[mynewt-core] branch master updated: baselibc: Add option to have thread-safe heap

[je...@apache.org]

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jerzy pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-core.git


The following commit(s) were added to refs/heads/master by this push:
     new 76c01ffae baselibc: Add option to have thread-safe heap
76c01ffae is described below

commit 76c01ffaec18d01cfebd59c60bd6e07c5134fc73
Author: Jerzy Kasenberg <je...@codecoup.pl>
AuthorDate: Tue Sep 27 20:39:37 2022 +0200

    baselibc: Add option to have thread-safe heap
    
    baselibc has option to lock the heap so malloc/free/calloc
    can be called from multi-threaded application.
    
    This adds implementation of this using os_mutex.
    When BASELIBC_THREAD_SAFE_HEAP_ALLOCATION is set to 1
    baselibc has package initialization functions that puts
    locking functionality in place.
    
    For now to preserve compatibility this functionality
    is not enabled by default leaving heap allocation
    not thread unsafe.
---
 libc/baselibc/pkg.yml      |  3 +++
 libc/baselibc/src/mynewt.c | 26 ++++++++++++++++++++++++++
 libc/baselibc/syscfg.yml   |  5 +++++
 3 files changed, 34 insertions(+)

diff --git a/libc/baselibc/pkg.yml b/libc/baselibc/pkg.yml
index 5c5a74230..1ec133b1e 100644
--- a/libc/baselibc/pkg.yml
+++ b/libc/baselibc/pkg.yml
@@ -27,3 +27,6 @@ pkg.deps:
     - "@apache-mynewt-core/kernel/os"
 pkg.req_apis:
     - console
+
+pkg.init.BASELIBC_THREAD_SAFE_HEAP_ALLOCATION:
+    baselibc_init: 0
diff --git a/libc/baselibc/src/mynewt.c b/libc/baselibc/src/mynewt.c
index 056c7cfe5..99b451335 100644
--- a/libc/baselibc/src/mynewt.c
+++ b/libc/baselibc/src/mynewt.c
@@ -19,6 +19,8 @@
 
 #include <stdio.h>
 #include <console/console.h>
+#include <os/os_time.h>
+#include <os/os_mutex.h>
 
 static size_t
 stdin_read(FILE *fp, char *bp, size_t n)
@@ -45,3 +47,27 @@ static struct File _stdin = {
 struct File *const stdin = &_stdin;
 struct File *const stdout = &_stdin;
 struct File *const stderr = &_stdin;
+
+#if MYNEWT_VAL(BASELIBC_THREAD_SAFE_HEAP_ALLOCATION)
+
+static struct os_mutex heap_mutex;
+
+bool heap_lock(void)
+{
+    return os_mutex_pend(&heap_mutex, OS_TIMEOUT_NEVER) == 0;
+}
+
+void heap_unlock(void)
+{
+    os_mutex_release(&heap_mutex);
+}
+
+void
+baselibc_init(void)
+{
+    /* Setup mutex to be used for malloc/calloc/free */
+    os_mutex_init(&heap_mutex);
+    set_malloc_locking(heap_lock, heap_unlock);
+}
+
+#endif
diff --git a/libc/baselibc/syscfg.yml b/libc/baselibc/syscfg.yml
index c300f0ba7..9820d8ed3 100644
--- a/libc/baselibc/syscfg.yml
+++ b/libc/baselibc/syscfg.yml
@@ -36,3 +36,8 @@ syscfg.defs:
             It is still possible to use C++ code when this is set to 0 but
             global variable can be in wrong state.
         value: 1
+
+    BASELIBC_THREAD_SAFE_HEAP_ALLOCATION:
+        description: >
+            Set to 1 if project requires malloc/calloc/free to be thread safe.
+        value: 0