Add support for condition variables on all platforms

include/uv-private/uv-unix.h

@@ -106,6 +106,7 @@ typedef pthread_t uv_thread_t;
 typedef pthread_mutex_t uv_mutex_t;
 typedef pthread_rwlock_t uv_rwlock_t;
 typedef UV_PLATFORM_SEM_T uv_sem_t;
+typedef pthread_cond_t uv_cond_t;
 
 /* Platform-specific definitions for uv_spawn support. */
 typedef gid_t uv_gid_t;

include/uv-private/uv-win.h

@@ -171,6 +171,10 @@ typedef int (WSAAPI* LPFN_WSARECVFROM)
   typedef NTSTATUS *PNTSTATUS;
 #endif
 
+#ifndef RTL_CONDITION_VARIABLE_INIT
+  typedef PVOID CONDITION_VARIABLE, *PCONDITION_VARIABLE;
+#endif
+
 typedef struct _AFD_POLL_HANDLE_INFO {
   HANDLE Handle;
   ULONG Events;
@@ -208,6 +212,23 @@ typedef HANDLE uv_sem_t;
 
 typedef CRITICAL_SECTION uv_mutex_t;
 
+/* This condition variable implementation is based on the SetEvent solution
+ * (section 3.2) at http://www.cs.wustl.edu/~schmidt/win32-cv-1.html
+ * We could not use the SignalObjectAndWait solution (section 3.4) because
+ * it want the 2nd argument (type uv_mutex_t) of uv_cond_wait() and
+ * uv_cond_timedwait() to be HANDLEs, but we use CRITICAL_SECTIONs.
+ */
+
+typedef union {
+  CONDITION_VARIABLE cond_var;
+  struct {
+    unsigned int waiters_count;
+    CRITICAL_SECTION waiters_count_lock;
+    HANDLE signal_event;
+    HANDLE broadcast_event;
+  } fallback;
+} uv_cond_t;
+
 typedef union {
   /* srwlock_ has type SRWLOCK, but not all toolchains define this type in */
   /* windows.h. */

include/uv.h

@@ -1790,6 +1790,36 @@ UV_EXTERN void uv_sem_post(uv_sem_t* sem);
 UV_EXTERN void uv_sem_wait(uv_sem_t* sem);
 UV_EXTERN int uv_sem_trywait(uv_sem_t* sem);
 
+/*
+ * Same goes for the condition variable functions.
+ */
+UV_EXTERN int uv_cond_init(uv_cond_t* cond);
+UV_EXTERN void uv_cond_destroy(uv_cond_t* cond);
+UV_EXTERN void uv_cond_signal(uv_cond_t* cond);
+UV_EXTERN void uv_cond_broadcast(uv_cond_t* cond);
+/* Waits on a condition variable without a timeout.
+ *
+ * Note:
+ * 1. callers should be prepared to deal with spurious wakeups.
+ */
+UV_EXTERN void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex);
+/* Waits on a condition variable with a timeout in nano seconds.
+ * Returns 0 for success or -1 on timeout, * aborts when other errors happen.
+ *
+ * Note:
+ * 1. callers should be prepared to deal with spurious wakeups.
+ * 2. the granularity of timeout on Windows is never less than one millisecond.
+ * 3. uv_cond_timedwait takes a relative timeout, not an absolute time.
+ * 4. the precision of timeout on OSX is never less than one microsecond.
+ *    Here is the reason.
+ *    OSX doesn't support CLOCK_MONOTONIC nor pthread_condattr_setclock()
+ *    (see man pthread_cond_init on OSX).
+ *    An example in man pthread_cond_timedwait on OSX uses gettimeofday()
+ *    and its resolution is a microsecond.
+ */
+UV_EXTERN int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex,
+    uint64_t timeout);
+
 /* Runs a function once and only once. Concurrent calls to uv_once() with the
  * same guard will block all callers except one (it's unspecified which one).
  * The guard should be initialized statically with the UV_ONCE_INIT macro.

src/unix/thread.c

@@ -26,6 +26,12 @@
 #include <assert.h>
 #include <errno.h>
 
+#if defined(__APPLE__) && defined(__MACH__)
+#include <sys/time.h>
+#endif /* defined(__APPLE__) && defined(__MACH__) */
+
+#undef NANOSEC
+#define NANOSEC ((uint64_t) 1e9)
 
 int uv_thread_join(uv_thread_t *tid) {
   if (pthread_join(*tid, NULL))
@@ -258,3 +264,109 @@ int uv_sem_trywait(uv_sem_t* sem) {
 }
 
 #endif /* defined(__APPLE__) && defined(__MACH__) */
+
+
+#if defined(__APPLE__) && defined(__MACH__)
+
+int uv_cond_init(uv_cond_t* cond) {
+  if (pthread_cond_init(cond, NULL))
+    return -1;
+  else
+    return 0;
+}
+
+#else /* !(defined(__APPLE__) && defined(__MACH__)) */
+
+int uv_cond_init(uv_cond_t* cond) {
+  pthread_condattr_t attr;
+
+  if (pthread_condattr_init(&attr))
+    return -1;
+
+  if (pthread_condattr_setclock(&attr, CLOCK_MONOTONIC))
+    goto error2;
+
+  if (pthread_cond_init(cond, &attr))
+    goto error2;
+
+  if (pthread_condattr_destroy(&attr))
+    goto error;
+
+  return 0;
+
+error:
+  pthread_cond_destroy(cond);
+error2:
+  pthread_condattr_destroy(&attr);
+  return -1;
+}
+
+#endif /* defined(__APPLE__) && defined(__MACH__) */
+
+void uv_cond_destroy(uv_cond_t* cond) {
+  if (pthread_cond_destroy(cond))
+    abort();
+}
+
+void uv_cond_signal(uv_cond_t* cond) {
+  if (pthread_cond_signal(cond))
+    abort();
+}
+
+void uv_cond_broadcast(uv_cond_t* cond) {
+  if (pthread_cond_broadcast(cond))
+    abort();
+}
+
+void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
+  if (pthread_cond_wait(cond, mutex))
+    abort();
+}
+
+#if defined(__APPLE__) && defined(__MACH__)
+
+int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
+  int r;
+  struct timeval tv;
+  struct timespec ts;
+  uint64_t abstime;
+
+  gettimeofday(&tv, NULL);
+  abstime = tv.tv_sec * 1e9 + tv.tv_usec * 1e3 + timeout;
+  ts.tv_sec = abstime / NANOSEC;
+  ts.tv_nsec = abstime % NANOSEC;
+  r = pthread_cond_timedwait(cond, mutex, &ts);
+
+  if (r == 0)
+    return 0;
+
+  if (r == ETIMEDOUT)
+    return -1;
+
+  abort();
+  return -1; /* Satisfy the compiler. */
+}
+
+#else /* !(defined(__APPLE__) && defined(__MACH__)) */
+
+int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
+  int r;
+  struct timespec ts;
+  uint64_t abstime;
+
+  abstime = uv_hrtime() + timeout;
+  ts.tv_sec = abstime / NANOSEC;
+  ts.tv_nsec = abstime % NANOSEC;
+  r = pthread_cond_timedwait(cond, mutex, &ts);
+
+  if (r == 0)
+    return 0;
+
+  if (r == ETIMEDOUT)
+    return -1;
+
+  abort();
+  return -1; /* Satisfy the compiler. */
+}
+
+#endif /* defined(__APPLE__) && defined(__MACH__) */

src/win/thread.c

@@ -27,6 +27,7 @@
 
 
 #define HAVE_SRWLOCK_API() (pTryAcquireSRWLockShared != NULL)
+#define HAVE_CONDVAR_API() (pInitializeConditionVariable != NULL)
 
 #ifdef _MSC_VER /* msvc */
 # define inline __inline
@@ -56,6 +57,23 @@ inline static int uv__rwlock_fallback_trywrlock(uv_rwlock_t* rwlock);
 inline static void uv__rwlock_fallback_wrunlock(uv_rwlock_t* rwlock);
 
 
+inline static int uv_cond_fallback_init(uv_cond_t* cond);
+inline static void uv_cond_fallback_destroy(uv_cond_t* cond);
+inline static void uv_cond_fallback_signal(uv_cond_t* cond);
+inline static void uv_cond_fallback_broadcast(uv_cond_t* cond);
+inline static void uv_cond_fallback_wait(uv_cond_t* cond, uv_mutex_t* mutex);
+inline static int uv_cond_fallback_timedwait(uv_cond_t* cond,
+    uv_mutex_t* mutex, uint64_t timeout);
+
+inline static int uv_cond_condvar_init(uv_cond_t* cond);
+inline static void uv_cond_condvar_destroy(uv_cond_t* cond);
+inline static void uv_cond_condvar_signal(uv_cond_t* cond);
+inline static void uv_cond_condvar_broadcast(uv_cond_t* cond);
+inline static void uv_cond_condvar_wait(uv_cond_t* cond, uv_mutex_t* mutex);
+inline static int uv_cond_condvar_timedwait(uv_cond_t* cond,
+    uv_mutex_t* mutex, uint64_t timeout);
+
+
 static NOINLINE void uv__once_inner(uv_once_t* guard,
     void (*callback)(void)) {
   DWORD result;
@@ -81,7 +99,7 @@ static NOINLINE void uv__once_inner(uv_once_t* guard,
 
   } else {
     /* We lost the race. Destroy the event we created and wait for the */
-    /* existing one to become signaled. */
+    /* existing one todv become signaled. */
     CloseHandle(created_event);
     result = WaitForSingleObject(existing_event, INFINITE);
     assert(result == WAIT_OBJECT_0);
@@ -367,3 +385,228 @@ inline static int uv__rwlock_fallback_trywrlock(uv_rwlock_t* rwlock) {
 inline static void uv__rwlock_fallback_wrunlock(uv_rwlock_t* rwlock) {
   uv_mutex_unlock(&rwlock->fallback_.write_mutex_);
 }
+
+
+
+/* This condition variable implementation is based on the SetEvent solution
+ * (section 3.2) at http://www.cs.wustl.edu/~schmidt/win32-cv-1.html
+ * We could not use the SignalObjectAndWait solution (section 3.4) because
+ * it want the 2nd argument (type uv_mutex_t) of uv_cond_wait() and
+ * uv_cond_timedwait() to be HANDLEs, but we use CRITICAL_SECTIONs.
+ */
+
+inline static int uv_cond_fallback_init(uv_cond_t* cond) {
+  /* Initialize the count to 0. */
+  cond->fallback.waiters_count = 0;
+
+  InitializeCriticalSection(&cond->fallback.waiters_count_lock);
+
+  /* Create an auto-reset event. */
+  cond->fallback.signal_event = CreateEvent(NULL,  /* no security */
+                                            FALSE, /* auto-reset event */
+                                            FALSE, /* non-signaled initially */
+                                            NULL); /* unnamed */
+  if (!cond->fallback.signal_event)
+    goto error2;
+
+  /* Create a manual-reset event. */
+  cond->fallback.broadcast_event = CreateEvent(NULL,  /* no security */
+                                               TRUE,  /* manual-reset */
+                                               FALSE, /* non-signaled */
+                                               NULL); /* unnamed */
+  if (!cond->fallback.broadcast_event)
+    goto error;
+
+  return 0;
+
+error:
+  CloseHandle(cond->fallback.signal_event);
+error2:
+  DeleteCriticalSection(&cond->fallback.waiters_count_lock);
+  return -1;
+}
+
+
+inline static int uv_cond_condvar_init(uv_cond_t* cond) {
+  pInitializeConditionVariable(&cond->cond_var);
+  return 0;
+}
+
+
+int uv_cond_init(uv_cond_t* cond) {
+  uv__once_init();
+
+  if (HAVE_CONDVAR_API())
+    return uv_cond_condvar_init(cond);
+  else
+    return uv_cond_fallback_init(cond);
+}
+
+
+inline static void uv_cond_fallback_destroy(uv_cond_t* cond) {
+  if (!CloseHandle(cond->fallback.broadcast_event))
+    abort();
+  if (!CloseHandle(cond->fallback.signal_event))
+    abort();
+  DeleteCriticalSection(&cond->fallback.waiters_count_lock);
+}
+
+
+inline static void uv_cond_condvar_destroy(uv_cond_t* cond) {
+  /* nothing to do */
+}
+
+
+void uv_cond_destroy(uv_cond_t* cond) {
+  if (HAVE_CONDVAR_API())
+    uv_cond_condvar_destroy(cond);
+  else
+    uv_cond_fallback_destroy(cond);
+}
+
+
+inline static void uv_cond_fallback_signal(uv_cond_t* cond) {
+  int have_waiters;
+
+  /* Avoid race conditions. */
+  EnterCriticalSection(&cond->fallback.waiters_count_lock);
+  have_waiters = cond->fallback.waiters_count > 0;
+  LeaveCriticalSection(&cond->fallback.waiters_count_lock);
+
+  if (have_waiters)
+    SetEvent(cond->fallback.signal_event);
+}
+
+
+inline static void uv_cond_condvar_signal(uv_cond_t* cond) {
+  pWakeConditionVariable(&cond->cond_var);
+}
+
+
+void uv_cond_signal(uv_cond_t* cond) {
+  if (HAVE_CONDVAR_API())
+    uv_cond_condvar_signal(cond);
+  else
+    uv_cond_fallback_signal(cond);
+}
+
+
+inline static void uv_cond_fallback_broadcast(uv_cond_t* cond) {
+  int have_waiters;
+
+  /* Avoid race conditions. */
+  EnterCriticalSection(&cond->fallback.waiters_count_lock);
+  have_waiters = cond->fallback.waiters_count > 0;
+  LeaveCriticalSection(&cond->fallback.waiters_count_lock);
+
+  if (have_waiters)
+    SetEvent(cond->fallback.broadcast_event);
+}
+
+
+inline static void uv_cond_condvar_broadcast(uv_cond_t* cond) {
+  pWakeAllConditionVariable(&cond->cond_var);
+}
+
+
+void uv_cond_broadcast(uv_cond_t* cond) {
+  if (HAVE_CONDVAR_API())
+    uv_cond_condvar_broadcast(cond);
+  else
+    uv_cond_fallback_broadcast(cond);
+}
+
+
+inline int uv_cond_wait_helper(uv_cond_t* cond, uv_mutex_t* mutex,
+    DWORD dwMilliseconds) {
+  DWORD result;
+  int last_waiter;
+  HANDLE handles[2] = {
+    cond->fallback.signal_event,
+    cond->fallback.broadcast_event
+  };
+
+  /* Avoid race conditions. */
+  EnterCriticalSection(&cond->fallback.waiters_count_lock);
+  cond->fallback.waiters_count++;
+  LeaveCriticalSection(&cond->fallback.waiters_count_lock);
+
+  /* It's ok to release the <mutex> here since Win32 manual-reset events */
+  /* maintain state when used with <SetEvent>. This avoids the "lost wakeup" */
+  /* bug. */
+  uv_mutex_unlock(mutex);
+
+  /* Wait for either event to become signaled due to <uv_cond_signal> being */
+  /* called or <uv_cond_broadcast> being called. */
+  result = WaitForMultipleObjects(2, handles, FALSE, dwMilliseconds);
+
+  EnterCriticalSection(&cond->fallback.waiters_count_lock);
+  cond->fallback.waiters_count--;
+  last_waiter = result == WAIT_OBJECT_0 + 1
+      && cond->fallback.waiters_count == 0;
+  LeaveCriticalSection(&cond->fallback.waiters_count_lock);
+
+  /* Some thread called <pthread_cond_broadcast>. */
+  if (last_waiter) {
+    /* We're the last waiter to be notified or to stop waiting, so reset the */
+    /* the manual-reset event. */
+    ResetEvent(cond->fallback.broadcast_event);
+  }
+
+  /* Reacquire the <mutex>. */
+  uv_mutex_lock(mutex);
+
+  if (result == WAIT_OBJECT_0 || result == WAIT_OBJECT_0 + 1)
+    return 0;
+
+  if (result == WAIT_TIMEOUT)
+    return -1;
+
+  abort();
+  return -1; /* Satisfy the compiler. */
+}
+
+
+inline static void uv_cond_fallback_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
+  if (uv_cond_wait_helper(cond, mutex, INFINITE))
+    abort();
+}
+
+
+inline static void uv_cond_condvar_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
+  if (!pSleepConditionVariableCS(&cond->cond_var, mutex, INFINITE))
+    abort();
+}
+
+
+void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
+  if (HAVE_CONDVAR_API())
+    uv_cond_condvar_wait(cond, mutex);
+  else
+    uv_cond_fallback_wait(cond, mutex);
+}
+
+
+inline static int uv_cond_fallback_timedwait(uv_cond_t* cond,
+    uv_mutex_t* mutex, uint64_t timeout) {
+  return uv_cond_wait_helper(cond, mutex, (DWORD)(timeout / 1e6));
+}
+
+
+inline static int uv_cond_condvar_timedwait(uv_cond_t* cond,
+    uv_mutex_t* mutex, uint64_t timeout) {
+  if (pSleepConditionVariableCS(&cond->cond_var, mutex, (DWORD)(timeout / 1e6)))
+    return 0;
+  if (GetLastError() != ERROR_TIMEOUT)
+    abort();
+  return -1;
+}
+
+
+int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex,
+    uint64_t timeout) {
+  if (HAVE_CONDVAR_API())
+    return uv_cond_condvar_timedwait(cond, mutex, timeout);
+  else
+    return uv_cond_fallback_timedwait(cond, mutex, timeout);
+}

src/win/winapi.c

@@ -45,6 +45,11 @@ sTryAcquireSRWLockShared pTryAcquireSRWLockShared;
 sTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive;
 sReleaseSRWLockShared pReleaseSRWLockShared;
 sReleaseSRWLockExclusive pReleaseSRWLockExclusive;
+sInitializeConditionVariable pInitializeConditionVariable;
+sSleepConditionVariableCS pSleepConditionVariableCS;
+sSleepConditionVariableSRW pSleepConditionVariableSRW;
+sWakeAllConditionVariable pWakeAllConditionVariable;
+sWakeConditionVariable pWakeConditionVariable;
 
 
 void uv_winapi_init() {
@@ -129,4 +134,19 @@ void uv_winapi_init() {
 
   pReleaseSRWLockExclusive = (sReleaseSRWLockExclusive)
     GetProcAddress(kernel32_module, "ReleaseSRWLockExclusive");
+
+  pInitializeConditionVariable = (sInitializeConditionVariable)
+    GetProcAddress(kernel32_module, "InitializeConditionVariable");
+
+  pSleepConditionVariableCS = (sSleepConditionVariableCS)
+    GetProcAddress(kernel32_module, "SleepConditionVariableCS");
+
+  pSleepConditionVariableSRW = (sSleepConditionVariableSRW)
+    GetProcAddress(kernel32_module, "SleepConditionVariableSRW");
+
+  pWakeAllConditionVariable = (sWakeAllConditionVariable)
+    GetProcAddress(kernel32_module, "WakeAllConditionVariable");
+
+  pWakeConditionVariable = (sWakeConditionVariable)
+    GetProcAddress(kernel32_module, "WakeConditionVariable");
 }

src/win/winapi.h

@@ -4426,6 +4426,25 @@ typedef VOID (WINAPI* sReleaseSRWLockShared)
 typedef VOID (WINAPI* sReleaseSRWLockExclusive)
              (PSRWLOCK SRWLock);
 
+typedef VOID (WINAPI* sInitializeConditionVariable)
+             (PCONDITION_VARIABLE ConditionVariable);
+
+typedef BOOL (WINAPI* sSleepConditionVariableCS)
+             (PCONDITION_VARIABLE ConditionVariable,
+              PCRITICAL_SECTION CriticalSection,
+              DWORD dwMilliseconds);
+
+typedef BOOL (WINAPI* sSleepConditionVariableSRW)
+             (PCONDITION_VARIABLE ConditionVariable,
+              PSRWLOCK SRWLock,
+              DWORD dwMilliseconds,
+              ULONG Flags);
+
+typedef VOID (WINAPI* sWakeAllConditionVariable)
+             (PCONDITION_VARIABLE ConditionVariable);
+
+typedef VOID (WINAPI* sWakeConditionVariable)
+             (PCONDITION_VARIABLE ConditionVariable);
 
 
 /* Ntdll function pointers */
@@ -4448,5 +4467,10 @@ extern sTryAcquireSRWLockShared pTryAcquireSRWLockShared;
 extern sTryAcquireSRWLockExclusive pTryAcquireSRWLockExclusive;
 extern sReleaseSRWLockShared pReleaseSRWLockShared;
 extern sReleaseSRWLockExclusive pReleaseSRWLockExclusive;
+extern sInitializeConditionVariable pInitializeConditionVariable;
+extern sSleepConditionVariableCS pSleepConditionVariableCS;
+extern sSleepConditionVariableSRW pSleepConditionVariableSRW;
+extern sWakeAllConditionVariable pWakeAllConditionVariable;
+extern sWakeConditionVariable pWakeConditionVariable;
 
 #endif /* UV_WIN_WINAPI_H_ */

test/test-condvar.c

@@ -0,0 +1,173 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv.h"
+#include "task.h"
+
+#include <string.h>
+#include <errno.h>
+
+typedef struct {
+  uv_mutex_t mutex;
+  uv_cond_t cond;
+  int delay;
+  int use_broadcast;
+  volatile int posted;
+} worker_config;
+
+
+static void worker(void* arg) {
+  worker_config* c = arg;
+
+  if (c->delay)
+    uv_sleep(c->delay);
+
+  uv_mutex_lock(&c->mutex);
+  ASSERT(c->posted == 0);
+  c->posted = 1;
+  if (c->use_broadcast)
+    uv_cond_broadcast(&c->cond);
+  else
+    uv_cond_signal(&c->cond);
+  uv_mutex_unlock(&c->mutex);
+}
+
+
+TEST_IMPL(condvar_1) {
+  uv_thread_t thread;
+  worker_config wc;
+
+  memset(&wc, 0, sizeof(wc));
+
+  ASSERT(0 == uv_cond_init(&wc.cond));
+  ASSERT(0 == uv_mutex_init(&wc.mutex));
+  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
+
+  uv_mutex_lock(&wc.mutex);
+  uv_sleep(100);
+  uv_cond_wait(&wc.cond, &wc.mutex);
+  ASSERT(wc.posted == 1);
+  uv_mutex_unlock(&wc.mutex);
+
+  ASSERT(0 == uv_thread_join(&thread));
+  uv_mutex_destroy(&wc.mutex);
+  uv_cond_destroy(&wc.cond);
+
+  return 0;
+}
+
+
+TEST_IMPL(condvar_2) {
+  uv_thread_t thread;
+  worker_config wc;
+
+  memset(&wc, 0, sizeof(wc));
+  wc.delay = 100;
+
+  ASSERT(0 == uv_cond_init(&wc.cond));
+  ASSERT(0 == uv_mutex_init(&wc.mutex));
+  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
+
+  uv_mutex_lock(&wc.mutex);
+  uv_cond_wait(&wc.cond, &wc.mutex);
+  uv_mutex_unlock(&wc.mutex);
+
+  ASSERT(0 == uv_thread_join(&thread));
+  uv_mutex_destroy(&wc.mutex);
+  uv_cond_destroy(&wc.cond);
+
+  return 0;
+}
+
+
+TEST_IMPL(condvar_3) {
+  uv_thread_t thread;
+  worker_config wc;
+  int r;
+
+  memset(&wc, 0, sizeof(wc));
+  wc.delay = 100;
+
+  ASSERT(0 == uv_cond_init(&wc.cond));
+  ASSERT(0 == uv_mutex_init(&wc.mutex));
+  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
+
+  uv_mutex_lock(&wc.mutex);
+  r = uv_cond_timedwait(&wc.cond, &wc.mutex, (uint64_t)(50 * 1e6));
+  ASSERT(r == -1);
+  uv_mutex_unlock(&wc.mutex);
+
+  ASSERT(0 == uv_thread_join(&thread));
+  uv_mutex_destroy(&wc.mutex);
+  uv_cond_destroy(&wc.cond);
+
+  return 0;
+}
+
+
+TEST_IMPL(condvar_4) {
+  uv_thread_t thread;
+  worker_config wc;
+  int r;
+
+  memset(&wc, 0, sizeof(wc));
+  wc.delay = 100;
+
+  ASSERT(0 == uv_cond_init(&wc.cond));
+  ASSERT(0 == uv_mutex_init(&wc.mutex));
+  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
+
+  uv_mutex_lock(&wc.mutex);
+  r = uv_cond_timedwait(&wc.cond, &wc.mutex, (uint64_t)(150 * 1e6));
+  ASSERT(r == 0);
+  uv_mutex_unlock(&wc.mutex);
+
+  ASSERT(0 == uv_thread_join(&thread));
+  uv_mutex_destroy(&wc.mutex);
+  uv_cond_destroy(&wc.cond);
+
+  return 0;
+}
+
+
+TEST_IMPL(condvar_5) {
+  uv_thread_t thread;
+  worker_config wc;
+
+  memset(&wc, 0, sizeof(wc));
+  wc.use_broadcast = 1;
+
+  ASSERT(0 == uv_cond_init(&wc.cond));
+  ASSERT(0 == uv_mutex_init(&wc.mutex));
+  ASSERT(0 == uv_thread_create(&thread, worker, &wc));
+
+  uv_mutex_lock(&wc.mutex);
+  uv_sleep(100);
+  uv_cond_wait(&wc.cond, &wc.mutex);
+  ASSERT(wc.posted == 1);
+  uv_mutex_unlock(&wc.mutex);
+
+  ASSERT(0 == uv_thread_join(&thread));
+  uv_mutex_destroy(&wc.mutex);
+  uv_cond_destroy(&wc.cond);
+
+  return 0;
+}

test/test-list.h

@@ -22,6 +22,11 @@
 TEST_DECLARE   (platform_output)
 TEST_DECLARE   (callback_order)
 TEST_DECLARE   (run_once)
+TEST_DECLARE   (condvar_1)
+TEST_DECLARE   (condvar_2)
+TEST_DECLARE   (condvar_3)
+TEST_DECLARE   (condvar_4)
+TEST_DECLARE   (condvar_5)
 TEST_DECLARE   (semaphore_1)
 TEST_DECLARE   (semaphore_2)
 TEST_DECLARE   (semaphore_3)
@@ -208,6 +213,11 @@ TASK_LIST_START
   TEST_ENTRY  (callback_order)
 #endif
   TEST_ENTRY  (run_once)
+  TEST_ENTRY  (condvar_1)
+  TEST_ENTRY  (condvar_2)
+  TEST_ENTRY  (condvar_3)
+  TEST_ENTRY  (condvar_4)
+  TEST_ENTRY  (condvar_5)
   TEST_ENTRY  (semaphore_1)
   TEST_ENTRY  (semaphore_2)
   TEST_ENTRY  (semaphore_3)

uv.gyp

@@ -305,6 +305,7 @@
         'test/test-mutexes.c',
         'test/test-signal.c',
         'test/test-thread.c',
+        'test/test-condvar.c',
         'test/test-timer-again.c',
         'test/test-timer.c',
         'test/test-tty.c',