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

1 files changed, 115 insertions, 0 deletions

diff --git a/fesvr/context.cc b/fesvr/context.cc
new file mode 100644
index 0000000..ca73813
--- /dev/null
+++ b/fesvr/context.cc
@@ -0,0 +1,115 @@
+#include "context.h"
+#include <assert.h>
+#include <sched.h>
+#include <stdlib.h>
+
+static __thread context_t* cur;
+
+context_t::context_t()
+  : creator(NULL), func(NULL), arg(NULL),
+#ifndef USE_UCONTEXT
+    mutex(PTHREAD_MUTEX_INITIALIZER),
+    cond(PTHREAD_COND_INITIALIZER), flag(0)
+#else
+    context(new ucontext_t)
+#endif
+{
+}
+
+#ifdef USE_UCONTEXT
+#ifndef GLIBC_64BIT_PTR_BUG
+void context_t::wrapper(context_t* ctx)
+{
+#else
+void context_t::wrapper(unsigned int hi, unsigned int lo)
+{
+  context_t* ctx = reinterpret_cast<context_t*>(static_cast<unsigned long>(lo) | (static_cast<unsigned long>(hi) << 32));
+#endif
+  ctx->creator->switch_to();
+  ctx->func(ctx->arg);
+}
+#else
+void* context_t::wrapper(void* a)
+{
+  context_t* ctx = static_cast<context_t*>(a);
+  cur = ctx;
+  ctx->creator->switch_to();
+
+  ctx->func(ctx->arg);
+  return NULL;
+}
+#endif
+
+void context_t::init(void (*f)(void*), void* a)
+{
+  func = f;
+  arg = a;
+  creator = current();
+
+#ifdef USE_UCONTEXT
+  getcontext(context.get());
+  context->uc_link = creator->context.get();
+  context->uc_stack.ss_size = 64*1024;
+  context->uc_stack.ss_sp = new void*[context->uc_stack.ss_size/sizeof(void*)];
+#ifndef GLIBC_64BIT_PTR_BUG
+  makecontext(context.get(), (void(*)(void))&context_t::wrapper, 1, this);
+#else
+  unsigned int hi(reinterpret_cast<unsigned long>(this) >> 32);
+  unsigned int lo(reinterpret_cast<unsigned long>(this));
+  makecontext(context.get(), (void(*)(void))&context_t::wrapper, 2, hi, lo);
+#endif
+  switch_to();
+#else
+  assert(flag == 0);
+
+  pthread_mutex_lock(&creator->mutex);
+  creator->flag = 0;
+  if (pthread_create(&thread, NULL, &context_t::wrapper, this) != 0)
+    abort();
+  pthread_detach(thread);
+  while (!creator->flag)
+    pthread_cond_wait(&creator->cond, &creator->mutex);
+  pthread_mutex_unlock(&creator->mutex);
+#endif
+}
+
+context_t::~context_t()
+{
+  assert(this != cur);
+}
+
+void context_t::switch_to()
+{
+  assert(this != cur);
+#ifdef USE_UCONTEXT
+  context_t* prev = cur;
+  cur = this;
+  if (swapcontext(prev->context.get(), context.get()) != 0)
+    abort();
+#else
+  cur->flag = 0;
+  this->flag = 1;
+  pthread_mutex_lock(&this->mutex);
+  pthread_cond_signal(&this->cond);
+  pthread_mutex_unlock(&this->mutex);
+  pthread_mutex_lock(&cur->mutex);
+  while (!cur->flag)
+    pthread_cond_wait(&cur->cond, &cur->mutex);
+  pthread_mutex_unlock(&cur->mutex);
+#endif
+}
+
+context_t* context_t::current()
+{
+  if (cur == NULL)
+  {
+    cur = new context_t;
+#ifdef USE_UCONTEXT
+    getcontext(cur->context.get());
+#else
+    cur->thread = pthread_self();
+    cur->flag = 1;
+#endif
+  }
+  return cur;
+}