Adjust IsReadable() for Termux environment without pthread_cancel()

INSTALL

@@ -157,10 +157,12 @@ sudo apk add alpine-sdk lmdb-dev openssl-dev bison flex-dev acl-dev pcre2-dev au
 
 Note that in order for process promises to work you must install the procps package for a "proper" ps command instead of busybox.
 
-* Termux (2020-04-24)
+* Termux (2025-10-10)
 
-pkg install build-essential git autoconf automake bison flex liblmdb openssl pcre2 libacl libyaml
-./autogen.sh --without-pam
+pkg install build-essential git autoconf automake bison flex liblmdb openssl pcre2 libacl libyaml binutils librsync
+# maybe binutils-is-llvm - Use llvm as binutils instead of binutils to get ld
+LDFLAGS='-landroid-glob' ./autogen.sh --without-pam --prefix=$PREFIX --with-workdir=$PREFIX/var/lib/cfengine --without-systemd-service --without-selinux-policy
+make && make install
 
 * OSX (2021-10-20)
 

ci/build.sh

@@ -5,7 +5,10 @@ set -ex
 thisdir="$(dirname "$0")"
 cd "$thisdir"/..
 
-source /etc/os-release
+if [ -f /etc/os-release ]; then
+  source /etc/os-release
+fi
+
 CFLAGS="-Wall"
 if [ "$ID" != "alpine" ]; then
   CFLAGS="$CFLAGS -Werror"

ci/configure.sh

@@ -4,15 +4,24 @@
 set -ex
 thisdir="$(dirname "$0")"
 cd "$thisdir"/..
-OPTS="--enable-debug"
+OPTS="--config-cache --enable-debug"
 
-source /etc/os-release
-if [ "$ID" = "alpine" ]; then
-    OPTS="" # we don't want --enable-debug so that libpromises/dbm_test_api is not built due to lack of srand48_r() and friends on alpine linux libmusl
+if [ -f /etc/os-release ]; then
+  source /etc/os-release
+  if [ "$ID" = "alpine" ]; then
+      OPTS="" # we don't want --enable-debug so that libpromises/dbm_test_api is not built due to lack of srand48_r() and friends on alpine linux libmusl
+  fi
 fi
 
 if [ -n "$TERMUX_VERSION" ] || [ "$ID" = "alpine" ]; then
     OPTS="$OPTS --without-pam"
 fi
+if [ -n "$TERMUX_VERSION" ]; then
+    export LDFLAGS+=" -landroid-glob"
+    OPTS="$OPTS --prefix=$PREFIX\
+      --with-workdir=$PREFIX/var/lib/cfengine \
+      --without-selinux-policy \
+      --without-systemd-service"
+fi
 
 ./autogen.sh $OPTS

configure.ac

@@ -182,6 +182,14 @@ CC="$PTHREAD_CC"
 CFLAGS="$PTHREAD_CFLAGS $CFLAGS"
 LIBS="$PTHREAD_LIBS $LIBS"
 
+dnl ######################################################################
+dnl libpromises/evalfunction.c isreadable() uses pthread_cancel so check
+dnl if available and reverts to pthread_kill if not.
+dnl This check must come after ACX_PTHREAD is called so that CC, CFLAGS,
+dnl and LIBS are appropriately set for the local pthreads situation.
+dnl ######################################################################
+AC_CHECK_FUNCS([pthread_cancel])
+
 dnl ######################################################################
 dnl Whether to build extensions as builtin extensions or a separate
 dnl plugin. The default is plugin.
@@ -1347,7 +1355,7 @@ AC_CHECK_DECLS([FALLOC_FL_PUNCH_HOLE], [], [], [
 ])
 AC_CHECK_HEADERS([sys/sendfile.h])
 AC_CHECK_FUNCS([sendfile])
-AC_CHECK_FUNCS([copy_file_range])
+AC_CHECK_DECL([copy_file_range])
 
 
 dnl #######################################################################

libpromises/dbm_test_api.c

@@ -22,8 +22,9 @@
   included file COSL.txt.
 */
 
+#ifndef __ANDROID__
 #include <platform.h>
-#include <stdlib.h>             /* lrand48_r() */
+#include <stdlib.h>             /* lrand48() */
 #include <unistd.h>             /* usleep(), syscall()/gettid() */
 #include <alloc.h>              /* xstrndup() */
 #include <dbm_api.h>
@@ -70,23 +71,22 @@ static void DBItemDestroy(DBItem *item)
     }
 }
 
-static __thread struct drand48_data rng_data;
 
 static void InitializeRNG(long int seed)
 {
-    srand48_r(seed, &rng_data);
+    srand48(seed);
 }
 
 static long GetRandomNumber(long limit)
 {
     long rnd_val;
-    lrand48_r(&rng_data, &rnd_val); /* generates a value in the [0, 2^31) interval */
+    rnd_val = lrand48();
     const long random_max = ((0x80000000 - 1) / limit) * limit;
     while (rnd_val > random_max)
     {
         /* got a bad value past the greatest multiple of the limit interval,
          * retry (see "modulo bias" if this is unclear) */
-        lrand48_r(&rng_data, &rnd_val);
+        rnd_val = lrand48();
     }
     return rnd_val % limit;
 }
@@ -735,3 +735,4 @@ void RemoveFilament(DBFilament *filament)
     free(filament);
     CloseDB(db);
 }
+#endif /* not __ANDROID__ */

libpromises/dbm_test_api.h

@@ -22,6 +22,7 @@
   included file COSL.txt.
 */
 
+#ifndef __ANDROID__
 #ifndef CFENGINE_DBM_TEST_API_H
 #define CFENGINE_DBM_TEST_API_H
 
@@ -55,3 +56,4 @@ DBFilament *FillUpDB(dbid db_id, int usage_pct);
 void RemoveFilament(DBFilament *filament);
 
 #endif  /* CFENGINE_DBM_TEST_API_H */
+#endif /* not __ANDROID__ */

libpromises/evalfunction.c

@@ -86,6 +86,7 @@
 #include <version_comparison.h>
 #include <mutex.h>          /* ThreadWait */
 #include <glob_lib.h>
+#include <signal_lib.h> /* MaskTerminationSignalsInThread */
 
 #include <math_eval.h>
 
@@ -9774,10 +9775,32 @@ struct IsReadableThreadData
     bool success;
 };
 
+#ifndef HAVE_PTHREAD_CANCEL
+#define PTHREAD_CANCELED ((void *)-1)
+static void ThreadSignalHandler(int signum)
+{
+    pthread_exit(PTHREAD_CANCELED);
+}
+#endif
+
 static void *IsReadableThreadRoutine(void *data)
 {
     assert(data != NULL);
 
+/*
+ * Termux environment has no pthread_cancel() so use MaskTerminationSignalsInThread() and pthread_kill()
+ */
+#ifndef HAVE_PTHREAD_CANCEL
+    MaskTerminationSignalsInThread();
+    struct sigaction actions;
+    memset(&actions, 0, sizeof(actions));
+    sigemptyset(&actions.sa_mask);
+    actions.sa_flags = 0;
+    actions.sa_handler = ThreadSignalHandler;
+    sigaction(SIGHUP, &actions, NULL);
+    MaskTerminationSignalsInThread();
+#endif
+
     struct IsReadableThreadData *const thread_data = data;
 
     // Give main thread time to call pthread_cond_timedwait(3)
@@ -9929,7 +9952,11 @@ static FnCallResult FnCallIsReadable(ARG_UNUSED EvalContext *const ctx,
                 "Read operation timed out, exceeded %ld seconds.", path,
                 timeout);
 
+#ifdef HAVE_PTHREAD_CANCEL
             ret = pthread_cancel(thread_data.thread);
+#else
+            ret = pthread_kill(thread_data.thread, SIGUSR2);
+#endif
             if (ret != 0)
             {
                 Log(LOG_LEVEL_ERR, "Failed to cancel thread");
@@ -9959,10 +9986,12 @@ static FnCallResult FnCallIsReadable(ARG_UNUSED EvalContext *const ctx,
         return FnFailure();
     }
 
+#ifdef HAVE_PTHREAD_CANCEL
     if (status == PTHREAD_CANCELED)
     {
         Log(LOG_LEVEL_DEBUG, "Thread was canceled");
     }
+#endif
 
     return FnReturnContext(success);
 }