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Clean up a bit. Use the correct TAILQ link when walking the thread

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lists to free thread resources after a fork (in the child).  Also
remember to free the dead thread list.
This commit is contained in:
deischen 2001-04-10 04:25:49 +00:00
parent ec98854211
commit f0c50f0089
3 changed files with 207 additions and 108 deletions
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105
lib/libc_r/uthread/uthread_fork.c
View File

@ -39,13 +39,15 @@
#include <pthread.h>
#include "pthread_private.h"
static void free_thread_resources(struct pthread *thread);
__weak_reference(_fork, fork);
pid_t
_fork(void)
{
struct pthread *curthread = _get_curthread();
int i, flags;
int i, flags, use_deadlist = 0;
pid_t ret;
pthread_t pthread;
pthread_t pthread_save;
@ -115,7 +117,10 @@ _fork(void)
* Enter a loop to remove all threads other than
* the running thread from the thread list:
*/
pthread = TAILQ_FIRST(&_thread_list);
if ((pthread = TAILQ_FIRST(&_thread_list)) == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
while (pthread != NULL) {
/* Save the thread to be freed: */
pthread_save = pthread;
@ -124,45 +129,37 @@ _fork(void)
* Advance to the next thread before
* destroying the current thread:
*/
pthread = TAILQ_NEXT(pthread, dle);
if (use_deadlist != 0)
pthread = TAILQ_NEXT(pthread, dle);
else
pthread = TAILQ_NEXT(pthread, tle);
/* Make sure this isn't the running thread: */
if (pthread_save != curthread) {
/* Remove this thread from the list: */
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
/*
* Remove this thread from the
* appropriate list:
*/
if (use_deadlist != 0)
TAILQ_REMOVE(&_thread_list,
pthread_save, dle);
else
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
if (pthread_save->attr.stackaddr_attr ==
NULL && pthread_save->stack != NULL) {
if (pthread_save->attr.stacksize_attr
== PTHREAD_STACK_DEFAULT) {
/*
* Default-size stack.
* Cache it:
*/
struct stack *spare_stack;
free_thread_resources(pthread_save);
}
spare_stack
= (pthread_save->stack
+ PTHREAD_STACK_DEFAULT
- sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq,
spare_stack, qe);
} else
/*
* Free the stack of
* the dead thread:
*/
free(pthread_save->stack);
}
if (pthread_save->specific_data != NULL)
free(pthread_save->specific_data);
if (pthread_save->poll_data.fds != NULL)
free(pthread_save->poll_data.fds);
free(pthread_save);
/*
* Switch to the deadlist when the active
* thread list has been consumed. This can't
* be at the top of the loop because it is
* used to determine to which list the thread
* belongs (when it is removed from the list).
*/
if (pthread == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
}
@ -219,3 +216,39 @@ _fork(void)
/* Return the process ID: */
return (ret);
}
static void
free_thread_resources(struct pthread *thread)
{
struct stack *spare_stack;
/* Check to see if the threads library allocated the stack. */
if ((thread->attr.stackaddr_attr == NULL) && (thread->stack != NULL)) {
if (thread->attr.stacksize_attr != PTHREAD_STACK_DEFAULT) {
/*
* The threads library malloc()'d the stack;
* just free() it.
*/
free(thread->stack);
} else {
/*
* This stack was allocated from the main threads
* stack; cache it for future use. Since this is
* being called from fork, we are currently single
* threaded so there is no need to protect the
* queue insertion.
*/
spare_stack = (thread->stack + PTHREAD_STACK_DEFAULT -
sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq, spare_stack, qe);
}
}
if (thread->specific_data != NULL)
free(thread->specific_data);
if (thread->poll_data.fds != NULL)
free(thread->poll_data.fds);
free(thread);
}

105
lib/libkse/thread/thr_fork.c
View File

@ -39,13 +39,15 @@
#include <pthread.h>
#include "pthread_private.h"
static void free_thread_resources(struct pthread *thread);
__weak_reference(_fork, fork);
pid_t
_fork(void)
{
struct pthread *curthread = _get_curthread();
int i, flags;
int i, flags, use_deadlist = 0;
pid_t ret;
pthread_t pthread;
pthread_t pthread_save;
@ -115,7 +117,10 @@ _fork(void)
* Enter a loop to remove all threads other than
* the running thread from the thread list:
*/
pthread = TAILQ_FIRST(&_thread_list);
if ((pthread = TAILQ_FIRST(&_thread_list)) == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
while (pthread != NULL) {
/* Save the thread to be freed: */
pthread_save = pthread;
@ -124,45 +129,37 @@ _fork(void)
* Advance to the next thread before
* destroying the current thread:
*/
pthread = TAILQ_NEXT(pthread, dle);
if (use_deadlist != 0)
pthread = TAILQ_NEXT(pthread, dle);
else
pthread = TAILQ_NEXT(pthread, tle);
/* Make sure this isn't the running thread: */
if (pthread_save != curthread) {
/* Remove this thread from the list: */
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
/*
* Remove this thread from the
* appropriate list:
*/
if (use_deadlist != 0)
TAILQ_REMOVE(&_thread_list,
pthread_save, dle);
else
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
if (pthread_save->attr.stackaddr_attr ==
NULL && pthread_save->stack != NULL) {
if (pthread_save->attr.stacksize_attr
== PTHREAD_STACK_DEFAULT) {
/*
* Default-size stack.
* Cache it:
*/
struct stack *spare_stack;
free_thread_resources(pthread_save);
}
spare_stack
= (pthread_save->stack
+ PTHREAD_STACK_DEFAULT
- sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq,
spare_stack, qe);
} else
/*
* Free the stack of
* the dead thread:
*/
free(pthread_save->stack);
}
if (pthread_save->specific_data != NULL)
free(pthread_save->specific_data);
if (pthread_save->poll_data.fds != NULL)
free(pthread_save->poll_data.fds);
free(pthread_save);
/*
* Switch to the deadlist when the active
* thread list has been consumed. This can't
* be at the top of the loop because it is
* used to determine to which list the thread
* belongs (when it is removed from the list).
*/
if (pthread == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
}
@ -219,3 +216,39 @@ _fork(void)
/* Return the process ID: */
return (ret);
}
static void
free_thread_resources(struct pthread *thread)
{
struct stack *spare_stack;
/* Check to see if the threads library allocated the stack. */
if ((thread->attr.stackaddr_attr == NULL) && (thread->stack != NULL)) {
if (thread->attr.stacksize_attr != PTHREAD_STACK_DEFAULT) {
/*
* The threads library malloc()'d the stack;
* just free() it.
*/
free(thread->stack);
} else {
/*
* This stack was allocated from the main threads
* stack; cache it for future use. Since this is
* being called from fork, we are currently single
* threaded so there is no need to protect the
* queue insertion.
*/
spare_stack = (thread->stack + PTHREAD_STACK_DEFAULT -
sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq, spare_stack, qe);
}
}
if (thread->specific_data != NULL)
free(thread->specific_data);
if (thread->poll_data.fds != NULL)
free(thread->poll_data.fds);
free(thread);
}

105
lib/libpthread/thread/thr_fork.c
View File

@ -39,13 +39,15 @@
#include <pthread.h>
#include "pthread_private.h"
static void free_thread_resources(struct pthread *thread);
__weak_reference(_fork, fork);
pid_t
_fork(void)
{
struct pthread *curthread = _get_curthread();
int i, flags;
int i, flags, use_deadlist = 0;
pid_t ret;
pthread_t pthread;
pthread_t pthread_save;
@ -115,7 +117,10 @@ _fork(void)
* Enter a loop to remove all threads other than
* the running thread from the thread list:
*/
pthread = TAILQ_FIRST(&_thread_list);
if ((pthread = TAILQ_FIRST(&_thread_list)) == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
while (pthread != NULL) {
/* Save the thread to be freed: */
pthread_save = pthread;
@ -124,45 +129,37 @@ _fork(void)
* Advance to the next thread before
* destroying the current thread:
*/
pthread = TAILQ_NEXT(pthread, dle);
if (use_deadlist != 0)
pthread = TAILQ_NEXT(pthread, dle);
else
pthread = TAILQ_NEXT(pthread, tle);
/* Make sure this isn't the running thread: */
if (pthread_save != curthread) {
/* Remove this thread from the list: */
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
/*
* Remove this thread from the
* appropriate list:
*/
if (use_deadlist != 0)
TAILQ_REMOVE(&_thread_list,
pthread_save, dle);
else
TAILQ_REMOVE(&_thread_list,
pthread_save, tle);
if (pthread_save->attr.stackaddr_attr ==
NULL && pthread_save->stack != NULL) {
if (pthread_save->attr.stacksize_attr
== PTHREAD_STACK_DEFAULT) {
/*
* Default-size stack.
* Cache it:
*/
struct stack *spare_stack;
free_thread_resources(pthread_save);
}
spare_stack
= (pthread_save->stack
+ PTHREAD_STACK_DEFAULT
- sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq,
spare_stack, qe);
} else
/*
* Free the stack of
* the dead thread:
*/
free(pthread_save->stack);
}
if (pthread_save->specific_data != NULL)
free(pthread_save->specific_data);
if (pthread_save->poll_data.fds != NULL)
free(pthread_save->poll_data.fds);
free(pthread_save);
/*
* Switch to the deadlist when the active
* thread list has been consumed. This can't
* be at the top of the loop because it is
* used to determine to which list the thread
* belongs (when it is removed from the list).
*/
if (pthread == NULL) {
pthread = TAILQ_FIRST(&_dead_list);
use_deadlist = 1;
}
}
@ -219,3 +216,39 @@ _fork(void)
/* Return the process ID: */
return (ret);
}
static void
free_thread_resources(struct pthread *thread)
{
struct stack *spare_stack;
/* Check to see if the threads library allocated the stack. */
if ((thread->attr.stackaddr_attr == NULL) && (thread->stack != NULL)) {
if (thread->attr.stacksize_attr != PTHREAD_STACK_DEFAULT) {
/*
* The threads library malloc()'d the stack;
* just free() it.
*/
free(thread->stack);
} else {
/*
* This stack was allocated from the main threads
* stack; cache it for future use. Since this is
* being called from fork, we are currently single
* threaded so there is no need to protect the
* queue insertion.
*/
spare_stack = (thread->stack + PTHREAD_STACK_DEFAULT -
sizeof(struct stack));
SLIST_INSERT_HEAD(&_stackq, spare_stack, qe);
}
}
if (thread->specific_data != NULL)
free(thread->specific_data);
if (thread->poll_data.fds != NULL)
free(thread->poll_data.fds);
free(thread);
}