Add fesvr; only globally install fesvr headers/libsstatic-link

1 files changed, 54 insertions, 0 deletions

diff --git a/fesvr/context.h b/fesvr/context.h
new file mode 100644
index 0000000..18bf50e
--- /dev/null
+++ b/fesvr/context.h
@@ -0,0 +1,54 @@
+#ifndef _HTIF_CONTEXT_H
+#define _HTIF_CONTEXT_H
+
+// A replacement for ucontext.h, which is sadly deprecated.
+
+#include <pthread.h>
+
+#if defined(__GLIBC__)
+# undef USE_UCONTEXT
+# define USE_UCONTEXT
+# include <ucontext.h>
+# include <memory>
+#include <limits.h>
+
+#if (ULONG_MAX > UINT_MAX) // 64-bit systems only
+#if (100*GLIB_MAJOR_VERSION+GLIB_MINOR_VERSION < 208)
+#define GLIBC_64BIT_PTR_BUG
+static_assert (sizeof(unsigned int)  == 4, "uint size doesn't match expected 32bit");
+static_assert (sizeof(unsigned long) == 8, "ulong size doesn't match expected 64bit");
+static_assert (sizeof(void*)         == 8, "ptr size doesn't match expected 64bit");
+#endif
+#endif /* ULONG_MAX > UINT_MAX */
+
+#endif
+
+class context_t
+{
+ public:
+  context_t();
+  ~context_t();
+  void init(void (*func)(void*), void* arg);
+  void switch_to();
+  static context_t* current();
+ private:
+  context_t* creator;
+  void (*func)(void*);
+  void* arg;
+#ifdef USE_UCONTEXT
+  std::unique_ptr<ucontext_t> context;
+#ifndef GLIBC_64BIT_PTR_BUG
+  static void wrapper(context_t*);
+#else
+  static void wrapper(unsigned int, unsigned int);
+#endif
+#else
+  pthread_t thread;
+  pthread_mutex_t mutex;
+  pthread_cond_t cond;
+  volatile int flag;
+  static void* wrapper(void*);
+#endif
+};
+
+#endif