Replace RWLockWrapper --> Mutex in DeviceInfoImpl
Reader-writer locks helps performance only when there are many
concurrent readers, and I would expect that isn't the case for this
class. Using a plain mutex reduces complexity.
Bug: webrtc:12102
Change-Id: I07c315bcbfc38f1d8befe5395c9ece54c673aeb7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/190722
Reviewed-by: Magnus Flodman <mflodman@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32547}
diff --git a/modules/video_capture/device_info_impl.cc b/modules/video_capture/device_info_impl.cc
index 91a7232..846977e 100644
--- a/modules/video_capture/device_info_impl.cc
+++ b/modules/video_capture/device_info_impl.cc
@@ -25,34 +25,25 @@
namespace videocapturemodule {
DeviceInfoImpl::DeviceInfoImpl()
- : _apiLock(*RWLockWrapper::CreateRWLock()),
- _lastUsedDeviceName(NULL),
- _lastUsedDeviceNameLength(0) {}
+ : _lastUsedDeviceName(NULL), _lastUsedDeviceNameLength(0) {}
DeviceInfoImpl::~DeviceInfoImpl(void) {
- _apiLock.AcquireLockExclusive();
+ MutexLock lock(&_apiLock);
free(_lastUsedDeviceName);
- _apiLock.ReleaseLockExclusive();
-
- delete &_apiLock;
}
int32_t DeviceInfoImpl::NumberOfCapabilities(const char* deviceUniqueIdUTF8) {
if (!deviceUniqueIdUTF8)
return -1;
- _apiLock.AcquireLockShared();
+ MutexLock lock(&_apiLock);
// Is it the same device that is asked for again.
if (absl::EqualsIgnoreCase(
deviceUniqueIdUTF8,
absl::string_view(_lastUsedDeviceName, _lastUsedDeviceNameLength))) {
- _apiLock.ReleaseLockShared();
return static_cast<int32_t>(_captureCapabilities.size());
}
- // Need to get exclusive rights to create the new capability map.
- _apiLock.ReleaseLockShared();
- WriteLockScoped cs2(_apiLock);
int32_t ret = CreateCapabilityMap(deviceUniqueIdUTF8);
return ret;
@@ -63,20 +54,14 @@
VideoCaptureCapability& capability) {
assert(deviceUniqueIdUTF8 != NULL);
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
if (!absl::EqualsIgnoreCase(
deviceUniqueIdUTF8,
absl::string_view(_lastUsedDeviceName, _lastUsedDeviceNameLength))) {
- _apiLock.ReleaseLockShared();
- _apiLock.AcquireLockExclusive();
if (-1 == CreateCapabilityMap(deviceUniqueIdUTF8)) {
- _apiLock.ReleaseLockExclusive();
- _apiLock.AcquireLockShared();
return -1;
}
- _apiLock.ReleaseLockExclusive();
- _apiLock.AcquireLockShared();
}
// Make sure the number is valid
@@ -98,17 +83,13 @@
if (!deviceUniqueIdUTF8)
return -1;
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
if (!absl::EqualsIgnoreCase(
deviceUniqueIdUTF8,
absl::string_view(_lastUsedDeviceName, _lastUsedDeviceNameLength))) {
- _apiLock.ReleaseLockShared();
- _apiLock.AcquireLockExclusive();
if (-1 == CreateCapabilityMap(deviceUniqueIdUTF8)) {
return -1;
}
- _apiLock.ReleaseLockExclusive();
- _apiLock.AcquireLockShared();
}
int32_t bestformatIndex = -1;
diff --git a/modules/video_capture/device_info_impl.h b/modules/video_capture/device_info_impl.h
index 37a457c..4b47389 100644
--- a/modules/video_capture/device_info_impl.h
+++ b/modules/video_capture/device_info_impl.h
@@ -18,7 +18,8 @@
#include "api/video/video_rotation.h"
#include "modules/video_capture/video_capture.h"
#include "modules/video_capture/video_capture_defines.h"
-#include "rtc_base/synchronization/rw_lock_wrapper.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/thread_annotations.h"
namespace webrtc {
namespace videocapturemodule {
@@ -45,15 +46,16 @@
* Fills the member variable _captureCapabilities with capabilities for the
* given device name.
*/
- virtual int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8) = 0;
+ virtual int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8)
+ RTC_EXCLUSIVE_LOCKS_REQUIRED(_apiLock) = 0;
protected:
// Data members
typedef std::vector<VideoCaptureCapability> VideoCaptureCapabilities;
- VideoCaptureCapabilities _captureCapabilities;
- RWLockWrapper& _apiLock;
- char* _lastUsedDeviceName;
- uint32_t _lastUsedDeviceNameLength;
+ VideoCaptureCapabilities _captureCapabilities RTC_GUARDED_BY(_apiLock);
+ Mutex _apiLock;
+ char* _lastUsedDeviceName RTC_GUARDED_BY(_apiLock);
+ uint32_t _lastUsedDeviceNameLength RTC_GUARDED_BY(_apiLock);
};
} // namespace videocapturemodule
} // namespace webrtc
diff --git a/modules/video_capture/linux/device_info_linux.h b/modules/video_capture/linux/device_info_linux.h
index a320c36..304ae71 100644
--- a/modules/video_capture/linux/device_info_linux.h
+++ b/modules/video_capture/linux/device_info_linux.h
@@ -33,13 +33,14 @@
* Fills the membervariable _captureCapabilities with capabilites for the
* given device name.
*/
- int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8) override;
+ int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8) override
+ RTC_EXCLUSIVE_LOCKS_REQUIRED(_apiLock);
int32_t DisplayCaptureSettingsDialogBox(const char* /*deviceUniqueIdUTF8*/,
const char* /*dialogTitleUTF8*/,
void* /*parentWindow*/,
uint32_t /*positionX*/,
uint32_t /*positionY*/) override;
- int32_t FillCapabilities(int fd);
+ int32_t FillCapabilities(int fd) RTC_EXCLUSIVE_LOCKS_REQUIRED(_apiLock);
int32_t Init() override;
private:
diff --git a/modules/video_capture/windows/device_info_ds.cc b/modules/video_capture/windows/device_info_ds.cc
index a163579..f43c508 100644
--- a/modules/video_capture/windows/device_info_ds.cc
+++ b/modules/video_capture/windows/device_info_ds.cc
@@ -99,7 +99,7 @@
return 0;
}
uint32_t DeviceInfoDS::NumberOfDevices() {
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
return GetDeviceInfo(0, 0, 0, 0, 0, 0, 0);
}
@@ -110,7 +110,7 @@
uint32_t deviceUniqueIdUTF8Length,
char* productUniqueIdUTF8,
uint32_t productUniqueIdUTF8Length) {
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
const int32_t result = GetDeviceInfo(
deviceNumber, deviceNameUTF8, deviceNameLength, deviceUniqueIdUTF8,
deviceUniqueIdUTF8Length, productUniqueIdUTF8, productUniqueIdUTF8Length);
@@ -287,7 +287,7 @@
int32_t DeviceInfoDS::GetWindowsCapability(
const int32_t capabilityIndex,
VideoCaptureCapabilityWindows& windowsCapability) {
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
if (capabilityIndex < 0 || static_cast<size_t>(capabilityIndex) >=
_captureCapabilitiesWindows.size()) {
@@ -584,7 +584,7 @@
void* parentWindow,
uint32_t positionX,
uint32_t positionY) {
- ReadLockScoped cs(_apiLock);
+ MutexLock lock(&_apiLock);
HWND window = (HWND)parentWindow;
IBaseFilter* filter = GetDeviceFilter(deviceUniqueIdUTF8, NULL, 0);
diff --git a/modules/video_capture/windows/device_info_ds.h b/modules/video_capture/windows/device_info_ds.h
index d782eb5..2fda325 100644
--- a/modules/video_capture/windows/device_info_ds.h
+++ b/modules/video_capture/windows/device_info_ds.h
@@ -85,7 +85,8 @@
char* productUniqueIdUTF8,
uint32_t productUniqueIdUTF8Length);
- int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8) override;
+ int32_t CreateCapabilityMap(const char* deviceUniqueIdUTF8) override
+ RTC_EXCLUSIVE_LOCKS_REQUIRED(_apiLock);
private:
ICreateDevEnum* _dsDevEnum;
