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Change stack allocation algorithm to make better use of memory

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(it was leaving an unused block).  Also protect the global stack
pointer from context changes while fiddling with it.
This commit is contained in:
deischen 1999-12-28 18:12:07 +00:00
parent 2a6c7913a0
commit 9321f383a2
6 changed files with 60 additions and 66 deletions

30
lib/libc_r/uthread/uthread_create.c

@ -118,12 +118,9 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
+ (void *) spare_stack
- PTHREAD_STACK_DEFAULT;
} else {
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Allocate a new stack. */
stack = _next_stack + PTHREAD_STACK_GUARD;
/*
* Even if stack allocation fails, we don't want
* to try to use this location again, so
@ -133,23 +130,26 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* overflow of the adjacent thread stack.
*/
_next_stack -= (PTHREAD_STACK_DEFAULT
+ PTHREAD_STACK_GUARD);
+ PTHREAD_STACK_GUARD);
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Red zone: */
if (mmap(_next_stack, PTHREAD_STACK_GUARD, 0,
MAP_ANON, -1, 0) == MAP_FAILED) {
if (mmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
free(new_thread);
}
/* Stack: */
else if (mmap(stack,
PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE,
MAP_STACK,
-1, 0) == MAP_FAILED) {
else if (mmap(stack, PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE, MAP_STACK,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
munmap(_next_stack,
PTHREAD_STACK_GUARD);
munmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD);
free(new_thread);
}
}
@ -159,7 +159,7 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* really know what they want, and simply malloc the stack.
*/
else if ((stack = (void *) malloc(pattr->stacksize_attr))
== NULL) {
== NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
free(new_thread);

12
lib/libc_r/uthread/uthread_init.c

@ -187,13 +187,11 @@ _thread_init(void)
SLIST_INIT(&_stackq);
/* Create the red zone for the main stack. */
if (mmap((void *) USRSTACK
- PTHREAD_STACK_INITIAL,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
if (mmap((void *) USRSTACK - PTHREAD_STACK_INITIAL -
PTHREAD_STACK_GUARD, PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED)
PANIC("Cannot allocate red zone for initial thread");
}
/*
* Write a magic value to the thread structure
* to help identify valid ones:
@ -248,7 +246,7 @@ _thread_init(void)
/* Get the signal handler details: */
else if (_thread_sys_sigaction(i, NULL,
&_thread_sigact[i - 1]) != 0) {
&_thread_sigact[i - 1]) != 0) {
/*
* Abort this process if signal
* initialisation fails:

30
lib/libkse/thread/thr_create.c

@ -118,12 +118,9 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
+ (void *) spare_stack
- PTHREAD_STACK_DEFAULT;
} else {
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Allocate a new stack. */
stack = _next_stack + PTHREAD_STACK_GUARD;
/*
* Even if stack allocation fails, we don't want
* to try to use this location again, so
@ -133,23 +130,26 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* overflow of the adjacent thread stack.
*/
_next_stack -= (PTHREAD_STACK_DEFAULT
+ PTHREAD_STACK_GUARD);
+ PTHREAD_STACK_GUARD);
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Red zone: */
if (mmap(_next_stack, PTHREAD_STACK_GUARD, 0,
MAP_ANON, -1, 0) == MAP_FAILED) {
if (mmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
free(new_thread);
}
/* Stack: */
else if (mmap(stack,
PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE,
MAP_STACK,
-1, 0) == MAP_FAILED) {
else if (mmap(stack, PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE, MAP_STACK,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
munmap(_next_stack,
PTHREAD_STACK_GUARD);
munmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD);
free(new_thread);
}
}
@ -159,7 +159,7 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* really know what they want, and simply malloc the stack.
*/
else if ((stack = (void *) malloc(pattr->stacksize_attr))
== NULL) {
== NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
free(new_thread);

12
lib/libkse/thread/thr_init.c

@ -187,13 +187,11 @@ _thread_init(void)
SLIST_INIT(&_stackq);
/* Create the red zone for the main stack. */
if (mmap((void *) USRSTACK
- PTHREAD_STACK_INITIAL,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
if (mmap((void *) USRSTACK - PTHREAD_STACK_INITIAL -
PTHREAD_STACK_GUARD, PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED)
PANIC("Cannot allocate red zone for initial thread");
}
/*
* Write a magic value to the thread structure
* to help identify valid ones:
@ -248,7 +246,7 @@ _thread_init(void)
/* Get the signal handler details: */
else if (_thread_sys_sigaction(i, NULL,
&_thread_sigact[i - 1]) != 0) {
&_thread_sigact[i - 1]) != 0) {
/*
* Abort this process if signal
* initialisation fails:

30
lib/libpthread/thread/thr_create.c

@ -118,12 +118,9 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
+ (void *) spare_stack
- PTHREAD_STACK_DEFAULT;
} else {
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Allocate a new stack. */
stack = _next_stack + PTHREAD_STACK_GUARD;
/*
* Even if stack allocation fails, we don't want
* to try to use this location again, so
@ -133,23 +130,26 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* overflow of the adjacent thread stack.
*/
_next_stack -= (PTHREAD_STACK_DEFAULT
+ PTHREAD_STACK_GUARD);
+ PTHREAD_STACK_GUARD);
/* Unlock the garbage collector mutex. */
if (pthread_mutex_unlock(&_gc_mutex) != 0)
PANIC("Cannot unlock gc mutex");
/* Red zone: */
if (mmap(_next_stack, PTHREAD_STACK_GUARD, 0,
MAP_ANON, -1, 0) == MAP_FAILED) {
if (mmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
free(new_thread);
}
/* Stack: */
else if (mmap(stack,
PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE,
MAP_STACK,
-1, 0) == MAP_FAILED) {
else if (mmap(stack, PTHREAD_STACK_DEFAULT,
PROT_READ | PROT_WRITE, MAP_STACK,
-1, 0) == MAP_FAILED) {
ret = EAGAIN;
munmap(_next_stack,
PTHREAD_STACK_GUARD);
munmap(stack - PTHREAD_STACK_GUARD,
PTHREAD_STACK_GUARD);
free(new_thread);
}
}
@ -159,7 +159,7 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
* really know what they want, and simply malloc the stack.
*/
else if ((stack = (void *) malloc(pattr->stacksize_attr))
== NULL) {
== NULL) {
/* Insufficient memory to create a thread: */
ret = EAGAIN;
free(new_thread);

12
lib/libpthread/thread/thr_init.c

@ -187,13 +187,11 @@ _thread_init(void)
SLIST_INIT(&_stackq);
/* Create the red zone for the main stack. */
if (mmap((void *) USRSTACK
- PTHREAD_STACK_INITIAL,
PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED) {
if (mmap((void *) USRSTACK - PTHREAD_STACK_INITIAL -
PTHREAD_STACK_GUARD, PTHREAD_STACK_GUARD, 0, MAP_ANON,
-1, 0) == MAP_FAILED)
PANIC("Cannot allocate red zone for initial thread");
}
/*
* Write a magic value to the thread structure
* to help identify valid ones:
@ -248,7 +246,7 @@ _thread_init(void)
/* Get the signal handler details: */
else if (_thread_sys_sigaction(i, NULL,
&_thread_sigact[i - 1]) != 0) {
&_thread_sigact[i - 1]) != 0) {
/*
* Abort this process if signal
* initialisation fails: