From 448e170ef8101f10e2f27d965d95ee5f51e04ecd Mon Sep 17 00:00:00 2001
From: Benjamin Gilbert <bgilbert@backtick.net>
Date: Fri, 13 Oct 2023 10:05:52 -0500
Subject: [PATCH] Deprecate dcm_init()

We can't remove it without breaking ABI, but we can avoid giving the
impression that applications need to call it.
---
 doc/source/usage.rst  |  5 -----
 include/dicom/dicom.h | 17 +++++++++++------
 tests/check_dicom.c   |  2 --
 tools/dcm-dump.c      |  2 --
 tools/dcm-getframe.c  |  2 --
 5 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/doc/source/usage.rst b/doc/source/usage.rst
index cae5801..fb68771 100644
--- a/doc/source/usage.rst
+++ b/doc/source/usage.rst
@@ -137,11 +137,6 @@ locked to prevent subsequent modification via :c:func:`dcm_sequence_lock()`.
 A Sequence is automatically locked when used as a value in a Data Element
 with Value Representation SQ (Sequence of Items).
 
-Call :c:func:`dcm_init()` from the main thread during program startup for
-libdicom initialisation to be threadsafe. If you do not call this, it will be
-triggered for you on first use, but in this case libdicom initialisation will
-not be threadsafe.
-
 Error handling
 ++++++++++++++
 
diff --git a/include/dicom/dicom.h b/include/dicom/dicom.h
index 1a14c0e..e4e04fe 100644
--- a/include/dicom/dicom.h
+++ b/include/dicom/dicom.h
@@ -116,15 +116,20 @@ typedef struct _DcmSequence DcmSequence;
 /**
  * Start up libdicom.
  *
- * Call this from the main thread during program startup for libdicom to be
- * threadsafe.
- *
- * If you don't do this, libdicom will attempt to call it for you in a safe
- * way, but cannot guarantee this on all platforms and with all compilers, and
- * therefore cannot guarantee thread safety.
+ * Call this from the main thread during program startup.
  *
  * This function can be called many times.
+ *
+ * .. deprecated:: 1.0.6
+ *    Calling this function is no longer necessary.
  */
+#ifndef BUILDING_LIBDICOM
+#if defined(_MSC_VER)
+__declspec(deprecated("dcm_init() no longer needs to be called"))
+#elif defined(__GNUC__)
+__attribute__((deprecated("dcm_init() no longer needs to be called")))
+#endif
+#endif
 DCM_EXTERN
 void dcm_init(void);
 
diff --git a/tests/check_dicom.c b/tests/check_dicom.c
index afe4081..56e9a85 100644
--- a/tests/check_dicom.c
+++ b/tests/check_dicom.c
@@ -849,8 +849,6 @@ static Suite *create_file_suite(void)
 
 int main(void)
 {
-    dcm_init();
-
     SRunner *runner = srunner_create(create_main_suite());
     srunner_add_suite(runner, create_data_suite());
     srunner_add_suite(runner, create_file_suite());
diff --git a/tools/dcm-dump.c b/tools/dcm-dump.c
index 2678deb..b8624ad 100644
--- a/tools/dcm-dump.c
+++ b/tools/dcm-dump.c
@@ -14,8 +14,6 @@ int main(int argc, char *argv[])
 {
     int i, c;
 
-    dcm_init();
-
     while ((c = dcm_getopt(argc, argv, "h?Vv")) != -1) {
         switch (c) {
             case 'h':
diff --git a/tools/dcm-getframe.c b/tools/dcm-getframe.c
index d43628b..ce5b0b9 100644
--- a/tools/dcm-getframe.c
+++ b/tools/dcm-getframe.c
@@ -20,8 +20,6 @@ int main(int argc, char *argv[])
 
     int c;
 
-    dcm_init();
-
     while ((c = dcm_getopt(argc, argv, "h?Vvo:")) != -1) {
         switch (c) {
             case 'h':