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feat: better passive waiting

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This commit is contained in:
Alessandre Laguierce 2025-03-21 08:43:57 +01:00
parent d3b39be57c
commit 7568525a4c
1 changed files with 32 additions and 22 deletions
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54
src/thread/thread.c
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@ -12,16 +12,16 @@
#define FINISHED 0x1
#define ALLOCATED 0x2
#define WAITING 0x4
#ifndef STACK_SIZE
#define STACK_SIZE 4096*4
#define STACK_SIZE 4096
#endif
struct context_entry {
TAILQ_ENTRY(context_entry) link;
ucontext_t context;
thread_t id;
thread_t parent;
void *retvalue;
int valgrind_id;
char status;
@ -32,10 +32,11 @@ static struct context_entry *running = 0;
static unsigned long long counter = 0;
int thread_yield(void) {
TRACE("thread_yield");
if (counter <= 1) {
return 0;
}
struct context_entry *first;
struct context_entry *first = NULL;
int count = 0;
do {
if (count++ == counter) {
@ -50,7 +51,9 @@ int thread_yield(void) {
if (first->id == running->id) {
return 0;
}
} while (first->status & FINISHED);
} while ((first->status & FINISHED) ||
((first->status & WAITING) && !(((struct context_entry *)first->retvalue)->status & FINISHED)));
TRACE("PICKING %p", first);
struct context_entry *old_runner = running;
running = first;
swapcontext(&old_runner->context, &running->context);
@ -64,21 +67,25 @@ thread_t thread_self(void) {
return running->id;
}
void thread_function_wrapper(void *(*func)(void *), void *funcarg) {
TRACE("Wrapper for %p\n", func);
thread_exit(func(funcarg));
}
int thread_create(thread_t *newthread, void *(*func)(void *), void *funcarg) {
TRACE("Create a new thread that execute function %p", func);
if (counter == 0) {
struct context_entry *main = malloc(sizeof(*main));
memset(main, 0, sizeof(*main));
getcontext(&main->context);
main->id = 0;
main->parent = 0;
main->status = 0;
main->retvalue = 0;
TAILQ_INSERT_HEAD(&head, main, link);
running = main;
counter++;
}
struct context_entry *new_entry = malloc(sizeof(*new_entry));
if (counter == 0) {
memset(new_entry, 0, sizeof(*new_entry));
getcontext(&new_entry->context);
new_entry->id = 0;
new_entry->status = 0;
new_entry->retvalue = 0;
TAILQ_INSERT_HEAD(&head, new_entry, link);
running = new_entry;
counter++;
new_entry = malloc(sizeof(*new_entry));
}
memset(new_entry, 0, sizeof(*new_entry));
getcontext(&new_entry->context);
new_entry->context.uc_stack.ss_sp = malloc(STACK_SIZE);
@ -88,18 +95,17 @@ int thread_create(thread_t *newthread, void *(*func)(void *), void *funcarg) {
new_entry->context.uc_stack.ss_sp + new_entry->context.uc_stack.ss_size
);
new_entry->id = new_entry;
new_entry->parent = running->id;
new_entry->status = ALLOCATED;
new_entry->retvalue = 0;
*newthread = new_entry;
makecontext(&new_entry->context, (void (*)()) func, 1, funcarg);
makecontext(&new_entry->context, (void (*)(void)) thread_function_wrapper, 2, func, funcarg);
counter++;
TAILQ_INSERT_HEAD(&head, new_entry, link);
return 0;
}
void print_entry(struct context_entry *entry) {
TRACE("CONTEXT (%p, %p, %d, %p);\n", entry, entry->id, (entry->status & FINISHED) > 0, entry->parent);
TRACE("CONTEXT (%p, %p, %d);", entry, entry->id, (entry->status & FINISHED) > 0);
}
int thread_join(thread_t thread, void **retval) {
@ -109,12 +115,14 @@ int thread_join(thread_t thread, void **retval) {
if (entry->id != thread) {
continue;
}
TRACE("FIND");
print_entry(entry);
while (!entry->status & FINISHED) {
TRACE("FIND %d",entry->status);
running->status |= WAITING;
running->retvalue = entry;
while (!(entry->status & FINISHED)) {
TRACE("NOT FINISHED");
thread_yield();
}
running->status &= ~WAITING;
TRACE("AFTER");
if (retval)
*retval = entry->retvalue;
@ -144,6 +152,8 @@ int thread_join(thread_t thread, void **retval) {
void thread_exit(void *retval) {
TRACE("Exit thread %p", running);
if (running == 0)
exit(0);
running->status |= FINISHED;
running->retvalue = retval;
thread_yield();