From 5008515b0379d9d23db6d1d37fa4d2433c1731ba Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Wed, 3 May 2023 14:33:52 -0300
Subject: [PATCH] builtin: heap memory usage api (#18103)

---
 vlib/builtin/builtin.c.v              | 30 +++++++++++++++++++++++++++
 vlib/builtin/builtin_d_gcboehm.c.v    |  3 +++
 vlib/builtin/builtin_notd_gcboehm.c.v |  4 ++++
 3 files changed, 37 insertions(+)

diff --git a/vlib/builtin/builtin.c.v b/vlib/builtin/builtin.c.v
index 3aca604374..a36719b97d 100644
--- a/vlib/builtin/builtin.c.v
+++ b/vlib/builtin/builtin.c.v
@@ -643,6 +643,36 @@ pub fn memdup_uncollectable(src voidptr, sz int) voidptr {
 	}
 }
 
+pub struct GCHeapUsage {
+pub:
+	heap_size      usize
+	free_bytes     usize
+	total_bytes    usize
+	unmapped_bytes usize
+	bytes_since_gc usize
+}
+
+// gc_heap_usage returns the info about heap usage
+pub fn gc_heap_usage() GCHeapUsage {
+	$if gcboehm ? {
+		mut res := GCHeapUsage{}
+		C.GC_get_heap_usage_safe(&res.heap_size, &res.free_bytes, &res.unmapped_bytes,
+			&res.bytes_since_gc, &res.total_bytes)
+		return res
+	} $else {
+		return GCHeapUsage{}
+	}
+}
+
+// gc_memory_use returns the total memory use in bytes by all allocated blocks
+pub fn gc_memory_use() usize {
+	$if gcboehm ? {
+		return C.GC_get_memory_use()
+	} $else {
+		return 0
+	}
+}
+
 [inline]
 fn v_fixed_index(i int, len int) int {
 	$if !no_bounds_checking {
diff --git a/vlib/builtin/builtin_d_gcboehm.c.v b/vlib/builtin/builtin_d_gcboehm.c.v
index 0a13b642ee..564c0ad0d7 100644
--- a/vlib/builtin/builtin_d_gcboehm.c.v
+++ b/vlib/builtin/builtin_d_gcboehm.c.v
@@ -132,3 +132,6 @@ pub fn gc_check_leaks() {
 		C.GC_gcollect()
 	}
 }
+
+fn C.GC_get_heap_usage_safe(pheap_size &usize, pfree_bytes &usize, punmapped_bytes &usize, pbytes_since_gc &usize, ptotal_bytes &usize)
+fn C.GC_get_memory_use() usize
diff --git a/vlib/builtin/builtin_notd_gcboehm.c.v b/vlib/builtin/builtin_notd_gcboehm.c.v
index 71ee1aaa79..56002ff54a 100644
--- a/vlib/builtin/builtin_notd_gcboehm.c.v
+++ b/vlib/builtin/builtin_notd_gcboehm.c.v
@@ -14,6 +14,10 @@ fn C.GC_REALLOC(ptr voidptr, n usize) voidptr
 
 fn C.GC_FREE(ptr voidptr)
 
+fn C.GC_get_heap_usage_safe(pheap_size &usize, pfree_bytes &usize, punmapped_bytes &usize, pbytes_since_gc &usize, ptotal_bytes &usize)
+
+fn C.GC_get_memory_use() usize
+
 // provide an empty function when manual memory management is used
 // to simplify leak detection
 //