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authorRickard Green <[email protected]>2011-11-13 21:43:04 +0100
committerRickard Green <[email protected]>2011-11-13 21:43:04 +0100
commit32ef224c9769cd9359496953075e0133358ccf86 (patch)
tree791517a9be6dbf7a9081192edbf96e69f086d2e1 /erts/include/internal/ethr_mutex.h
parentca58731b5df58aa2a8b42c583d1ba7bb929e72b2 (diff)
parent15774d2ac5ba38dba287309f91eb7e4f58b9a636 (diff)
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Merge branch 'rickard/win-cs-mutex/OTP-9671'
* rickard/win-cs-mutex/OTP-9671: Use critical sections as mutex implementation on Windows
Diffstat (limited to 'erts/include/internal/ethr_mutex.h')
-rw-r--r--erts/include/internal/ethr_mutex.h115
1 files changed, 111 insertions, 4 deletions
diff --git a/erts/include/internal/ethr_mutex.h b/erts/include/internal/ethr_mutex.h
index a0685ea3c0..86a1e9fbdf 100644
--- a/erts/include/internal/ethr_mutex.h
+++ b/erts/include/internal/ethr_mutex.h
@@ -22,6 +22,23 @@
* Author: Rickard Green
*/
+/*
+ * IMPORTANT note about ethr_cond_signal() and ethr_cond_broadcast()
+ *
+ * POSIX allow a call to `pthread_cond_signal' or `pthread_cond_broadcast'
+ * even though the associated mutex/mutexes isn't/aren't locked by the
+ * caller. We do not allow that by default in order to avoid a performance
+ * penalty on some platforms.
+ *
+ * Mutexes and condition variables can, however, be initialized as POSIX
+ * compliant. When initialized as such ethr_cond_signal(), and
+ * ethr_cond_broadcast() are allowed to be called even though the associated
+ * mutexes aren't locked. This will, however, incur a performance penalty on
+ * some platforms.
+ *
+ * POSIX compliant mutexes and condition variables *need* to be used together.
+ */
+
#ifndef ETHR_MUTEX_H__
#define ETHR_MUTEX_H__
@@ -40,6 +57,14 @@
#endif
#endif
+/* #define ETHR_DBG_WIN_MTX_WITH_PTHREADS */
+#ifdef ETHR_DBG_WIN_MTX_WITH_PTHREADS
+typedef pthread_mutex_t CRITICAL_SECTION;
+int TryEnterCriticalSection(CRITICAL_SECTION *);
+void EnterCriticalSection(CRITICAL_SECTION *);
+void LeaveCriticalSection(CRITICAL_SECTION *);
+#endif
+
#ifdef ETHR_MTX_HARD_DEBUG
# ifdef __GNUC__
# warning ETHR_MTX_HARD_DEBUG
@@ -140,13 +165,19 @@ struct ethr_mutex_base_ {
typedef struct {
int main_spincount;
int aux_spincount;
+ int posix_compliant;
} ethr_mutex_opt;
+#define ETHR_MUTEX_OPT_DEFAULT_INITER {-1, -1, 0}
+
typedef struct {
int main_spincount;
int aux_spincount;
+ int posix_compliant;
} ethr_cond_opt;
+#define ETHR_COND_OPT_DEFAULT_INITER {-1, -1, 0}
+
#ifdef ETHR_USE_OWN_MTX_IMPL__
typedef struct ethr_mutex_ ethr_mutex;
@@ -179,7 +210,7 @@ struct ethr_cond_ {
#endif
};
-#else /* pthread */
+#elif defined(ETHR_PTHREADS) && !defined(ETHR_DBG_WIN_MTX_WITH_PTHREADS)
typedef struct ethr_mutex_ ethr_mutex;
struct ethr_mutex_ {
@@ -197,7 +228,36 @@ struct ethr_cond_ {
#endif
};
-#endif /* pthread */
+#elif defined(ETHR_WIN32_THREADS) || defined(ETHR_DBG_WIN_MTX_WITH_PTHREADS)
+# define ETHR_WIN_MUTEX__
+
+typedef struct ethr_mutex_ ethr_mutex;
+struct ethr_mutex_ {
+ int posix_compliant;
+ CRITICAL_SECTION cs;
+ ethr_ts_event *wakeups;
+ ethr_atomic32_t have_wakeups; /* only when posix compliant */
+ ethr_atomic32_t locked; /* only when posix compliant */
+ ethr_spinlock_t lock; /* only when posix compliant */
+#if ETHR_XCHK
+ int initialized;
+#endif
+};
+
+typedef struct ethr_cond_ ethr_cond;
+struct ethr_cond_ {
+ int posix_compliant;
+ CRITICAL_SECTION cs;
+ ethr_ts_event *waiters;
+ int spincount;
+#if ETHR_XCHK
+ int initialized;
+#endif
+};
+
+#else
+# error "no mutex implementation"
+#endif
int ethr_mutex_init_opt(ethr_mutex *, ethr_mutex_opt *);
int ethr_mutex_init(ethr_mutex *);
@@ -573,7 +633,7 @@ ETHR_INLINE_MTX_FUNC_NAME_(ethr_mutex_unlock)(ethr_mutex *mtx)
#endif /* ETHR_TRY_INLINE_FUNCS */
-#else /* pthread_mutex */
+#elif defined(ETHR_PTHREADS) && !defined(ETHR_DBG_WIN_MTX_WITH_PTHREADS)
#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_MUTEX_IMPL__)
@@ -605,7 +665,54 @@ ETHR_INLINE_MTX_FUNC_NAME_(ethr_mutex_unlock)(ethr_mutex *mtx)
#endif /* ETHR_TRY_INLINE_FUNCS */
-#endif /* pthread_mutex */
+#elif defined(ETHR_WIN32_THREADS) || defined(ETHR_DBG_WIN_MTX_WITH_PTHREADS)
+
+#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_MUTEX_IMPL__)
+
+static ETHR_INLINE int
+ETHR_INLINE_MTX_FUNC_NAME_(ethr_mutex_trylock)(ethr_mutex *mtx)
+{
+ if (!TryEnterCriticalSection(&mtx->cs))
+ return EBUSY;
+ if (mtx->posix_compliant)
+ ethr_atomic32_set(&mtx->locked, 1);
+ return 0;
+}
+
+static ETHR_INLINE void
+ETHR_INLINE_MTX_FUNC_NAME_(ethr_mutex_lock)(ethr_mutex *mtx)
+{
+ EnterCriticalSection(&mtx->cs);
+ if (mtx->posix_compliant)
+ ethr_atomic32_set(&mtx->locked, 1);
+}
+
+void ethr_mutex_cond_wakeup__(ethr_mutex *mtx);
+
+static ETHR_INLINE void
+ETHR_INLINE_MTX_FUNC_NAME_(ethr_mutex_unlock)(ethr_mutex *mtx)
+{
+ if (mtx->posix_compliant) {
+ ethr_atomic32_set_mb(&mtx->locked, 0);
+ if (ethr_atomic32_read_acqb(&mtx->have_wakeups))
+ goto cond_wakeup;
+ else
+ goto leave_cs;
+ }
+
+ if (mtx->wakeups) {
+ cond_wakeup:
+ ethr_mutex_cond_wakeup__(mtx);
+ }
+ else {
+ leave_cs:
+ LeaveCriticalSection(&mtx->cs);
+ }
+}
+
+#endif /* ETHR_TRY_INLINE_FUNCS */
+
+#endif
#ifdef ETHR_USE_OWN_RWMTX_IMPL__