X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fkern%2Fproc.c;h=a18fc40498d52e85e198ee54e5e13a1e90e2c49e;hb=d1b1e979862ca866eaee324e0363d57bf5a0e13b;hp=713c457f9c701820cf8d32a26e11d9d719b926db;hpb=8203999c6575e646b16363b40eaca03c6ea4f447;p=bertos.git

diff --git a/bertos/kern/proc.c b/bertos/kern/proc.c
index 713c457f..a18fc404 100644
--- a/bertos/kern/proc.c
+++ b/bertos/kern/proc.c
@@ -139,11 +139,6 @@ void proc_init(void)
 	monitor_init();
 	monitor_add(current_process, "main");
 #endif
-
-#if CONFIG_KERN_PREEMPT
-	preempt_init();
-#endif
-
 	MOD_INIT(proc);
 }
 
@@ -425,11 +420,41 @@ void proc_exit(void)
 	ASSERT(0);
 }
 
-
 /**
- * Get the pointer to the user data of the current process
+ * Call the scheduler and eventually replace the current running process.
  */
-iptr_t proc_currentUserData(void)
+void proc_schedule(void)
 {
-	return current_process->user_data;
+	Process *old_process = current_process;
+
+	IRQ_ASSERT_DISABLED();
+
+	/* Poll on the ready queue for the first ready process */
+	LIST_ASSERT_VALID(&proc_ready_list);
+	while (!(current_process = (struct Process *)list_remHead(&proc_ready_list)))
+	{
+		/*
+		 * Make sure we physically reenable interrupts here, no matter what
+		 * the current task status is. This is important because if we
+		 * are idle-spinning, we must allow interrupts, otherwise no
+		 * process will ever wake up.
+		 *
+		 * During idle-spinning, an interrupt can occur and it may
+		 * modify \p proc_ready_list. To ensure that compiler reload this
+		 * variable every while cycle we call CPU_MEMORY_BARRIER.
+		 * The memory barrier ensure that all variables used in this context
+		 * are reloaded.
+		 * \todo If there was a way to write sig_wait() so that it does not
+		 * disable interrupts while waiting, there would not be any
+		 * reason to do this.
+		 */
+		IRQ_ENABLE;
+		CPU_IDLE;
+		MEMORY_BARRIER;
+		IRQ_DISABLE;
+	}
+	if (CONTEXT_SWITCH_FROM_ISR())
+		proc_switchTo(current_process, old_process);
+	/* This RET resumes the execution on the new process */
+	LOG_INFO("resuming %p:%s\n", current_process, proc_currentName());
 }