solve partial builing and running issues for ARM machines

runtime/include/arch/aarch64/context.h

@@ -4,7 +4,6 @@
 #include <assert.h>
 
 #include "arch/common.h"
-#include "current_sandbox.h"
 
 #define ARCH_SIG_JMP_OFF 0x100 /* Based on code generated! */
 
@@ -46,25 +45,22 @@ arch_context_switch(struct arch_context *a, struct arch_context *b)
 	/*
 	 * Assumption: In the case of a slow context switch, the caller
 	 * set current_sandbox to the sandbox containing the target context
+	 * Temporally comment because it will cause compilation error
 	 */
-	if (b->variant == ARCH_CONTEXT_VARIANT_SLOW) {
+	/*if (b->variant == ARCH_CONTEXT_VARIANT_SLOW) {
 		struct sandbox *current = current_sandbox_get();
 		assert(current != NULL && b == &current->ctxt);
-	}
+	}*/
 #endif
 
 	/* if both a and b are NULL, there is no state change */
-	assert(a != NULL || b != NULL);
+	assert(a != NULL && b != NULL);
 
 	/* Assumption: The caller does not switch to itself */
 	assert(a != b);
 
-	/* Set any NULLs to worker_thread_base_context to resume execution of main */
-	if (a == NULL) a = &worker_thread_base_context;
-	if (b == NULL) b = &worker_thread_base_context;
-
 	/* A Transition {Unused, Running} -> Fast */
-	assert(a->variant == ARCH_CONTEXT_VARIANT_UNUSED || a->variant == ARCH_CONTEXT_VARIANT_RUNNING);
+	assert(a->variant == ARCH_CONTEXT_VARIANT_RUNNING);
 
 	/* B Transition {Fast, Slow} -> Running */
 	assert(b->variant == ARCH_CONTEXT_VARIANT_FAST || b->variant == ARCH_CONTEXT_VARIANT_SLOW);
@@ -87,6 +83,8 @@ arch_context_switch(struct arch_context *a, struct arch_context *b)
 	                 "ldr x1, [%[bv]]\n\t"
 	                 "sub x1, x1, #2\n\t"
 	                 "cbz x1, slow%=\n\t"
+                         "mov x3, #3\n\t" 
+                         "str x3, [%[bv]]\n\t" /* b->variant = ARCH_CONTEXT_VARIANT_RUNNING; */
 	                 "ldr x0, [%[b]]\n\t"
 	                 "ldr x1, [%[b], 8]\n\t"
 	                 "mov sp, x0\n\t"
@@ -95,8 +93,6 @@ arch_context_switch(struct arch_context *a, struct arch_context *b)
 	                 "br %[slowpath]\n\t"
 	                 ".align 8\n\t"
 	                 "reset%=:\n\t"
-	                 "mov x1, #3\n\t"
-	                 "str x1, [%[bv]]\n\t"
 	                 ".align 8\n\t"
 	                 "exit%=:\n\t"
 	                 :
@@ -109,6 +105,35 @@ arch_context_switch(struct arch_context *a, struct arch_context *b)
 	return 0;
 }
 
+
+/**
+ * Load a new sandbox that preempted an existing sandbox, restoring only the
+ * instruction pointer and stack pointer registers.
+ * @param active_context - the context of the current worker thread
+ * @param sandbox_context - the context that we want to restore
+ */
+static inline void
+arch_context_restore_fast(mcontext_t *active_context, struct arch_context *sandbox_context)
+{
+        assert(active_context != NULL);
+        assert(sandbox_context != NULL);
+
+        /* Assumption: Base Context is only ever used by arch_context_switch */
+        assert(sandbox_context != &worker_thread_base_context);
+
+        assert(sandbox_context->regs[UREG_SP]);
+        assert(sandbox_context->regs[UREG_IP]);
+
+        /* Transitioning from Fast -> Running */
+        assert(sandbox_context->variant == ARCH_CONTEXT_VARIANT_FAST);
+        sandbox_context->variant = ARCH_CONTEXT_VARIANT_RUNNING;
+
+        //active_context->gregs[REG_RSP] = sandbox_context->regs[UREG_SP];
+        //active_context->gregs[REG_RIP] = sandbox_context->regs[UREG_IP];
+        active_context->sp = sandbox_context->regs[UREG_SP];
+        active_context->pc = sandbox_context->regs[UREG_IP];
+}
+
 #else
 #warning "Neither AARCH64 nor aarch64 was defined, but aarch64/context.h was included!"
 #endif

runtime/include/sandbox_set_as_initialized.h

@@ -34,7 +34,7 @@ sandbox_set_as_initialized(struct sandbox *sandbox, sandbox_state_t last_state)
 	}
 
 	/* State Change Bookkeeping */
-	assert(now > sandbox->timestamp_of.last_state_change);
+	assert(now >= sandbox->timestamp_of.last_state_change);
 	sandbox->duration_of_state[last_state] += (now - sandbox->timestamp_of.last_state_change);
 	sandbox->timestamp_of.last_state_change = now;
 	sandbox_state_history_append(&sandbox->state_history, SANDBOX_INITIALIZED);

runtime/src/main.c

@@ -102,6 +102,7 @@ runtime_get_processor_speed_MHz(void)
 {
 	uint32_t return_value;
 
+	/* TODO: Find another way to get the cpu speed for ARM machines, this only works for Intel machines */
 	FILE *cmd = popen("grep '^cpu MHz' /proc/cpuinfo | head -n 1 | awk '{print $4}'", "r");
 	if (unlikely(cmd == NULL)) goto err;