid semaphore number\n", i));
result = EINVAL;
break;
}
@@ -1100,12 +1112,10 @@ _user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
// We acquired the semaphore, now records the sem_undo
// requests
XsiSemaphore *semaphore = NULL;
short numberOfSemaphores = semaphoreSet->NumberOfSemaphores();
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
unsigned short value = semaphore->Value();
short operation = operations[i].sem_op;
if (operations[i].sem_flg & SEM_UNDO)
if (semaphore->RecordUndo(semaphoreSet->ID(),
@@ -1129,7 +1139,8 @@ _user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
result = ENOSPC;
}
}
// TODO: Also set last PID for this semaphore set
// We did it. Set the pid.
semaphore->SetPid(getpid());
}
}
return result;
src/system/libroot/posix/sys/xsi_sem.cpp
+1 -13
View File
@@ -15,22 +15,10 @@
#include <OS.h>
//#include <posix/xsi_semaphore_defs.h>
#include <posix/xsi_semaphore_defs.h>
#include <syscall_utils.h>
#include <syscalls.h>
// TODO: this should be removed when the above commented header exists
#if 1
/*
* For the semctl option argument, the user
* should declare explicitly the following union
*/
union semun {
int val;
struct semid_ds *buf;
unsigned short *array;
};
#endif
int
semget(key_t key, int numSems, int semFlags)