--- configure.ac.orig	2021-09-11 04:43:11 UTC
+++ configure.ac
@@ -101,6 +101,8 @@ AC_CHECK_FUNC(sin,,[AC_CHECK_LIB(m,sin)])
 AX_PTHREAD()
 AX_OPENMP()
 
+AM_CONDITIONAL([HAVE_PTHREAD], [test "x$ax_pthread_ok" = "xyes"])
+
 dnl We should default this to off in future releases.
 AC_MSG_CHECKING([whether to support gd image formats])
 AC_ARG_ENABLE([gd-formats],
--- src/Makefile.am.orig	2021-09-11 04:43:11 UTC
+++ src/Makefile.am
@@ -129,4 +129,9 @@ libgd_la_LDFLAGS = -version-info $(GDLIB_LT_CURRENT):$
 
 libgd_la_LIBADD = $(LTLIBICONV)
 
+if HAVE_PTHREAD
+libgd_la_SOURCES += \
+	gdinitfini.c
+endif
+
 LDADD = libgd.la $(LIBICONV)
--- src/gdft.c.orig	2021-09-11 04:43:11 UTC
+++ src/gdft.c
@@ -890,7 +890,17 @@ BGD_DECLARE(void) gdFreeFontCache ()
  */
 BGD_DECLARE(void) gdFontCacheShutdown ()
 {
+#if defined(HAVE_PTHREAD)
+	/* referring to bundled with php */
+	gdMutexLock(gdFontCacheMutex);
 	if (fontCache) {
+		gdCacheDelete(fontCache);
+		fontCache = NULL;
+		FT_Done_FreeType(library);
+	}
+	gdMutexUnlock(gdFontCacheMutex);
+#else
+	if (fontCache) {
 		gdMutexLock(gdFontCacheMutex);
 		gdCacheDelete (fontCache);
 		/* 2.0.16: Gustavo Scotti: make sure we don't free this twice */
@@ -899,6 +909,7 @@ BGD_DECLARE(void) gdFontCacheShutdown ()
 		gdMutexShutdown (gdFontCacheMutex);
 		FT_Done_FreeType (library);
 	}
+#endif
 }
 
 /**
@@ -948,11 +959,18 @@ BGD_DECLARE(int) gdFontCacheSetup (void)
 		/* Already set up */
 		return 0;
 	}
+#if defined(HAVE_PTHREAD)
+	/* referring to bundled with php */
+	if (FT_Init_FreeType (&library)) {
+		return -1;
+	}
+#else
 	gdMutexSetup (gdFontCacheMutex);
 	if (FT_Init_FreeType (&library)) {
 		gdMutexShutdown (gdFontCacheMutex);
 		return -1;
 	}
+#endif
 	fontCache = gdCacheCreate (FONTCACHESIZE, fontTest, fontFetch, fontRelease);
 	if (!fontCache) {
 		return -2;
@@ -1144,6 +1162,10 @@ BGD_DECLARE(char *) gdImageStringFTEx (gdImagePtr im, 
 	                          tweenColorRelease);
 
 	/***** initialize font library and font cache on first call ******/
+#if defined(HAVE_PTHREAD)
+	/* referring to bundled with php */
+	gdMutexLock(gdFontCacheMutex);
+#endif
 	if (!fontCache) {
 		if (gdFontCacheSetup () != 0) {
 			gdCacheDelete (tc_cache);
@@ -1151,7 +1173,11 @@ BGD_DECLARE(char *) gdImageStringFTEx (gdImagePtr im, 
 		}
 	}
 	/*****/
+#if defined(HAVE_PTHREAD)
+	/* referring to bundled with php */
+#else
 	gdMutexLock (gdFontCacheMutex);
+#endif
 	/* get the font (via font cache) */
 	fontkey.fontlist = fontlist;
 	if (strex)
--- src/gdhelpers.h.orig	2021-09-11 04:43:11 UTC
+++ src/gdhelpers.h
@@ -51,11 +51,22 @@ extern "C" {
 # define gdMutexUnlock(x) LeaveCriticalSection(&x)
 #elif defined(HAVE_PTHREAD)
 # include <pthread.h>
+# include "gd_errors.h"
 # define gdMutexDeclare(x) pthread_mutex_t x
 # define gdMutexSetup(x) pthread_mutex_init(&x, 0)
 # define gdMutexShutdown(x) pthread_mutex_destroy(&x)
-# define gdMutexLock(x) pthread_mutex_lock(&x)
-# define gdMutexUnlock(x) pthread_mutex_unlock(&x)
+# define gdMutexLock(x) do {\
+		int pten = 0;\
+		if ((pten = pthread_mutex_lock(&x)) != 0) {\
+			gd_error_ex(GD_DEBUG, "gdMutexLock(%s<%p>) %s\n", #x, x, strerror(pten));\
+		}\
+	} while (0)
+# define gdMutexUnlock(x) do {\
+		int pten = 0;\
+		if ((pten = pthread_mutex_unlock(&x)) != 0) {\
+			gd_error_ex(GD_DEBUG, "gdMutexUnlock(%s<%p>) %s\n", #x, x, strerror(pten));\
+		}\
+	} while (0)
 #else
 # define gdMutexDeclare(x)
 # define gdMutexSetup(x)
--- src/gdinitfini.c.orig	1970-01-01 00:00:00 UTC
+++ src/gdinitfini.c
@@ -0,0 +1,31 @@
+#include <string.h>
+#include "gd.h"
+#include "gd_errors.h"
+#include "gdhelpers.h"
+
+#if defined(CPP_SHARP)
+#elif defined(_WIN32)
+#elif defined(HAVE_PTHREAD)
+
+extern gdMutexDeclare(gdFontCacheMutex);
+
+void
+_init()
+{
+	int pten = 0;
+	if ((pten = gdMutexSetup(gdFontCacheMutex)) != 0) {
+		gd_error_ex(GD_ERROR, "%s gdMutexSetup %s\n", __func__, strerror(pten));
+	}
+}
+
+void
+_fini()
+{
+	int pten = 0;
+	if ((pten = gdMutexShutdown(gdFontCacheMutex)) != 0) {
+		gd_error_ex(GD_ERROR, "%s gdMutexShutdown %s\n", __func__, strerror(pten));
+	}
+}
+
+#else
+#endif