Multiple process suspension queues

kernel/proc/mutex.c

@@ -2,6 +2,7 @@
 #include <libk/rbtree.h>
 #include <libk/std.h>
 #include <libk/string.h>
+#include <mm/liballoc.h>
 #include <proc/mutex.h>
 #include <proc/proc.h>
 #include <sync/spin_lock.h>
@@ -9,23 +10,20 @@
 #include <sys/smp.h>
 #include <sys/spin_lock.h>
 
-bool proc_create_resource_mutex (struct proc_mutex* mutex) {
-  memset (mutex, 0, sizeof (*mutex));
-
-  return true;
-}
-
-void proc_cleanup_resource_mutex (struct proc* proc, struct proc_resource* resource) {
-  struct proc_mutex* mutex = &resource->u.mutex;
-
-  /* proc_mutex_unlock (proc, mutex); */
-}
-
 static void proc_mutex_suspend (struct proc* proc, struct proc_suspension_q* sq,
                                 spin_lock_t* resource_lock, spin_lock_ctx_t* ctxrl) {
   spin_lock_ctx_t ctxpr, ctxcpu, ctxsq;
   struct cpu* cpu = proc->cpu;
 
+  struct proc_sq_entry* sq_entry = malloc (sizeof (*sq_entry));
+  if (!sq_entry) {
+    spin_unlock (resource_lock, ctxrl);
+    return;
+  }
+
+  sq_entry->proc = proc;
+  sq_entry->sq = sq;
+
   spin_lock (&cpu->lock, &ctxcpu);
   spin_lock (&proc->lock, &ctxpr);
   spin_lock (&sq->lock, &ctxsq);
@@ -33,7 +31,10 @@ static void proc_mutex_suspend (struct proc* proc, struct proc_suspension_q* sq,
   spin_unlock (resource_lock, ctxrl);
 
   atomic_store (&proc->state, PROC_SUSPENDED);
-  proc->suspension_q = sq;
+
+  list_append (sq->proc_list, &sq_entry->sq_link);
+
+  list_append (proc->sq_entries, &sq_entry->proc_link);
 
   list_remove (cpu->proc_run_q, &proc->cpu_run_q_link);
   atomic_fetch_sub (&cpu->proc_run_q_count, 1);
@@ -41,7 +42,6 @@ static void proc_mutex_suspend (struct proc* proc, struct proc_suspension_q* sq,
   if (cpu->proc_current == proc)
     cpu->proc_current = NULL;
 
-  list_append (sq->proc_list, &proc->suspension_link);
   proc->cpu = NULL;
 
   spin_unlock (&sq->lock, &ctxsq);
@@ -51,34 +51,45 @@ static void proc_mutex_suspend (struct proc* proc, struct proc_suspension_q* sq,
   cpu_request_sched (cpu);
 }
 
-static void proc_mutex_resume (struct proc* proc) {
+static void proc_mutex_resume (struct proc* proc, struct proc_sq_entry* sq_entry) {
   spin_lock_ctx_t ctxsq, ctxpr, ctxcpu;
   struct cpu* cpu = cpu_find_lightest ();
+  struct proc_suspension_q* sq = sq_entry->sq;
 
   spin_lock (&cpu->lock, &ctxcpu);
   spin_lock (&proc->lock, &ctxpr);
-
-  proc->cpu = cpu;
-  struct proc_suspension_q* sq = proc->suspension_q;
-
   spin_lock (&sq->lock, &ctxsq);
 
-  list_remove (sq->proc_list, &proc->suspension_link);
+  list_remove (sq->proc_list, &sq_entry->sq_link);
+  list_remove (proc->sq_entries, &sq_entry->proc_link);
 
-  proc->suspension_q = NULL;
+  proc->cpu = cpu;
+
+  if (proc->sq_entries == NULL)
     atomic_store (&proc->state, PROC_READY);
 
   list_append (cpu->proc_run_q, &proc->cpu_run_q_link);
   atomic_fetch_add (&cpu->proc_run_q_count, 1);
 
   spin_unlock (&sq->lock, &ctxsq);
-
   spin_unlock (&proc->lock, &ctxpr);
   spin_unlock (&cpu->lock, &ctxcpu);
 
+  free (sq_entry);
+
   cpu_request_sched (cpu);
 }
 
+bool proc_create_resource_mutex (struct proc_mutex* mutex) {
+  memset (mutex, 0, sizeof (*mutex));
+
+  return true;
+}
+
+void proc_cleanup_resource_mutex (struct proc* proc, struct proc_resource* resource) {
+  struct proc_mutex* mutex = &resource->u.mutex;
+}
+
 void proc_mutex_lock (struct proc* proc, struct proc_mutex* mutex) {
   spin_lock_ctx_t ctxmt;
 
@@ -108,18 +119,19 @@ bool proc_mutex_unlock (struct proc* proc, struct proc_mutex* mutex) {
 
   spin_lock (&mutex->suspension_q.lock, &ctxsq);
 
-  struct proc* resumed_proc = NULL;
   struct list_node_link* node = mutex->suspension_q.proc_list;
 
   if (node) {
-    resumed_proc = list_entry (node, struct proc, suspension_link);
+    struct proc_sq_entry* sq_entry = list_entry (node, struct proc_sq_entry, sq_link);
+    struct proc* resumed_proc = sq_entry->proc;
+
     mutex->owner = resumed_proc;
     mutex->locked = true;
 
     spin_unlock (&mutex->suspension_q.lock, &ctxsq);
     spin_unlock (&mutex->resource->lock, &ctxmt);
 
-    proc_mutex_resume (resumed_proc);
+    proc_mutex_resume (resumed_proc, sq_entry);
 
     return true;
   }

kernel/proc/proc.h

@@ -42,12 +42,19 @@ struct proc_resources {
   rw_spin_lock_t lock;
 };
 
+struct proc_sq_entry {
+  struct list_node_link sq_link;
+  struct list_node_link proc_link;
+  struct proc* proc;
+  struct proc_suspension_q* sq;
+};
+
 struct proc {
   int pid;
   struct rb_node_link proc_tree_link;
   struct list_node_link cpu_run_q_link;
-  struct list_node_link suspension_link;
   struct list_node_link reap_link;
+  struct list_node_link* sq_entries;
 
   struct list_node_link* mappings; /* pd.lock implicitly protects this field */
   struct proc_platformdata pdata;
@@ -56,7 +63,6 @@ struct proc {
   spin_lock_t lock;
   struct cpu* cpu;
   atomic_int state;
-  struct proc_suspension_q* suspension_q;
   struct proc_resources* resources;
 };