1 files changed, 170 insertions, 0 deletions
diff --git a/innobase/sync/sync0ipm.c b/innobase/sync/sync0ipm.c
new file mode 100644
index 00000000000..e10e1c85da5
--- /dev/null
+++ b/innobase/sync/sync0ipm.c
@@ -0,0 +1,170 @@
+/******************************************************
+A fast mutex for interprocess synchronization.
+mutex_t can be used only within single process,
+but ip_mutex_t also between processes.
+
+(c) 1995 Innobase Oy
+
+Created 9/30/1995 Heikki Tuuri
+*******************************************************/
+#include "sync0ipm.h"
+#ifdef UNIV_NONINL
+#include "sync0ipm.ic"
+#endif
+
+#include "mem0mem.h"
+
+/* The performance of the ip mutex in NT depends on how often
+a thread has to suspend itself waiting for the ip mutex
+to become free. The following variable counts system calls
+involved. */
+
+ulint	ip_mutex_system_call_count	= 0;
+
+/**********************************************************************
+Creates, or rather, initializes
+an ip mutex object in a specified shared memory location (which must be
+appropriately aligned). The ip mutex is initialized in the reset state.
+NOTE! Explicit destroying of the ip mutex with ip_mutex_free
+is not recommended
+as the mutex resides in shared memory and we cannot make sure that
+no process is currently accessing it. Therefore just use
+ip_mutex_close to free the operating system event and mutex. */
+
+ulint
+ip_mutex_create(
+/*============*/
+					/* out: 0 if succeed */
+	ip_mutex_t*	ip_mutex,	/* in: pointer to shared memory */
+	char*		name,		/* in: name of the ip mutex */
+	ip_mutex_hdl_t** handle)	/* out, own: handle to the
+					created mutex; handle exists
+					in the private address space of
+					the calling process */
+{
+	mutex_t*	mutex;
+	char*		buf;
+	os_event_t	released;
+	os_mutex_t	exclude;
+	
+	ip_mutex_set_waiters(ip_mutex, 0);
+
+	buf = mem_alloc(strlen(name) + 20);
+
+	strcpy(buf, name);
+	strcpy(buf + strlen(name), "_IB_RELS");
+
+	released = os_event_create(buf);
+
+	if (released == NULL) {
+		mem_free(buf);
+		return(1);
+	}
+
+	strcpy(buf + strlen(name), "_IB_EXCL");
+
+	exclude = os_mutex_create(buf);
+
+	if (exclude == NULL) {
+		os_event_free(released);
+		mem_free(buf);
+		return(1);
+	}
+
+	mutex = ip_mutex_get_mutex(ip_mutex);
+
+	mutex_create(mutex);
+	mutex_set_level(mutex, SYNC_NO_ORDER_CHECK);
+	
+	*handle = mem_alloc(sizeof(ip_mutex_hdl_t));
+
+	(*handle)->ip_mutex = ip_mutex;
+	(*handle)->released = released;
+	(*handle)->exclude = exclude;
+
+	mem_free(buf);
+
+	return(0);
+}
+
+/**********************************************************************
+NOTE! Using this function is not recommended. See the note
+on ip_mutex_create. Destroys an ip mutex */
+
+void
+ip_mutex_free(
+/*==========*/
+	ip_mutex_hdl_t*	handle)		/* in, own: ip mutex handle */
+{
+	mutex_free(ip_mutex_get_mutex(handle->ip_mutex));
+
+	os_event_free(handle->released);
+	os_mutex_free(handle->exclude);
+
+	mem_free(handle);
+}
+
+/**********************************************************************
+Opens an ip mutex object in a specified shared memory location.
+Explicit closing of the ip mutex with ip_mutex_close is necessary to
+free the operating system event and mutex created, and the handle. */
+
+ulint
+ip_mutex_open(
+/*==========*/
+					/* out: 0 if succeed */
+	ip_mutex_t*	ip_mutex,	/* in: pointer to shared memory */
+	char*		name,		/* in: name of the ip mutex */
+	ip_mutex_hdl_t** handle)	/* out, own: handle to the
+					opened mutex */
+{
+	char*		buf;
+	os_event_t	released;
+	os_mutex_t	exclude;
+	
+	buf = mem_alloc(strlen(name) + 20);
+
+	strcpy(buf, name);
+	strcpy(buf + strlen(name), "_IB_RELS");
+
+	released = os_event_create(buf);
+
+	if (released == NULL) {
+		mem_free(buf);
+		return(1);
+	}
+
+	strcpy(buf + strlen(name), "_IB_EXCL");
+
+	exclude = os_mutex_create(buf);
+
+	if (exclude == NULL) {
+		os_event_free(released);
+		mem_free(buf);
+		return(1);
+	}
+
+	*handle = mem_alloc(sizeof(ip_mutex_hdl_t));
+
+	(*handle)->ip_mutex = ip_mutex;
+	(*handle)->released = released;
+	(*handle)->exclude = exclude;
+
+	mem_free(buf);
+
+	return(0);
+}
+
+/**********************************************************************
+Closes an ip mutex. */
+
+void
+ip_mutex_close(
+/*===========*/
+	ip_mutex_hdl_t*	handle)		/* in, own: ip mutex handle */
+{
+	os_event_free(handle->released);
+	os_mutex_free(handle->exclude);
+
+	mem_free(handle);
+}