1 files changed, 94 insertions, 0 deletions
diff --git a/circuitpython/shared-module/memorymonitor/AllocationAlarm.c b/circuitpython/shared-module/memorymonitor/AllocationAlarm.c
new file mode 100644
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+++ b/circuitpython/shared-module/memorymonitor/AllocationAlarm.c
@@ -0,0 +1,94 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/memorymonitor/__init__.h"
+#include "shared-bindings/memorymonitor/AllocationAlarm.h"
+
+#include "py/gc.h"
+#include "py/mpstate.h"
+#include "py/runtime.h"
+
+void common_hal_memorymonitor_allocationalarm_construct(memorymonitor_allocationalarm_obj_t *self, size_t minimum_block_count) {
+    self->minimum_block_count = minimum_block_count;
+    self->next = NULL;
+    self->previous = NULL;
+}
+
+void common_hal_memorymonitor_allocationalarm_set_ignore(memorymonitor_allocationalarm_obj_t *self, mp_int_t count) {
+    self->count = count;
+}
+
+void common_hal_memorymonitor_allocationalarm_pause(memorymonitor_allocationalarm_obj_t *self) {
+    // Check to make sure we aren't already paused. We can be if we're exiting from an exception we
+    // caused.
+    if (self->previous == NULL) {
+        return;
+    }
+    *self->previous = self->next;
+    self->next = NULL;
+    self->previous = NULL;
+}
+
+void common_hal_memorymonitor_allocationalarm_resume(memorymonitor_allocationalarm_obj_t *self) {
+    if (self->previous != NULL) {
+        mp_raise_RuntimeError(translate("Already running"));
+    }
+    self->next = MP_STATE_VM(active_allocationalarms);
+    self->previous = (memorymonitor_allocationalarm_obj_t **)&MP_STATE_VM(active_allocationalarms);
+    if (self->next != NULL) {
+        self->next->previous = &self->next;
+    }
+    MP_STATE_VM(active_allocationalarms) = self;
+}
+
+void memorymonitor_allocationalarms_allocation(size_t block_count) {
+    memorymonitor_allocationalarm_obj_t *alarm = MP_OBJ_TO_PTR(MP_STATE_VM(active_allocationalarms));
+    size_t alert_count = 0;
+    while (alarm != NULL) {
+        // Hold onto next in case we remove the alarm from the list.
+        memorymonitor_allocationalarm_obj_t *next = alarm->next;
+        if (block_count >= alarm->minimum_block_count) {
+            if (alarm->count > 0) {
+                alarm->count--;
+            } else {
+                // Uncomment the breakpoint below if you want to use a C debugger to figure out the C
+                // call stack for an allocation.
+                // asm("bkpt");
+                // Pause now because we may alert when throwing the exception too.
+                common_hal_memorymonitor_allocationalarm_pause(alarm);
+                alert_count++;
+            }
+        }
+        alarm = next;
+    }
+    if (alert_count > 0) {
+        mp_raise_memorymonitor_AllocationError(translate("Attempt to allocate %d blocks"), block_count);
+    }
+}
+
+void memorymonitor_allocationalarms_reset(void) {
+    MP_STATE_VM(active_allocationalarms) = NULL;
+}